[Elecraft] K3 Using RFV and dBV

[Kenneth A. Christiansen]

the earlier talk about the K3 S meter got me to thinking about a problem 
I wanted to address.

I wanted to use the S meter to track small changes in level. My IC-746 
PRO has twice the segments of my K3 but that was not enough either. The 
K3 S meter is great on the air as I never give anyone a 5 5.4 9 report 
anyway HI HI. I had never used the RFV and dBV features of the K3 and 
find they are just the powerful feature I needed but there is not much 
in the way of instructions on how to use them. Here is what I found 
works well for me.

My vertical is my nosiest antenna so I would tune the receiver to a 
clear frequency on 20 meters with the AGC-F and the RF gain MAX CW. I 
would get a AFV reading that would jump between about 105 and 111. I 
change the selection to dBV just as I see the meter read about 108, 
(average of 105 and 111). The reading takes a second or so to calibrate 
to something near 0 DB and it will bounce around a bit above and below. 
I changed AGC to OFF and adjusted the RF GAIN control to bring back a 
reading near ZERO DB. This completed my calibration and now I am ready 
to make my measurements.

My vertical still measured ZERO DB but my beam would peak up about -3 DB 
and at times drop to -18 DB as I rotated it. I often have trouble with 
noise when working KD5ONS on the 00:00 20 meter Elecraft NET. I found a 
small change in beam heading dropped my noise to -18 DB from the -5 DB 
of my usual beam heading for KD5ONS. I was able to check into the net 
tonight and the signals were weak but I think this procedure made the 
difference between hearing and not hearing. The dip in the pattern on my 
beam is extremely sharp so I had to hit my rotator bar several times to 
catch it.

I also have a MFJ 1026 that I never hooked up because it was too hard to 
adjust on my IC-746PRO. I am looking forward to getting cables and try 
it with my K3 now that I have a way to measure the levels so well.

I hope these instructions can help others use this powerful feature. The 
dBV calibration stays calibrated over a time of at least an hour and 
also works to play with the NB and NR features.

73

Ken W0CZ
w0cz at arrl.net