[Elecraft] Re: K2/SSB Construction

W3FPR - Don Wilhelm w3fpr at earthlink.net
Tue Mar 1 08:12:06 EST 2005


Geoff and all,

The real problem is that the insulation on the wire can be scraped during
the process of winding RFC1 and 2 (not during the process of mounting them
between the smooth surface of the R-Pak and the crystal body) - so just
being careful and re-wind if the wire is scraped is the better answer IMHO.
A bit of Teflon tape just dangled between the crystal can and the choke may
provide that bit of 'slipperyness' needed to insert the choke, but I would
hesitate to rely on the thin Teflon tape for its insulation properties in
this application.

Reminds me of one of my favorite adages - 'If you don't do it right the
first time, you get to do it over and over again until you get it right'!
While that may be great fun for some activities, it gets old for most - so
the best answer is to do the best one can to get it right the first time.
With the K2, you are building a quality piece of gear - don't compromise it
by taking shortcuts.

Actually, I have not found any case where the space is too tight - but I may
be winding the toroids a bit more snug than some - I just smooth the wire
with my thumb on each turn and check to see if any turns have been crossed
over another.  Both things are important in winding a choke that fits
properly.

73,
Don W3FPR

> -----Original Message-----
>
> In my humble opinion you are 100% correct. RFC1 and 2 are a very tight fit
> when all other components are mounted properly. I believe that
> they used to
> be on the bottom of the PCB, but were moved to the top for very good
> reasons. I wonder whether some Plumbers' Teflon Tape (the thin
> white stuff)
> put around crystals X3 and X5 during installation would help
> prevent shorts
> between choke and crystal can.
>
> 73,
> Geoff    GM4ESD
>
> ----- Original Message -----
>
> >
> > >Any thoughts will be appreciated.  Thanks for the help.
> >
> > A while back, I reported this on the KSB2. Allthough some reactions
> > suggested I must have put in the resistor packs tilted, I'm certain they
> > are straight. Also, some other people reported the chokes *are* a tight
> > fight. Your mileage may very.
> >
> > ----begin old message---
> >
> > Maybe it's just me, but I found RFC1 and RFC2 on the KSB2 to be
> very tight
> > fits. They are both quite stuck between the crystal and resistor pack.
> That
> > would normally not be a problem, but allthough the manual says
> to 'try to
> > avoid scrapping the wire', one of my RFC's apparently did not
> come through
> > unscraped. After mounting and checking for continuity, I had the good
> sense
> > to check for a short to the crystal can and Bingo! Shorted!
> >
> > I might have made some more room, if the manual had warned that the
> crystal
> > and the resistor pack should have been soldered as far away
> from eachother
> > as possible. I'm not sure, as this is my first KSB2. I'd rather
> not start
> > messing with them now they are already in there.
> >
> > ----end old message---
> >
> > Good luck!
> >
> > Bart de PA3GYU
> >
>
>
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