Re: Releases v3.8.4.0 and v3.9.3.0

[Chris Vine]

On Sat, 20 Nov 2021 13:12:02 -0500
Glen Langston <glen.i.langston@gmail.com> wrote:
> Hi Chris,> 
> Thanks for  your reply.
> 
> After countless hours of messing around, I partially have 
> SDRPlay supported on a Raspberry PI 4 with gnuradio 3.8.2
> 
> Within gnuradio and osmosdr source blocks, I have SDRPlay data streaming, but 
> I’ve not been
> able to turn the bias-tee on or make any sense of the gain settings.
> 
> With gr-soapy source
> 
> I’ve got trouble getting the stream of data to flow.
> 
> with  SoapySDRUtil —find  I do find the device with reasonable values
> 
> ######################################################
> ##     Soapy SDR -- the SDR abstraction library     ##
> ######################################################
> 
> Found device 0
>   driver = sdrplay
>   label = SDRplay Dev0 RSP1A 190316E696
>   serial = 190316E696
> 
> So, my question is:
> 
> Do you (or anyone) have examples of the values to put in
> either of the source blocks to control the bias-tee 
> gains and notch filters?

You cannot set notch filters on the RSP1A using gr-osmosdr, and as far
as I recall (I no longer have gnuradio-3.8 installed) you cannot set
bias tee either.  There is also a problem with manaul gain control in
the gr-osmosdr block with gnuradio-companion (the rf gain cannot be set
properly manually but you can control if gain manually); but curiously
manual gain controls work OK when using gr-osmosdr with gqrx, and
gnuradio-companion works OK with gr-osmosdr with gain mode set to
automatic.

That is one of the reasons why I recommended that you should use the
gr-soapy block.  With that you can set the notch filters, bias tee,
manual gain and many other things.  The gr-soapy block is much superior
to the gr-osmosdr one, and is built-in with gnuradio-3.9.  gr-osmosdr is
virtually unsupported now and should really only be used with devices
for which soapySDR is not an option, or if you have to use gqrx.  I
would also use gnuradio-3.9 rather than gnuradio-3.8, if you can.

If you want to control gain manually then SoapySDRUtil --probe will
tell you more about values.[1]

In summary, for grqx, use gr-osmosdr with the soapy backend with the
device string "soapy=0,driver=sdrplay".  Otherwise use gr-soapy, which
is much superior.

Chris

[1]  Note that the gr-soapy block with gnuradio-3.8 has separate
manual controls for rf gain and if gain.  The built-in soapy block for
gnuradio-3.9 has a single control for both.