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. My Kenwood receivers and transceivers (e.g.,
R-5000 and TS-590s) both work that way, but the sweet spot (i.e., the
S-meter reversal point) is much higher in the scale -- the TT rigs use
much more of the turning radius - so that SSB signals are best between
20% and 50% - with a wide range of play - but the Kenwood rigs do all
of that in the upper 30 percent of the turning range, say between 70%
and 85%, so that it works the same way, but is MUCH MORE TOUCHY to tune.
Here is what it says in the Kenwood manual:
RF (RADIO FREQUENCY) GAIN
The RF gain is normally configured to the maximum
level regardless of the operating modes. The
transceiver has been configured to the maximum
level at the factory. However, you may decrease the
RF gain slightly when you have trouble hearing the
desired signal due to excessive atmospheric noise or
interference from other stations.
First, take note of the peak S-meter reading of
the desired signal. Then, turn the RF control
counterclockwise until the S-meter reads the peak
value that you noted.
• Signals that are weaker than this level will be
attenuated and reception of the station will become
easier.
Depending on the type and gain of your antenna and
the condition of the band, adjust the RF gain. When
using FM mode, always adjust the RF gain to the
maximum level.
TenTec rigs seem to give much wider range to the RF Gain control, which
is like having a "bandspread" or fine-tuning control on old SW receivers
- it is a wider, smoother, easier to work control. The additional
range is very helpful in that you can dial it in with ease, whereas on
my other brand radios, the range is vary narrow and you can easily
overshoot it and kill the intended or desired signal right along with
the background noise. As there is no point to ever tune RF Gain down
below the point where the signal and noise are both gone, there is, for
that reason, no good reason to limit or crowd the range of the control.
TT uses the whole range of the control... while Kenwood uses only the
upper third of it for no reason I can fathom.
Again I hope this makes sense as I find it difficult to say all this is
words.
================ K8JHR ===========================
On 4/23/2012 8:58 AM, Rsoifer@aol.com wrote:
Cecil,
Right on. The RF gain setting is critical. I set it by ear, don't know
any other way of doing it. I used to use an external Autek QF-1. The O II
SAF is better (less ringing, easier to use) if set right. 10 Hz is too narrow
for me -- the ringing is counterproductive.
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