[RTTY] Some basic RTTY radio questions

[Bill Turner]

Well, this is all very interesting. Thanks to David and Chen for
enlightening me. Your recommendation is something I would never have
guessed, but of course I don't write RTTY demodulator software. 

I will definitely be trying out different AGC settings in future
contests. 

Thanks again,

73, Bill W6WRT


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On Mon, 7 Mar 2016 20:22:59 -0000, David wrote:

>I see Chen got into this one before me. Chen and I both design and make
>available RTTY decoders. The internal workings of those decoders for best
>performance requires that the AGC does not change the receiver gain abruptly
>and it stays reasonably constant over several character times. Fast AGC will
>cause problems with the automatic threshold "circuit" (software actually),w
>which can be avoided by using slow AGC.
>
>As Chen says manual gain control that is set and left is best of all but in
>something like a RTTY contest not practical as the human also wants to hear
>the signal at a reasonable level. So the compromise is slow AGC. Hang AGC
>can also work well if the parameters are set correctly.
>
>73 David G3YYD