[Elecraft] K2/100 Shuts Power Down

[Kevin Rock]

Sounds like a problem I have had.  The power just folds for some reason.   
Well, I fixed it, but the problem is not what you may expect.  My K2/100,  
SN #2511, has been working fine for years but it, too, experienced this  
problem starting a few months ago.  I thought it was the power supply so I  
tried my battery power.  This worked for a while.  So I tried another  
power supply.  This too worked for a short while but the problem  
recurred.  A friend said look at the Anderson PP connectors and see if  
there is a loose connection or corrosion.  So, I made and broke the  
connection between both ends of the cables multiple times to wipe the  
silver connectors clean.  This worked for a while but the problem came  
back.  What did fix the problem for more than just a short period of time  
was to hang my power cable from hooks to take the strain off the  
connectors.  The weight of the cable was pulling on the connections  
creating an intermittent fault.  When the K2/100 warmed up enough the  
power connection would fail, the rig would emit some odd noises, power  
cycle, and I'd not be able to transmit at full power.  After hanging the  
cable this has not occurred again in twenty or more hours on the air.  Now  
I can run from either my batteries or from a power supply at 100 watts  
with no difficulty for an hour or more of CW.
    Good luck,
       Kevin.   KD5ONS


On Sun, 19 Nov 2006 20:21:45 -0800, Patrick DalPorto <dalporto at alltel.net>  
wrote:

> The K2/100 has been working very well for a couple of years but it has  
> developed a problem.  I was on 15 m. SSB and made a quick call and the  
> rig made a noise, shut down, and restarted.  It had shifted frequency  
> and the fan was running when it came back on.  I readusted the tPA.   
> When I try to tune the radio at low power it tunes but will shut down  
> very shortly.
> I thought I may have a bad diode in the SWR bridge but D16 and D17 seem  
> to be fine when checked in the circuit.  Is it necessary to remove them  
> from the circuit board to check them properly?
>
> Anyone have any clues where I can start looking for the trouble.  I have  
> put the low power top and tuner back on the rig and it works just fine.   
> I also tried the KAT100 and another tuner and the result is the same.
>
> 73,
> Pat W8FV/5H9PD