K3: High VSWR indication on 6m only

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K3: High VSWR indication on 6m only

Stephen  Prior
Whilst calling CQ on 6m tonight (100W into about 1.3:1 VSWR), all of a
sudden I got a high SWR indication (4.9:1).  Forcing a retune of the auto
ATU did not improve it.  I checked the VSWR with my Kuranishi BR210 analyser
and it reported about 1.5:1 VSWR.

I then connected the K3 to a Bird dummy load.  The K3 reports the VSWR on 6m
into the dummy load as 3.6:1.  On all other bands the K3 reports 1.0:1.  My
Kuranishi meter confirms the VSWR of the Bird load to be no more than 1.2:1
up above 150MHz.

It is as if the K3's reflected power measurement on 6m only has become
faulty. Has this been seen before?

Stephen G4SJP



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Re: K3: High VSWR indication on 6m only

Stephen  Prior
I should add that I do not have the KAT3 internal ATU.  When I refer to the
auto ATU I am referring to the external ATU at the feedpoint of the antenna,
which happens to be an Icom AH-4 ATU.  However, since this problem occurs
too when the K3 is connected directly to my dummy load, I can only assume
that the problem lies within the K3 (but not its tuner which I don't have!).

73 Stephen G4SJP


On 07/06/2009 20:45, "Stephen  Prior" <[hidden email]> wrote:

> Whilst calling CQ on 6m tonight (100W into about 1.3:1 VSWR), all of a sudden
> I got a high SWR indication (4.9:1).  Forcing a retune of the auto ATU did not
> improve it.  I checked the VSWR with my Kuranishi BR210 analyser and it
> reported about 1.5:1 VSWR.
>
> I then connected the K3 to a Bird dummy load.  The K3 reports the VSWR on 6m
> into the dummy load as 3.6:1.  On all other bands the K3 reports 1.0:1.  My
> Kuranishi meter confirms the VSWR of the Bird load to be no more than 1.2:1 up
> above 150MHz.
>
> It is as if the K3's reflected power measurement on 6m only has become faulty.
> Has this been seen before?
>
> Stephen G4SJP



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