[Milsurplus] TCS Low-Power Operation

[Hubert Miller]

Anyone know the "why" of TCS low-power operation?
I think this is only referred to on the transmitter schematic, where it, if i recall, shows screen resistors jumpered.
Why would they want to operate on the same B+ as the receiver?
My first thought was harbor use, but no other boat radios turned down their power for local use. You had 
everything going from 10 watts to 150 watts.
What say?
-Hue