I tried this with my OII, think that I must have missed something. I
simply never see the S-meter drop and then rise as I decrease RF
gain. Of course, it will drop if I turn off the preamp, but not as I
change the RF gain setting using the multi knob. What I see is that
the minimum S-meter reading rises as RF gain is reduced (as if the
AGC voltage is being increased which is, in some sense, what's
happening). At some point the minimum S-meter reading is above the
maximum deflection due to static crashes. Then, any signals stronger
than the static crashes will lead to an upward deflection. Am I
missing something subtle? Does anyone else see the S-meter drop then
rise as the RF gain is decreased?
I set my SAF by ear as per the TT instructions, decreasing RF gain
until I hear only a little ringing. Even though I am almost
exclusively CW, I tried it a couple of times on SSB was surprised how
much it helped on weak signals.
73,
Kim N5OP
At 02:38 PM 4/23/2012, you wrote:
A visual clue for setting RF Gain is the S-meter. While listening to
just noise, as you decrease the RF-Gain, the S-meter noise level drops,
and continues to drop, until you reach a point where the S-meter
reverses and starts to climb - while the RF-Gain continues to be turned
down. Thus, there is a point where the S-meter changes direction while
the RF-Gain is still being turned down. (Sorry... I find this
difficult to say in words...) The point where the S-meter reverses is
the sweet spot (although I find it is really just above that point...)
Play with it and you will SEE what I mean. I think you will find the
S-meter reverses just at or just below the point where you can HEAR it
change over.
I have an Omni VII and this works on it -- I spent time on my friend's
Orion II and it seemed to work exactly the same way, albeit at different
points on the dial. ...snip...
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