[Milsurplus] FT-241 LF Crystals as a Long - Term Investment Instrument

[Kenneth G. Gordon]

On 6 Nov 2019 at 11:42, Jack Antonio wrote:

> I was gathering up some of the FT-241s for a project, both
> the ones around 300 to 500kc used in BC-683 family of transmitters,
> and some around 900kc used in AN/TRC-1. And the ones I found were also
> generally bad. Would not oscillate, or pass RF from a signal generator.
> Didn't keep exact notes, but more than half were bad.

That pretty much agrees with my own experience with those. I have a very large box full of 
them at the moment. I'm not sure what I will do with them though.
 
> I opened a few up, and was surprised at how small the crystals are,
> quite thin, and maybe a 1/4" square, I was expecting a fairly
> substantial chunk of quartz in there. Did not see any mechanical
> or obvious defects.

The few I've opened here are a small blank with a plated "spot" or larger on each side with a 
very small wire welded to the plated area. Those I found bad here showed the small wire 
corroded off or open.

> The project was (and still is) to get a VRC-2 on 10 meters.
> (918.75 kc is the target crystal frequency for 29.4)
> When I find the time, I'm looking at using some of the
> QRP Labs Prog rocks as crystal substitutes.

I can look through my pile of them. If I have any good ones in that frequency, I'll send them 
to you.

Ken W7EKB