Hi Mr. Simon,

So, you can send but you can't receive. I would suggest you get an opamp in front of the 8880 to limit the signal the 8880 see’s.You probably are experiencing different conditions in this area which would keep the 8880 from working reliaby. I would also suggest you establish what is working and what is not working. You can step by step determine this with an analog VOM. When you establish where in the process things are breaking down then you can fix your problem(s).

Oh, by the way I don't work for Rigel!

Regards,

Charles Bannister