[Elecraft] KX3 Shutdown

[Barry LaZar]

I found the problem, I think. It was not the power supply; I checked 
everything.

Here is what happened. I went into the menu on the KX3 and turned off 
the amp. I tried to break the radio using CW at 10 Watts; nothing 
happened. Next, I turned on the amp again and then tried to shut down 
again starting at 20 Watts and every 10 Watts after that; nothing 
happened. So I tried full power, 100 Watts, and still everything stayed 
up, no problem.

My hypothesis is this. Over time, something became corrupted in the 
software. By "resetting" the amplifier/radio connection, the software 
sorted itself out. I suspect it was really a timing problem that was 
created and then removed. Nothing ever happened in receive, but it 
started while running in CW at 20-25 WPM. SSB wasn't a problem until a 
few days ago, so it appeared to be getting worse. I was operating last 
night without a problem. I, therefore, declare the problem solved. 
However, if anyone with more insight into this has any information, I'd 
sure like to know about it.

73,
Barry
K3NDM



On 10/7/2014 3:44 PM, Barry LaZar wrote:
> John,
>     Thanks. I'll check that. I hope that is all it is as that is the 
> same  35 Amp supply that I use.
>
> 73,
> Barry
> K3NDM
>
>
> On 10/7/2014 3:25 PM, John Nogatch wrote:
>> On Tue, Oct 7, 2014 at 6:40 PM, Barry LaZar <k3ndm at comcast.net> wrote:
>>> ... has begun to shut down unexpectedly while running CW or SSB. The
>>> power supply is an Astron 35 Amp linear that appears to be rock 
>>> solid....
>> I had a similar problem with my K3. Suspecting a power supply problem,
>> and after reading:
>>
>> http://www.repeater-builder.com/astron/astron-intro-stuff.html
>>
>> I found that the RS-35M pass transistor mounting screws were slightly
>> loose, i.e. I could easily tighten them perhaps 1/8 turn.
>> After adding "split-ring" lockwashers to the pass transistor mounting
>> screws, the problem has not recurred.
>>
>> Also, I have added fans to the backs of the heatsinks. The RS-35M no
>> longer gets hot, like it used to.
>>
>> -John AC6SL
>>
>
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