Re: [Elecraft_K3] change the processor board?


Geoffrey Downs
 

If your K3 is an older one that doesn’t have gold pins for the front panel, it might be oxidation on some of the pins. It might not be, of course, but it may be worth checking by removing the front panel, cleaning the pins and putting it back, maybe even with a little Deoxit or Contralube on them. I’ve not had exactly the same faults with my senior K3 (#266) but twice over its 8+ yr life have had esoteric happenings relating to frequency, power or error messages that were cured by doing this.
 
GL es 73
 
Geoff
G3UCK
 

Sent: 21 August, 2016 5:50 PM
Subject: [Elecraft_K3] change the processor board?
 
 

My K3 now has two distinct bugs.  One bug that's been present for several months occurs during the first few minutes of warm-up (until the indicated FacePlate FP temperature is above about 27C), when I turn the VFO control the relays click and the freq jumps to an arbitrary and non-standard value such as 246.200 MHz.  Yes, I wrote two hundred and forty six point two Megahertz.  The second bug is more recent and highly frustrating.  Only on 75/80 meter band does this occur.  After about one minute of transmission the output power will drop back from 100 W down to about 35 W (CW output for example or simply pressing XMIT to send a constant carrier) .  The only way to clear this condition is by turning off the rig and turning it back on.  This is when running into a known good 50 Ohm dummy load.  It's not heat related, it's not the SWR foldback function kicking in.  Nothing like that.  It appears to be a "control related bug'.  When it is limited to about 35 W out (Bird Wattmeter), adjusting the power out control indicates "100 W" but it's outputting about 35 Watts.  All other bands do not do this while the rig is confirmed in this trouble condition on 75/80 meters.  In other words when the power is limited to about 35 W out on 75/80 meters I confirmed a proper 100 W out on all other bands.  Very strange to be limited to the one band.

My question to the K3 owners out there - have any of you had similar apparent processor related bugs and simply shot gunned the repair by changing out the main board that contains the uP?  That may be less expensive than pursuing the formal evaluation/repair approach.

Thanks for any suggestions.  I know I can send it to the K3 hospital but it's not covered by Obamacare (yet anyway) so I'm looking at other possible approaches.  Anybody been down this buggy road?

73 N6AF Chas




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