Split band speech processor for SSB transmission
	I built this processor in 1976, when my rig was Drake 4C-line. Drake did not have integral speech processor.
	Later I had Collins S-line and the processor served well also with it.
	When I returned to ham radio after 10 years of QRT in early 90's I bought Icom rigs. Currently I use IC-756.
	When I tested this processor against the Icom internal one, I always got better reports with this processor.
	Is it because of my personal voice or what, I do not know.
	So I decided to use it again, even it is 30 years old with 741 op amps etc. But it is reliable and effective.
	I remember that winding and trimming the coils on potcore forms was quite a job.
	The concept is to divide the spectrum coming from the microphone into three frequency bands, each about one octave.
	These one octave bands are then clipped and put through similar band pass filters and summed up. The purpose of
	the second filter is to clean up the intermodulation products generated in the clipping and falling outside the band.
	This way amount of distortion is minimized.
	My microphone today is Heil HC5 ( Pro-set Plus head-set).
	I will try to record some sound samples in near future.
	OH1TV
	30.3.2007
	Schematics
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