|experience with mini dongles?||wa5ngp||10/20/13 2:00 PM|
does anyone have any pix or info on what these things look like inside?
Antenna MINI FM+DAB+DVB-T+SDR Dongle STICK RTL2832U R820T SDR Radio
I have an e4000 version but I was thinking of getting one of these and trying my hand at desoldering those caps and running it in direct mode without the tuner. If these things are somehow double sided components that makes it impossible to get to those coupling caps I'd like to know. Its going to be difficult enough already. Fortunately, my neighbor has a nice microscope to help me do this.
|AW: [ultra-cheap-sdr] experience with mini dongles?||DG9BFC Sigi||10/22/13 8:00 AM|
No need for de-soldering caps if you use a stick with r820t tuner
The r820t tuner does not use a zero if like the e4k sticks
It uses a low if and only the I inputs on the rtl chip
So ... the q inputs are left free
Tacksolder 2 small wires on pin 4 and 5 (balanced q input)
Set direct sample q branch in the driver window of the rtl stick
Enjoy shortwave with direct sampling :-)
If you select i/q sampling (when used on vhf uhf) then the driver takes care
of just using the I inputs
If you select q branch direct sampling you can receive shortwave without any
upconverter needed (but upconverter should work maybe a bit better?!?)
... so .. with adding a 1:4 balun on the q inputs and another coax connector
you will not loose vhf uhf ... but additionally "gain" shortwave
> -----Ursprüngliche Nachricht-----
> Von: ultra-c...@googlegroups.com [mailto:ultra-cheap-
> s...@googlegroups.com] Im Auftrag von wa5ngp
> Gesendet: Sonntag, 20. Oktober 2013 21:01
> An: ultra-c...@googlegroups.com
> Betreff: [ultra-cheap-sdr] experience with mini dongles?
> You received this message because you are subscribed to the Google Groups
> "Ultra Cheap SDR" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to ultra-cheap-s...@googlegroups.com.
> To post to this group, send email to ultra-c...@googlegroups.com.
> Visit this group at http://groups.google.com/group/ultra-cheap-sdr.
> For more options, visit https://groups.google.com/groups/opt_out.
|Re: [ultra-cheap-sdr] experience with mini dongles?||David Jones||10/22/13 7:26 PM|
and what if i attach Q-input to stock mcx antenna,
will it overlap with shortwave or add noise when using default mode I/Q?
|Re: experience with mini dongles?||wa5ngp||10/23/13 5:35 AM|
tks for that info Sigi, I need to go back and study those block diagrams again. I should have raised my ebay bid yesterday. :(
I am wanting to run in "direct mode" so that I can listen to the 3.395mhz IF in my old SB101. At the moment with my e4000 and upconverter I'm getting a lot of FM radio bleed thru and what looks like other false signals from intermod or something.
have you noticed how hot 10M is the last week or so?
|AW: [ultra-cheap-sdr] experience with mini dongles?||DG9BFC Sigi||10/23/13 12:42 PM|
You should use 2 different connectors (or a switch) between your 2 inputs
Vhf uhf goes to tuner chip
Hf goes via balun dir3ect to sampling chip
I would NOT MIX them together (you can never say what will happen)
Just use 2 coax connectors and youre set
> s...@googlegroups.com] Im Auftrag von David Jones
> Gesendet: Mittwoch, 23. Oktober 2013 02:26
> An: ultra-c...@googlegroups.com
> Betreff: Re: [ultra-cheap-sdr] experience with mini dongles?
> > Betreff: [ultra-cheap-sdr] experience with mini dongles?> RTL2832U-R820T- <http://www.ebay.com/itm/MINI-FM-DAB-DVB-T-SDR-Dongle-
> > Antenna-SDR-Radio-New-
> > or
> > http://www.ebay.com/itm/New-DVB-T-RTL-SDR-Realtek-RTL2832U-R820T-
> USB-DVB- <http://www.ebay.com/itm/New-DVB-T-RTL-SDR-Realtek-RTL2832U-
> > Visit this group at http://groups.google.com/group/ultra-cheap-sdr> <http://groups.google.com/group/ultra-cheap-sdr> .
> > For more options, visit https://groups.google.com/groups/opt_out> <https://groups.google.com/groups/opt_out> .
|Re: experience with mini dongles?||wa5ngp||10/23/13 7:09 PM|
here are the pix I was looking for
after looking at the wiring in these pix I see your point that the I signals are not used on the 820 version. Furthermore, looking at the spec of the 820 only a differential IF is output, not differential I Q signals like E4000. So this must mean that the 2832 can create I and Q internally if needed.
furthermore, I can see that the mini version is no worse to unsolder.