K3 - RF Board - C238 - AGC change

[Andrew Catanzaro]

I did the mod shortly after it was described here.  The change in AGC behavior was not subtle.  Yes it improved copy in pileups when I was the DX.  I found it a bit difficult to cope with, though, because the changes in audio strength amongst the stations was more than my ears have an appetite for.  I had some trouble putting up with the loud signals challenging my ears by the time I had the volume up enough to discern the weak ones.  I believe subsequent firmware changes have obviated the need for this mod.  I plan on removing the extra cap. YMMV.  This is only my experience and my observations.

73,

Andy

 
_                                                                       _
Message: 11
Date: Mon, 04 Feb 2013 16:37:20 -0500
From: "N2TK, Tony"<[hidden email]>
To: "'elecraft'"<[hidden email]>
Subject: [Elecraft] K3 - RF Board - C238 - AGC change
Message-ID:<001801ce031f$d0937fc0$71ba7f40$@verizon.net>
Content-Type: text/plain; charset="US-ASCII"

A year or so ago there was discussion about adding additional caps to C238
to reduce IMD. I believe it was two 1-uf caps.

What was the outcome of that? Did it make a noticeable difference in pileups
or for weak signal detection?

Is it a recommended mod?

 

73,

N2TK, Tony


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[N2TK]

Tnx Andy for the info. I decided against installing the additional caps. I
am using 4.61. The AGC seems to work fine. Will have another chance to check
it at KP2M for the ARRL SSB upcoming contest.

 

73,

N2TK, Tony

 

From: Andrew Catanzaro [mailto:[hidden email]]
Sent: Tuesday, February 05, 2013 9:33 AM
To: [hidden email]; [hidden email]
Subject: K3 - RF Board - C238 - AGC change

 

I did the mod shortly after it was described here.  The change in AGC
behavior was not subtle.  Yes it improved copy in pileups when I was the DX.
I found it a bit difficult to cope with, though, because the changes in
audio strength amongst the stations was more than my ears have an appetite
for.  I had some trouble putting up with the loud signals challenging my
ears by the time I had the volume up enough to discern the weak ones.  I
believe subsequent firmware changes have obviated the need for this mod.  I
plan on removing the extra cap. YMMV.  This is only my experience and my
observations.
 
73,
 
Andy
 
 
                                                                     
Message: 11
Date: Mon, 04 Feb 2013 16:37:20 -0500
From: "N2TK, Tony"  <mailto:[hidden email]> <[hidden email]>
To: "'elecraft'"  <mailto:[hidden email]>
<[hidden email]>
Subject: [Elecraft] K3 - RF Board - C238 - AGC change
Message-ID:  <mailto:001801ce031f$d0937fc0$71ba7f40$@verizon.net>
<001801ce031f$d0937fc0$71ba7f40$@verizon.net>
Content-Type: text/plain;      charset="US-ASCII"
 
A year or so ago there was discussion about adding additional caps to C238
to reduce IMD. I believe it was two 1-uf caps.
 
What was the outcome of that? Did it make a noticeable difference in pileups
or for weak signal detection?
 
Is it a recommended mod?
 
 
 
73,
 
N2TK, Tony
 
 
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Please help support this email list: http://www.qsl.net/donate.html