[Milsurplus] RS-6 Set. Oddity

[David Stinson]

Tim, N6CC has a web page dedicated to the RS-6.

http://www.n6cc.com/the-rs-6-radio-set

Scroll down and you will see a schematic of 
the transmitter.  Odd-  Why is the "REC ANTENNA"
terminal connected to the keying buss via a .01 cap??

73 Dave AB5S