What detector is best for Photo Radar?

[nvr2fast]

ANother forum member, Ali-Gator, took video of his tests against the multanova. They got uploaded here:

http://davidson.smugmug.com/gallery/374874/1

In these test results, out of the non-remote detectors Valentine gave the best warning against the Multanova. The Target966 Euro (remote mount) gave the best warning by far though, and this is supposably the european version of the BEL 975R.

After these tests, a lot of people were wondering about this, since the 975R didn't do wall in Roy's tests at all. Maybe the 966 and 975 have the same hardware, but different software?

I was corresponding with someone about this. Here's what he actually sent me:

Hello. I don't know if you remember but we were investigating why the BEL 975R with Ka narrow On outperforms the X50, RX65 ... (roughly 800 feet versus 250 feet detection range) against the Multanova 6F.

In fact it seems that it's only a software trick that make the BEL 975R better because if you set the Ka narrow option to OFF, the BEL 975R is crappy again (150 feet detection range).

Moreover a guy in the Czech Republic was able to flash the BEL 980 eprom and to add the Ka narrow option to it. Once the Ka Narrow mode was set to on, The BEL 980 rocks like the BEL 975R. Otherwise the BEL 980 was "crappy".
So it seems to have nothing to do with the detector hardware.
Perhaps since the Multanova 6F is low-powered (0,5 mW), standard detectors consider its signal as background noise while scanning the whole Ka band.

I'm not exactly sure if the narrow option he is referring to is BEL's "Accusweep" or not, it almost sounds like it though. If that is the case, then this could be turned on in the RX-65 too (USA/Intl)...

I would definitely like to hear from anyone who knows anything more about this though...

Jim

I have a Bel 990i, which has the most frequencies selectable. I can actually pinpoint a frequency to detect, such as 34.3. This is NOT accusweep, because accusweep auto-selects a bunch of frequencies and does not let you select it yourself.

The RX65 "USA" mode does NOT detect photoradar, because it is essentially accusweep and does not cover the photo radar frequencies (34.3 +/- .1). I know... i tried.

This is actually why i talked to you about the speed of POP at:
http://www.radardetector.net/viewtop...r=asc&start=15

because some people said that if you remove the other bands and have the detector concentrate/scan only on 1 band (eg. 34.3) then it would detect quicker, and i thought POP mode would be able to accomplish a similar thing by scanning the entire KA band quicker. But you said the detector scans the entire KA in 300ms anyway... which sort of conflicts with this (not trying to flame or anything, just trying to learn the secrets of the detectors here 8) ).

I wonder if there is a way to make the X50/RX65 scan 34.3Ghz more often, like with POP, or to make that frequency more "sensitive" so at the slightest faintest signal it warns immediately. I have NEVER seen any false alarm on 34.3Ghz... so any signal on or around that MUST be real.

Anyone have any ideas?

[brick]

ANother forum member, Ali-Gator, took video of his tests against the multanova. They got uploaded here:

http://davidson.smugmug.com/gallery/374874/1

In these test results, out of the non-remote detectors Valentine gave the best warning against the Multanova. The Target966 Euro (remote mount) gave the best warning by far though, and this is supposably the european version of the BEL 975R.

After these tests, a lot of people were wondering about this, since the 975R didn't do wall in Roy's tests at all. Maybe the 966 and 975 have the same hardware, but different software?

I was corresponding with someone about this. Here's what he actually sent me:

Hello. I don't know if you remember but we were investigating why the BEL 975R with Ka narrow On outperforms the X50, RX65 ... (roughly 800 feet versus 250 feet detection range) against the Multanova 6F.

In fact it seems that it's only a software trick that make the BEL 975R better because if you set the Ka narrow option to OFF, the BEL 975R is crappy again (150 feet detection range).

Moreover a guy in the Czech Republic was able to flash the BEL 980 eprom and to add the Ka narrow option to it. Once the Ka Narrow mode was set to on, The BEL 980 rocks like the BEL 975R. Otherwise the BEL 980 was "crappy".
So it seems to have nothing to do with the detector hardware.
Perhaps since the Multanova 6F is low-powered (0,5 mW), standard detectors consider its signal as background noise while scanning the whole Ka band.

I'm not exactly sure if the narrow option he is referring to is BEL's "Accusweep" or not, it almost sounds like it though. If that is the case, then this could be turned on in the RX-65 too (USA/Intl)...

I would definitely like to hear from anyone who knows anything more about this though...

Jim

I have a Bel 990i, which has the most frequencies selectable. I can actually pinpoint a frequency to detect, such as 34.3. This is NOT accusweep, because accusweep auto-selects a bunch of frequencies and does not let you select it yourself.

The RX65 "USA" mode does NOT detect photoradar, because it is essentially accusweep and does not cover the photo radar frequencies (34.3 +/- .1). I know... i tried.

This is actually why i talked to you about the speed of POP at:
http://www.radardetector.net/viewtop...r=asc&start=15

because some people said that if you remove the other bands and have the detector concentrate/scan only on 1 band (eg. 34.3) then it would detect quicker, and i thought POP mode would be able to accomplish a similar thing by scanning the entire KA band quicker. But you said the detector scans the entire KA in 300ms anyway... which sort of conflicts with this (not trying to flame or anything, just trying to learn the secrets of the detectors here 8) ).

I wonder if there is a way to make the X50/RX65 scan 34.3Ghz more often, like with POP, or to make that frequency more "sensitive" so at the slightest faintest signal it warns immediately. I have NEVER seen any false alarm on 34.3Ghz... so any signal on or around that MUST be real.

Anyone have any ideas?

Well, there's nothing that we could do ourselves but the manufacturers might be able to make it a "priority channel" like on some scanners. If you could skip back to it every so often in the sweep cycle you might be able to improve the chances of detecting very weak, quick signals. I think that the devil is really in the software, though. With photoradar the problem really isn't detecting the signal since it's always there. The problem is reducing the threshold at which the detector decides that it must be real. How low you can set it depends on how much background noise the manufacturer anticipates. That might make things very tough, considering that every electronic device inadvertently emits. Hence the problem with many POP detection schemes.

[nvr2fast]

Indeed, but as i mentioned, the background noise at 34.3 is virtually non-existant... it is a very "clear" channel with no interference.

But what you said is a good idea... to have the detectors be more sensitive and faster on the photo radar frequencies (i think there really is only 2 or 3 frequencies that have photo radar) which would give the detectors double or triple the sensitivity.

If indeed this is all done in software, and the hardware doesn't make a HUGE differnce (since ppl said the old 996 performs well against photo radar, which presumably has an older antenna design compared to the latest/greatest RX65/X50) then why hasn't this ALREADY been done?

[jimbonzzz]

Well, there's nothing that we could do ourselves but the manufacturers might be able to make it a "priority channel" like on some scanners. If you could skip back to it every so often in the sweep cycle you might be able to improve the chances of detecting very weak, quick signals. I think that the devil is really in the software, though. With photoradar the problem really isn't detecting the signal since it's always there. The problem is reducing the threshold at which the detector decides that it must be real. How low you can set it depends on how much background noise the manufacturer anticipates. That might make things very tough, considering that every electronic device inadvertently emits. Hence the problem with many POP detection schemes.

I think this is the most likely scenario here, and I don't think I could have said it better myself. I don't think it is necessarily a matter of not scanning the frequency often enough, it is more of a matter of lowering the threshold enough to pick out the weak signals.

Indeed, but as i mentioned, the background noise at 34.3 is virtually non-existant... it is a very "clear" channel with no interference.

There is definitely interference here, especially from other detectors. Many detectors (including some Escorts) sweep their first LO in the 11-12 GHz range, which produces harmonics at 34.3 GHz and adjacent frequencies: 11.433 * 3 = ~34.3 Ghz.
That's the biggest problem they've had with providing decent pop warning without falses, other detectors sweep their LOs and produce a very brief harmonic on the Bee III's freq of 33.8 Ghz, and this looks very much like POP. I would bet some mfrs raised their threshold here to prevent POP falses all the time....

The Valentine has an option to turn off the "False Alert Guard" on Ka... Someone should test that against photo radar...

Jim

[jimbonzzz]

Exactly. The Bel 915/975R and the Bel Target Europa/EVO 966R are superb at detecting Multanova photo radar. One more thing to add would be the positioning of the antenna. It has to be placed vertically. If you position if horizontally, the range reduces by over 30%. Something about the Multanova and Traffipax radars using vertical polarization, while radar detectors are using horizontal polarization. Maybe jimbonzzz would be better suited to answer this one.

I hadn't heard this before about photo radar, but I do know the concept to be true from ham radio. And I'm pretty sure the 30% figure is what I've always heard for regular radio too...

Jim

[2220]

Hello from Spain

Here the best radar detectors are the Bel 975R, 966R/660R and work much better than the X50, RX65, V1.

The RX75 works ok but are worse then the 975/966/660 units.

[compu44]

I really wonder how much of it is to do with the detector and how much is the mounting. I've noticed that the remote units tend to do better with photo radar than dash mount. Might this be because of the angle of the photo radar beam (down and across)?

I'd be interrested to see a test of the Whistler Pro remote against a photoradar.

[Flitsservice.nl]

I support the Bel 975. We have nothing but photoradar here in Holland. Bel 975 is the best we have over here, although there is a new player with the Stinger DSI that only works on K en Ka (34.6) band. (www.stinger.com)

[nvr2fast]

I support the Bel 975. We have nothing but photoradar here in Holland. Bel 975 is the best we have over here, although there is a new player with the Stinger DSI that only works on K en Ka (34.6) band. (www.stinger.com)

Mmm won't work against the Multanovas then at 34.3

[Crash]

I support the Bel 975. We have nothing but photoradar here in Holland. Bel 975 is the best we have over here, although there is a new player with the Stinger DSI that only works on K en Ka (34.6) band. (www.stinger.com)

Mmm won't work against the Multanovas then at 34.3

He meant 34.36 GHz, nothing to worry about.