K2: 12m alignment problem

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K2: 12m alignment problem

Mike Markowski
I was doing testing & alignment tonight with everything going perfectly
until 12m alignment, the very last band on the list.  All other bands
had no problems during alignment, but with power set at 2.0 W the power
output on 12m shows just 0.2 W.  Bumping the power setting up has no
effect on power output; still 0.2 W.

I'm going to start tracing it back to see what I can find.  But since
I'm just learning my way around the K2 I thought I'd mention it here in
case someone can point me to likely candidates faster.  Such torture to
run into a problem at the very last step of alignment!  (Well, it
happened on prealignment, too, but I was naively hoping alignment would
sort it all out.)

Thanks!
Mike  AB3AP
Avondale, PA
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RE: K2: 12m alignment problem

Don Wilhelm-3
Mike,

There is not much difference between the 10 meter and the 12 meter operation
of the K2.
Assuming that you are seeing a good peak on 10 meters, your problem is
likely connected with the bandpass filter. Check C45, the trimmers C44 and
C46, and the relay points of K6 carefully.  Other than those components,
there is no difference between 10 meters and 12 meters.

Check your soldering carefully, then check it again, and if all else fails,
check the soldering - that is the most common cause of failure in the K2
kit.

If all else fails, you may want to check the VCO frequency for 12 meters -
with the dial indication at the low end of the 12 meter band, the VCO should
be producing a signal at 19975 kHz (read the frequency in CAL FCTR mode with
the counter probe in TP1).  If the frequency is incorrect, the problem will
be found in the VCO area and not the BPF.

73,
Don W3FPR


> -----Original Message-----
>
> I was doing testing & alignment tonight with everything going perfectly
> until 12m alignment, the very last band on the list.  All other bands
> had no problems during alignment, but with power set at 2.0 W the power
> output on 12m shows just 0.2 W.  Bumping the power setting up has no
> effect on power output; still 0.2 W.
>
> I'm going to start tracing it back to see what I can find.  But since
> I'm just learning my way around the K2 I thought I'd mention it here in
> case someone can point me to likely candidates faster.  Such torture to
> run into a problem at the very last step of alignment!  (Well, it
> happened on prealignment, too, but I was naively hoping alignment would
> sort it all out.)
>
> Thanks!
> Mike  AB3AP
> Avondale, PA
>


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Re: K2: 12m alignment problem - FIXED!

Mike Markowski
In reply to this post by Mike Markowski
Hey all,

My 12m alignment problem is fixed - yay!  I had a bad 1 pF (C45)
capacitor, which I swapped out just minutes ago & 12m tx output
immediately matched the power setting at last.  So K2 #4834 is up and
fully functional and has even had its first QSO.  It now awaits the
addition of some of the optional boards...

My thanks to Don, Walt, and Gary for their help in speeding me along to
track down the one naughty component.  What a great way to end the work day!

73,
Mike  AB3AP
Avondale, PA

Mike Markowski wrote:
> I was doing testing & alignment tonight with everything going perfectly
> until 12m alignment, the very last band on the list.  All other bands
> had no problems during alignment, but with power set at 2.0 W the power
> output on 12m shows just 0.2 W.  Bumping the power setting up has no
> effect on power output; still 0.2 W.
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