strange S-meter behaviour

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strange S-meter behaviour

Karsten Eppert (DK4AS)
Re: K2 #4764. I receive a signal with - let us say - S8. So the S-meter
jumps between S0 and S8. Now I would expect, that if I reduce RF-gain so
that the S-meter-bar just rests at S8, there would not be any variation
in S-meter-reading anymore. Wrong! Doing this, the S-meter peak reading
increases to S9 plus something. Once I reduce RF-gain even more, the
s-meter peak reading increases a bit more up to a top value.
Is there anything wrong with my K2? Wchich s-meter-reading should I
regard as "true"?
Any hints from the elecraft community?
73
Karsten
DK4AS
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RE: strange S-meter behaviour

Ron D'Eau Claire-2
Hello Karsten!

Do not worry, your S-meter is behaving normally. Here is what is happing.

The RF gain in your K2 is controlled by a d-c voltage. This voltage may come
from the RF Gain control or it may come from the Automatic Gain Control
(AGC) circuit.

When you have the AGC on and the RF Gain at maximum and encounter a signal
(or noise), your AGC circuit senses the signal and increases the AGC voltage
to turn down the gain. The stronger the signal or noise, the stronger the
d-c voltage and the more the gain is turned down.

The S-meter monitors the AGC voltage. As the AGC voltage goes higher to turn
the gain down further on stronger signals, the S-meter indicates a higher
signal strength reading.

The RF gain control knob changes the AGC voltage manually. Turning the RF
gain down using the knob also increases the AGC voltage, even though no
signal may be present. This causes the gain to be lower and the S-meter to
read higher, just as if you were receiving a strong signal. That is
perfectly normal behavior.

To use the S-meter normally, you will have the AGC on and the RF gain full
"up" (at maximum).

Ron AC7AC

-----Original Message-----

Re: K2 #4764. I receive a signal with - let us say - S8. So the S-meter
jumps between S0 and S8. Now I would expect, that if I reduce RF-gain so
that the S-meter-bar just rests at S8, there would not be any variation
in S-meter-reading anymore. Wrong! Doing this, the S-meter peak reading
increases to S9 plus something. Once I reduce RF-gain even more, the
s-meter peak reading increases a bit more up to a top value.
Is there anything wrong with my K2? Wchich s-meter-reading should I
regard as "true"?
Any hints from the elecraft community?
73
Karsten
DK4AS

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com