[Milsurplus] FT-241 surplus LF crystals chan - freq list ?

[WA5CAB at cs.com]

>From examining two or three about 10 or 15 years ago, I concluded that the 
failure (or actually the failure to remain resonant at the original 
frequency because I found several that oscillated reliably in the range of about 3X 
the original frequency) was caused by a buildup of something green on both 
sides of the blank.  A magic potion that could dissolve the green without 
effecting the original constituents would be a possible solution.

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480

In a message dated 11/12/2017 20:27:37 PM Central Standard Time, 
Kargo_cult at msn.com writes: 
> I appreciate your effort, but...this chart is not useful, I think, 
> because the LF frequencies are rounded off the whole kHz.
> I am actually sort of rethinking the whole idea of picking out any 'good' 
> freqs anyway. Considering the half-life of the group
> at around 70 years, it seems to me the failures will proceed steadily. I 
> do not recall any of the early 'conversion' articles 
> mentioning the high failure rate, so it has a time factor. I certainly at 
> this time wouldn't attempt one of the conversion book
> lattice filters, even if I wanted to replicate the circuit; I'd worry too 
> much about one of the 4 to 6 crystals quitting on the job.
> I was kinda thinking of crystals around 455 or 465 (or is it 470 )? For 
> add-on single crystal filters, or replacement use for same,
> for receivers. But the high failure rate has me thinking now, maybe I 
> should just not bother with these.
> I read online some suggestion to refasten the wires plated to the quartz 
> with some kind of conductive glue, but no one had 
> apparently actually tried this. Dunno if I want to spend time on that 
> effort. Oh well...at one time, I thought these crystals were
> really a swell thing. 
> -H 
> 
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