TX High Cut For FM

david_TG9AMM

Hi everyone,

I am exploring 10m FM on my 8400 and I would like to setup a really nice rag chew audio for FM QSOs. I am confused about how to set the TX High Cut in SmartSDR though. FM has a TX bandwidth of 16K, so what would be the maximum number I can use for the high cut on FM?

On SSB the norm is 3K. So, for 3K on SSB I simply set the high cut to 3K. But FM is not SSB and I have the feeling that I shouldn’t be setting the FM high cut to 16K!

Also, I read that using anything other than the processor set to normal is not a good idea as it will introduce distortion in the audio. Is that true?

Any suggestions gratefully received.

Thank you,

David

KD0RC

Hi David, I just leave the TX bandwidth the same for FM that I use for SSB and get good results.

Yes, turn off the processor when in FM. I got reports of terrible audio on my local 2 meter repeater (using a transverter). I turned off the processor and got great audio reports again. I turn it off, not just set it to normal.

david_TG9AMM

Thank you Len. I appreciate the information. David

John KB4DU

One of the side benefits of FM is that the Low audio frequencies don't increase transmit power requirements like AM/SSB. Might sound better (natural) if the low frequencies are allowed to pass through the EQ.

david_TG9AMM

Thank you John. I have tried to make the audio EQ as nice as possible using the FDX feature in SmartSDR.