[Elecraft] KAT-500 Unreliable Tuning

Wed Mar 10 12:57:01 EST 2021

I think you have one of the newer units where Elecraft improved the design by putting one wire above and another below the PC board.  Mine was #309 with both wires above the PC board.  They had arced.

Raj, N2RD

> On Mar 10, 2021, at 12:53 PM, Dennis Moore <dennis at mail4life.net> wrote:
> 
> I checked inside my tuner, I only have one green wire instead of two. Serial #2120.
> 
> I also have the issue of erratic tuning when applying power, adding an additional common mode choke helped calm things down.
> 
> Dennis NJ6G
> 
> On 3/8/2021 09:07, Rajiv Dewan wrote:
>> I had a similar issue with my KAT500.  I opened it up and the problem was obvious: there are two green 12g wire bridges that cross. (You can see them in this image: (kat500_inside_500_530x at 2x.jpg  <https://cdn.shopify.com/s/files/1/2029/4979/products/[email protected]?v=1536760566>. You can see one end of the longer green wire near the big red toroid.) There had been arcing between them.  My guess is that they arced at higher power levels. I replaced them with slightly longer wires and bent them to create more clearance.  That solved my problem.
>> 
>> I recommend taking taking the cover off and taking a look.  The problem may be obvious as it was for me.
>> 
>> Raj, N2RD
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