Recovered FM Audio

Mark NS9N

What level of signal is needed to hear an FM signal on a Flex Signature Series radio? I am using a new 2 meter transverter with my 6600 and have a noise floor of -125 dBm. I can see signals on the band scope at -115 dBm but can not hear the recovered audio. FM repeaters and simplex signals at -90 dBm are very clear. My question is, at what signal level should I be able to hear the signal audio? 

Rick - W5FCX

Lower the SQL squelch level. You should be able to lower it to hear the noise floor.

Mark NS9N

Thanks Rick, that is the strange part. I have the squelch level at zero and can hear the noise floor. I would think if I could see the signal I should be able to hear recovered audio.

Rick - W5FCX

Very odd.

Mark NS9N

Agreed time to drag the test equipment from the basement lab to the shack on the second floor.

Ken - NM9P

Obviously the detection threshold will be poorer than with SSB, but I never thought it was too bad when listening to FM on the transverter. The squelch response needs a little work — random opening of the squelch, and the hysteresis (sp.) response curve could stand some adjustment — but the decode always seemed to be OK. Though I haven’t done a lot of comparison testing with other rigs.

Stan VA7NF