[Elecraft] Watery,scratchy,chirpy sound

[dk4lx]

Hi everybody,

I've been a happy user of K2 #2626 for a week now. One thing I'd like
to alert you to is the sound of the rig which may sometimes be a
little watery, even scratchy or worse. Initially I got very nice
feedback on the quality of my sigs. But when I met this brutally
honest German radio pal of mine (thanks again guy), I knew I had a
problem. Especially since another om immediately recognized me by my
CW note before I had even menttioned my call. Apparently my sigs were
slightly scatchy and watery, not much of a problem, but, yes,
noticeable and irksome - at least to me, hi.  So something had to be
wrong. Thank God I had been diligently reading this reflector and
remembered Steve's (G3VMW) mail addressing what seemed to me a
similar problem. Apparently, it is critical to ensure your VCO
voltage readings are within the limits specified on page 58 of the
manual! 40m is especially susceptible to develop a problem, if the
voltage on 7.300 Mhz is >7.5 volts. Mine was at 8.21 volts, which
initially didn't set me worrying because, living in the old world, I
was only concerned about the 7.1 Mhz value, which was o.k. Even
before buying the K2, I had noticed quite a few K2s to have this
peculiar watery sound. What helped in my case was the mod suggested
by G3VMW per reflector mail of 2 Jul 02:  
a) remove CAP C70 (4.7pF)       
b) pad CAP C72 with a 10pF cap in parallel soldered on the bottom of
the PCB.

Another thing: to all those who currently building their K2s I would
strongly recommend the mod concerning the grounding of the xtal
filters 7-11 which is also available as .pdf file on the Elecraft
website. Ground each crystal from both (small) sides with short
ground leads. Solder them in the lower half of the small side area
and not on top of the cans. This seems to improve filter rejection
considerably - and audibly.

73, Holger, DK4LX
K2 #2626  


___________________________
Holger Matthiessen
Hosenfeld/nr Frankfurt
LOC: JO40RM
email: dk4lx@darc.de
PostMe 3.02