[Elecraft] K3: Poor sound on FM

[Lyle Johnson]

Michael,

Standard CTCSS tones used on FM can range up to 254 Hz.  So, on Tx we 
have to block microphone energy below about 300 Hz.  Likewise, on Rx, we 
have to suppress things below about 300 Hz so you won't hear continuous 
CTCSS tones in the audio.

The DSP filters have some slope, so the audio filter corner frequencies 
must be a bit higher than this.

I'll look into the firmware and see if there is a way to reduce the low 
frequency corner frequency without degrading CTCSS.

Thank you for bringing this to our attention.

73,

Lyle KK7P

> But i observed a lack of quality on FM-the sound is very thin compared to AM
> and SSB.
> It seems that the DSP cuts out the range from 400 to 2700Hz (uuh!).