The AM Forum

From the NSA web site:

“On August 4, 1945, Soviet school children gave a carving of the Great Seal of the United States to U.S. Ambassador Averell Harriman. It hung in the ambassador's Moscow residential office until 1952 when the State Department discovered that it was 'bugged.' "

http://www.audiodesignline.com/howto/173602214

 ;D

                 _-_-bear

I'm sure the battery was long dead powering tubes.

It didn't use a battery.  It was completely passive.

No wonder they're in trouble...Look who they listened to.... ;D

What was the range to a RX.

FYI

http://www.spybusters.com/Great_Seal_Bug.html

If ya get the chance, the following is a good book and has some info on the 'Great Seal'

Spycatcher: The Candid Autobiography of a Senior Intelligence Officer (also Spycatcher), is a book written by Peter Wright, former MI5 secret service officer and Assistant Director, and co-author Paul Greengrass.


klc

It was a radar system. The greater the TX power, the greater the range.

So did the bug place modulation on the reflected signal?

Yes. Cavity resonator.

Yup, I read the article. A lot easier today with newer toys.

Yes. Kind of like the passive tag readers.  The microphone modulated the amplitude of the reflected signal. They were beaming a narrow microwave beam into the room from a van parked nearby. I'd imagine it had to be almost LOS to avoid losses and to receive the weak signal.

Good Science why would you want it active continuously..

On Demand Spying...pretty sneaky these agencies...