[ARC5] move an FT-243

[wb3fau55 at neo.rr.com]

anyone  ever hand grind a xtal up 115kc?  I actually moved up a 7185 xtal to
7290kc.  Most people  told me,   you cannot do it.  I used wet and dry sandpaper,
as for cleaning,  handsoap and water...Russ.
---- Dennis Monticelli <dennis.monticelli at gmail.com> wrote: 
> Hello Bruce,
> 
> It's great to meet someone that was right in the middle of that amazing
> effort to literally create a broad crystal manufacturing effort overnight.
> 
> Yes, the pressure on the blank, the exact placement of the pressure, the
> air gaps, etc all matter.  The small mass of the plated contacts on modern
> crystals are used to fine tune the frequency and these regions can display
> aging characteristics too.  The well-etched defect-free crystal mand-made
> quartz blank all by itself is extremely stable with time.  It only needs
> temp correction and/or temp stabilization.
> 
> Perhaps you could share more stories with us about those crystals in our
> past.
> 
> Dennis AE6C
> 
> On Fri, Mar 15, 2013 at 9:47 AM, Bruce Long <coolbrucelong at yahoo.com> wrote:
> 
> > Sorry Kennth for sending this email originally just to you instead of the
> > group   bruce
> >
> >
> >
> > with respect to HF  I discovered to my surprise some small bottle rust
> > removing potions available at the big orange box are actually dilute HF
> > solutions.  They work really well for me.
> >
> > I am also very happy to
> >  see this discussion of the important of WW2 quartz crystal technology-
> > having been previously employed at Piezo Crystal Company, McCoy
> > electronics and Bliely- the latter as a consultant.
> >
> > The huge
> > expansion of the quartz crystal industry in the USA was in my opinion a
> > very important aspect of the American war effort and is not widely
> > understood or recognized.  IIRC the war time expansion when from fewer
> > than 10 very small pre-war crystal companies that catered to the amateur
> >  and custom experimental market to well over 300 companies at the peak
> > manufacturing what was at the time an extremely high tech,
> >  precision product.
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