[Elecraft] K2 RF Speech Processor?

[Geoffrey Mackenzie-Kennedy]

Henry,  K4tmc at aol.com , wrote:

> Has anyone tried any of the DF4ZS RF speech processors
> (http://jwm.de/afu/index0.htm) with a K2 yet?
>
> For those who think the SSB "punch" is a little weak, maybe this would 
> help.
> In fact, maybe this would be a good Mini-Module Kit.

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Great idea! Although I have not used DF4ZS's speech processor, I have used 
various forms of this type of audio processor and RF clippers over the years 
and have found that they are useful, perhaps more so than low cost (not 
studio) audio compression devices. Personally if I intended to buy one of 
his processors I would go for the larger external unit, because reasonably 
good SSB filters should be used before and after the RF clipping circuits, 
all followed by an audio low pass filter at the output with a cutoff around 
3kHz, all of which I believe he has included in the larger unit.  This could 
of course be done with a smaller unit which included these items, but is 
there enough space inside the K2 to fit it in? Also the processor should be 
shielded to avoid the risk of RF feedback, and prevent the processor's LO 
signal from getting out.

When used with a K2, I suspect that the K2's audio compressor should be set 
for a small degree of compression, if any, and most / all of the audio 
processing done by the RF clipper - just an unproven hunch.

73,
Geoff
GM4ESD