Hi,
I remember reading about the Brits searching for spies who were tuned to
certain frequencies that transmitted coded information to the agents who
might not have even had transmitters.
A quick clarification. The IF stage is 455kc and the LO is an HF oscillator
that is offset from the tuned frequency by 455kc so that the difference is
fed into the IF stage for amplification. (I decided to use Kc rather than
khz as wwii predates the change in terms lol). By searching for the actual
LO frequency - the Brits counterintellegence people could identify which
radios were listening to the enemy's coded messages and avoid wasting time
on those listening to Churchill's speeches.
best regards,
Charles
wb5izd
_______________________________________________
Elecraft mailing list
Post to:
[hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help:
http://mailman.qth.net/subscribers.htmElecraft web page:
http://www.elecraft.com
Locked
