[Icom] Icom 756-Pro II audio/mic input alternatives

[HFSSB]

It's unusual to find fault with Adam's outstanding contributions to our hobby
but re-reading Adam's comment here I see that the error is in the latter part of
this statement, "... to cut off low-frequency components of the microphone
output (below 250~300 Hz). These components contribute virtually nothing to
articulation at the receiver,..."

If we could take everything out of normal conversation below 250-300 Hz we would
quickly miss the richest sounding component of the human voice, the bass.  By
putting this lower audio component back into the SSB signal we are adding the
fullness in the human voice giving it a more "life-like" natural sound.  Adam's
statement is then only true if you receive with filters cutting off these lower
frequencies.  Today however, there is tremendous interest in SSB audio
improvement and you have Hams listening on rigs with filters opened up from 0 Hz
to 3-4k, even 6k if conditions allow.

The problem comes when a novice in HiFi SSB (of course, we all start out as
novices) over-drives the low frequencies which then overpowers the mids and
highs, that's when you hear comments like "mushy audio".  There is a learning
curve to the Ham audio hobby as in most things worth while.  With the exception
of prejudice against the audio hobby itself, everyone who listens to a properly
balanced Hi-Fi audio SSB transmission on a properly adjusted and capable
receiver (meaning filters open from 0-50 Hz to 3k or more and a decent spkr or
studio headphones) is at awe of the sounds that can come through in SSB mode.
It is not unusual to hear comments like "Sounds like FM broadcast station".

I have heard half a dozen or so 756 users who use the acc jack and without
exception said they get better audio results by going direct to the balanced
modulator.

Marty
http://groups.yahoo.com/group/hfssbaudio/

-----Original Message-----
Adam I don't know what you know technically and I respect your knowledge
however I am amble to run my Heil HC5 through the W2IHY EQ and noise gate
and get a nicer and more full range of audio by going direct through the
balance modulator than through the front mic input ...
73, Steve
----- Original Message -----
> Larry,
>...the design intent
> is probably to cut off low-frequency components of the microphone output
(below
> 250~300 Hz). These components contribute virtually nothing to articulation
at
> the receiver, ....
> Best 73,
> Adam, VA7OJ/AB4OJ