[ARC5] ARC-5 Crystal Question

[Michael]

Sorry about the delay here; I'm trying to catch up with reality and it is
being terribly elusive.

-----Original Message-----
From: arc5-bounces at mailman.qth.net [mailto:arc5-bounces at mailman.qth.net] On
Behalf Of Dennis Monticelli
> I have experimented with many WWII surplus rocks and can attest to this
> effect.  If you take an old FT-243 and first measure its freq, then open
it
> up and do a brief 1 min dip in a weak buffered HF solution (be careful
with
> this stuff!!) you will find upon scrupulous washing and subsequent
> reassembly that the freq has jumped up a Kc or more and that the activity
> has improved.

When I was still making crystals back in the 60s, I used a rather violent
bath (which sometimes fractured a blank or two ... oh, well) followed by
running in an oscillator that had a fairly high crystal current for around a
month after which they were decently stable with only a little creepage.
(There was a bath and a couple other steps in there but that's the thumbnail
version.)  Since Hydrofluoric acid is all but impossible to get by us
citizens of the Peace and Freedom Loving People's Democratic Republic - er,
State of Hawaii due to restrictions set by the capitalistic yellow dog
imperialists on the mainland*, alternative means that don't take quite that
long are very desirable.  One thing I want to try is an ultrasonic cleaner
which I think should work at least to some degree.  I already have one that
I use for cleaning watch movements although possibly a different cleaning
agent may be needed.

* Okay, so it's postal regulations and is one of the downsides of living
here in the middle of the ocean.  The problem still exists.  ORM-D is bad
enough; HazMat is neigh unto impossible.

A fairly recent acquisition brought me over 100 FT-243 and similar blanks
(and I'm always interested in more, of course, especially larger ones like
for FT-171 and other large holders) so I'll be back making custom crystals
for my projects again.  Some of the large blanks will go into open holders a
la the 20s & some 30s rigs others will join the smaller FT-243 et al blanks
in more conventional holders including some homemade ones.  As a result,
I'll be doing a bit of "adjusting" and would really rather not have to do
the aging thing I did before.

Best regards,
 
Michael, WH7HG BL01xh
http://www.nationalmssociety.org/chapters/NTH/index.aspx 
http://wh7hg.blogspot.com/ 
http://kludges-other-blog.blogspot.com 
Hiki Nô!