[Elecraft] Re: K1 Problem

[Morrow, Michael A.]

Hi Phil,

Phil wrote:

> ... it appears that both 30 and 40 have low output.  Looks like I
> need to pull off the KAT1 and re-align the rig.  Odd thing is that
> I use it maybe twice a year for camping and have to re-do it before
> each trip.
>
> I thought replacing the trimmers was the fix for this problem,
> but apparently not.

I also hoped that periodic re-alignments would become unnecessary
after I replaced all the old white trimmer caps on my KFL1-4.  I
find that I still have to "refresh" the alignment about every six
months or so.  Now, I'd never lose all power output, but I would
find that maybe only 2 to 3 watts could be obtained where at one
time a full 7 watts could be had.  Still, this is a *great*
improvement over what was required when the old caps were still
in place.  The cap replacement made such an improvement that the mod
should be considered mandatory, not optional.  I always take
a moment to check the power output into a dummy load on each band
before taking the K1 out.  The re-alignment simply consists of
peaking the trimmers for max power output, so it doesn't take long.
The main aggravation comes from having to remove the KAT1 and
having to tack solder R36 back.  Overall, I'm still very happy with
the K1, and hardly ever go on a trip without it. =20

> Is there any mod which will fix this periodic re-alignment need
> problem?

I did one other mod to my KFL1-4 that would help you some.  I
doubled the size of KFL1-4 40m/30m interstage coupling caps C10 and
CK, to 4.7 pF.  I did this in order to get full power output across
the 170 kHz tuning range of my K1 on 40m.  This was recommended in
an Elecraft bulletin to compensate for the detuning effects of the
old white caps, but it did wonders in slightly broadening the
bandpass to allow full power output across the entire 40m CW band.
Without it, I could get 7 watts at one end, but less than 2 at the
other.

Regardless, I can't think of a better multi-band backpack rig than
the K1.  I simply love mine.

73,
Mike / KK5F
K1 No. 175