[BC] Radar detector QRM

[Cowboy]

On Thursday 24 July 2014 07:57:45 pm Craig Bowman wrote:
> Do you mean Police radar or radar detectors?

> > I traced QRM  (natural interference) and QRN (man made interference) to police radar detectors.

 Detectors.

 Consumer radar detectors are nothing more than a GUNN diode mixer
 in the feed horn. As such, the "local oscillator" is *in* the feed horn.
 Can you say "transmitter" ?     I thought so.
 Like most heterodyne receivers, the LO signal is relatively strong.

 Worse, most of them have no discretion at all. They try and sweep
 below X to above Ka, so they are "transmitting" a sweep from
 about 7 GHz through 45 GHz or so, then a break ( more or less )
 up to the laser detector.

 This is also how and why police radar detector detectors can work.
 They are similar, so also dirty. Therefore some radar detectors have
 the ability to detect police radar detector detectors using the same
 principal, then temporarily disable their LO to temporarily
 stop transmitting.

 As far as I know, none of them meet spec for incidental radiators.

-- 
Cowboy