PROBLEM SOLVED [Elecraft] K3 #195 FW:Beta 2.10 Output Pwr Out Of Control

[Don Ehrlich]

I yelled for help too soon.  When checking around with a scope I found that 
my Astron linear power supply has failed.  The K3 is healthy.

Don K7FJ


> Starting with my first qso after loading Beta 2.10 last week my K3 shut 
> down (turned off) unexpectedly in the middle of an SSB qso while I was 
> transmitting at about 60 watts PEP out.  Later I was able, after several 
> failed attempts, to turn it on again and now, a few days later, it is 
> happening again.  Now, though, it looks like a hard failure.  Any attempt 
> to transmit at over about 30 watts out results in shutdown.  This occurs 
> on both 160 and 80 meters.  I have not tried other bands.
>
> The symptoms are that indicated peak output power is is about three times 
> the specified amount.  At around 40 watts commanded actual power is up to 
> over 120 watts and that is about the level where shutdown occurs.  As I 
> write this the K3 is in CW mode on 80 meters connected to a 50 ohm dummy 
> load.  The output power is set to 30 watts and when I press the TUNE 
> button actual output power indicated by an external meter (average, not 
> peak mode) shows a power of 30 watts varying 1 or 2 watts plus and minus. 
> When switched to peak mode the external wattmeter indicates 70 watts. 
> The input current is varying from 6 to 13 amps as indicated on the K3 
> digital display, and the SWR indication on the display is flashing 1.0 - 1 
> on and off at an uneven rate and the RF output indication on the K3 
> display is 70 watts but also flashing and jittering.
>
> This started with FW beta 2.10 and I hope that is the problem but I'm 
> worried that it might be something more serious.
>
> I have made no changes to settings recently.
>
> HELP!
>
> Don K7FJ