[Elecraft] S-meter activation, a simple cure

Thu Dec 26 10:50:04 2002

I have installed Marteinn's simple AGC IF filter. It really decreases
the S-meter activity from signals that you cannot hear in the passband,
so I am very happy with it. Now I have made the OP1-filter (SSB filter)
to be FL1 in my CW setup again, as I had removed it due to the S-meter
activation problem previously.

The filter will reduce gain in the AGC loop slightly, meaning that the
overall gain of the K2 will increase. This can be compensated by
adjusting R1 on the control board so that pin 5 on U2 reads about 4.1
Volts (Elecraft's serial # 3000+ recommended value is 3.90 Volts). If
you already have a K2 where the gain reduces a little too much on a
quiet band when the AGC is turned off, insertion of this filter will
alleviate this problem.

73 and Merry Christmas
Sverre LA3ZA
www.qsl.net/la3za

> -----Original Message-----
> From: [email protected] 
> [mailto:[email protected]] On Behalf Of Marteinn 
> Sverrisson
> Sent: 16. desember 2002 10:51
> 
> S-meter/AGC activation from strong out of band stations has 
> long been a problem for me when I use the OP1 filter.
.....
> 
> You should readjust the AGC threshold - R1 on the control 
> board - to compensate for the insertion loss of the filter. 
> (tnx Sverre LA3ZA)
> 
> Details on: http://www.raunvis.hi.is/~matti/TF3MA/agc.html
> 
> 