[Elecraft] AGC and AF gain

[Don Wilhelm]

Greg,

Yes, it certainly seems like your AGC threshold could stand to be
re-adjusted.  The recommended 3.8 volts will be close, but is not any magic
number - the proper setting will vary from one K2 to another.  I have seen
good results with voltages as low as 3.6 volts, but none higher than 3.8
volts.  If you have the XG1, you can also set the S-9 point on the S-meter
at the 50 uV level (with the pre-amp on) by changing the AGC Threshold, S-HI
and S-LO - it usually takes me about 3 times 'round the horn' to get
everything lined up, so plan on some trial and error.  I find that simply
adjusting S-HI to set the S-9 level often limits the full range of the
S-meter.

Before you get started, be certain that you are evaluatiing the AGC on/AGC
off difference on a band that is quiet - remember that an S-3 noise level
will create some AGC action just from the noise.

If you are working on a noisy band, the best 'cure' is to simply turn the RF
gain down until the noise no longer activates the receiver AGC.  (Reducing
the RF Gain in the K2 does the same thing as reducing the AGC Threshold).
The AGC will still work on signals stronger than the noise, even though the
S-meter will not be as 'lively'.

73,
Don W3FPR

----- Original Message ----- 

I turned the AGC off the other day and was suprised to note a very noticible
increase in audio volume.  I had to back the AF gain down by a quarter to  a
third turn to get it at a reasonable listening level.  I tried this on
several signals and it was the same.  It has always seemed that my K-2 has
been weak in audio volume. Doesn't seem like this should be so.  Any
thoughts?  Recheck the AGC threashold setting?