> SOME of the newest radar detectors do not emit the signal the trouper can
> >detect
The reason many radar detectors can be detected by a properly equipped police unit
is that the detector uses a superhetrodyne receiver like your car stereo, your CB,
or most any radio set of any kind. This circuit emits a low level signal than can
be received by a receiver tuned to the band it is on. The police receivers are
looking only for signals in the microwave band so they don't respond to your
stereo or your CB. The signal is often strong enough to be heard from as far as
300 yards. The cure used in some of the new "undetectable" models is to shield
the internal receiver so that its signal can be heard only a few feet.( usually 3
to 5 feet). The police receiver is not sensitive enough to pick up these weak
signals. This stealth technology is not new and was developed during WW2 to
prevent the German subs from locating our ships by listening for their radio
sets. These older shortwave receivers would emit a signal detectable for miles so
shielded models were developed to prevent this. It was not necessary to shield
radar detectors until some smarty developed the receivers for the cops. As you
might imagine if somebody can invent a new trap device, somebody can find a way to
defeat it. The new shielded detectors are as cheap as the older ones too. BTW I
have had a grill mounted detector for several years and it will pick up rear radar
from at least 1/4 mile.
Jim in Waco.
Ham call WB5OXQ for 25 years
Radio station engineer for 30 years
Waiting on 99 R/T (probably this coming week)
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