What is it and what price? ----- Original Message ----- From: "Brian Carling" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" <amradio@mailman.qth.net> Sent: Tuesday, July 06, 2004 8:20 AM Subject: RE: [AMRadio] COMDEL CSP 11
> I have a really nice Japanese speech compressor for sale if anyone would like it. > > Regards - Brian, AF4K > > On 18 Jun 2004 at 17:39, Donald Chester wrote: > > > > > > > >Any one out there got comments on the Comdel speech processor > > > > They work on AM as well as SSB. I built a homebrew version back it > > the late 70's using a set of 64 kHz mechanical filters removed from > > telephone multiplexing equipment. Mine had better audio quality than > > the original Comdel and was quite effective, but it was nothing to > > write home about. The design eliminates the harmonic distortion of > > speech clipping, but does nothing to reduce intermodulation > > distortion. Intermod is much more objectionable than harmonic > > distortion. > > > > The purpose of the Comdel was to allow for speech clipping on SSB, > > since due to fundamental modulation theory, simply clipping the audio > > to flat peaks before applying it to a SSB generator generates high > > amplitude rf peaks, just exactly the opposite of what you are trying > > to accomplish with clipping. The extreme case of applying squarewave > > audio to a SSB generator produces peaks of theoritically INFINITE > > amplitude. > > > > The processor works by generating a low-frequency SSB signal (below > > 100 kHz), clipping and filtering the SSB signal, and demodulating the > > clipped SSB and applying the resulting audio to the transmitter. The > > result is a near 1:1 peak-to-average ratio with heavy clipping, but > > the intermod makes the audio sound mushy. > > > > -k4kyv > > > > _________________________________________________________________ Stop > > worrying about overloading your inbox - get MSN Hotmail Extra Storage! > > http://join.msn.click-url.com/go/onm00200362ave/direct/01/ > > > > _______________________________________________ > > AMRadio mailing list > > AMRadio@mailman.qth.net > > http://mailman.qth.net/mailman/listinfo/amradio > > > _______________________________________________ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio > >
