[ARC5] WHINK and crystals.

[Dennis Monticelli]

Jeep,

I have read it, Jeep.  Thanks for informing the group.

Dennis AE6C


On Thu, Jun 27, 2013 at 6:52 AM, D. Platt <jeepp at comcast.net> wrote:

> 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:
>>
>>
>>
> ______________________________**______________________________**__
> ARC5 mailing list
> Home: http://mailman.qth.net/**mailman/listinfo/arc5<http://mailman.qth.net/mailman/listinfo/arc5>
> Help: http://mailman.qth.net/mmfaq.**htm<http://mailman.qth.net/mmfaq.htm>
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>