[JMS] How does one "grind a crystal" to change its frequency ?

[john]

Ah, so do I understand correctly that you sandwich the crystal blank 
between two pieces of glass , holding the small top one, with the slurry 
and the crystal blank in between?

John


At 08:09 PM 5/31/2007, you wrote:
>What you need is a small (1" x 1" piece of 1/4" or 3/16" PLATE glass. You 
>can get a piece from your local glass shop for nothing... I was lucky, my 
>father was in the glass business,  HI. With this thickness glass, you have 
>some thing "to hold on to"... (the edges). Plate glass is used for it's 
>inability to "bend". The idea is to 'try; to get an 'even' grind. If you 
>use just your finger, you will put more pressure on the center than the 
>edges and ruin the parallelism. Yes, you can ruin one easily without even 
>trying hard... We used to wash the blanks, holding them by the edges... 
>and rubber gloves are a good idea. The surface tension be=tween the small 
>piece of glass and the blank is 'supposed' to hold it... Never had any 
>luck changing them more than a few kilocycles, OOPS I mean a few 
>kiloHertz. You can rinse then off in tap water and then clean them with 
>isopropyl alcohol.
>Tap water in some areas contain impurities and the slightest bit will keep 
>the thing from oscillating...that is why distilled water is recommended. 
>More info???   73  Joe W4CBJ/WX4TRA.(Ancient One).
>
>
>>From: john <johnmb at nc.rr.com>
>>Reply-To: The James Millen Society Members Email Reflector 
>><james_millen_society at mailman.qth.net>
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