[Milsurplus] Some TBY history

[Hue Miller]

1. TRP of  CAY-43006,  10 Nov 1939,  28 - 65 Mcs., uses NT-51020 headphone assembly.

2. TBY of  CAY-43007  12 Jun 1940, frequency range changed to 28 - 80 Mcs., includes 
crystal calibrator,uses headphone assembly NT-51022

3. Westinghouse HR radio described in Electronics magazine, Dec. 1940. This is the 
28 - 65 Mcs. TRP for commercial market.

4. TBY-5 of  CFE-43007-A, same as  -43007 except circuit modified for better selectivity.

Sorry, no more detail. This is from Navy Catalog, Ships 900,109 - a few pages i have,
plus the Electronics magazine. This partial list also doesn't list the change to radium
painted controls from the twin pilot lamps.  -Hue Miller