[ARC5] Etching Crystals and WHINK Revisited - contact resistance.

[Dennis DuVall]

The frequency can be changed a small amount by grinding adjacent edges of the crystal element.  To do this the crystal must be carefully unsoldered from the two semi-circular support wires and then soldered back in place again after grinding.  Guys did this back in the early days of SSB to make up sideband filters with these crystals.  If the small wire coming off the plated surface of the crystal breaks off in the process that’s the end of that unit.

Dennis D.  W7QHO
Glendale, CA

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> On Nov 5, 2014, at 7:41 AM, Kenneth G. Gordon <kgordon2006 at frontier.com> wrote:
> 
> I have quite a number of those LF FT-241s which were used in the SCR-608. 
> There is no way that I know of to change their frequency.