[Boatanchors] Subject: SSB Generation - Phasing VS Filter Opinion - HT-32A/B vs HT-37 Example

[Doug Hensley]

A long time ago during the heavy entrance of hams into SSB,  I remember that
the HT-37 had a reputation for exceptional audio quality which was not heard in the
more expensive HT-32A/B rigs.  The HT-37 audio was so enjoyable that it stood out causing
ham after ham to respond: "boy you sound good.  What kind of rig is that?".  We were
all evaluating SSB rigs during this period and pretended to listen to "sound quality"
as if we knew what we were doing.

Well, the applauded rig, the HT-37, was a manually adjusted phasing rig as opposed to
the no tune/no adjust crystal filter units.   I used mine with both an EV 729SR, a little
dark gray, flat face ceramic with a rocker switch and an EV-674 which looked great
but not sure if there was much improvement.  Both were cardioid mics.  In on the air
tests I remember the general audio stood out over and above the peculiarities of a
different microphone (within reason of course) and frequently one just sounded
different without degrading the audio.

Before "CQ", we would turn the power way down, un-mute the receiver and listen to
ourselves in headphones saying 'test 1 2 3 ....' as we phased out any discernible carrier.
Can't explain why, and certainly have no technical reason for it, but I miss that kind of
up front and personal interaction with my transmitter today.

The point is that there are other considerations in the trade off between constructing
the crystal filter generator versus the balanced side-band phasing generator.  In the end,
the crystal filter method usually wins out because of its easier construction and the fact
that it fixes carrier suppression so that there is no need for adjustment during operation.
The audio quality is never a consideration and that argument is moved to an endless string
of conversations on mike quality, audio eq's & pre's, etc etc.

My 2 cents.  Hope this adds some flavor to the ideas you are thinking through.  Forgive
any glaring mistakes or blunders here.  Just passing on what my memory recalls.

Cheers,

Doug W5JV










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