[Orion] AGC Threshold

[Richard Detweiler]

Hi Gary,

The AGC has a a two fold function, the first is as you have described,  to 
attenuate higher level signals than the threshold,  The second is to 
'increase' the level of signals less than the threshold,  So there is 
actually an amplification going on to maintain a specific volume.

When the noise drops down as the agc threshold is increased,what is 
happening, is the noise is dropping below the point at which the AGC will 
try to amplify.

This is a Good thing,  because hopefully the weak signal just above the 
noise is not below that point and it will then amplify only the signal of 
interst,

Others here can better describe the function, but that is how I've 
understood it.

Best 73's
Rich
K5SF

>From: Gary Tuck <gtuck at mac.com>
>To: "Orion @contesting.com" <orion at contesting.com>
>Subject: [Orion] AGC Threshold
>Date: Sat, 6 Nov 2004 09:34:26 -0800
>
>I've been reading all the past threads on the Ten Tec list regarding 
>adjusting AGC and am still at a loss about one thing (well, one that I know 
>about).
>
>If the Threshold setting determines the point at which AGC action begins to 
>attenuate the signal, then why does the noise level go down when the 
>Threshold is made higher.  I guess I have this image of signals below the 
>Threshold level as not being reduced in strength by AGC action.  So, it 
>seems that to turn AGC off would result in a maximum Threshold, (>191 uv) 
>not .37uv as the menu reads.
>
>Can someone explain this to me in two syllable words cuz I'm just not 
>getting it.
>
>tnx, Gary W7TEA
>
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