If the AGC is working right, it is equivalent to manually riding the RF
gain control. It shouldn't affect the decoding.
If the AGC time constant is too fast then, yes, it can cause distortion
and degrade the decoding. But that should never happen in a
properly-designed AGC system.
AGC makes the decoder's job easier, not harder, because it reduces the
dynamic range the decoder has to deal with.
Alan N1AL
On 03/07/2017 01:19 PM, Ed Muns wrote:
Decoders operate on the audio stream presented to them from the receiver.
The decoding algorithms use the difference in audio level at each instant in
time to make bit decisions. AGC reduces those differences and thus
increases the bit error rate.
Of course, it is important to adjust the absolute audio levels so that the
dynamic range of the signal(s) is placed within the dynamic range of the
decoder. But, compressing the dynamic range, i.e., AGC, increases the error
rate of the decoder.
Ed W0YK
_________________________________________________________________
-----Original Message-----
From: Bill Frantz [mailto:[email protected]]
Sent: 07 March, 2017 13:05
To: [email protected]
Cc: [email protected]
Subject: RE: [Elecraft] [K3] AGC White Paper
What I get using a relatively flat AGC is automation of my
riding the RF gain control. I don't see how this kind of
automation affects decoder performance. It should help
performance as the decoder has a nearly constant level signal to
work with. Please explain.
Thanks - Bill AE6JV
On 3/7/17 at 11:37 AM, [email protected] (Ed Muns) wrote:
Just the opposite. Most digital signal decoders work best with the least
AGC action possible, even AGC Off. AGC constrains decoder performance.
Ed W0YK
_____________________________________________________________________
-----Original Message-----
From: Elecraft [mailto:[email protected]] On Behalf Of Bill
Frantz
...
Now to use SLP=15 for digital, where I want the AtoD to not
have to deal with a big range, while using something with more
dynamic range for voice/CW.
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Bill Frantz |Security, like correctness, is| Periwinkle
(408)356-8506 |not an add-on feature. - Attr-| 16345
Englewood Ave
www.pwpconsult.com |ibuted to Andrew Tanenbaum | Los Gatos,
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