[ARC5] Crystals in WWII

[D C _Mac_ Macdonald]

"HF" ?
 
* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* k2gkk at hotmail.com * 
* Oklahoma City, OK * 
* USAF & FAA (Ret.) * 
* * * * * * * * * * * 
 
 
 


 

> From: kgordon2006 at frontier.com
> To: dennis.monticelli at gmail.com; arc5 at mailman.qth.net
> Date: Fri, 15 Mar 2013 01:07:27 -0700
> Subject: Re: [ARC5] Crystals in WWII
> 
> On 15 Mar 2013 at 0:40, Dennis Monticelli wrote:
> 
> > I think the "dirt" problem had mostly to do with fine grit left over
> > from the grinding process and also quartz molecules left weakly
> > attached to the crystal.
> 
> Yes. Exactly.
> 
> > Neither would appear to the eye after a
> > routine wash.
> 
> I know that when grinding crystals to frequency by hand, a good method of 
> cleaning them is with a toothbrush and plenty of scrubbing. But, even doing 
> that will not get the crystals completely clean.
> 
> To REALLY get them clean requires etching with HF.
> 
> > The fix was discovered and implemented by Bliley. They
> > were doing an acid etch to take a ground blank a short distance to the
> > final freq. It turned out that the etch also did an outstanding job
> > of removing several atomic layers (where the surface damage was) and
> > leaving behind a clean nicely ordered crystal lattice.
> 
> Yup.
> 
> > There was
> > nothing left on the surface to redistribute after manufacture and use,
> > hence no "aging." Bliley didn't want to share the knowledge because
> > they wanted to retain an advantage in the market after the war. The
> > govt twisted their arm and the technique was shared, just as all the
> > previous crystal technology had been shared earlier in the war to
> > create the cottage industry.
> 
> Yes, but if the gummint hadn't twisted some arms then and there, many lives 
> would have been lost.
> 
> BTW, for those who are interested, a product named "Whink", available in 
> most supermarkets in the laundry supplies section contains a small amount 
> of HF.
> 
> It will etch crystals, although very slowly. It does an excellent job of cleaning 
> crystals after grinding them by hand.
> 
> Ken W7EKB