I remember the article - I think it may have been reproduced in "SSB for the Radio Amateur" published by the ARRL in the 50's or 60's. Since I work with semiconductors, I tried moving a crystal up by etching in "BOE" (Buffered Oxide Etch) I had access to, several years ago. Ihe rate of frequency change was so slow I gave up on the project! A more aggressive (read more concentrated) solution would have been faster, but I ran out of time & patience to experiment. This method is NOT recommended - most of the solutions contain HF (hydrofluoric acid), very nasty stuff! (I'm also a chemist, BTW...)
73, -Larry/NE1S Brian Carling wrote: > > 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.... > > _______________________________________________ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio --------------------------------------------- Introducing NetZero Long Distance 1st month Free! Sign up today at: www.netzerolongdistance.com
