[Elecraft] Detecting the LO [was: plexiglass]

[Vic K2VCO]

Alexandra Carter wrote:

> I've heard that detecting the 455-kHz LO of a superhet 
> isn't all that hard, and that for instance in countries that require a 
> radio license, they use such techniques to check if people in their 
> houses have radios (or TVs) that they're not on record of having 
> licenses for! 

Here in Fresno, there's a billboard that detects the FM station to which 
car radios passing it are tuned, and summarizes the data for marketing 
purposes.

I always switch to AM when I see it.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco