[Elecraft] K2 current draw

Vic Rosenthal vic at rakefet.com
Sun May 15 18:39:22 EDT 2005


I just noticed an interesting thing about my K2/100:  the current drawn by the 
low-power part of the K2 (that's the current measured when you tap DISPLAY) is 
extra high on one band: 20 meters.  When I'm running 100 watts out, the current 
displayed varies from about 2.2-2.8 amps on all bands other than 20.  On 20, 
it's 3.5 amps.

My first thought was that the bandpass filter was misaligned on 20.  Sure 
enough, after adjusting L7 and L8 on 30 meters, the 20-meter trimmers were at 
minimum capacity when the output peaked.  I had to add an 8 pf capacitor across 
one of them and a 27 pf capacitor (!) across the other in order to have the peak 
fall in the adjustment range of the trimmer.  Very suspicious.

After doing this, I verified that the current draw when running 10 watts on 20 
meters was in line with the other bands.  But when running 100 watts, I still 
get 3.5 amps!

Something funny is going on.  Why was I unable to get a peak on 20 without extra 
capacity across the bandpass filter trimmers?  And why is the current drawn at 
10 watts normal, but high at 100 watts?

This is not something new, I've just ignored it until now!

-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco



More information about the Elecraft mailing list