Thanks for all your help. This afternoon I connected my RPi with Langstone to my Pluto and my QO-100 setup and it all worked well.
My setup includes a pre-amp a SG-Lab PA running about 3 watts into a 5m cable and a 90cm off-set dish.
The Pluto has been modified to include a TCXO and is stable to ~ 10 hz and I have a Bullseye LNB which has about a 10kHz offset
but does have some drift
This setup has been proof tested over several months using a PC and SDR Console.
Using this I made several qso's (including a BG0!) the signal seemed to be down a little compared to using the PC,
but I will measure this using a SA/power meter to get an objective comparison.
Also I struggled a bit with the Bullseye drift - this can be compensated on the PC by locking to the central psk beacon -
is this an option for the Langstone project?
I would also be interested to know what audio processing and noise reduction is included in the software.
Regards
Paul M1BKL
All up and running on QO-100
Re: All up and running on QO-100
There is no means of locking a drifting LNB. It is assumed that you are using a modified LNB with good stability.
The Raspberry Pi has a limited capability compared to a PC. It is already working quite hard. It is unlikely that it could handle the bandwidth required to receive the beacon at the same time as the tuned signal.
For the same reason there is no special audio processing on transmit or receive. The GNU radio .grc source files are included if anyone wants to try to improve them.
Colin.
The Raspberry Pi has a limited capability compared to a PC. It is already working quite hard. It is unlikely that it could handle the bandwidth required to receive the beacon at the same time as the tuned signal.
For the same reason there is no special audio processing on transmit or receive. The GNU radio .grc source files are included if anyone wants to try to improve them.
Colin.