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Farhan's AGC

 

Has anybody built and installed farhan's AGC? Does it work well? I think it's high time I install one.

Joel
KB6QVI
Baruch Atta
 

See this article for AGC -?

On Wed, Dec 7, 2016 at 1:11 PM, caulktel@... [BITX20] <BITX20@...> wrote:
?

Has anybody built and installed farhan's AGC? Does it work well? I think it's high time I install one.

Joel
KB6QVI
 

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Thanks, I'm aware of the article, what I'm asking is, who has built it and is using everyday, and how do they like it? Does it work good? I've built a lot of audio derived AGCs and some raise the background noise level so bad I end up removing them.

Joel Caulkins
KB6QVI

On Dec 7, 2016, at 10:20 AM, Baruch Atta baruchatta@... [BITX20] <BITX20@...> wrote:

?

See this article for AGC -?

On Wed, Dec 7, 2016 at 1:11 PM, caulktel@... [BITX20] <BITX20@...> wrote:
?

Has anybody built and installed farhan's AGC? Does it work well? I think it's high time I install one.

Joel
KB6QVI
 

I laid out a small circuit board and built it up.? It seems to work quite well from the little I have used it.? Only thing I noticed was a decrease in total audio level.? I compensated for that by increasing the value of the capacitor between 1 and 8 on the LD386, I think I used a 4.7uF instead of the 1 uF.? Have not noticed any appreciable increase in the background noise.? Nice thing about it is you do not need to make any changes to the board, everything just gets tacked onto the volume control.? I plan on making some measurements of the audio response with and without the AGC when I get time.? But right now I am working on a si5351 VFO to get rid of the drivt problem.
DuWayne KV4QB
 

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Thanks DuWayne,

Just the info I was looking for. I think I'll build one and give it a try. I already removed the cap between pins 1 and 8 on the 386, so might have to increase gain a bit, we'll see.

Joel Caulkins
KB6QVI

On Dec 7, 2016, at 11:15 AM, duwayne@... [BITX20] <BITX20@...> wrote:

?

I laid out a small circuit board and built it up.? It seems to work quite well from the little I have used it.? Only thing I noticed was a decrease in total audio level.? I compensated for that by increasing the value of the capacitor between 1 and 8 on the LD386, I think I used a 4.7uF instead of the 1 uF.? Have not noticed any appreciable increase in the background noise.? Nice thing about it is you do not need to make any changes to the board, everything just gets tacked onto the volume control.? I plan on making some measurements of the audio response with and without the AGC when I get time.? But right now I am working on a si5351 VFO to get rid of the drivt problem.
DuWayne KV4QB

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