[Elecraft] KPA500 gain variation with serial number

[Andy Durbin]

I now have data for nine KPA500 with serial numbers ranging from 11x to 478x (exact serial number intentionally obscured).  Thanks to everyone who contributed.

The data show no significant increase in gain from the earliest to the latest serial numbers.  However, the data do seem to suggest that serial numbers near 2,000  have gain well above average.

Perhaps the most interesting data came from one owner of two KPA500.  Serial 209x had a gain of 14.4 dB but serial 478x had a gain of 12.0.  These numbers are from the same person using the same power measurement device and same measurement technique.

Lowest reported gain was 11.5 dB (2 samples) and one of those is mine.  There are three others at 11.8 dB.  All except 3 fall in the range 11.5 to 12.0.

Plot can be found here - https://www.dropbox.com/s/jk1t9j2417lh9gz/KPA500%2020%20m%20gain.png?dl=0

I also have some information on two other KPA500 that have high gain but I don't have serial numbers for them.  I'll update my plot if I receive any additional data.

73,
Andy, k3wyc