My Whistler XTR-330 detects other RD !?!?

[Vandko]

Hello, i noticed that my Whistwer XTR-330 (on Highway Mode) detects others radar detectors on K-Band, especially Cobra's.
Any one have an idea how to change this?

Sorry if this question i repeated, but i did not find anything in the search.

[xxpor]

cobras are known to leak a significant amount, though usually on Ka band. As for what you can do about it, not much.

[Vandko]

This is very strange
Are Radar Detectors receivers not transmitter?

[Michael B]

Radar Detectors are active devices and as such require a Local Oscillator.

This local oscillator beats agains a mixer diode to convert the oncoming frequency into a lower frequency.

This local oscillator frequency is also available to be detected outside the radar detector for al units with the exception of the Redline, Sti, Sti-R, and 9500ci.

The local oscillator not only creates issues at the fundamental frewuency but it also creats issues with multiples of that frequency.

For instance a certain brand ofdetector offering 9 band may have an LO operating from 10.8Ghz to 12.2Ghz

the 2nd harmonic of that is 21.6Ghz to 24.4Ghz.

Police K band is 24.050 to 24.250Ghz.

You can see where the certain brand of detector can create an issue at K band

the 10 band model I think operated at 10.95Ghz to 11.35Ghz and as such can create an issue at Ka band as the 33rd harmonic of the local oscillator is 32.85Ghz to 34.0Ghz and police Ka band is 33.4Ghz to 36.0Ghz.

The lower window of the Ka band could see the 10 band detector and alert.

[Whistler1]

I recently had a car pass in the opposite direction while running the Pro78SE. I got a brief KA alert at 34.3 GHZ, not other cars were in the area. The only conclusion I can come to was a leaky Cobra detector.



Whistler1

[Gokhos]

Radar Detectors are active devices and as such require a Local Oscillator.

This local oscillator beats agains a mixer diode to convert the oncoming frequency into a lower frequency.

This local oscillator frequency is also available to be detected outside the radar detector for al units with the exception of the Redline, Sti, Sti-R, and 9500ci.

The local oscillator not only creates issues at the fundamental frewuency but it also creats issues with multiples of that frequency.

For instance a certain brand ofdetector offering 9 band may have an LO operating from 10.8Ghz to 12.2Ghz

the 2nd harmonic of that is 21.6Ghz to 24.4Ghz.

Police K band is 24.050 to 24.250Ghz.

You can see where the certain brand of detector can create an issue at K band

the 10 band model I think operated at 10.95Ghz to 11.35Ghz and as such can create an issue at Ka band as the 33rd harmonic of the local oscillator is 32.85Ghz to 34.0Ghz and police Ka band is 33.4Ghz to 36.0Ghz.

The lower window of the Ka band could see the 10 band detector and alert.

Good explanation. Thanks. I recently was getting a strong countinuous K detect in town. I know that one of the local jurisdictions recently installed K band radar inside both front and rear so at first I thought it was an unmarked vehicle. But then the vehicle direction behind me pulled out and passed me on the left and then I saw the other brand of RD mounted on his windshield (it was even mounted straight and level!) and after that vehicle made a left turn, the detect went away. I have also seen this on the interstate where I was getting blips of K when I noticed a pickup bobbing in and out of traffic to the rear. Everytime he would pull into the left lane I would get a K detect. When he finally passed me on the left, I saw the RD.


Thanks.