[GreenKeys] RTTY in WW-II

[Larry Tighe]

Jim et.al.,

When I was a teen, I had a Model 15 and this big, black dual diversity unit 
with a door in the front.  Most of the tubes were metal...like the 6SK7, 
6SN7 variety.  I fed it from the IF of my NC-300 receiver.  This TTY unit 
took up about 12 inches of rack space and weighted in big time...a 2 man 
lift, if you will.

When you mentioned drift and the 850 cycle shift....were they using a BFO 
(audio) or IF feeds to these units?

lar
K2JIA
www.antiquetelephone.com


>
> The standard shift in those days was 850Hz.  This was used not because
> the signaling speed demanded it, but to accomodate the drifty transmitters
> and receivers of those days.  Even then there was some use of AFC in
> receivers to compensate for the drift and make it unnecessary to have
> an operator constantly retuning the receiver.