R820T tuner?

Showing 21-144 of 144 messages
R820T tuner? JP 8/21/12 2:10 PM
I placed an order for an e4000 based dongle but the seller said that it was no longer available (no more e4000 chips!). He suggested a dongle with an R820T tuner. Has anybody ever heard of this tuner? A different seller on ebay lists the R820T as 'Latest Chip Better Quality' :)

JP

Re: [ultra-cheap-sdr] R820T tuner? jdow 8/21/12 4:09 PM
It is not on the latest compatibility list from April 18th this year.

I'd be wary of it. Somebody will have to learn how to program it and
make the mods to rtlsdr.

Replacements for E4000 that are accepted include "FC0012", "FC0013" with
the RealTek chip. There are several other chips that work instead of the
RealTek (2832) chip with the tuner chip unknown. None of them work over
as wide a temperature range.

http://www.rtlsdr.com/2012/04/rtlsdr-compatibility-list/

That's all I know about it.

{^_^}   Joanne, W6MKU
Re: [ultra-cheap-sdr] R820T tuner? Adam Nielsen 8/21/12 4:39 PM
> Replacements for E4000 that are accepted include "FC0012", "FC0013" with
> the RealTek chip. There are several other chips that work instead of the
> RealTek (2832) chip with the tuner chip unknown. None of them work over
> as wide a temperature range.

Which other controller chips work?  I thought only the RTL2832 was usable for SDR?

> On 2012/08/21 14:10, JP wrote:
>> I placed an order for an e4000 based dongle but the seller said that it was no
>> longer available (no more e4000 chips!). He suggested a dongle with an R820T
>> tuner. Has anybody ever heard of this tuner? A different seller on ebay lists
>> the R820T as 'Latest Chip Better Quality' :)

See if you can get a datasheet out of them, that's the only way to know 1)
whether it's better or worse and 2) if there's any chance of getting support
for it added.

Cheers,
Adam.

Re: [ultra-cheap-sdr] R820T tuner? jdow 8/21/12 4:49 PM
Um, if you'd not clipped so much out the URL you want is in that poorly
quoted message, Adam.

http://www.rtlsdr.com/2012/04/rtlsdr-compatibility-list/

{^_-}
Re: [ultra-cheap-sdr] R820T tuner? Adam Nielsen 8/21/12 4:51 PM
> Um, if you'd not clipped so much out the URL you want is in that poorly
> quoted message, Adam.
>
> http://www.rtlsdr.com/2012/04/rtlsdr-compatibility-list/

I did look, but that page only says the RTL2832 is supported...

Cheers,
Adam.

Re: [ultra-cheap-sdr] R820T tuner? jdow 8/21/12 5:34 PM
Look at the "LogLink VG0002a" and subsequent. It appears there are other
chips that are supported. Where RTL2832U is listed above that line you
see other chips listed. I take that to mean they are either compatible
with the 2832 or are otherwise supported.

{^_^}

Re: [ultra-cheap-sdr] R820T tuner? Adam Nielsen 8/21/12 7:05 PM
>>> http://www.rtlsdr.com/2012/04/rtlsdr-compatibility-list/
>>
>> I did look, but that page only says the RTL2832 is supported...
>
> Look at the "LogLink VG0002a" and subsequent. It appears there are other
> chips that are supported. Where RTL2832U is listed above that line you
> see other chips listed. I take that to mean they are either compatible
> with the 2832 or are otherwise supported.

I must be blind, I can't see this at all.  I can see the device called
"Logilink VG0002A", and it says this uses the RTL2832U chip with the
FC0013 tuner, and that it's supported.

But it also lists the same "Logilink VG0002A" as having an IT9135 chip
instead of the RTL, and this is listed as unsupported.

So in this case the one device produced by Logilink comes in two
versions, one with RTL2832 that's supported, and one with IT9135 that
doesn't work.

The only devices on that page that have "Yes" in the "Compatible?"
column all use the RTL2832 chip.  The other alternatives to the RTL2832
(that I can see) all say "No" in the "Compatible?" column.

So as far as I can see, only the RTL2832U is supported.  None of the
alternative chips work.

...unless I'm missing something?

Cheers,
Adam.
Re: [ultra-cheap-sdr] R820T tuner? jdow 8/21/12 7:40 PM
Ah, yes. I scanned from the bottom of the list up. And now I see that you
scanned from the top down. You get two different answers for the two
different methods. Can you guess why?

Sorry about that.

{^_-}   Joanne, W6MKU
        (Yes, there are two entries for that device.)
Re: [ultra-cheap-sdr] R820T tuner? jdow 8/21/12 7:41 PM
On 2012/08/21 19:05, Adam Nielsen wrote:
Oops - and if I had scanned to the right I'd have noticed it does NOT work
for that second incarnation.

Doubly sorry.

{^_^}
Re: [ultra-cheap-sdr] R820T tuner? Adam Nielsen 8/21/12 9:08 PM
> Oops - and if I had scanned to the right I'd have noticed it does NOT work
> for that second incarnation.

No worries, glad I wasn't misreading anything!  I was kind of hoping
though that some manufacturer had brought out a superior ADC to the
RTL2832 that was in the same price range!

Cheers,
Adam.
Re: R820T tuner? MikeB 8/28/12 1:33 PM
Have you found a way to use the R820T device yet?

Mike
TV28T - antenna connector - MCX or MMCX? asbokid 8/30/12 4:10 PM
Hello!

I have this device, too.

Perhaps unsurprisingly, given the minuscule antenna included in the box, i can't even get it to work for DVB-T / DAB / FM Radio.

I would like to try and attach the dongle to a rooftop antenna for better gain.  But what is the name of the antenna connector on the dongle?  The dongle is sold sometimes in green packaging as the "Newsky TV28T" (see attached photo).

Some have said the antenna connector is an MCX (mini coax) whereas others have called it an MMCX (micro-mini coax).   The difference is subtle, just a millimetre less in diameter.

It's not even clear from photos of the MCX and MMCX connectors which it is (see attached)

I have found some cheap pigtails (US$3.00)  So whether it is an MCX or MMCX connector, what would be best for the other end of the pigtail?  SMA? TNC? N-Type?  BNC?

cheers, a
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? R Wall 8/30/12 4:39 PM
Hi,
 
My dongle looks to have the same connector as your dongle. My dongle came with a Belling Lee adaptor that fits the dongle. Maybe you can purchase a adaptor for your dongle?
 
Maybe a search for “adaptors” and look for Belling Lee.
 
Roderick.
 
From: asbokid
Sent: Friday, August 31, 2012 9:10 AM
Subject: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX?
 
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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? jdow 8/30/12 4:58 PM
A picture of the end of the cable provided would be more entertaining.
(Forget the mag mount end. The cable end connector is probably your key
for determining what it is.)

{^_^}   Joanne, W6MKU

On 2012/08/30 16:10, asbokid wrote:
> Hello!
>
> I have this device, too.
>
> Perhaps unsurprisingly, given the minuscule antenna included in the box, i can't
> even get it to work for DVB-T / DAB / FM Radio.
>
> I would like to try and attach the dongle to a rooftop antenna for better gain.
> But what is the name of the antenna connector on the dongle?  The dongle is sold
> sometimes in green packaging as the "Newsky TV28T" (see attached photo).
>
> Some have said the antenna connector is an MCX (mini coax) whereas others have
> called it an MMCX (micro-mini coax).   The difference is subtle, just a
> millimetre less in diameter.
>
> It's not even clear from photos of the MCX and MMCX connectors which it is (see
> attached)
>
> I have found some cheap pigtails (US$3.00) So whether it is an MCX or MMCX
> connector, what would be best for the other end of the pigtail?  SMA? TNC?
> N-Type?  BNC?
>
> cheers, a*
>
>
>
>
>
>
> *
> On Tuesday, August 28, 2012 9:33:50 PM UTC+1, MikeB wrote:
>
>     Have you found a way to use the R820T device yet?
>
>     Mike
>
>     On Tuesday, August 21, 2012 5:10:54 PM UTC-4, JP wrote:
>
>         I placed an order for an e4000 based dongle but the seller said that it
>         was no longer available (no more e4000 chips!). He suggested a dongle
>         with an R820T tuner. Has anybody ever heard of this tuner? A different
>         seller on ebay lists the R820T as 'Latest Chip Better Quality' :)
>         http://www.ebay.com/itm/1x-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/261084027023?pt=US_Video_Capture_TV_Tuner_Cards&hash=item3cc9d2188f
>         <http://www.ebay.com/itm/1x-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/261084027023?pt=US_Video_Capture_TV_Tuner_Cards&hash=item3cc9d2188f>
>
>         JP
>
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> 2008111423394080480.jpg
>
>
>
> 220-608-thickbox.jpg
>
>
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? asbokid 8/30/12 7:08 PM
Hello again!

Fair point well made fine maiden!

See attached images of the connector on the DVB-T dongle itself and on the antenna cable.

A few more (hi-res) images of the dongle ensemble are here:

http://asbokid.picturepush.com/album/226075/p-Newsky-TV28T---DVB-T-stick-with-RTL2832U-for-SDR.html

The specs for MCX and MMCX connectors, published by Pasternack Enterprises are here:

http://www.pasternack.com/images/pdf/ConnectorIdentifier.pdf

Also, on the back of the dongle packaging it states "Input terminal:  75 Ohm Din"

Yet elsewhere 50 ohm impedance is stated.  Hmm!

Thanks for you're time :)

cheers, a
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? jdow 8/30/12 8:40 PM
It's definitely the MCX connector. It's way to small to be the other
most common connector for this use. And it's not shaped correctly for
any other similarly sized connector.

{^_^}
>>> To post to this group, send email to ultra-c...@googlegroups.com<javascript:>.
>>
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>>> 2008111423394080480.jpg
>>>
>>>
>>>
>>> 220-608-thickbox.jpg
>>>
>>>
>>
>
>
> DSC_0789.JPG
>
>
>
> DSC_0791.JPG
>
>
Re: R820T tuner? JP 8/30/12 9:19 PM
On Tuesday, August 28, 2012 3:33:50 PM UTC-5, MikeB wrote:
Have you found a way to use the R820T device yet?

Mike

Actually, I never bought the devices. I was just wondering whether the statement on their description 'Latest Chip Better Quality' actually meant something.

JP

Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? Adam Nielsen 8/31/12 4:45 AM
> It's definitely the MCX connector. It's way to small to be the other
> most common connector for this use. And it's not shaped correctly for
> any other similarly sized connector.

Agreed.  While it's a similar size to MMCX the shape of the shielding on the
connector matches the MCX in your original image.  Plus it looks identical to
the connector on my antenna which is MCX.

Cheers,
Adam.

Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? R Wall 8/31/12 4:56 AM
Hi,

If it's a MCX connector, then there are a lot of adaptors for sale on ebay.

http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=MCX+adaptor&_sacat=0

Roderick.
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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? asbokid 8/31/12 8:03 AM
Thanks, guys,

Yes it's clear now from studying the white insulation inside the RF connector on the dongle that it is an MCX (and not MMCX).

I would like to use an HF upconverter, to listen to signals from DC up to 30MHz.  Not even sure what antenna to use yet though for such a wide frequency range. Maybe to begin with, just a simple AM broadcast radio loop, tuned or not.

The (pricey) up-converter kits for these dongles use an SMA connector. Although perhaps that could be swapped to match the pigtail.  Suggestions gratefully received!   

cheers, a




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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? Adam Nielsen 8/31/12 8:09 AM
> I would like to use an HF upconverter, to listen to signals from DC up to
> 30MHz.  Not even sure what antenna to use yet though for such a wide frequency
> range. Maybe to begin with, just a simple AM broadcast radio loop, tuned or not.
>
> The (pricey) up-converter kits for these dongles use an SMA connector.
> Although perhaps that could be swapped to match the pigtail.  Suggestions
> gratefully received!

Investigate the experimental direct sampling mode, so you don't need the
upconverter at all.

Cheers,
Adam.

Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? asbokid 8/31/12 2:44 PM
Thanks Adam,

Is the performance likely to be as good (or better) for direct sampling?

cheers, a



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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? jdow 8/31/12 2:58 PM
More specifically it's the 75 ohm version. Video has traditionally used
75 ohms which is a simple 4:1 balun away from 300 ohms for cheap twinlead.

{^_^}
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? jdow 8/31/12 3:02 PM
A smart person might use a pigtail to reduce stress on the connector
body for the dongle. 1 foot or so of that little "stuff" won't hurt as
much as a cracked circuit board. Then you can use LMR400 to the antenna
if you want to get silly.

{o.o}
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? jdow 8/31/12 3:03 PM
Use an upconverter. You might get marginally better performance with
regards to sampling aliases.

{^_^}

On 2012/08/31 14:44, Ballymunboy wrote:
> Thanks Adam,
>
> Is the performance likely to be as good (or better) for direct sampling?
>
> cheers, a
>
> On Fri, Aug 31, 2012 at 4:09 PM, Adam Nielsen <a.ni...@shikadi.net
> <mailto:a.ni...@shikadi.net>> wrote:
>
>         I would like to use an HF upconverter, to listen to signals from DC up to
>         30MHz.  Not even sure what antenna to use yet though for such a wide
>         frequency
>         range. Maybe to begin with, just a simple AM broadcast radio loop, tuned
>         or not.
>
>         The (pricey) up-converter kits for these dongles use an SMA connector.
>         Although perhaps that could be swapped to match the pigtail.  Suggestions
>         gratefully received!
>
>
>     Investigate the experimental direct sampling mode, so you don't need the
>     upconverter at all.
>
>     Cheers,
>     Adam.
>
>
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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? asbokid 8/31/12 3:14 PM
Thanks Joanne,

A search turned up a few open design schematics for HF upconverter.  Some not as well received as others ;-)   So maybe it's worth designing one from the bottom upwards. It would be nice to have it SMD for low-cost and simple assembly. First things first though, the dongle scarcely works with the existing antenna at the radio frequencies it was sold for !

cheers, a


On Fri, Aug 31, 2012 at 11:03 PM, jdow <jd...@earthlink.net> wrote:
Use an upconverter. You might get marginally better performance with
regards to sampling aliases.

{^_^}


On 2012/08/31 14:44, Ballymunboy wrote:
Thanks Adam,

Is the performance likely to be as good (or better) for direct sampling?

cheers, a

On Fri, Aug 31, 2012 at 4:09 PM, Adam Nielsen <a.ni...@shikadi.net
<mailto:a.ni...@shikadi.net>> wrote:

        I would like to use an HF upconverter, to listen to signals from DC up to
        30MHz.  Not even sure what antenna to use yet though for such a wide
        frequency
        range. Maybe to begin with, just a simple AM broadcast radio loop, tuned
        or not.

        The (pricey) up-converter kits for these dongles use an SMA connector.
        Although perhaps that could be swapped to match the pigtail.  Suggestions
        gratefully received!


    Investigate the experimental direct sampling mode, so you don't need the
    upconverter at all.

    Cheers,
    Adam.


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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? asbokid 8/31/12 3:27 PM
Ahh.. Too late!  I did the exact opposite and plumped for a monster sized adaptor!  Maybe a USB extension cable can provide some flexibility though.

http://www.ebay.co.uk/itm/IEC-Female-To-MCX-Male-Coax-Adapter-Connector-/260923857004

Have these Chinese designed dongle PCBs been studied?  It is said that they are quite different to the RTL/Euronics reference design.   It would be tidy and convenient to integrate a (switchable) up-converter, E4000 and the RTL controller all on a single board.   The RTL2832U is apparently available in China as a separate IC for under a dollar, e.g.

http://item.taobao.com/item.htm?id=15059005964

cheers, a


On Fri, Aug 31, 2012 at 11:02 PM, jdow <jd...@earthlink.net> wrote:
A smart person might use a pigtail to reduce stress on the connector
body for the dongle. 1 foot or so of that little "stuff" won't hurt as
much as a cracked circuit board. Then you can use LMR400 to the antenna
if you want to get silly.

{o.o}


On 2012/08/31 04:56, R Wall wrote:
Hi,

If it's a MCX connector, then there are a lot of adaptors for sale on ebay.

http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=MCX+adaptor&_sacat=0

Roderick.

-----Original Message----- From: jdow
Sent: Friday, August 31, 2012 1:40 PM
To: ultra-c...@googlegroups.com
Subject: Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX?

It's definitely the MCX connector. It's way to small to be the other
most common connector for this use. And it's not shaped correctly for
any other similarly sized connector.

{^_^}

On 2012/08/30 19:08, asbokid wrote:
Hello again!

Fair point well made fine maiden!

See attached images of the connector on the DVB-T dongle itself and on the
antenna cable.

A few more (hi-res) images of the dongle ensemble are here:

http://asbokid.picturepush.com/album/226075/p-Newsky-TV28T---DVB-T-stick-with-RTL2832U-for-SDR.html


The specs for MCX and MMCX connectors, published by Pasternack Enterprises
are here:

http://www.pasternack.com/images/pdf/ConnectorIdentifier.pdf

Also, on the back of the dongle packaging it states "Input terminal:  75
Ohm Din"

Yet elsewhere 50 ohm impedance is stated.  Hmm!

Thanks for you're time :)

cheers, a


On Friday, August 31, 2012 12:58:47 AM UTC+1, jdow wrote:

A picture of the end of the cable provided would be more entertaining.
(Forget the mag mount end. The cable end connector is probably your key
for determining what it is.)

{^_^}   Joanne, W6MKU

On 2012/08/30 16:10, asbokid wrote:
Hello!

I have this device, too.

Perhaps unsurprisingly, given the minuscule antenna included in the box,
i can't
even get it to work for DVB-T / DAB / FM Radio.

I would like to try and attach the dongle to a rooftop antenna for
better gain.
But what is the name of the antenna connector on the dongle?  The dongle
is sold
sometimes in green packaging as the "Newsky TV28T" (see attached photo).

Some have said the antenna connector is an MCX (mini coax) whereas
others have
called it an MMCX (micro-mini coax).   The difference is subtle, just a
millimetre less in diameter.

It's not even clear from photos of the MCX and MMCX connectors which it
is (see
attached)

I have found some cheap pigtails (US$3.00) So whether it is an MCX or
MMCX
connector, what would be best for the other end of the pigtail?  SMA?
TNC?
N-Type?  BNC?

cheers, a*






*
On Tuesday, August 28, 2012 9:33:50 PM UTC+1, MikeB wrote:

     Have you found a way to use the R820T device yet?

     Mike

     On Tuesday, August 21, 2012 5:10:54 PM UTC-4, JP wrote:

         I placed an order for an e4000 based dongle but the seller said
that it
         was no longer available (no more e4000 chips!). He suggested a
dongle
         with an R820T tuner. Has anybody ever heard of this tuner? A
different
         seller on ebay lists the R820T as 'Latest Chip Better Quality'
:)

http://www.ebay.com/itm/1x-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/261084027023?pt=US_Video_Capture_TV_Tuner_Cards&hash=item3cc9d2188f

         <
http://www.ebay.com/itm/1x-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/261084027023?pt=US_Video_Capture_TV_Tuner_Cards&hash=item3cc9d2188f>



         JP


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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? pksato 8/31/12 3:28 PM
Hi,
Always I read about connectors, I ask-me, whats is problem to cut
provided, useless, antenna cable, and put a more standard connector?
Making a type of pig tail.
I done it,  I cut one of antenna cable and soldered a  BNC-F connector.

To use direct conversion to listen HF, need to solder an tiny wires on
PCB, it is not easy task even for experienced persons.

And, the CT1FFU kit is very expensive.

--
Paulino
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? jdow 8/31/12 3:32 PM
You want one with a good selection of front end filters if you can
gat it. In particular you'll want a high pass to limit broadcast band
interference when tuning about 1.7 MHz. You'll want a low pass to
limit broadcast band interference when tuning below 500 KHz. Then you
will probably want filters for each band in which you are interested.
With 8 bit sampling the interference free dynamic range is rather
starkly limited on these little dongles. This is a problem when in
the presence of really large signals. With an up-converter the E4000's
filter can help a little bit if you can deploy it skillfully. I am not
sure rtlsdr.dll will allow setting the tuner filter frequency different
from its "LO" frequency.

{^_^}   Joanne, W6MKU

On 2012/08/31 15:14, Ballymunboy wrote:
> Thanks Joanne,
>
> A search turned up a few open design schematics for HF upconverter.  Some not as
> well received as others ;-)   So maybe it's worth designing one from the bottom
> upwards. It would be nice to have it SMD for low-cost and simple assembly. First
> things first though, the dongle scarcely works with the existing antenna at the
> radio frequencies it was sold for !
>
> cheers, a
>
>
> On Fri, Aug 31, 2012 at 11:03 PM, jdow <jd...@earthlink.net
> <mailto:jd...@earthlink.net>> wrote:
>
>     Use an upconverter. You might get marginally better performance with
>     regards to sampling aliases.
>
>     {^_^}
>
>
>     On 2012/08/31 14:44, Ballymunboy wrote:
>
>         Thanks Adam,
>
>         Is the performance likely to be as good (or better) for direct sampling?
>
>         cheers, a
>
>         On Fri, Aug 31, 2012 at 4:09 PM, Adam Nielsen <a.ni...@shikadi.net
>         <mailto:a.ni...@shikadi.net>
>         <mailto:a.ni...@shikadi.net <mailto:a.ni...@shikadi.net>>__> wrote:
>
>                  I would like to use an HF upconverter, to listen to signals
>         from DC up to
>                  30MHz.  Not even sure what antenna to use yet though for such a
>         wide
>                  frequency
>                  range. Maybe to begin with, just a simple AM broadcast radio
>         loop, tuned
>                  or not.
>
>                  The (pricey) up-converter kits for these dongles use an SMA
>         connector.
>                  Although perhaps that could be swapped to match the pigtail.
>           Suggestions
>                  gratefully received!
>
>
>              Investigate the experimental direct sampling mode, so you don't
>         need the
>              upconverter at all.
>
>              Cheers,
>              Adam.
>
>
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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? jdow 8/31/12 3:36 PM
If you can make the PCB and handle the soldering task it well might be
the way to go. On the other hand, if you are going there it might become
more worth your time and effort to build a different tool than the RTL
beastie into it so you can get more than 8 bit sampling. That does get
expensive, fast, unfortunately.

{^_^}   Joanne, W6MKU

On 2012/08/31 15:27, Ballymunboy wrote:
> Ahh.. Too late!  I did the exact opposite and plumped for a monster sized
> adaptor!  Maybe a USB extension cable can provide some flexibility though.
>
> http://www.ebay.co.uk/itm/IEC-Female-To-MCX-Male-Coax-Adapter-Connector-/260923857004
>
> Have these Chinese designed dongle PCBs been studied?  It is said that they are
> quite different to the RTL/Euronics reference design.   It would be tidy and
> convenient to integrate a (switchable) up-converter, E4000 and the RTL
> controller all on a single board.   The RTL2832U is apparently available in
> China as a separate IC for under a dollar, e.g.
>
> http://item.taobao.com/item.htm?id=15059005964
>
> cheers, a
>
>
> On Fri, Aug 31, 2012 at 11:02 PM, jdow <jd...@earthlink.net
> <mailto:jd...@earthlink.net>> wrote:
>
>     A smart person might use a pigtail to reduce stress on the connector
>     body for the dongle. 1 foot or so of that little "stuff" won't hurt as
>     much as a cracked circuit board. Then you can use LMR400 to the antenna
>     if you want to get silly.
>
>     {o.o}
>
>
>     On 2012/08/31 04:56, R Wall wrote:
>
>         Hi,
>
>         If it's a MCX connector, then there are a lot of adaptors for sale on ebay.
>
>         http://www.ebay.com/sch/i.__html?_trksid=p5197.m570.l1313&___nkw=MCX+adaptor&_sacat=0
>         <http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=MCX+adaptor&_sacat=0>
>
>         Roderick.
>
>         -----Original Message----- From: jdow
>         Sent: Friday, August 31, 2012 1:40 PM
>         To: ultra-cheap-sdr@googlegroups.__com
>         <mailto:ultra-c...@googlegroups.com>
>         Subject: Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX?
>
>         It's definitely the MCX connector. It's way to small to be the other
>         most common connector for this use. And it's not shaped correctly for
>         any other similarly sized connector.
>
>         {^_^}
>
>         On 2012/08/30 19:08, asbokid wrote:
>
>             Hello again!
>
>             Fair point well made fine maiden!
>
>             See attached images of the connector on the DVB-T dongle itself and
>             on the
>             antenna cable.
>
>             A few more (hi-res) images of the dongle ensemble are here:
>
>             http://asbokid.picturepush.__com/album/226075/p-Newsky-__TV28T---DVB-T-stick-with-__RTL2832U-for-SDR.html
>             <http://asbokid.picturepush.com/album/226075/p-Newsky-TV28T---DVB-T-stick-with-RTL2832U-for-SDR.html>
>
>
>             The specs for MCX and MMCX connectors, published by Pasternack
>             Enterprises
>             are here:
>
>             http://www.pasternack.com/__images/pdf/__ConnectorIdentifier.pdf
>                 http://www.ebay.com/itm/1x-__RTL-FM-DAB-USB-DVB-T-Dongle-__DVB-T-STICK-RTL2832U-R820T-/__261084027023?pt=US_Video___Capture_TV_Tuner_Cards&hash=__item3cc9d2188f
>                 <http://www.ebay.com/itm/1x-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/261084027023?pt=US_Video_Capture_TV_Tuner_Cards&hash=item3cc9d2188f>
>
>                               <
>
>                 http://www.ebay.com/itm/1x-__RTL-FM-DAB-USB-DVB-T-Dongle-__DVB-T-STICK-RTL2832U-R820T-/__261084027023?pt=US_Video___Capture_TV_Tuner_Cards&hash=__item3cc9d2188f
>                 <http://www.ebay.com/itm/1x-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/261084027023?pt=US_Video_Capture_TV_Tuner_Cards&hash=item3cc9d2188f>>
>
>
>
>                               JP
>
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>             DSC_0789.JPG
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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? - Now Antenna Impedance is....? R Wall 8/31/12 3:47 PM
If I've read it correctly, the E4000 can be programmed to be 50ohm or 75ohm
impedance.

I've asked this question before but didn't get an answer. When the correct
driver is installed for the dongle to work with SDRsharp or whatever, is the
E4000 tuner programmed for 50ohm or 75ohm? Anyone know???

I wonder what impedance the add on up converters etc. presents to the E4000
tuner in the dongle?

Roderick.

-----Original Message-----
From: jdow
Sent: Saturday, September 01, 2012 7:58 AM
To: ultra-c...@googlegroups.com
Subject: Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX?

On 2012/08/31 04:45, Adam Nielsen wrote:
>> It's definitely the MCX connector. It's way to small to be the other
>> most common connector for this use. And it's not shaped correctly for
>> any other similarly sized connector.
>
> Agreed.  While it's a similar size to MMCX the shape of the shielding on
> the
> connector matches the MCX in your original image.  Plus it looks identical
> to
> the connector on my antenna which is MCX.
>
> Cheers,
> Adam.

More specifically it's the 75 ohm version. Video has traditionally used
75 ohms which is a simple 4:1 balun away from 300 ohms for cheap twinlead.

{^_^}
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? asbokid 8/31/12 4:03 PM


On Fri, Aug 31, 2012 at 11:28 PM, Paulino Kenji Sato <pks...@gmail.com> wrote:
Hi,
Always I read about connectors, I ask-me, whats is problem to cut
provided, useless, antenna cable, and put a more standard connector?
Making a type of pig tail.
I done it,  I cut one of antenna cable and soldered a  BNC-F connector.

That's a good idea, Paulino! Except we are only allowed plastic knives in here :(
 
To use direct conversion to listen HF, need to solder an tiny wires on
PCB, it is not easy task even for experienced persons.

And, the CT1FFU kit is very expensive.

Redicerlus price. The filter design for the earlier kits was reportedly poor, too.

http://f5rct.free.fr/explorer/Documents/Banc.Essai/HFconverterReport.pdf

There are no schematics for later kits, so it's hard to know if they are designed well or not.  Very cheap to make though.  The ADE-1 mixer is 30 cents, the crystal 15c and even the SMD coils are only 5c each.  The most expensive parts are perhaps the SMA connectors and the board itself.  It should be a US$4 kit not US$70 ;(
 
George Smart published an earlier HF upconverter design, but he didn't finish it (it was time for tea).

http://george-smart.co.uk/wiki/FunCube_Upconverter

And then someone called Paulino Sato released a new HF upconverter design based on the TA7358

https://www.dropbox.com/sh/4mugo92a115rk2g/F8Z3cXvEHn/sdr-drm/rtlsdr/ta7358_-_hf-to-vhf-upconverter.pdf

Maybe Paulino, if he reads this list, would know if it could convert easily to an SMD design?!

cheers, a

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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? Adam Nielsen 8/31/12 5:00 PM
> A search turned up a few open design schematics for HF upconverter.  Some not
> as well received as others ;-)   So maybe it's worth designing one from the
> bottom upwards. It would be nice to have it SMD for low-cost and simple
> assembly. First things first though, the dongle scarcely works with the
> existing antenna at the radio frequencies it was sold for !

You might want to check your device is working correctly.  Mine works
extremely well for the frequencies it was sold for (88-108MHz wide-band FM),
so much so that with the gain turned up I can even see FM signals all over the
various bands ;-)

There have been a few people who received 'deaf' devices, so make sure you
haven't gotten one of those.

Cheers,
Adam.

Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? Adam Nielsen 8/31/12 5:04 PM
> Always I read about connectors, I ask-me, whats is problem to cut
> provided, useless, antenna cable, and put a more standard connector?
> Making a type of pig tail.
> I done it,  I cut one of antenna cable and soldered a  BNC-F connector.

 From what I've read, the cable that comes with the built in antenna is really
poor quality, so for those people who want to listen to very faint signals
using a proper pigtail would result in less signal loss.

> To use direct conversion to listen HF, need to solder an tiny wires on
> PCB, it is not easy task even for experienced persons.
>
> And, the CT1FFU kit is very expensive.

Direct sampling might not be easy to set up, but it sure is cheap :-)

Cheers,
Adam.

Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? - Now Antenna Impedance is....? Adam Nielsen 8/31/12 5:15 PM
> If I've read it correctly, the E4000 can be programmed to be 50ohm or 75ohm
> impedance.

Where did you read this?

> I've asked this question before but didn't get an answer. When the correct
> driver is installed for the dongle to work with SDRsharp or whatever, is the
> E4000 tuner programmed for 50ohm or 75ohm? Anyone know???

Looking at the E4000 datasheet, it has a 50 ohm input only (page 7).  There
are graphs showing signal levels if you feed a 75 ohm input to it (page 16),
but as far as I can tell the E4000 is designed for 50 ohm input only, and the
loss is greater if you feed it a 75 ohm input (page 11).

Cheers,
Adam.

Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? - Now Antenna Impedance is....? jdow 9/1/12 12:34 AM
In practical terms it won't matter. It might cause a fractional dB worse
noise figure. (An ultra low noise front end usually is NOT impedance
matched to the coax. I've had designs that were considerably below
50 ohms in a 50 ohm system. These had a common base transistor
configuration. And more usually I've had actual input impedances well
above 50 ohms to get really low noise figures. The most dramatic case
was a 1/4dB noise figure 11.5 MHz IF amp built as an experiment. It, er,
had a "slight" (cough) overload problem with modestly large signals.)

{^_^}   Joanne, W6MKU (I had to turn off the noise figure meter to let
         the noise head settle to room temperature, fire it up, take a
         quick reading, and turn it back off in order to get accurate
         results. This was one of the first things I did out of college.
         I took somebody's 1dB design and tweaked it. That's one way to
         enter the "boy's club.")
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? Dragan 9/1/12 4:46 AM

Schematics for the 3.1 versions of the CT1FFU kit: http://www.ct1ffu.com/site/hf-convertor-manual3.1.pdf

Schematics of the ver. 4 are also available at the same page but you have to read the values of components from the 3.1 version.

As for the 4$ kit, hardly. Try to calculate the BOM cost for lets say 500 kits.
If you are doing it in the house and ordering components from 2-3 vendors just the shipping is going to be substantial.
Anyway everyone forgets the amount of work required just to pack and ship items.

I guess the new mantra is something for nothing these days.
http://www.youtube.com/watch?v=jy6ennSQGbs
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? asbokid 9/1/12 6:37 AM


On Sat, Sep 1, 2012 at 1:00 AM, Adam Nielsen <a.ni...@shikadi.net> wrote:
A search turned up a few open design schematics for HF upconverter.  Some not
as well received as others ;-)   So maybe it's worth designing one from the
bottom upwards. It would be nice to have it SMD for low-cost and simple
assembly. First things first though, the dongle scarcely works with the
existing antenna at the radio frequencies it was sold for !

You might want to check your device is working correctly.  Mine works extremely well for the frequencies it was sold for (88-108MHz wide-band FM), so much so that with the gain turned up I can even see FM signals all over the various bands ;-)

It does seem faulty.   However, it did pick up an FM radio station. Just the one, though. And that was only outside.  Hmm :(

There have been a few people who received 'deaf' devices, so make sure you haven't gotten one of those.

Perhaps it's time to track down this fault, if that's what it is. I was expecting to find a more complicated board, but there's not really much on it. It's just very small, mainly 0402 and only two layers.
 

Cheers,
Adam.


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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? asbokid 9/1/12 7:02 AM


On Sat, Sep 1, 2012 at 12:46 PM, Dragan <d.mili...@gmail.com> wrote:

Schematics for the 3.1 versions of the CT1FFU kit: http://www.ct1ffu.com/site/hf-convertor-manual3.1.pdf

Schematics of the ver. 4 are also available at the same page but you have to read the values of components from the 3.1 version.

 
The components don't look the same. The filters are different, iirc. And since the component values aren't given, there is no useful schematic.  The schematic from the v.3.1 had mistakes, unidentified components and one or more missing components.
 
As for the 4$ kit, hardly. Try to calculate the BOM cost for lets say 500 kits.

That's exactly what was done.  All the components cost just a few dollars. Much less than $5, and that was on 100 not 500.

If you are doing it in the house and ordering components from 2-3 vendors just the shipping is going to be substantial.
 
It was priced up. The costings can be posted here..

Anyway everyone forgets the amount of work required just to pack and ship items.
 
The real concern is that the design is reportedly poor.

Is it open source hardware?   Can we copy it, and improve it, for much less than the following prices:

World Wide Version 4.0 Kit - With Traking #   52€     

World Wide - Ready build and tested - Version 4.0 - With traking #   68€      
 
I guess the new mantra is something for nothing these days.
http://www.youtube.com/watch?v=jy6ennSQGbs


The RTL2832 dongles cost <$10 retail. Components cost maybe $1. So an HF-converter kit, which has even less to it, should cost much less.  Definitely not $65 for kit. Everyone needs to make a profit, but that's very greedy.
 
cheers, a


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Re: R820T tuner? Dragan 9/1/12 10:42 AM
Ok, lets see the part list and prices.
There are a lot of people here who can design it and test it.
Lets make an open hardware product by crowd sourcing.

I'm willing to spend the same amount as the cost of the kit, if someone can show me how to obtain just 2 set of parts so I can experiment.
I will etch my own boards, to cut the cost down, and maybe I can get a friend (who has access to some high class test gear) to test it.




On Tuesday, August 21, 2012 11:10:54 PM UTC+2, JP wrote:
I placed an order for an e4000 based dongle but the seller said that it was no longer available (no more e4000 chips!). He suggested a dongle with an R820T tuner. Has anybody ever heard of this tuner? A different seller on ebay lists the R820T as 'Latest Chip Better Quality' :)

JP

Re: R820T tuner? Dragan 9/1/12 10:43 AM
Ups, wrong message
Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? Dragan 9/1/12 10:43 AM
Ok, lets see the part list and prices.
There are a lot of people here who can design it and test it.
Lets make an open hardware product by crowd sourcing.

I'm willing to spend the same amount as the cost of the kit, if someone can show me how to obtain just 2 set of parts so I can experiment.
I will etch my own boards, to cut the cost down, and maybe I can get a friend (who has access to some high class test gear) to test it.


Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? jdow 9/1/12 11:28 AM
And don't forget that this board has quite a few plated through holes.
They add considerably to the cost. (And they perform differently from
wired through holes. Remember that RF travels on surfaces.)

{^_^}

On 2012/09/01 04:46, Dragan wrote:
>
> Schematics for the 3.1 versions of the CT1FFU kit:
> http://www.ct1ffu.com/site/hf-convertor-manual3.1.pdf
>
> Schematics of the ver. 4 are also available at the same page but you have to
> read the values of components from the 3.1 version.
>
> As for the 4$ kit, hardly. Try to calculate the BOM cost for lets say 500 kits.
> If you are doing it in the house and ordering components from 2-3 vendors just
> the shipping is going to be substantial.
> Anyway everyone forgets the amount of work required just to pack and ship items.
>
> I guess the new mantra is something for nothing these days.
> http://www.youtube.com/watch?v=jy6ennSQGbs
>
> On Saturday, September 1, 2012 1:03:17 AM UTC+2, asbokid wrote:
>
>
>
>     On Fri, Aug 31, 2012 at 11:28 PM, Paulino Kenji Sato <pks...@gmail.com
>         <javascript:>.
>         To unsubscribe from this group, send email to
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Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? jdow 9/1/12 11:29 AM
No diode. You blew the front end on the LNA?

{^_^}

On 2012/09/01 06:37, Ballymunboy wrote:
>
>
> On Sat, Sep 1, 2012 at 1:00 AM, Adam Nielsen <a.ni...@shikadi.net
> <mailto:a.ni...@shikadi.net>> wrote:
>
>         A search turned up a few open design schematics for HF upconverter.
>           Some not
>         as well received as others ;-)   So maybe it's worth designing one from the
>         bottom upwards. It would be nice to have it SMD for low-cost and simple
>         assembly. First things first though, the dongle scarcely works with the
>         existing antenna at the radio frequencies it was sold for !
>
>
>     You might want to check your device is working correctly.  Mine works
>     extremely well for the frequencies it was sold for (88-108MHz wide-band FM),
>     so much so that with the gain turned up I can even see FM signals all over
>     the various bands ;-)
>
> It does seem faulty.   However, it did pick up an FM radio station. Just the
> one, though. And that was only outside.  Hmm :(
>
>     There have been a few people who received 'deaf' devices, so make sure you
>     haven't gotten one of those.
>
> Perhaps it's time to track down this fault, if that's what it is. I was
> expecting to find a more complicated board, but there's not really much on it.
> It's just very small, mainly 0402 and only two layers.
>
>
>     Cheers,
>     Adam.
>
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Re: [ultra-cheap-sdr] Re: R820T tuner? W9RAN 9/2/12 10:47 AM
Like Elonics, it seems that Rafael Micro is a fabless semiconductor
company (based in Taiwan this time), that holds information on its
designs close. The only information I've been able to find is an
unhelpful one-page teaser, and even it is marked "confidential and
proprietary". The relevant content is:

Features:
• Support all digital TV standards: DVB-T, ATSC, DTMB, IRIB and ISDB-T.
• Lowest BOM cost WITHOUT external SAW filters, LNA, balun, LDO, and
adjustable parts.
• Low cost Single-In Digital TV Application
• Compliant with EN 300 744, Nordig 2.2, D-BOOK 7.0, ARIB B21, ABNT
15604, ATSC A74 and GB20600-2006
• Compliant with EN-55020, EN55013 and FCC
• Ultra low power consumption < 190mA
• Single power supply with 3.3V
• 2-wired I2C interface
• 24-pin 4x4 QFN lead-free package

(The referenced specifications are for various digital TV standards,
where EN 300 744 is the DVB-T spec and ATSC A74 describes tuner
performance for the NA-based ASTC standard.)

On an unlinked page of their sparse website, I found this listing for a
developers kit: DVB-T Tuner Module Reference Design:Application
Note(PDF), Kit X 1 Document:Include Datasheet, Reference Schematic,
Gerber.

But all links, including those I found with the Wayback Machine to 2009,
produced only one actual document - which is a datasheet on the previous
RT 800 tuner IC. The RT 800 (which has presumably been replaced by newer
designs) had an input frequency range from 48MHz to 900MHz and output
intermediate frequency range from 30MHz to 75MHz. Since a top end of 900
Mhz would still allow compatibility with the stated TV system specs, I
would guess that the R820T may not have the coverage about 1 Ghz that
the E4000 has.

But, unless/until someone gets hold of this information or does some
clever reverse engineering, we probably won't have drivers for the
publicity-shy R820T tuner IC...

73, Bob W9RAN
Re: [ultra-cheap-sdr] Re: R820T tuner? mr.sneezy 9/3/12 2:02 AM
Hi Bob,

I tried out my R820T equipped dongle that I got from an Ebay vendor who said it was an e4000 type. 
It seems to have three tuning scan modes in the OEM software app supplied, FM, DTV and I think satellite TV bands.
I saw it tune to 1700Mhz or more in the third type of scan I tried. That may mean it will go much higher than the RT800 ?

Cheers,
Martin
Re: [ultra-cheap-sdr] Re: R820T tuner? Adam Nielsen 9/3/12 2:11 AM
> I saw it tune to 1700Mhz or more in the third type of scan I tried. That
> may mean it will go much higher than the RT800 ?

I just got a response from Rafael Micro.  Still working on them for a
datasheet, but they told me the frequency range of the R820T is 42 to
1002MHz.

They also said they have been getting lots of questions about SDR :-)

Cheers,
Adam.
Re: [ultra-cheap-sdr] Re: R820T tuner? Mikhail Genin 9/3/12 5:29 AM

They also said they have been getting lots of questions about SDR :-)



Hi Adam.
They said something about the possibility of a detailed use R820 in SDR?
I'd like to hope that these dongles can work as SDR receivers.

73, Mikhail RW3ADK 
Re: [ultra-cheap-sdr] Re: R820T tuner? Adam Nielsen 9/3/12 5:34 AM
> They said something about the possibility of a detailed use R820 in SDR?
> I'd like to hope that these dongles can work as SDR receivers.

The impression I got was that they were a bit confused as to why people were
asking these questions about a digital TV receiver.  (For instance why someone
asked about 0-100MHz tuning when there are no TV channels there.)  I think in
general the people who make these dongles don't really understand that we're
buying them for SDR.

I gave them a bit of background about what we're doing with their devices, and
explained why the E4000 was so good.  I hope they will understand that and
consider making a device optimised for SDR use rather than digital TV reception.

Cheers,
Adam.

Re: [ultra-cheap-sdr] Re: R820T tuner? W9RAN 9/3/12 8:13 AM
On 9/3/2012 7:34 AM, Adam Nielsen wrote:
> I hope they will understand that and consider making a device
> optimised for SDR use rather than digital TV reception.

That would be great, but I doubt there's much of a commercial reason to
do so.  But your news is encouraging!  Even if they want to continue to
restrict access to the full spec, just sharing a limited amount of
information with designers to allow the creation of an rtl driver that
can tune and adjust the gain, etc would be terrific. After all, we're
more interested in utilizing the dongles manufactured by others with
their tuner inside than in creating a new product from scratch.

Hopefully the number of supported ultra-cheap tuner options will
continue to grow.

73, Bob W9RAN
Re: [ultra-cheap-sdr] Re: R820T tuner? jdow 9/3/12 9:43 AM
How so? The E4000 I have tunes to 2214 MHz from 52 MHz with a gap near
the middle at 1108 through 1239.

{^_^}
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Re: [ultra-cheap-sdr] Re: R820T tuner? jdow 9/3/12 9:46 AM
And the people asking them about 0-100MHz use are showing their ignorance
quite plainly. Any use below about 50 MHz requires either an up-converter
or bypassing the tuner chip, the R820T in this case.

{^_-}
Re: [ultra-cheap-sdr] Re: R820T tuner? jdow 9/3/12 9:47 AM
Maybe they are trying to hide the detail that they are using other people's
patents in their design?

{o.o}
Re: [ultra-cheap-sdr] Re: R820T tuner? Adam Nielsen 9/3/12 4:27 PM
> And the people asking them about 0-100MHz use are showing their ignorance
> quite plainly. Any use below about 50 MHz requires either an up-converter
> or bypassing the tuner chip, the R820T in this case.

The only reason an up-converter is needed is because the E4000 will only tune
down to 50MHz.  There's nothing stopping a replacement IC from tuning all the
way down to 0Hz, and then you wouldn't need an up-converter.  I think people
were wanting to know whether the R820T did this.  Unfortunately it doesn't, so
now we know that an up-converter would still be required.

Cheers,
Adam.

Re: [ultra-cheap-sdr] Re: R820T tuner? mr.sneezy 9/4/12 5:33 AM
Hi Adam,

Firstly well done on getting dialogue happening with Rafael Micro, as it's not an easy thing with Taiwanese/Chinese companies at times. I have a good email rapport with a Chinese RC product manufacturer that was cultivated over a couple of years (my main hobby is RC aircraft). I find that the Chinese vendors will help you out if they understand you are trying to help them out too. Letting them know semi-indirectly, that there is a potential to sell more units if you can write SDR software to use their device should interest them (whether you do that personally is not important). Keep using the same contact you made, even if they need to refer technical questions to others there, that seems to be the way they like to do things in my experience...
Hopefully with some gentle encouragement you'll be able to get sent a PDF or two.

Also, is there potential in your opinion that the upper/lower frequencies they gave you are only the 'spec' limits, and that they may go higher if the software pushes them ?
If not it's still a reasonable range, and for the price these dongles cost it's pretty good value and will help people get into UC-SDR.
Martin

Re: [ultra-cheap-sdr] TV28T - antenna connector - MCX or MMCX? mr.sneezy 9/4/12 5:42 AM


It does seem faulty.   However, it did pick up an FM radio station. Just the one, though. And that was only outside.  Hmm :(


Just thought I'd mention that my R820T type dongle seemed faulty too at first. Wouldn't pick up anything in the scans. I uninstalled the software, then reinstalled, making sure the OEM driver got loaded first. Worked like a cracker after that. 
Martin
Re: R820T tuner? darky 9/4/12 8:37 AM
Hi All,
 
I just joined to the group. I have the same dongle with R820T. I decided to contact Rafaelmicro and asked very politely about technical documentation and linux drivers. My mail was redirected to marketing / sales and I managed to get some technical support.
 
I would like to provide the information to anyone interested, who wants to try to build the linux software for this dongle, I have the source code.
 
Datasheet look like a preliminary version, there a lot of things missing or just cut from it. The application / refference design looks usefull, it isn't very complex.
 
Please, let me know if you are interested. I would send you the information which I have, for the momment I prefer not to publish it.
 
I hope that at the end we will be able to use this dongle also for SDR.
 
Cheers,
Darky
Re: R820T tuner? g0nbd 9/4/12 11:05 AM
Just a  teck  note  , All  the up convertors  are  using a  local  oscillator  and mixer to  translate   HF to VHF  , All  will  have  problems  as  the  wanted  HF  signal  frequency  passed lower than   1 MHz  , under  this the  local  oscillator / mixer  set  up will  start to  fall over .. the method  described  as  'direct sampling'  has the  ability to  tune  down to  zero Hz  with  no  problems , with the  post  processing  given by the  demodulation  software the  dynamic  range  of the  8 bit  device is  extended  to  70 or 80 dB , just as  good  as  most  SW sets  and  with  no  mixer , the  all  important  noise  figure is  lower   ... for the  want  of a  new  set of  drivers  and  second 'HF'  dongle  , (if the  first one  is  ok .. don't touch it !!)  with a  link to the  ADC , the  cost  of these  HF>VHF  1>30 Mhz  converters  cannot  be  justified  ,other  than  , it was  allays  done  that  way !

G..
Re: R820T tuner? janSenior 9/4/12 11:10 AM

Well I do have software for sw and wfm for rtl based sticks. (The software for the dongle is a rewrite of osmocom-based software). One of the users of the
software complained that he had an R820T tuner in his dongle. So, I would be interested in getting any information on the tuner.


Best
jan
Op dinsdag 4 september 2012 17:37:48 UTC+2 schreef darky het volgende:
Re: [ultra-cheap-sdr] Re: R820T tuner? jdow 9/4/12 12:29 PM
How do you deal with the aliasing that happens, particularly with AM
broadcast stations?

(I can't quite light an LED off the captured energy from a very modest
antenna here. It gets into EVERYTHING and the fool station is only in
the 1 to 5 kW power regime. It's quite close, though - about 3 miles
away. It pegs the S meter on a ProII with its twenty dB attenuator
kicked into the circuit. KFI at 50 kW is a little farther away, about
15 dB farther. So.... How would you do weak signal SSB work, for example?)

{^_-}   Joanne, W6MKU
>         <http://www.ebay.com/itm/1x-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/261084027023?pt=US_Video_Capture_TV_Tuner_Cards&hash=item3cc9d2188f>
>
>         JP
>
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Re: [ultra-cheap-sdr] Re: R820T tuner? darky 9/5/12 2:30 AM
HI,
 
In normal radios you normally have a presector filter, BPF to allow only the desired band to pass to mixer. In case you have 5kW transmitter just 3 miles away ... well, you need very sharp BPF, maybe in combination with notch filter and the hope that sooner or later they will decomission the transmitter :)
 
BTW why do you expect that the SDR will be able to solve problems which exist since the begining of radio? If you look at the schematics it is more like a very basic front-end, but without RX BPF, LNA, IF filters, IF processing.
 
If you want to make it fully functional you need to add some HW - at least BPF, good LNA and maybe to optimize the IF LPF.
 
Best Regards,
Darky
Re: [ultra-cheap-sdr] Re: R820T tuner? jdow 9/5/12 3:03 AM
No, I don't expect it to solve the problems. I expect 8 bit quantization
to make the problems particularly dramatic.

{^_-}   Joanne, W6MKU
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Re: [ultra-cheap-sdr] Re: R820T tuner? g0nbd 9/5/12 6:57 AM
Jon the  club , I have a  bbc 3  carrier   station close  by , so  get  blocking  and  nice  inter mods  from the  3  carriers ....  all  you  can  do  is  make  one of the  Broadcast Filters  from the ARRL hand book and  fit  this  in series with the  Ae  feed  ...if your  lucky and the  station  is  only  on 1 frequency  , then  either  a  parallel  cct or  series  cct  as  rejecter  or  trap  will   work  , or  both  .... at least  you  have a  signal to  tune  it  with .... :(



73 -Graham
G0NBD
Re: [ultra-cheap-sdr] Re: R820T tuner? jdow 9/5/12 3:47 PM
And by extension if you have a fellow ham a couple blocks away who runs
a full legal limit station you've often obliterated a whole band. I had
that happen to me once, sorta kinda. As it turns out my R390A had a
weak mechanical filter in it. One day the guy down the street was
transmitting I watched that filter die. Fortunately I worked for Rockwell
at the time and had internal phone books at my beck and call. I found
the phone number for one of the sales critters for the Collins mechanical
filter people and called him. He allowed as how it surprised him, he
wanted it to analyze the failure, and sent me a replacement. So I was
back up with the 2kHz filter in about a week. And the new one never blew
when the fellow down the street transmitted.

Um, at the time he was using a beam at about 40-45'. I was using a new
beam at 70', the highest the city would allow me to put up. (And I won
a bet with my ex about putting it up. "If you dig that 40" square 8'
deep hole yourself, you can get the tower and put it up." Erm, that is
where I learned I really COULD be self-reliant - and Irish stubborn. It
took me 6 months if near killing myself digging in very sandy and rocky
clay. But I did it.) Needless to say we put in MASSIVE signals at each
other's QTHs even with me only at 100 Watts. (Why go for a 10dB signal
increase for $XXX when I could go for closer to 20dB and some interference
nulling, to boot, for about the same money?)

{^_^}   Joanne, W6MKU - and, yes, I am moderately large in the vertical
         direction and lately even the horizontal directions <gigasigh>
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Re: R820T tuner? g0nbd 9/5/12 4:23 PM
Q Is  the  software windows based ?  if so  is there  a  download link ?   Tnx -Graham.
Re: R820T tuner? Dennis Yusupoff 9/6/12 2:21 AM
Hello all!

I've just got a 25-pages datasheet on R820T from AstroMeta Co. and moreover, Linux drivers. 


Hope it will helps in implementing support in SDR soft.
Re: R820T tuner? mr.sneezy 9/6/12 2:37 AM
Thanks Dennis, 
I pulled down those files and opened them fine. I'm don't have the skills to comment on the contents, I'll leave that to the guru's.
cheers, Martin
Re: [ultra-cheap-sdr] Re: R820T tuner? Colorado Rob 9/6/12 5:32 AM

The datasheet appears to be password protected.

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Re: [ultra-cheap-sdr] Re: R820T tuner? Colorado Rob 9/6/12 5:34 AM

Nevermind. Missed the passwd in the email -- even after reading it 3 times

Re: [ultra-cheap-sdr] Re: R820T tuner? Dennis Yusupoff 9/6/12 5:35 AM
So placing password at the end of letter extremely useful method to make read carefully, isn't it? ;)


06.09.2012 16:34, Colorado Rob пишет:

Nevermind. Missed the passwd in the email -- even after reading it 3 times

On Sep 6, 2012 7:32 AM, "Colorado Rob" <colora...@gmail.com> wrote:

The datasheet appears to be password protected.

On Sep 6, 2012 4:21 AM, "Dennis Yusupoff" <yus...@gmail.com> wrote:
Hello all!

I've just got a 25-pages datasheet on R820T from AstroMeta Co. and moreover, Linux drivers. 




Re: [ultra-cheap-sdr] Re: R820T tuner? Adam Nielsen 9/6/12 5:57 AM
> I've just got a 25-pages datasheet on R820T from AstroMeta Co. and moreover,
> Linux drivers.

This is great!  Thanks for posting.  Unfortunately it's only an incomplete
datasheet, as it doesn't contain either a register map or a list of I2C
commands to control the device.  (For instance, nowhere in the datasheet does
it tell you how to tune it to a specific LO frequency.)

It's possible to figure some of this out from reading the rather poor quality
source code (which is only for the digital TV part of the device, not SDR),
but it would be very tedious and from looking at the code, there's a lot of
"magic numbers" (numbers that aren't documented, so you have no idea what
they're for or what effect it would have to change them.)  This makes it a
very slow and error-prone process to figure out what anything does.

I haven't heard back from Rafael or AstroMeta yet, so hopefully they'll
provide a somewhat more detailed datasheet.

Cheers,
Adam.

Re: [ultra-cheap-sdr] Re: R820T tuner? linagee 9/6/12 9:00 AM
" as it doesn't contain either a register map or a list of I2C commands to control the device."

I found page 16 of the PDF informative.
I don't think there are any commands. I think it's just I2C writes to registers. (as seen on page 16 of the PDF: Start,ChipID,Register,Data,Data,Data,etc,Stop) R828_I2C in the file is register byte/data byte. R828_I2C_Len is register byte/50 data byte array/length.

Everything below is from tuner_r820t.c in the RAR mentioned earlier.

Defaults of registers appears to be at line 607.
UINT8 R828_iniArry[27] = {0x83, 0x32, 0x75, 0xC0, 0x40, 0xD6, 0x6C, 0xF5, 0x63,
                                        /* registers:     0x05  0x06  0x07  0x08  0x09  0x0A  0x0B  0x0C  0x0D                                                    */
                                                   0x75, 0x68, 0x6C, 0x83, 0x80, 0x00, 0x0F, 0x00, 0xC0,//xtal_check
                                        /* registers:    0x0E  0x0F  0x10  0x11  0x12  0x13  0x14  0x15  0x16                                                    */
                                                   0x30, 0x48, 0xCC, 0x60, 0x00, 0x54, 0xAE, 0x4A, 0xC0};
                                        /* registers:    0x17  0x18  0x19  0x1A  0x1B  0x1C  0x1D  0x1E  0x1F                                                    */

Reading through tuner_r820t.c, I tried to extract the meaning of the registers. Please see attached file. I only got to line 1975, then I had to step away because I had other things to do.
(See attached XLS)

I hope someone finds this of minor use, I'm not a programmer by trade or anything.
It *will* be far easier to get the proper datasheet out of the manufacturer.

Cheers,
linagee







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Re: [ultra-cheap-sdr] Re: R820T tuner? Dennis Yusupoff 9/6/12 9:06 AM
06.09.2012 20:00, linagee пишет:
It *will* be far easier to get the proper datasheet out of the manufacturer.

It's on the way, as I hope. I've sent appropriate request to manager who gave me first specification. It seems what he doesn't clearly understand what exactly we needs:

As my understanding that is just the Linux Driver of (R820T and others tuner + RTL2832U)

But it doesn’t seem to fit for you, right ?

So that, could you tell me clearly what the document you need.

I wrote:

List of I2C commands and configuration registers.
FYI - there was over 70 registers on Elonics E4000 tuner, see pages 17-23 and especially "Example of Frequency synthesizer configuration" on page 27 there: http://erewhon.superkuh.com/gnuradio/Elonics-E4000-Low-Power-CMOS-Multi-Band-Tunner-Datasheet.pdf
That's what we need.

As far as I'm not a programmer, I can't define it more clearly.


---
With best regards,
Dennis Yusupoff,
network engineer of
Smart-Telecom ISP
Russia, Saint-Petersburg
Re: [ultra-cheap-sdr] Re: R820T tuner? asbokid 9/6/12 12:18 PM
Hello Linagee,

Those pages from the datasheet just describe the electrical signalling for the i2c interface. (Should be the same for all devices that use an i2c bus).

On a positive note, the archive of C source includes some code for tuners other than the Elonics E4000 and the Raphael R820T.

cheers, a
Re: [ultra-cheap-sdr] Re: R820T tuner? asbokid 9/6/12 12:34 PM
Sorry, Linagee,

Completely missed your attached spreadsheet, of tentative register purposes..

cheers, a
Re: [ultra-cheap-sdr] Re: R820T tuner? Adam Nielsen 9/6/12 5:02 PM
> Those pages from the datasheet just describe the electrical signalling for the
> i2c interface. (Should be the same for all devices that use an i2c bus).

Actually they do show how to write data to registers which I also missed on
the first look, thinking it was just electrical signalling.  Well spotted linagee!

> On a positive note, the archive of C source includes some code for tuners
> other than the Elonics E4000 and the Raphael R820T.

Nothing new here unfortunately - all this code is straight out of the Linux
DVB project and has been freely available for a while.  Rafael just copied it
and added new code for their own tuner IC.

> On Thu, Sep 6, 2012 at 4:00 PM, linagee <lin...@gmail.com
> <mailto:lin...@gmail.com>> wrote:
>
>     Reading through tuner_r820t.c, I tried to extract the meaning of the
>     registers. Please see attached file. I only got to line 1975, then I had
>     to step away because I had other things to do.
>     (See attached XLS)
>
>     I hope someone finds this of minor use, I'm not a programmer by trade or
>     anything.
>     It *will* be far easier to get the proper datasheet out of the manufacturer.

Unfortunately, as you can see in your spreadsheet, it is quite difficult to
extract meaning from the numbers.  For example your spreadsheet shows that the
default value for register 0x0E is 0x75, but what does this mean?  What
happens if it's changed to 0x76?  Those are the things you need to know, and
only a datasheet (or *very* well documented code) will tell you.

As it stands now, the spreadsheet would only be useful as a quick reference.
Because all the register writes are taken out of context, you couldn't use it
alone when writing a driver.  For example, when setting the frequency, some
unknown registers might be changed at the same time.  Everything might fail
unless you also set the unknown registers when changing the frequency, even
though you don't know what they actually do.  You can't see from your
spreadsheet which registers are required and at what values, when setting
other registers.

It's all this sort of dependency tracking and unknowns that make this sort of
reverse engineering so time consuming.

It's *much* easier to get a datasheet, where all this information is already
explained in the detail needed.

Also as a side note, it would be better if you listed which bits in each byte
affect the values.  You have (for example) "Current AND 0x60 OR 0x0B" means
something.  But you don't say whether you do the AND first or the OR first,
and doing this in the wrong order gives you the wrong value.  AND also turns
bits on or off, but OR always turns them on, so you need to know which bits
are being changed and why.  In order to be able to work off the spreadsheet,
it would need to say - like a datasheet does - that register 0x0B bit 4
controls the AGC, 0=on, 1=off, for example.  But again this goes back to being
unable to figure out what each number means, because it's not documented in
the code.

And of course if you ignore all this and just write the same numbers to the
same registers in your own driver, you can get strange things happening
because you are writing to registers and you don't know what they do.  For
example adjusting the gain might cause the LO frequency to change without you
knowing, because those registers are written at the same time in the code you
copied.  Remember how the original E4000 driver often came up with I2C errors
after changing the LO frequency?  Now you know why :-)

This is why getting source code is no substitute for getting a datasheet.

Cheers,
Adam.

Re: [ultra-cheap-sdr] Re: R820T tuner? James Alton 9/6/12 8:03 PM
On Thu, Sep 6, 2012 at 6:02 PM, Adam Nielsen <a.ni...@shikadi.net> wrote:
Also as a side note, it would be better if you listed which bits in each byte affect the values.  You have (for example) "Current AND 0x60 OR 0x0B" means something.  But you don't say whether you do the AND first or the OR first, and doing this in the wrong order gives you the wrong value.  AND also turns bits on or off, but OR always turns them on, so you need to know which bits are being changed and why.  In order to be able to work off the spreadsheet, it would need to say - like a datasheet does - that register 0x0B bit 4 controls the AGC, 0=on, 1=off, for example.  But again this goes back to being unable to figure out what each number means, because it's not documented in the code.

I agree that bit set values is the way to go, unfortunately they didn't document what bits they were setting in code. The AND/ORs are the order that they appear in code. Some things can start to be inferred, for example on register 0x10. Another thing that I can infer from the code is that they are getting the values from a register map, so one must exist! :)

There does appear to be a lot of procedural steps above and beyond setting registers if you look through that same file. (With sparsely detailed comments.)

Cheers,
linagee
Re: R820T tuner? Gaston Picard 9/7/12 4:38 AM
Unfortunately, and from what can be seen in the datasheet, there is no I and Q outputs, only one standard IF out. As thus, IMO, with this tuner is not possible to do SDR, which relies on that quadrature signals...

G.


On Tuesday, August 21, 2012 6:10:54 PM UTC-3, JP wrote:
I placed an order for an e4000 based dongle but the seller said that it was no longer available (no more e4000 chips!). He suggested a dongle with an R820T tuner. Has anybody ever heard of this tuner? A different seller on ebay lists the R820T as 'Latest Chip Better Quality' :)

JP

Re: [ultra-cheap-sdr] Re: R820T tuner? James Hall 9/7/12 4:47 AM
IIRC, if you can digitize the whole signal you are interested in, you can decode it in software. I think there are some SDR concepts that directly digitize a wide-bandwidth and then implement more of the receiver in software. One of the websdr people do that I think.

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Re: [ultra-cheap-sdr] Re: R820T tuner? Adam Nielsen 9/7/12 5:16 AM
> Unfortunately, and from what can be seen in the datasheet, there is no I and Q
> outputs, only one standard IF out. As thus, IMO, with this tuner is not
> possible to do SDR, which relies on that quadrature signals...

It's actually got two IF outputs, just not labelled I and Q.  It must be IQ
though, otherwise they wouldn't be able to get FM reception to work just by
adding code for their tuner.

Cheers,
Adam.

Re: [ultra-cheap-sdr] Re: R820T tuner? jdow 9/7/12 9:55 PM
The Realtek chip has a capability to work with an "if" on its input. That
is the basis of the ultra-cheap HF modification.

{^_^}
>     <http://www.ebay.com/itm/1x-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/261084027023?pt=US_Video_Capture_TV_Tuner_Cards&hash=item3cc9d2188f>
>
>     JP
Re: [ultra-cheap-sdr] Re: R820T tuner? g0nbd 9/8/12 6:13 AM
Can anyone  layout  what  needs to  be  done to  access  the '' ultra-cheap HF modification.''  
Is this  c dongle  different to  the  ezcap  that  works nicely on vhf  > up ?  or  has the  ezcap  the  ability to  tune HF (IF) with  no  modification  .(.ie   wire soldered to pin ?)

Tnx -G.
Re: R820T tuner? bruce buffalo 9/9/12 10:54 AM
r820t not supported , yet. and vendors will post them as e4000 tuner such as this one did.
look at the description below.  the ad and you will see its copy and paste. as a rtl-2832u+4000 tuner. when the listing is for a r820t tuner.
http://www.ebay.ca/itm/NEW-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/180963047655?pt=LH_DefaultDomain_0&hash=item2a223cf8e7#ht_1871wt_1111 


On Tuesday, 21 August 2012 15:10:54 UTC-6, JP wrote:
I placed an order for an e4000 based dongle but the seller said that it was no longer available (no more e4000 chips!). He suggested a dongle with an R820T tuner. Has anybody ever heard of this tuner? A different seller on ebay lists the R820T as 'Latest Chip Better Quality' :)

JP

Re: R820T tuner? Mikhail Genin 9/10/12 2:23 AM
good news everyone :)

Steve Markgraf , added support to libraries in the R820T librtlsdr. I think soon it will work!


воскресенье, 9 сентября 2012 г., 21:54:20 UTC+4 пользователь bruce buffalo написал:
r820t not supported , yet. and vendors will post them as e4000 tuner such as this one did.
look at the description below.  the ad and you will see its copy and paste. as a rtl-2832u+4000 tuner. when the listing is for a r820t tuner.
http://www.ebay.ca/itm/NEW-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-RTL2832U-R820T-/180963047655?pt=LH_DefaultDomain_0&hash=item2a223cf8e7#ht_1871wt_1111 
Re: [ultra-cheap-sdr] Re: R820T tuner? darky 9/10/12 2:32 AM
Great! I was hoping for that. When do you think the official release will come ?
 
Chears,
Darky

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Re: [ultra-cheap-sdr] Re: R820T tuner? Mikhail Genin 9/10/12 2:45 AM
If you are running Linux, you can already start R820T. Need to compile a new version of the library.

If windows, you need to wait for someone to do a compilation under Windows. I do not write in C and can not compile.

If anyone can do it, please do!



понедельник, 10 сентября 2012 г., 13:32:38 UTC+4 пользователь darky написал:
Re: [ultra-cheap-sdr] Re: R820T tuner? Alexandr Igumnov 9/11/12 4:20 AM
Precompiled win32  rtlsdr.dll.  Created from GIT snapshot 11 Sep 2012. Tested with SDR#.


понедельник, 10 сентября 2012 г., 15:45:33 UTC+6 пользователь Mikhail Genin написал:
Re: [ultra-cheap-sdr] Re: R820T tuner? Mikhail Genin 9/11/12 5:26 AM
Спасибо тебе добрый человек!!!

вторник, 11 сентября 2012 г., 15:20:58 UTC+4 пользователь Alexandr Igumnov написал:
Re: [ultra-cheap-sdr] Re: R820T tuner? mr.sneezy 9/14/12 5:04 AM
I tried the rtlsdr.dll version in the linked zip on my installed SDR#. I get a error warning of this when I run SDR# now and RTL-SDR / USB is not in the device selection list.
---------------------------
Error loading 'SDRSharp.RTLSDR.RtlSdrIO,SDRSharp.RTLSDR' - Exception has been thrown by the target of an invocation.
---------------------------
Restoring to the old DLL fixes that report.
I suspect maybe I didn't understand something about the context of Alexandr's post ??

Martin
Re: [ultra-cheap-sdr] Re: R820T tuner? Alexandr Igumnov 9/15/12 5:56 AM
Fresh version of rtlsdr.dll is now available at the osmocom site http://sdr.osmocom.org/trac/wiki/rtl-sdr
So I remove my build from my site.
Re: [ultra-cheap-sdr] Re: R820T tuner? Amogh Desai 9/21/12 12:50 PM
Hi,

So should I go for the r820t based dongle ?? or is it risky ??

e4000 ones are doesnt seem to be available :(

Regards
Amogh
Re: [ultra-cheap-sdr] Re: R820T tuner? darky 9/21/12 2:18 PM
It's not risky, I have both and they work with last version of osmocom
soft, even I think the one with r820t is working a little bit better.
Software can handle them automatically, no need even to specify which
device is exactly in. The Rafael chip does not have this gap in the
middle as e4000. My r820t dongle is also better design, pcb looks
better, all soldering is nicely done and the solder joints are shiny.

Both are available to buy from ebay. I ordered mine just 2-3 weeks ago
and received them very fast.
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Re: [ultra-cheap-sdr] Re: R820T tuner? mr.sneezy 9/22/12 6:50 PM

So the R820T dongle IS working on SDR# from what is written above. 
I however can't get it going. 
Should it be as simple as replacing the previous rtlsdr.dll with the new updated one, or was there another step required ?

Martin
Re: [ultra-cheap-sdr] Re: R820T tuner? Isaac Gerg 9/22/12 9:51 PM
I have said dongle and have it working.  I used the instructions here:
http://rtlsdr.org/softwarewindows#installing_sdr 

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Re: [ultra-cheap-sdr] Re: R820T tuner? darky 9/22/12 11:56 PM
Yes, the R820T chipset is working just fine. I just followed the
instructions on osmocom website for my Linux laptop, gnuradio is very
good I was really surprised.

For my windows 7 laptop I followed the instructions here :

http://rtlsdr.org/softwarewindows

do exactly what is written there, step by step, all steps. And also
very important - download the packages from this link, not the stable
SDRSharp release because it doesn't work for rtlsdr.

Good luck! Enjoy it!

And a note to all e4000 users - be aware that there are dongles
without ESD protection diodes on the input. It is extremely easy to
damage the dongle if it is not protected. I did damaged mine, the
effect is that it become very insensitive to RF signals, all other
functions work. Repair is not possible! When you receive your dongle -
open it and inspect for the diode on the input, if the diode is not
there avoid connecting other antennas then the original one provided
together with it. If you want to use it as SDR with other antennas you
need to install the diode first.
Re: [ultra-cheap-sdr] Re: R820T tuner? mr.sneezy 9/23/12 4:33 AM
Thanks, I'll do that.
I'll uninstall the installation I have now first, to make sure it's all the right file versions. I'll let you know how it goes in a day or so.

I've had my R820T dongle apart and took images when I got it. It appears to have some protection on the RF input. 
I'd guess the three pin SOT-28 part on the input is a diode, followed by ceramic caps...
Cheers,
Martin
Re: [ultra-cheap-sdr] Re: R820T tuner? darky 9/23/12 6:36 AM
Yes, your guess is right, the small 3 pin or sometimes 2 pin device exactly next to the antenna is the ESD protection, usually followed by ceramic cap to remove DC signal if there is any, the DC is usually there for the LNA power supply.

I had to return my e4000 stick back to ebay seller, I am sorry for him but those few cents that they saved actually caused the stick to get damaged ... That's what I say bad business.

Does anyone know a good HF upconverter which can be used together with the stick? If someone has experience with such device, please share with me.

Does anyone tried to put device toghether with web sdr, so that many people can observe the reception over the www? Maybe I would do so, but I need to do a little research first.

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Re: R820T tuner? mr.sneezy 9/24/12 6:14 AM

I have got the R820T chip dongle working fine now with SDR#. All that was needed was a free install of the Automatic install package (the batch file and auto download script). Selected the dongle in Zadig and RTL-SDR / USB option.

I tried it on a NetBook first with Win7 Starter edition, and it's OK but for running at 100% CPU (Atom N450). Also running fine with Win7 64bit on a desktop with Dual Core 2Ghz CPU. Interestingly I get better results in received RF and demodulation on the Netbook, as with the Desktop the noise floor is much higher and there are a lot of birdie signals visible across the spectrum. This is regardless of antenna position. looks like interference from the PC itself right now.

Martin
Re: [ultra-cheap-sdr] Re: R820T tuner? CT1FFU 9/24/12 6:29 AM
Velkov


Of course, there also now some copys of my convertor on web.

Best 73

Tony



2012/9/24 mr.sneezy <mr.s...@bigpond.com>

I have got the R820T chip dongle working fine now with SDR#. All that was needed was a free install of the Automatic install package (the batch file and auto download script). Selected the dongle in Zadig and RTL-SDR / USB option.

I tried it on a NetBook first with Win7 Starter edition, and it's OK but for running at 100% CPU (Atom N450). Also running fine with Win7 64bit on a desktop with Dual Core 2Ghz CPU. Interestingly I get better results in received RF and demodulation on the Netbook, as with the Desktop the noise floor is much higher and there are a lot of birdie signals visible across the spectrum. This is regardless of antenna position. looks like interference from the PC itself right now.

Martin

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--
António Matias

CT1FFU - CR5A 


QRV: HF, 6m, 4m,2m,70cm,23cm
SSB, CW, MGM
DX, EME, Contest,Sat.

POBOX-38
2504-909
Caldas da Rainha
Portugal

Re: [ultra-cheap-sdr] Re: R820T tuner? Michi Sakayama 9/25/12 1:58 AM
 
Just want to say,  a friend of mine let me borrow his CT1FFU upconverter for the weekend.  Frankly it was competitive to my Perseus and made me second guess spending all of that money for the Perseus. It really does do HF very well. I was monitoring the entire AM broadcast band at once, and WWV  (and sometimes WWVH) came in fine at 2500, 5000, 10000 and 15000 khz. I even had 3.8 MSPS working with only a blip every minute or so. (Though SDR# does seem to 'chug' a bit with that rate.)
 
So I can really recommend Tony's upconverter after spending a weekend with it.  And unfortunately I have to give it back so I will have to get my own soon; I just can't decide now between v3.0 or v4.0. 
 
(Tony just a side note, if you could make the on/off HF-VHF switching be a momentary switch instead of having to unplug it from USB, i'd be all over that!!  Also, maybe an LED to let us know it's getting power to the oscillator+mixer! I was confused for a good hour until I found out I had a bad USB extension cable!)
 
I really will be ordering one for myself soon!
 
-michi
Re: [ultra-cheap-sdr] Re: R820T tuner? CT1FFU 9/25/12 3:44 AM
Hi there Michi

Many tnx for this nice feedback.
The main diference on version 3.0 to 4.0 is teh antenna swiching and the use of High Pass Filter on VHF side, so avoid  WFM broadcasting interference.
If dongles  have phantom-power it´s easy to swich on-off the antenna/conversion, on program, but with no phantom power just unpluging the USB will do.
Goog idea about the led indication Michi.
Will add it on next versions.

Many tnx 
Best 73

Tony

2012/9/25 Michi Sakayama <sku...@gmail.com>
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--
António Matias

CT1FFU - CR5A 


QRV: HF, 6m, 4m,2m,70cm,23cm
SSB, CW, MGM
DX, EME, Contest,Sat.

POBOX-38
2504-909
Caldas da Rainha
Portugal

CT1FFU Adam Nielsen 9/25/12 6:05 AM
> Just want to say,  a friend of mine let me borrow his CT1FFU upconverter for
> the weekend.  Frankly it was competitive to my Perseus and made me second
> guess spending all of that money for the Perseus. It really does do HF very
> well. I was monitoring the entire AM broadcast band at once, and WWV  (and
> sometimes WWVH) came in fine at 2500, 5000, 10000 and 15000 khz.

Interesting, I wondered whether it would be possible to do that.  I figured it
would, but nobody has actually said they've done that yet!

> So I can really recommend Tony's upconverter after spending a weekend with
> it.  And unfortunately I have to give it back so I will have to get my own
> soon; I just can't decide now between v3.0 or v4.0.

How does the device actually work?  It's got a USB plug on it - does that mean
you need to load drivers?  Does it work with any SDR software?  Do the
frequencies appear correct in the SDR program or do you need to manually enter
in an adjustment/offset amount?  How do you connect it to the dongle?

Cheers,
Adam.

Re: R820T tuner? mr.sneezy 9/25/12 6:32 AM

I got time to do some basic testing of the R820T type dongle today with a borrowed signal generator and SINAD'er on the audio out of the Netbook PC. I didn't have a lot of time though, so I only tested the dongle with N-FM signals. 

I started at 500Mhz as a base line for setting up. I noticed right away that the Sinader gave much lower readings than my ear told me was right (I can pick it by +-1dB by ear normally, from years of professional radio tuning). 
I got a 12dB SINAD of -110dBm by the instrument, but by ear I marked it at about -115dBm. I tested my 'ear meter' on a known good handheld receiver and got a result I expected. So I think there may be some distortion on the recovered audio that the SINAD reading is picking up. I did not have time to check it with a CRO. One clue in that theory is that adding +20dB of RF (-90dBm) only got me a SINAD of 14dB, normally I'd expect over 20dB...
Frequency offset error was about -30khz, and I measured that at two other frequencies. I could not get the PPM offset in config settings to work, it may not be implemented yet.

Moving on and lower. I'll give both results and you can use whichever feels good to you.
400Mhz -115dBm by ear, -110dBm by instrument. Frequency offset error was approx -25khz
300Mhz -119dBm by ear, -112dBm by instrument. Frequency offset error was approx -18khz
200Mhz -120dBm by ear, -111dBm by instrument.  
100Mhz -120dBm by ear, -111dBm by instrument. 
50Mhz -118dBm by ear, -107dBm by instrument. 
40Mhz -115dBm by ear, -111dBm by instrument. 
30Mhz -115dBm by ear, -110dBm by instrument. 
25Mhz -115dBm by ear, -107dBm by instrument. 

If I leave the center frequency on SDR# at 24.1Mhz (not lower) I can chase a good signal down to 23.1Mhz by sliding the spec-an displays filter leftwards.
So this chip is just inside the HF band in my unit by the look of it. When I get more time I'll see if I can hear 27Mhz AM or USB stations locally.

Going upwards. I tried 600, 700, 800 and 900Mhz and got good sensitivity, just like the lower frequencies. At around 960Mhz I could not demodulate anything recognisable, but then again I'm not sure my sig-gen was working well up that high either. 

So thus far 25Mhz to 950Mhz is OK on my dongle. Testing higher will need a different sig gen and more time...





Re: [ultra-cheap-sdr] Re: R820T tuner? darky 9/25/12 7:01 AM
Hey,

Thanks a lot! Amazing results, thanks a lot for posting them here. I
am sure the others will enjoy to have them too.

What about the performance above 1GHz? I managed to receive the ADS-B
signals with it and it managed to do a 200 - 260 km diameter with
antenna on the balcony. I used a 3 sections colinear omnidirectional
antenna which I build out of copper wire 1.5 mm diameter. So I wander
what will be the performance.

Also interesting is how much it can go with frequency? Is it like
e400o able to go up to 1700MHz or above?

Best Regards,
Darky
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Re: [ultra-cheap-sdr] CT1FFU CT1FFU 9/25/12 7:57 AM
Hello Adam
The USB connector is just a way i found to get the VCC
Just use to feed the circuit with 5V. This will make easy connection and avoid wires. No drives needed.
About performance: It is in fact good reception, and  with a surprising performace.
That is beacouse the use of a top quality RF-mixer as is double balance diode mixer from minicircuits.
This mixers is the responsable for the good behavior of device in all HF, due is design to handle with very strong and rugh signals.
The local oscillator is relativly clean and all the filterings are well calibrated to the impedance and frequency.
So, in fact, no big secret, just typical RF-radio-engeneering.

73
Tony



2012/9/25 Adam Nielsen <a.ni...@shikadi.net>


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António Matias

CT1FFU - CR5A 


QRV: HF, 6m, 4m,2m,70cm,23cm
SSB, CW, MGM
DX, EME, Contest,Sat.

POBOX-38
2504-909
Caldas da Rainha
Portugal

CT1FFU Michi Sakayama 9/26/12 3:54 AM
Adam,

No driver needed - just gets power from USB. You enter the Local Oscillator frequency into the SDR program and then everything shows up correctly. The LO Freq for Tony's converters is 106.250 MHz . So for example in SDR# you would enter a "shift" of -106,250,000 or in HDSDR you would enter a "LO Offset" of 106250000. Most SDR programs have a facility for this. After that everything shows up just as it should.  I've received signals from 530 kHz to 21500 kHz with it so far.

-michi

Re: [ultra-cheap-sdr] CT1FFU ik7tad 9/26/12 9:28 AM
Hi Antonio (and all the list as well),

how about interferences from local FM stations?

I'm interested in receiving medium waves too, and in case of receiving
the lower edge of 531 kHz the receiver would actually be receiving
106,250+0,531=106,781 MHz, a frequency well inside the FM band where,
especially here in Italy, there are very strong signals.

How does your converter cope with these strong signals?

Would it be possible to change the local oscillator frequency to, say,
200 MHz to stay away from the FM band interferences?

Thanks for answering.

73s de ik7tad
Re: [ultra-cheap-sdr] CT1FFU CT1FFU 9/26/12 9:37 AM
I Ricardo.
No, problem with FM broadcasting
The LO leakage is much stronger then any sig surging from antenna of FM and this  LO sig  still make no problems.
unless you leave a few meters from a FM emission antennas, you will have no problems.
Change frequency of LO is possible, but would need redesing all circuits.
I leave 500m meter from local radio TXrs and its on 103.1Mhz  with several Kws  EIRP.
Never had any problem with converter receive eben lowband.
With Dongle direct to antena, YES, it make dongle deaf.

All the broadcsting station received by the convertor are moved up to 200Mhz , so, they no problem.


Tony

2012/9/26 ik7tad op. Riccardo <ik7...@gmail.com>

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António Matias

CT1FFU - CR5A 


QRV: HF, 6m, 4m,2m,70cm,23cm
SSB, CW, MGM
DX, EME, Contest,Sat.

POBOX-38
2504-909
Caldas da Rainha
Portugal

Re: [ultra-cheap-sdr] CT1FFU Michi Sakayama 9/27/12 12:43 AM
I can say that I live one mountain over from a mountain that's loaded up with local high-powered FM transmitters; one of them at 105.9 and one at 106.7, and one at 107.5.  I have not heard a peep of them on the HF bands with the upconverter.  (Even with 107.5 FM local, I can tune MW stations at 1250 AM (exactly 107.5)  just fine and even do DX.) So I can say rather definitively that it does not appear to be an issue at all. 
Re: [ultra-cheap-sdr] CT1FFU ik7tad 9/29/12 9:33 AM
2012/9/27 Michi Sakayama <sku...@gmail.com>:
> 106.7, and one at 107.5.  I have not heard a peep of them on the HF bands
> with the upconverter.  (Even with 107.5 FM local, I can tune MW stations at

Hi Michi,
are you using António's CT1FFU upconverter or another one?
Thank you.
Re: [ultra-cheap-sdr] CT1FFU Michi Sakayama 9/30/12 3:54 AM
This was one of Antonio's, for sure, lent to me last weekend from a local ham that just received it rather recently from CT1FFU. It was a 3.0 I think, (or 3.1?)- I'm going to order the 4.0 here for myself because it really did work that well.

Was able to get some distant numbers stations and decode RNZI's DRM stream with DReaM even!

Re: [ultra-cheap-sdr] CT1FFU Michi Sakayama 9/30/12 3:56 AM
Oh yeah - also , my RTL-SDR is an RT820 based one.
Re: [ultra-cheap-sdr] Re: R820T tuner? mp_...@yahoo.com 3/2/13 4:03 AM

I am the main designer of R820.

I just found and was surprised this baby get so much notice in SDR group.

I can give some answer for several  previous questions:

1. Yes, it can go up to 1.8Ghz since the internal PLL  osc over 3.6Ghz.
2. Further, the external FM filter was for cutting some FM band by purpose. Just de-soldering the shunt inductor if you want best NF in FM band. (pay the risk if strong FM became the interference and not the band you want)
3. Inquire forward to our official mailbox or 3rd party vendors is useless since they are not tech guy and probably bad english, no idea what you are taking about.  You can let me know your feedback of this tuner or any recommendation is welcome to my private: mp_...@yahoo.com.

PS: I can be very busy, Delay reply might occur.



Adam Nielsen於 2012年9月3日星期一UTC+8下午8時34分41秒寫道:
> They said something about the possibility of a detailed use R820 in SDR?
> I'd like to hope that these dongles can work as SDR receivers.

The impression I got was that they were a bit confused as to why people were
asking these questions about a digital TV receiver.  (For instance why someone
asked about 0-100MHz tuning when there are no TV channels there.)  I think in
general the people who make these dongles don't really understand that we're
buying them for SDR.

I gave them a bit of background about what we're doing with their devices, and
explained why the E4000 was so good.  I hope they will understand that and
consider making a device optimised for SDR use rather than digital TV reception.

Cheers,
Adam.

Re: [ultra-cheap-sdr] R820T tuner? Adam Nielsen 3/10/13 3:32 AM
> I am the main designer of R820.

Thanks for stopping by!  Sorry about the delay in my reply but your e-mail
went to my spam folder :-(

> I just found and was surprised this baby get so much notice in SDR group.

Yes, your IC is now the only one in production that serves our purposes since
the Elonics E4000 stopped being made.  Luckily the R820T seems to perform better!

> You can let me know your feedback of this tuner or any
> recommendation is welcome

Is there any possibility of getting a datasheet for the R820T without signing
an NDA?  There is a short datasheet already public, but it does not contain
register mappings, and these are very helpful for writing good quality
software.  Are you able to supply us with a good quality datasheet?

Is there also any possibility of tuning below 50MHz to receive shortwave
transmissions?

Many thanks for your time.

Cheers,
Adam.

Re: [ultra-cheap-sdr] R820T tuner? markotime 3/10/13 8:35 AM
http://superkuh.com/gnuradio/R820T_datasheet-Non_R-20111130_unlocked.pdf
google is your friend <g> /mark
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Re: [ultra-cheap-sdr] R820T tuner? jdow 3/10/13 10:35 AM
It is known that just below 25 MHz works. Any further is likely out of
range of any option. But....

{^_^}
Re: [ultra-cheap-sdr] R820T tuner? jdow 3/10/13 11:02 AM
Wonderful. I do note that the reference clock is normally 16 MHz. The
word here is that many dongles seem to be made with 28.8 MHz crystals.
Is there a separate app note for that condition? I am sure if affects
frequency synthesizer settings.

{^_^}   Joanne, W6MKU
Re: [ultra-cheap-sdr] R820T tuner? jdow 3/10/13 11:17 AM
Hm, Mark, I also notice that there is no programming information beyond
the bare fact that there are some number of 8 bit data registers. How many
registers are there and what data goes into which bits? That would help
use (and creatively abuse) the modules.

{^_^}   Joanne, W6MKU

On 2013/03/10 08:35, markotime wrote:
Re: [ultra-cheap-sdr] R820T tuner? Adam Nielsen 3/10/13 12:26 PM
> http://superkuh.com/gnuradio/R820T_datasheet-Non_R-20111130_unlocked.pdf
> google is your friend <g> /mark

This is the short datasheet I was referring to, and it has been available for
a few months now.  But as Joanne has pointed out, it lacks any sort of
register table, so it doesn't explain how to actually program the device to do
something.  Without that information the datasheet isn't especially useful for
improving SDR software.

Cheers,
Adam.

Re: [ultra-cheap-sdr] R820T tuner? Adam Nielsen 3/10/13 12:55 PM
Hi MP,

A register table would certainly be helpful.  So far all we have to go on is
example source code, so a register table would help us to visualise how
everything fits together.  It would be great if you're able to send that through!

You are right - people have successfully tuned the R820T between 24MHz and
1.9GHz.  There is a lot of interest in tuning well below 24MHz, so if this is
possible do let me know!

The only other functions the SDR community is interested in is enabling and
disabling all the gain functions.  Some people want the most gain they can
get, and others want no gain at all.  I think the R820T works well in this
regard, but being able to look at a register table to make sure all relevant
registers are being set would be very helpful.

Thanks again for your time!

Cheers,
Adam.

-------- Original Message --------
Subject: Re: [ultra-cheap-sdr] R820T tuner?
From: MengPing Kan <mp_...@yahoo.com>
To: Adam Nielsen <a.ni...@shikadi.net>
Date: Mon Mar 11 2013 04:45:25 GMT+1000 (EST)

> Hi, Adam
>
> Actually, we don't have a detail datasheet as you are looking for, but only
> register table.
> But I guess this register map is useless  without further explanation. The
> explanation effort would that takes my time.
>
> For example, the PLL frequency was actually set by a series of internal
> hardware-based variables and a complex formula (total 4 register). EVen me
> have to spend a time to refresh this formula about. But, for software
> application level, one needn't to track the inside hardware mechanisim, and
> instead just set a top level soft variable PLL_freq to any desired frequency.
>
> Of course, some functions, e.g disable AGC mode  or LNA manual gain setting
> are probably less complex and very straightforward than PLL.
>
> So far it seems people had set R820T from 24Mhz to 1.9Ghz sucesfully. Well,
> that is already hardware limitation, not more, not less.
>
> So could you tell more specifically, what more functions are the SDR group
> soft need to know?
>
> MP
>
>
>
> --- *13/3/10 (日),Adam Nielsen /<a.ni...@shikadi.net>/* 寫道:
>
>
>     寄件者: Adam Nielsen <a.ni...@shikadi.net>
>     主旨: Re: [ultra-cheap-sdr] R820T tuner?
>     收件者: ultra-c...@googlegroups.com
>     副本: mp_...@yahoo.com
>     日期: 2013年3月10日,日,下午6:32
unk...@googlegroups.com 1/9/14 12:48 PM <This message has been deleted.>
Re: R820T tuner? Euheny 1/9/14 12:51 PM
Hi Darky!
I also just joined the group. I am very interested in the R820T for my own development (especially register map and description of programming). Please send your existing information on R820T. I promise not to publish it.
Cheers,
Euheny

вторник, 4 сентября 2012 г., 18:37:48 UTC+3 пользователь darky написал:
Hi All,
 
I just joined to the group. I have the same dongle with R820T. I decided to contact Rafaelmicro and asked very politely about technical documentation and linux drivers. My mail was redirected to marketing / sales and I managed to get some technical support.
 
I would like to provide the information to anyone interested, who wants to try to build the linux software for this dongle, I have the source code.
 
Datasheet look like a preliminary version, there a lot of things missing or just cut from it. The application / refference design looks usefull, it isn't very complex.
 
Please, let me know if you are interested. I would send you the information which I have, for the momment I prefer not to publish it.
 
I hope that at the end we will be able to use this dongle also for SDR.
 
Cheers,
Darky
 

On Tuesday, August 21, 2012 11:10:54 PM UTC+2, JP wrote:
I placed an order for an e4000 based dongle but the seller said that it was no longer available (no more e4000 chips!). He suggested a dongle with an R820T tuner. Has anybody ever heard of this tuner? A different seller on ebay lists the R820T as 'Latest Chip Better Quality' :)

JP

AW: [ultra-cheap-sdr] Re: R820T tuner? DG9BFC Sigi 1/10/14 9:35 AM
Ask

mp_...@yahoo.com

he is the main designer of that tuner chip

if anybody knows something about that chip then it is THIS guy

dg9bfc

sigi

> -----Ursprüngliche Nachricht-----
> Von: ultra-c...@googlegroups.com [mailto:ultra-cheap-
> s...@googlegroups.com] Im Auftrag von Euheny
> Gesendet: Donnerstag, 9. Januar 2014 20:52
> An: ultra-c...@googlegroups.com
> Betreff: [ultra-cheap-sdr] Re: R820T tuner?
> <http://www.ebay.com/itm/1x-RTL-FM-DAB-USB-DVB-T-Dongle-DVB-T-STICK-
> RTL2832U-R820T-
> /261084027023?pt=US_Video_Capture_TV_Tuner_Cards&hash=item3cc9d2188f>
>
>
>                 JP
>
>
> --
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AW: [ultra-cheap-sdr] Re: R820T tuner? DG9BFC Sigi 1/10/14 9:36 AM
FORWARDED MESSAGE!!! :

.............................................

I am the main designer of R820.

I just found and was surprised this baby get so much notice in SDR group.

I can give some answer for several  previous questions:

1. Yes, it can go up to 1.8Ghz since the internal PLL  osc over 3.6Ghz.
2. Further, the external FM filter was for cutting some FM band by purpose.
Just de-soldering the shunt inductor if you want best NF in FM band. (pay
the risk if strong FM became the interference and not the band you want) 3.
Inquire forward to our official mailbox or 3rd party vendors is useless
since they are not tech guy and probably bad english, no idea what you are
taking about.  You can let me know your feedback of this tuner or any
recommendation is welcome to my private: mp_...@yahoo.com.

PS: I can be very busy, Delay reply might occur.

:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::


Dg9bfc

Sigi



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