On Jun 12, 11:35*am, Telstar Electronics
wrote:
As I said. "Obviously they have to contain 'all the works' (oscillator,
balanced modulator, compressor, clipper, filters, balanced demodulator
etc)."

That sounds very complex and expensive all right.
Another problem I see is that they only work on SSB.
My customers insist on something small that fits inside the radio and
processes in all modes. The VoiceMax does that with less than 1% THD.
Can't build them fast enough to keep them in stock...

DF4ZS developed a RF speech clipper that fits into the Yaesu MH-31
microphone shell. This mic is used with the popular, tiny FT-817
transceiver along with others and in all speech modes. His clipper has
a SSB IF.

Details: http://jwm.de/afu/0ft817eng.htm
Reviews: http://www.eham.net/reviews/detail/2732 (6)

There are no reviews of the VoiceMax on eham.net while there are 21 of
the W4RT Electronics "One Big Punch" which uses a similar IC and can
be installed either in the MH-31 or inside the case of the FT-817 et
al.

DF4ZS also makes an outboard RF Clipper with adjustable a.f.
compression and integrated noise gate.

If you don't mind tying up a computer to do your speech processing,
VE3NEA developed freeware to work with a soundcard between the mic and
the transmitter that functions as bandpass filter, 7-band equalizer,
noise gate, compressor, and RF envelope clipper. http://www.dxatlas.com/VShaper/