Tony and the group- Acid etching process was invented by Bliley
Electric- here in Erie, They had it down to timing of dipping the
quartz wafers in an acid bath. They knew exactly how much material
would be etched away, and as a result had crystals
of far greater acuracy and produced in record time and quantity.
During WWII, the Army paid Blileys a visit, and forced them to
reveal their secret process to the other manufacturers. Blileys never
got patent rights for their process. I contacted Charles Bliley on the
matter, he told me it didnot matter, as they got their share of
military contracts. Some other well known publication played up James
Knights Co. as the crystal gods- sorry
not so. Russ.
From: "Brian Carling" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: [AMRadio] Crystal Grinding
Date: Fri, 13 Dec 2002 14:30:09 -0500
On 12 Dec 2002 at 19:39, [EMAIL PROTECTED] wrote:
> Along the same lines, does anyone know about chemical etching of
> crystals to shift frequency? I expect it requires some nasty hazmat
> stuff to cut the quartz. I saw a reference in an old QST but didn't
> have the issue mentioned.
>
> -Tony, K1KP
I don't think chemical etching is recommended.
The commercial boys do it with first a grinder to shape the crystal "bar"
and then
a SAW, to get the slices made aproximately right.
Of course the wafers then are actually thicker than they will need to be in
the end.
The final step is to put them in a lapping machine which rubs them down to
the
required thickness, and up to the required frequency in a lubricative
cutting paste
slurry which combines lubricants, cutting compounds and a means to conduct
heat away into the lapping machine
from the crystals so that they don't break.
Of course radio amateurs have been known to use all kinds of unconventional
methods and perhaps that could include chemical etching....
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