[Elecraft] Cautionary tale

Tue Aug 13 06:06:01 2002

One of the great things about kit and homebrew rigs is that if they 
break you can fix them. Downside of this is that if you think the're 
broken you start to fix them even when they are not.

Last night I was working in the shack with the K2 monitoring a net on 
80m. Suddenly the K2's audio died. On investigation the K2 was 
DEAD, the screen displayed OK but no audio, no TX lights, button 
presses did nothing, complete lock-up - couldn't even hit 5757x to 
reset processor. Powered on/off but still no dice, fired up OK but 
locked on 80m freq with no RX. OK - onto the workbench, off with the 
cover, check the control board is seated firmly, same for each of the 
microcontrollers. Apply power - K2 is fixed, all seems OK. 

Back into the operating position, attach antennas, computer, ground, 
mic and power cables. Power up K2 is dead!! Locked on the same 
80m freq. Don't you just hate those faults that go away and then come 
back.

This time I forget to switch the K2 off whilst unplugging the antennas, 
computer cable, ground and microphone - hey I'm getting audio! K2 is 
alive again.

Check microphone - it's a hokey homebrew affair using a Kenwood 
MC-60 amplified base into a Shure stage mike body which hosts a Heil 
cartridge. It has an LED to indicate the amp is powered which wasn't 
illuminated but the Lock button was down (must have knocked it while 
working) so PTT was locked but with no TX audio - hence K2 was not 
showing any TX power lights (in SSB mode). Unlock Mike and K2 is 
"mended" again.

Had me really worried for a while there!

Brian G0UKB
K2 #1115