for some reason my bel v985 if in the same car as my v1, will constantly go off on ka band from the v1. does that mean my v1 is leaking?
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for some reason my bel v985 if in the same car as my v1, will constantly go off on ka band from the v1. does that mean my v1 is leaking?
Yes. All RDs leak emissions from their local oscillators. Your V985 also leaks, but your V1 is ignoring it even though this could seriously hamper the V1's detection range.Quote:
Originally Posted by 06blackgto
Yeah in my experience, the V1 is one of the most resistant detectors to Ka leakage. It's pretty clear Valentine put some extra effort into addressing the issue of Ka falsing from other oscillators in the vincinity, but indeed this almost certainly means the V1 is ignoring a certain spectrum of Ka band to filter out that detector. The million dollar question is, if a police radar gun is sitting in this frequency, would the V1 turn a blind eye? :)
Quote:
Originally Posted by jdong
No it would not. It's years of using the same design detector which has a detector that's almost Ka false fear.
Jimbonzzz could explain this better, but basically a RD looks for the primary LO frequency and/or the first harmonic whenever it detects Ka band radar. If the RD sees the LO or harmonic then it assumes that the Ka signal is a false higher harmonic. This is a simplistic way of describing what occurs during signal processing, but it should give you the basic idea. So, as long as there is no other radar detector around, then the RD will alert to the radar gun, assuming that the RD is a Belscort, Whistler or Valentine. This might not be true for cheap import models which may employ strong notch filters in order to ignore specific Ka frequencies. Belscort, Whistler and Valentine own all of the patents for false signal rejection. This doesn't leave any alternatives for the cheap import RD manufacturers.Quote:
Originally Posted by jdong
The others must be horrible then, because on my trip to Floridia and back, I encountered at least six Ka false alerts that were attributed to nearby RDs. I'm not good enough at visual RD identification to confirm that they were Cobras, so I'm not sure what they were. Are there other RDs besides Cobra that cause false Ka alerts?Quote:
Originally Posted by jdong
What revision V1 do you have? I've seen videos of the 3.813/3.826 falsing to Ka on Cobras, but I have not been able to get any Cobras to set off my 3.863, even with POP enabled.
Not sure. Bought it new from VR in July. I'd have to find the box to find out, I guess. It's in default settings, A mode.Quote:
Originally Posted by jdong
Pretty much... except that the "first harmonic" is the same as the fundamental LO freq. Two times the fundamental is the "2nd harmonic".... but I've made this same mistake on occasion in the past, so it's all good ;) If someone wants a real explanation they can go here: Radar Detector Filtering - Guys of LIDARQuote:
Originally Posted by MEM-TEK
Of course, for best results a modern detector would have different algorithms and schemes to deal with different "platforms" of leaky detector models.
I once heard a story about a certain detector engineer at who (of course) drove with his detector in his vehicle for testing purposes. Out on the road, when he encountered a new false alert from a leaky detector, he would try to identify the vehicle and either follow them to their destination or try and flag them down, and then offer them $$$ for their detector. Then, he could take it back and analyze it in the lab to develop the best scheme to prevent the false alerts caused by that particular unit. :D
Could it be Mike B. and how FILTER,FILTER 1,FILTER 2 started. I use Filter 2 95% of the time and its super quiet on the interstates. I have seen as many as 2 Cobras in the same car side by side :mad: