[Elecraft] When S-Meters are Useful (WAS: When do you use fast AGC?)

[Rick Dettinger]

> Maybe Elecraft would consider this as a future external option  for
> the K2 . It certainly would be a first for a ham radio, that is
> having a inbuilt calibrated S meter. The crunched up S meter
> bargraph is highly annoying and close to useless on the k2.
>
> Craig
> VK3HE
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Last year, I posted my intent to recalibrate my K2  S meter to give one bar
per S unit.  I used my XG-1 50 microvolt output to set the S meter reading
to light 9 bars, with the preamp off.  Of course, I can't use the
calibration scale for signal strength, but I can use the power out scale, up
to S9, to ret a reading.  I like this method of using the S meter.  I don't
mind losing  the db over 9 readings.  Some meters use up to half of the
scale on this with S9 being near the middle.  I think that is a waste.  Not
sure what this does to linearity, but it seems to cover the range nicely.
As for not having an S meter with the AGC turned off, I have found that
setting the AF gain to a given position, like mid scale, and using the RF
gain to control AF output,  the position of the RF gain control gives me a
good enough idea of signal strength to give a meaningfull report to the
other operator.  I use this method with simple rigs, like my Sierra or Oak
Hills 100 A.  I have been considering changing the AF gain on my K1 to an RF
gain control, with a set and forget internal adjustment for the AF gain.
This works well on my Nor Cal 40A.  The main reason for changing the
receiver gain is to compensate for changing signal strength and I think this
is best done as early as possible in the receive chain.  Operating without
an AGC gives a whole new dimension to the receiver, like depth of field in
photography.  Sometimes this is desireable, sometimes not.
Rick Dettinger
K7MW