[ARC5] WHINK and crystals.

[D. Platt]

Gents,

This process, in fact the whole gamut of the crystal industry at the 
time of WWII is written up in the book "Crystal Clear" (Richard J. 
Thompson, Jr. IEEE Press.)  Its av ery good book on the subject and not 
at all hard to read.  It does go into the minutia as has been discussed 
here but also delves into many other interesting aspects of the 
subject.  There's a huge list of all the manufacturers in the back that 
will bring tears and/or memories to many.  All those companies gone bust 
over the years.

Jeep  K3HVG


On 6/27/2013 2:00 AM, Dennis Monticelli wrote:
> Ken,
>
> The etch rate is faster at first and then reduces.  Crystals of pre-1944
> and partially of 1944 manufacture were simply washed after lapping.   This
> left many loose particles still weakly attached to the surface as well as a
> rough crystal surface in which the crystal bonds were partially broken.
>   The HF attacks this mass of quartz first and after it has been removed
> must then etch away at a more resistant well-ordered crystal surface.
>   These WW2 crystals drifted upward soon after being placed in service (the
> mass of loose particles redistributed) and that was a problem.  Bliley then
> developed the HF dip process whereupon a crystal was ground to slightly
> below its target freq and then given a short dip in HF to bring it the
> final distance.  In the meantime the HF did a great job of "cleaning" the
> blank.  Drift problem solved.  The government forced Bliley to disclose
> their technique to all other US crystal makers.
>
> Dennis AE6C
>
>
> On Wed, Jun 26, 2013 at 10:27 PM, Kenneth G. Gordon <
> kgordon2006 at frontier.com> wrote:
>
>