Joe McElvenney wrote:
Hi,

Yesterday I bought a 'BOX BX-49-A' (coil/crystal set for the
BC-611 walkie-talkie) with a view to starting a crystal
collection. It contained 24 FT243 rocks from eight different WWII
manufacturers. Just to get an idea of the task ahead, has anyone
compiled a list of these manufacturers from that period?

The few I have so far are marked -

Univ K.C. Telev M.O.
Valpey Crystal
Turner Company, Cedar Rapids
Scientific Radio Prod.
RS MC
Camb Thermionic, Camb Mass
Gentleman Products, Omaha
H.I. Inc
Stand. Piezo
M.P. CO.

Joe, you may add Tedford Crystals (later R/T Labs), Cincinnati, Ohio.

Dave Heil K8MN