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

[Kenneth G. Gordon]

On 5 Nov 2014 at 0:49, Mike Everette via ARC5 wrote:

> With the FT-241, the leads from the holder pins are soldered or welded to
> electrodes attached to the quartz.

The electrodes are plated onto the quartz, which is usually circular, not 
rectangular like in FT-243s. If one attempted to etch those, the plating would 
come off and there would be no way that **I** know of to reattach the 
electrode to the quartz.

>  I've seen many of these wherein the welds
> (?) have broken.  No idea how to fix this.  Out of a box full of these
> crystals which were given to me maybe 30 years ago, about half of them are bad.

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.

> The FT-243s I have opened up have responded rather well to cleaning the brass
> plates (BE CAREFUL), and/or washing the quartz.  I've been able to repair
> several holders with brass plates broken away from the pins.  Not all,
> though.  

Yes. Some simply will no longer work no matter what we do to them.

Ken W7EKB