AM mode Passband tuning

[rsku...@gmail.com]

I'm probably not doing this right but passband tuning doesn't seem to be working as I would expect it to on AM mode.

I've used it for decades on SSB on various radios. The BFO and tuning move to slide the passband up or down the dial. But this is not what happens in AM mode in Linrad.

I click the control to "P" and I have the tuning step set to 1 KHz. But, I was expecting the small center carrier filter to stay put and that the main demodulator filter would slide up and down the frequency scale to allow for sliding the passband up or down to get away from adjacent channel sideband splatter. But it doesn't do that. It seems to tune the same as if I have the "T" selected.

Shouldn't there be a way to slide the main demod filter up and down and keep the carrier filter for the COH modes centered on the carrier frequency?

Thanks in advance,

Rick Kunnth, K9AO

[Leif Asbrink]

Hello Rick,

Passband tuning is not intended for AM mode, you should use notches
instead. Set a suitable bandwidth that includes everything you want
plus things you do not want on one or the other side. Then apply
a notch on the side where you want to remove interference.

Put additional notches as required if you have unwanted carriers
and maybe also a notch on the center frequency.

73

Leif

> --
> There is an excellent Linrad User Guide by Gaetan, ON4KHG, at:
> http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf
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[Rick Kunath]

Thanks Leif, that makes perfect sense :)

Rick

[Leif Asbrink]

Hi All,

I have added a new version on the repo with the support for SDRPlay duo
that was written by Franco Venturi.

I can currently not update my web site. The provider has improved security
somehow and I can not log in any more:-(

73

Leif

[Franco Venturi]

Thanks Leif!

While you sort out the security issues with your provider, I copied all your source code from subversion revision 1002 to a new branch called 'sm5bsz' (https://github.com/fventuri/linrad/tree/sm5bsz), and then created a new tag called '5.02-1002-SM5BSZ'. The GitHub CI compiled everything from your code without any errors, and created a new release here: https://github.com/fventuri/linrad/releases/tag/5.02-1002-SM5BSZ that contains the binaries for Windows 32 and 64 bit (and the source code).

This way those interested can try it out in the meanwhile.

73

Franco

[Rick Kunath]

Franco,

Does Leif's new code have the recording fix in it?

Rick Kunath

--

There is an excellent Linrad User Guide by Gaetan, ON4KHG, at:
http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf
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[Franco Venturi]

Rick, I just ran the command:

    git diff main sm5bsz sdrplay3.c

and there are no differences between the code in the main branch (that has the fix for the case of the RSPduo saving a raw file in dual tuner mode) and Leif's 5.02 rev 1002 code.

Franco

[Jurgen van de Glind]

Thanks Franco and Leif for the nice work.

installed the 5.02 version on my 64bit machine and it runs smooth (rsp1a/linrad 5.02/map65)

after sending timf2 to port 50004  it send the data to map65 for 11 seconds and stopped ,and start sending again on the next full minute for 11 seconds . and this sequent repeats

any bug in the program or my setup ?

best regards  PE1LWT Jurgen

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[on4khg]

Hi Jurgen,


Be sure to set Linrad so that the sampling rate is 96 kHz to send data
to MAP65.
I had a similar issue when running Linrad at 196 kHz instead of 96.
73,

Gaëtan, ON4KHG

Le 2023-02-13 19:25, Jurgen van de Glind a écrit :
> Thanks Franco and Leif for the nice work.
> installed the 5.02 version on my 64bit machine and it runs smooth
> (rsp1a/linrad 5.02/map65)
> after sending timf2 to port 50004 it send the data to map65 for 11
> seconds and stopped ,and start sending again on the next full minute
> for 11 seconds . and this sequent repeats
> any bug in the program or my setup ?
>
> best regards PE1LWT Jurgen
>
>> Op 12 feb. 2023, om 04:49 heeft Franco Venturi
>> <fven...@comcast.net> het volgende geschreven:
>>
>> Thanks Leif!
>>
>> While you sort out the security issues with your provider, I copied
>> all your source code from subversion revision 1002 to a new branch
>> called 'sm5bsz' (https://github.com/fventuri/linrad/tree/sm5bsz

>> [1]), and then created a new tag called '5.02-1002-SM5BSZ'. The

>> GitHub CI compiled everything from your code without any errors, and
>> created a new release here:

>> https://github.com/fventuri/linrad/releases/tag/5.02-1002-SM5BSZ [2]

>> that contains the binaries for Windows 32 and 64 bit (and the source
>> code).
>> This way those interested can try it out in the meanwhile.
>>
>> 73
>> Franco
>>
>> On Saturday, February 11, 2023 at 9:46:13 PM UTC-5 Leif Asbrink
>> wrote:
>>
>>> Hi All,
>>>
>>> I have added a new version on the repo with the support for
>>> SDRPlay duo
>>> that was written by Franco Venturi.
>>>
>>> I can currently not update my web site. The provider has improved
>>> security
>>> somehow and I can not log in any more:-(
>>>
>>> 73
>>>
>>> Leif
>>
>> --
>> There is an excellent Linrad User Guide by Gaetan, ON4KHG, at:
>>
> http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf

>> [3]

>> ---
>> You received this message because you are subscribed to the Google
>> Groups "Linrad" group.
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>> send an email to linrad+un...@googlegroups.com.
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>>
> https://groups.google.com/d/msgid/linrad/6f788d69-edf4-4ebf-aafe-d3e77a6298f2n%40googlegroups.com

>> [4].

>
> --
> There is an excellent Linrad User Guide by Gaetan, ON4KHG, at:
>
> http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf

> [5]

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> [6].
>
>
> Links:
> ------
> [1] https://github.com/fventuri/linrad/tree/sm5bsz
> [2] https://github.com/fventuri/linrad/releases/tag/5.02-1002-SM5BSZ
> [3]
> http://w3sz.com/Linrad%20Installation%20&amp;%20Configuration%20User%20Guide%20-%20V1-0.pdf
> [4]
> https://groups.google.com/d/msgid/linrad/6f788d69-edf4-4ebf-aafe-d3e77a6298f2n%40googlegroups.com?utm_medium=email&amp;utm_source=footer
> [5]
> http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf
> [6]
> https://groups.google.com/d/msgid/linrad/FA46DE33-7642-4DC8-A8FE-43EC68277DB7%40xs4all.nl?utm_medium=email&utm_source=footer

[Franco Venturi]

Hi Jurgen

As suggested by Gaëtan, ON4KHG I would double check your Linrad settings.

I do not have MAP65 here, but at the end of October Joe Taylor K1JT reported using a slightly older version of Linrad (I think it was 5.01-999-sdrplay3 back then) with an RSPduo and MAP65 for EME: https://groups.google.com/g/linrad/c/0J6dOLdothA/m/fY3KluVuAAAJ (the RSPduo was likely running in single tuner mode in order to have a sample rate compatible with MAP65).

I am confident that they would have reported a serious issue like yours if it had occurred.

I think there are only a few minor bug fixes between that version and 5.02, so it is unlikely that those are the problem (the old version is still available here https://github.com/fventuri/linrad/releases); I would check the sample rate first to rule that out; if you don't see anything in your settings, then try with that the old version, and let me know if it doesn't have the problem (with the same settings of course).

73,

Franco K4VZ

[Jurgen van de Glind]

Hi Franco and Gaëtan ,

thanks for the hints

my sampling rate was 48000 , so that was a wrong setting .  while changing the parameter and restarting linrad and map65 I must have changed some other parameters as well. no timf2 data .is getting into map 65 via port 50004

i have to back from where i started and get port 50004 running again.

thanks so far

73’s  Jurgen 

To view this discussion on the web visit https://groups.google.com/d/msgid/linrad/9cf27506-4095-4739-af53-024a761e7786n%40googlegroups.com.

[rsku...@gmail.com]

Franco,

You must be right in that Joe is running the Duo in single tuner mode. I know we spent enough time on testing and could not get the Duo into a compatible sample rate for MAP65 in dual-tuner mode. According to Leif we would need to feed the output to a second Linrad instance to do another conversion for dual-channel in MAP65. 

So a couple of thoughts still come to mind. 

I don't think that MAP65 is in current development, at least that was the impression that I got, but wouldn't adding the 125K sample rate to MAP65 be ideal for using the Duo to feed it? (I and others would like to see that option happen.) 

The other question was, as I understand MAP65, one of it's strengths is to handle the dual polarization from a dual-channel input, so going single-channel into it would not take advantage of that. I'm wondering in single-channel mode what MAP65 still might buy you over WSJTX?

Rick Kunath, K9AO

[on4khg]

Jurgen,


Every time you change a parameter in Linrad, it stops sending data on
the network.
When you restart Linrad, you have to press "T" to send data on the
network again, then "W" to save and then you start Linrad by choosing
the mode, for example "D" for SSB.
When Linrad has started, you see some info (I can't check, I'm not at
home now) in red at the top left indicating that data are sent on the
network.
73,

Gaëtan, ON4KHG
http://on4khg.be

Le 2023-02-14 19:01, Jurgen van de Glind a écrit :
> Hi Franco and Gaëtan ,
> thanks for the hints
> my sampling rate was 48000 , so that was a wrong setting . while
> changing the parameter and restarting linrad and map65 I must have
> changed some other parameters as well. no timf2 data .is getting into
> map 65 via port 50004
> i have to back from where i started and get port 50004 running again.
>
> thanks so far
>
> 73’s Jurgen
>
>>>
>
>>>
>
>> Op 14 feb. 2023, om 03:44 heeft Franco Venturi
>> <fven...@comcast.net> het volgende geschreven:
>>
>> Hi Jurgen
>> As suggested by Gaëtan, ON4KHG I would double check your Linrad
>> settings.
>>
>> I do not have MAP65 here, but at the end of October Joe Taylor K1JT
>> reported using a slightly older version of Linrad (I think it was
>> 5.01-999-sdrplay3 back then) with an RSPduo and MAP65 for EME:

>> https://groups.google.com/g/linrad/c/0J6dOLdothA/m/fY3KluVuAAAJ [9]

>> (the RSPduo was likely running in single tuner mode in order to have
>> a sample rate compatible with MAP65).
>>
>> I am confident that they would have reported a serious issue like
>> yours if it had occurred.
>>
>> I think there are only a few minor bug fixes between that version
>> and 5.02, so it is unlikely that those are the problem (the old
>> version is still available here

>> https://github.com/fventuri/linrad/releases [10]); I would check the

>>> [2] [2]

>>> [3]

>>>> [5]
>>>> ---
>>>> You received this message because you are subscribed to the
>>> Google
>>>> Groups "Linrad" group.
>>>> To unsubscribe from this group and stop receiving emails from
>>> it,
>>>> send an email to linrad+un...@googlegroups.com.
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>>>>
>>>
>>
> https://groups.google.com/d/msgid/linrad/FA46DE33-7642-4DC8-A8FE-43EC68277DB7%40xs4all.nl

>>> [5]
>>>> [6].
>>>>
>>>>
>>>> Links:
>>>> ------
>>>> [1] https://github.com/fventuri/linrad/tree/sm5bsz [1]
>>>> [2]
>>> https://github.com/fventuri/linrad/releases/tag/5.02-1002-SM5BSZ
>>> [2]
>>>> [3]
>>>>
>>>
>>
> http://w3sz.com/Linrad%20Installation%20&amp;%20Configuration%20User%20Guide%20-%20V1-0.pdf
>>> [6]
>>>> [4]
>>>>
>>>
>>
> https://groups.google.com/d/msgid/linrad/6f788d69-edf4-4ebf-aafe-d3e77a6298f2n%40googlegroups.com?utm_medium=email&amp;utm_source=footer
>>> [7]
>>>> [5]
>>>>
>>>
>>
> http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf
>>> [3]
>>>> [6]
>>>>
>>>
>>
> https://groups.google.com/d/msgid/linrad/FA46DE33-7642-4DC8-A8FE-43EC68277DB7%40xs4all.nl?utm_medium=email&utm_source=footer
>>> [8]

>>
>> --
>> There is an excellent Linrad User Guide by Gaetan, ON4KHG, at:
>>
> http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf
>> [3]
>> ---
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>> To view this discussion on the web visit
>>

> https://groups.google.com/d/msgid/linrad/9cf27506-4095-4739-af53-024a761e7786n%40googlegroups.com
>> [11].

>
> --
> There is an excellent Linrad User Guide by Gaetan, ON4KHG, at:
>
> http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf

> [12]

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> [13].

>
>
> Links:
> ------
> [1] https://github.com/fventuri/linrad/tree/sm5bsz
> [2] https://github.com/fventuri/linrad/releases/tag/5.02-1002-SM5BSZ
> [3]
> http://w3sz.com/Linrad%20Installation%20&amp;%20Configuration%20User%20Guide%20-%20V1-0.pdf
> [4]
> https://groups.google.com/d/msgid/linrad/6f788d69-edf4-4ebf-aafe-d3e77a6298f2n%40googlegroups.com

> [5]
> https://groups.google.com/d/msgid/linrad/FA46DE33-7642-4DC8-A8FE-43EC68277DB7%40xs4all.nl
> [6]
> http://w3sz.com/Linrad%20Installation%20&amp;amp;%20Configuration%20User%20Guide%20-%20V1-0.pdf
> [7]
> https://groups.google.com/d/msgid/linrad/6f788d69-edf4-4ebf-aafe-d3e77a6298f2n%40googlegroups.com?utm_medium=email&amp;amp;utm_source=footer
> [8]
> https://groups.google.com/d/msgid/linrad/FA46DE33-7642-4DC8-A8FE-43EC68277DB7%40xs4all.nl?utm_medium=email&amp;utm_source=footer
> [9] https://groups.google.com/g/linrad/c/0J6dOLdothA/m/fY3KluVuAAAJ
> [10] https://github.com/fventuri/linrad/releases
> [11]
> https://groups.google.com/d/msgid/linrad/9cf27506-4095-4739-af53-024a761e7786n%40googlegroups.com?utm_medium=email&amp;utm_source=footer
> [12]
> http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf
> [13]
> https://groups.google.com/d/msgid/linrad/8F4919F7-0866-466F-B7DA-E3150785659D%40xs4all.nl?utm_medium=email&utm_source=footer

[Franco Venturi]

Rick,

short of SDRplay adding to their API sample rates like 3,072kHz or 1,536kHz in dual tuner mode (I mentioned that in the SDRPlayUsers mailing list a couple of months ago, but now with the upcoming SDRConnect release and all the related work in the short term I wouldn't hold my breath that it is going to occur any time soon), it is clear to me that some resampling has to happen 'somewhere'.

This 'somewhere' can roughly be in three different places in the receiving chain:

1. before Linrad

2. inside Linrad

3. after Linrad

Option 1 would be something like a GNU Radio flowgraph (or perhaps a modified version of RSPduoEME) that reads the two I/Q streams directly from the RSPduo in dual tuner mode, resamples them to have a sample rate of say 96kHz and hands them down to Linrad; the drawback of this approach is that it requires the user to run an additional application besides Linrad and MAP65, and this makes things more complicated to make sure all the planets are aligned

Option 2 would require adding the resampling code to Linrad (perhaps following what David Warwick G4EEV does with RSPduoEME); this would simplify things for the actual user because they would just run the 'enhanced' version of Linrad, and send its output directly to MAP65; it would require adding another thread to Linrad to do this kind of DSP work, possibly using fast mathematical operations as they are available in the CPU (things like AVX, etc) in order to avoid using too much CPU and not being able to keep up with the input sample rate. I see it as a significant amount of work, but I don't know Linrad internals very well, so I might be wrong on this

Finally option 3 could be what you suggested like modifying MAP65 to accept sample rates different from 96kHz; Joe Taylor K1JT mentioned a while ago that MAP65 can also run with a sample rate of 95,238Hz, but I think this works because the two sample rates are not too different so he made some minor adjustments to the coefficients to accommodate 95,238; I am not sure the same thing could be done with say a sample rate of 125kHz. A month or two ago I took a quick look at the source code of MAP65, and I got the impression many of the numbers there assume that the sample rate is 96kHz, so it would be necessary to understand how they are derived from the sample rate, recompute them for 125kHz, and hope for the best.

I am sorry that at this time I can't give you a better answer.

73,

Franco K4VZ

[Conrad PA5Y]

It seems to me that the RSPDuo is not a good choice for adaptive EME at this current time. Why not cut your losses and buy a 2 channel VHF Afedri? It is directly supported by Linrad and the Ethernet interface is bomb proof. Frequency stability is good and there are less in band spurs on 144MHz. Dynamic range is adequate for EME except in the most extreme situations. If you have such a situation you will have the same problems with the RSPDuo.

 

You can bet that sample rate conversion will end up creating low level artefacts that reduce decodes for signals near the noise floor, at least in my experience. Of course not all sample rate convertors are made equal.

 

73

 

Conrad PA5Y

To view this discussion on the web visit https://groups.google.com/d/msgid/linrad/95fe03c2-bfb7-4487-bc5c-8e4370c364d2n%40googlegroups.com.

[Joe Taylor]

Hi all,

Yes, at W2ZQ we use the RSPduo in single-tuner mode. A single instance
of Franco's Linrad build is configured to produce I/Q output at 96000
frames per second. Linrad's 'timf2' data is sent onward to program
QMAP. (Presumably Leif's latest Linrad would work just as well, though
I haven't tried that yet.) QMAP is a slimmed-down, single-channel,
receive-only version of the basic MAP65 idea. It works with all
60-second submodes of Q65. There's no longer any code having to do with
JT65 or adaptive polarization; instead, QMAP has enhancements that allow
it to work cooperatively with WSJT-X.

QMAP provides waterfall display for a 90 kHz slice of a band, decodes
all Q65-60x signals that it finds, and forwards these decodes to WSJT-X.
WSJT-X handles all necessary details of rig control, including EME
Doppler compensation, T/R switching, message sequencing, and logging.
We have found the combination a pleasure to use for 1296 MHz EME.

So far, QMAP is targeted to our Club Station's specific needs. If there
is sufficient interest, in due course we might add capabilities to
handle I/Q data at other sample rates.

Finally: I'm spread pretty thinly, these days, and I no longer have a
station that needs adaptive polarization features. Consequently, as
Rick surmised, MAP65 development is not high on my priorities list.
Of course, someone else is welcome to undertake making enhancements to
open-source MAP65.

-- 73, Joe, K1JT

> --
> There is an excellent Linrad User Guide by Gaetan, ON4KHG, at:

> http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf <http://w3sz.com/Linrad%20Installation%20&%20Configuration%20User%20Guide%20-%20V1-0.pdf>

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[Jurgen van de Glind]

Gaetan,


thanks for the tip/info
I am familiair with Linrad and do know most of the commands but for some reason there is something changed in my pc, but haven’t found it out yet .
but the timf2 stream is not getting into map 65 . can it be something with windows firewall ?

best 73’s Jurgen

> To view this discussion on the web visit https://groups.google.com/d/msgid/linrad/47d24c5ef5440cf205bb76a9f9f19177%40voo.be.