Why is 35.5 GHz so hard to detect?

[MEM-TEK]

Actually, Bel/Escort holds a patent for detecting radar signals buried in the electronic noise floor of the radar detector's detection circuitry. I think that it is this patented technology which comes into play when detecting radar over a hill.

[Freebird]

Actually, Bel/Escort holds a patent for detecting radar signals buried in the electronic noise floor of the radar detector's detection circuitry. I think that it is this patented technology which comes into play when detecting radar over a hill.

How does the differance in horn shape between manuf. effect performance if any? Is horn shape a compromise and is this why STI uses a second for x?

[Eloi]

''Actually, Bel/Escort holds a patent for detecting radar signals buried in the electronic noise floor of the radar detector's detection circuitry. I think that it is this patented technology which comes into play when detecting radar over a hill.''

Mem is bringing a good point there . Any detector can be
made ultra-super-sensitive , but what is the point if the
rd alerts constantly to true-falses .

Discrimination is the key point .I would do the comparison
with an excellent watch-dog : he won't bark at any sounds .
Perhaps we should train our rd ?[replacer_img]

We could take the problem in reverse : why did some
radar manufacturers choose the 35.5 ? They surely
had studied each actual rd to find their Achille's talon.

I discard the atmospheric absorbtion because it
works both side of the fence . The known atmospheric
absorbtion is for the +-22.5 gig for water molecule
(moisture)

[MEM-TEK]

How does the differance in horn shape between manuf. effect performance if any? Is horn shape a compromise and is this why STI uses a second for x?

The reason that the STi uses a separate horn for X is related to the stealth requirement of the design. If Bel's engineers could have figured out a way to keep the design stealth while using just one horn, then they would have used just one horn. They also have to keep X band detection because the X band horn also looks for primary LO signals from other radar detectors. If the STi couldn't detect these LO signals, then the STi would false to just about every radar detector it encounters on the road.

[MEM-TEK]

...We could take the problem in reverse : why did some
radar manufacturers choose the 35.5 ?...

Because 35.5 is the third harmonic of the local oscillators used in lots of radar detector models. And since Cobra can't infringe on other manufacturer's patents, this is why Cobras are horrible at detecting 35.5 which is the second most common Ka band radar gun frequency. This left Cobra with no choice except to use a notch filter around 35.5 so that they can detect 35.5 only moderately well, but won't get false alerts from other radar detectors until the other radar detectors get really close to a Cobra. At least this is what I have been able to figure out. I might be wrong and could really be pegging out my BS meter on this one.

[Freebird]

Thanks for the explaination MEM-TEK