[Elecraft] KPA100 high current draw

[Don Wilhelm]

Jim,

Please differentiate between HI CUR messages and a measured power supply 
current to the K2/100.  The answer will tell you where to look.

If you are simply seeing HI CUR messages, check the power output from 
the KPA100 - if  you find that it is putting out max power (100 watts or 
greater) for all setting of the power control above 10 watts, then look 
for the trouble in the KPA100 wattmeter first.  It is quite likely that 
diodes D16 and D17 were zapped by a lightning surge (it is summertime 
and lightning surges are not uncommon) - if this is the case, just 
replacing the diodes will usually cure the problem - and make a mental 
memo to disconnect your antennas when not in use.

The HI CUR messages indicate only that the current being drawn by the 
base K2 (not the KPA100) is in excess of the setting you have for CAL 
CUR.  You might want to check the CAL CUR setting - with the KPA100 it 
should be set to 3.50 amps or higher.

Another cause of HI CUR messages can be a low voltage from your power 
supply - check its output and the connecting cables for good low 
resistance connections.  The way the K2 controls power results in a 
higher current draw when the voltage at the KPA100 (or K2) power 
connector is reduced.

If you are having excessive current draw from your power supply (as 
measured by an external meter - perhaps on your power supply *and* you 
have power control from end to end of the power pot, then you should be 
looking at either the T/R switch or the Low Pass Filters in the KPA100 
*or* at your antenna and feedline for the problem source.

73,
Don W3FPR

Soaring Eagles wrote:
> Folks,
>
> My K2/100 has been working fine for over 6 months. Today I turned it 
> on and I get a high current draw anytime the KPA100 is inline. Setting 
> power <10 works fine. I haven't even moved the radio since it last 
> worked, so I'm not sure how to go about troubleshooting.
>
> Thanks for any help!
>
> Jim, WD9HBC
> K2 #5757
> KX1 #1517
>