[Milsurplus] Liquid solder and xtals

[CL in NC]

I remember trying that as a kid on something, it is not solder or metal impregnated glue, it is just silver colored glue, at least that is how it was around 1963.  Seem to remember the tube labeling had some twisted wires shown in a picture, and a stream of it leaving the tube and covering the connection.   Mechanical twisting was the key there, and the liquid solder a free form wire nut.  Also, JB Weld contains aluminum, but it is not conductive either, know this from Hi-pot testing it and the manufacturer said so too.

The FT243's had the two metal plates with the raised corners that suspended the crystal between the plates allowing it to vibrate, but the metal on quartz with the wire going from that metal to the crystal pins, you would think the metal on both sides would quench the vibrations, but maybe the whole sandwich is vibrating suspended from the wire attached to it, acting like springs.  Info gleaned from links said crystal companies prior to WW II were what were classified as mom and pop operations with none of them having more than 20 folks working.  Interesting to note that RCA figured out how to do crystals right in the early 30's, and the FT241 failure investigations re-discovered everything RCA figured out on how to make a long lived and freq. stable crystals, but nobody asked them and they didn't tell anybody since they were not making crystals during the war.


Charlie, W4MEC in NC