[Elecraft] SWR difference between 2 different K3's

[Richard Thorne]

Thanks for the ideas guys.

I've emailed support at Elecraft to see what their thoughts are.  I did 
some additional testing.

I connected K3-B to my KPA-500/KAT-500 combo and I'm finding that the 
K3-B sees a 1.5:1 swr while driving the KPA-500.  The SWR of the KPA and 
KAT swr meters both measure near 1.0:1.  All other bands show 1.0:1 
while driving the amp.  K3-A sees a 1.0:1 SWR on 40m while driving the 
KPA-500.

Something is up with measuring SWR on 40m with K3-B, even after 
calibrating the wattmeter.

Rich - N5ZC

On 7/19/2014 7:10 PM, Richard Thorne wrote:
> I have a strange swr issue I'm trying to resolve.
>
> I have two K3's for an SO2R setup, lets call them K3-A and K3-B. On 40 
> meters the swr that the K3 displays on K3-A indicates what is to be 
> expected 1.5:1 at 7.001 and 2.0:1 at 7.105, however on K3-B  the K3 
> displays 1.0:1 at 7.001 and 2.7:1 at 7.105.
>
> I'm using the same exact coax to connect to both rigs and I'm going 
> directly to ant port 1 on both rigs.  Neither rig has the ATU in line 
> (K3-B doesn't even have an internal ATU).  The antenna is a 2 element 
> 40m yagi.
>
> I've used an external Daiwa swr/power meter which agrees with rig 
> K3-A's swr  when connected to either radio.
>
> So it appears that the displayed swr on rig K3-B is giving an 
> incorrect reading.
>
> Any ideas?  Is it time to calibrate the wattmeter?
>
> Thanks
>
> Rich - N5ZC
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