[Elecraft] High SWR in to dummyload on 6/10M

[Joe Subich, W4TV]

Did you try engaging the KAT3 on 10 and 6 meters and *tuning* into
the dummy load?  After that, bypass the tuner and check the SWR.

The KAT3 (as opposed to the KAT3A) has no hard bypass.  To bypass
the tuner, the K3 selects the "tuned to 50 Ohm" state.

Note: the tuning solutions (including bypass) are stored separately
for ANT 1 and ANT 2 but are not reset if one changes KAT3 boards.

73,

    ... Joe, W4TV


On 2026-04-27 10:19 AM, Peter via Elecraft wrote:
> Hi
> 
> I have a K3 that needs some maintenance.
> The SWR on 10 and 6 meters is high (1:2).  On the bands below it is OK 
> (1:1).
> The ATU had a burnt L  (L10 (IF stage trap)). Both the C and the L have 
> been removed and a jumper has been installed.
> 
> After reinstalling the ATU, there was hardly any change. The SWR was now 
> 1:1.9 on 10 and 6 meters.
> After this, the ATU was swapped with another ATU from a properly working 
> K3.
> However, the SWR on 10 and 6 meters remains unchanged and high.
> 
> A second test was swap the output pin from ATU to PL259. On ANT 1 the 
> SWR remained bad and on ANT 2 it was good.
> 
> Then, I directly connected the PL259 on the back to P70 on pins 17-20.
> Now the SWR is OK on all bands.
> 
> In my view, the cause lies in the control via the P70 pin 1-5 because I 
> tested it with 2 ATUs that react the same way.
> Does anyone have a tip on how to check its operation?
> 
> 73 Peter
> PC2A