K1 20m power out

[Lloyd Lachow-2]

I recently bought a two-band K1, s/n unknown. It puts out 6W on 40m, but
only one watt on 20m, measured with a WM-2 and a dummy load... and the
display on the rig. Internal ATU installed. 13+V supply.

What to check first? etc.
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[Mike Morrow-3]

> I recently bought a two-band K1, s/n unknown.
> It puts out 6W on 40m, but only one watt on 20m,
> measured with a WM-2...

The most likely problem is misalignment of band 2 of the KFL1-2.  Perform a realignment of the 20m portion per the K1 manual.

Don't waste too much time optimizing the settings of the KFL1-2 for maximum receiver sensitivity.  The same inductances must be adjusted for maximum transmitter power output, and those adjustments are far far more critical.

OR...for a direct simple shortcut, put the K1 on 20m in TUNE mode and peak L3, L4, L7, and L8 for maximum power output.

Mike / KK5F
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[Don Wilhelm]

Lloyd,

The first thing you should do is adjust the Pre-mixer and RF Bandpass
filters for the 20 meter band.  See the K1 manual for the adjustment
procedure.

If that does not bring the output up to at least 5 watts (when using a
13.8 volt or greater power source), then suspect the 22MHz crystal used
for the 20 meter mixer.

73,
Don W3FPR

On 9/9/2019 9:14 PM, LL wrote:

> I recently bought a two-band K1, s/n unknown. It puts out 6W on 40m, but
> only one watt on 20m, measured with a WM-2 and a dummy load... and the
> display on the rig. Internal ATU installed. 13+V supply.
>
> What to check first? etc.
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

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