[Elecraft] KPA1500 SWR meter

[john at kk9a.com]

Hopefully Elecraft can duplicate the apparent temperature related SWR
problem and resolve it.

The loud fan noise contradicts preliminary reviews. Perhaps the early
testers did not run the amp in a contest environment where it heated up.
There are over 125 KPA1500's that have been manufactured so they should be
getting used in all types of environments now. I hope to order one for my
station, eventually.

John KK9A


from: Don Butler n5lz at comcast.net
date: Sun May 6 18:41:31 EDT 2018

contest..... which is the first contest I have operated with the KPA1500
.... the heatsink temperature was down in the mid 40s C at the time .... and
in my case it occurred on 160 meters only .... SWR as per other meters as
well as the digital readout on the 1500 were reading 1.2:1 ... and did not
change even when the LED flashing occurred ..... but I was getting
intermittent flashing of all LEDs on the amp's SWR meter ....

During the contest I was continuously running on CW with hourly QSO rates
running between the 70s and 110s .... I opted to manually switch on the fan
to keep the temperature below 60 degs C ..... level 2 seemed to keep it
there most of the time .... but I did move up to level 3 a few times  (and
BTW, at that speed the KPA1500 is clearly the noisiest amp I have ever owned
.... but, arguably, it may very well be the "coolest" also ..... headphones
were absolutely necessary with that noisy fan ..... clearly much noisier
than the Alpha 9500 sitting right next door ... which I also used during the
same contest...

So Mike, you're not the only one experiencing this phenomenon.... whatever
it is..

Don, N5LZ   (KPA1500 #45)