[Elecraft] K1 AGC time constant

[Tom Althoff]

Ron ZL1TW and I have played with the AGC on the K1...here's a cut and paste
from one of our exchanges earlier this year.

My mod adds a .47 cap in series with the AGC On-Off line so that by turning
the AGC "off" I can return to the longer recovery time (which I never choose
to do).

Not sure if the 22K between 9 and 10 of RP3 really did anything..I just left
it in.

My K1 effectively has a pair of .01 rf bybass caps in the AGC circuit in
place of the original caps.

Tom K2TA
----------------------------------------------------------------------------
-----------------------
<<<<< So I'm running .22 at C31    .01uf at hmmm C67?...the one at the mixer
chip.
22K across Pins 9 and 10 of RP3.  (this is slightly less than your 47K
across the same terminals).

Lastly, I have the .47 in series with the AGC ON-OFF line.

I must say there wasn't as dramatic change going from the .22 to the .01 as
there was going from the 2.2 to the .22 but it is definitely better and as
you say...probably can't hope for much more than that.>>>>>>>>
__________________________________________________________________
----- Original Message ----- 
From: "Ralph Tyrrell" <w1tf at yahoo.com>
To: <Elecraft at mailman.qth.net>
Sent: Wednesday, April 05, 2006 12:59 PM
Subject: Re: [Elecraft] K1 AGC time constant


> I did the exact same thing you did Rick. Same RS cap
> and AGC did not speed up as I had hoped.
> Also wonder what other might have done?
>
> 73, TY, W1TF, K1 # 1423
>
> --- Rick Dettinger <k7mw at cmc.net> wrote:
>
> > I changed C31 on the RF board to 1uf  but it still
> > seems very slow.  When I
> > remove an S9 siginal  (50uv) it takes about 15
> > seconds for the S meter to
> > decay to one bar.  I used a non polorized
> > electrolitic cap as that is what
> > they had at RS.  It is physically larger than the
> > original cap but there is
> > plenty of room.  I am not sure what a non polorized
> > electrolitic capacitor
> > is but there are no polarity marks,  which I haven't
> > seen before.  Should I
> > try a smaller value for C31?         Thanks - Rick -
> > K7MW
> >
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