[op25-dev] rx.py Airspy MASTER GAIN Setting option?????

wllmbecks at gmail.com wllmbecks at gmail.com
Tue Sep 8 15:32:31 UTC 2020


You should be good to go if you have 10 MHz reference clock available.  The Airspy's
accept anything from 10 MHz to 100 MHz external clock reference on the MCX connector.

Don't ask me how the internals figure this out or if any configuration is necessary to specify
the source reference.     I haven't tried this but will go back to my shop and connect a 10 MHz
reference to an R2 to see what if any affect it has on op25 receiving a live p25 system.

Bill


-----Original Message-----
From: op25-dev <op25-dev-bounces at lists.osmocom.org> On Behalf Of op25 at zellners.com
Sent: Tuesday, September 8, 2020 10:05 AM
To: op25-dev at lists.osmocom.org
Subject: Re: [op25-dev] rx.py Airspy MASTER GAIN Setting option?????


Quoting wllmbecks at gmail.com:

> A good tool is to take a look at your symbols and mixer plots to 
> verify if the (-q 2) is the


Thats why I use OP25 for the constellation etc. that other software  
doesn't provide. More accurate to tune.

The 2 ppm is accurate as its confirmed with other programs. Which  
start with a 0 and over time it is steady at 2ppm +- a little...


> However, I have run the calibration utility on all of my Airspy  
> devices using a GPSDO

What is the CLKIN expecting? I'd have to check to see that our GPS  
simulcast controllers put out a similar or compatible signal... and I  
might drag one to a site when I go to test with...

But the -q 2 setting is accurate as anything or more less, and nothing  
decodes, nice tight constellation.






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