Do radar guns "Leak" energy?

First I would like to thank all those that provide the great info that allows for an informed buy. I also say thanks for turning me into a junky before buying my new Bel 895. It seems to work very well and the tests I have read show that it is a top performer in picking up k and ka. It saved my bacon twice on only my third outing. Ka both times but I wasn't gunned myself. This leads me to a question I havn't been able to search out. Do radar guns leak energy that the detector picks up? My Bel hasn't pegged out when I have been near a police radar but it does show two to three bars on the scale Ka. My understanding was that the detector won't pick up anything unless the gun is actually on. Am I picking up a standby mode or something? I became really curious when I was pumping gas and a sheriff was parked in front of me facing away towards the front of the store. I was getting a low Ka alert. Thanks again and keep up the great work!

No, police radar units do not leak any radar when in standby mode.

There might have been one exception: I seem to remember tales of an old Kustom unit (KR-11?) that DID emit low power radar when in standby mode to keep the patrol car speed. But that was either X or K band, and there's probably VERY few of these units left on the road today (if any). To my knowledge, no other radar units ever used such a technique.

The low Ka alerts you've experienced could happen if the radar is pointing away from you, and there isn't a lot around to reflect the radar back.

Jim

I figured that might be the case. The one thing that still makes me curious is that the officer's car was parked right in front of the station and i was probably two car lengths of my focus ZTS behind him, I figured I would of had a higher reading on the detector.

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Originally Posted by jimbonzzz

The low Ka alerts you've experienced could happen if the radar is pointing away from you, and there isn't a lot around to reflect the radar back.

Jim

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Another possible suggestion of the low Ka alerts that are being recieved is maybe the unit(s) (if it is a handheld unit) may be sitting (turned on)on the seat which often times allows the ability for the RD to pick up the signal, but (sometimes) at a (greatly) reduced signal strength.

MAN WON THING I FOGOT TO SAY ABOUT THE BEL V895 IT NEVER GOES TO FULL STRENTH ON THE BARS NEVER ATLEAST NOT ON MY 895 I THINK ITS INSTANT-ON HITS WHEN ONLY MY SIGNAL STRENTH BARS WOULD ALL LIGHT UP I THINK ONLY 5 BARS THO BUT OTHER TIMES I WOULD BE COMEING UP ON A COP HEADING MY WAY CONSTANT-*ON KA AND ONLY 3 BARS WILL LIGHT UP AT THE MOST MAYBE 4 BUT RARE THIS IS ONE THIS HAPPENS TO MANY TIMES SO I SOLD IT.

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Originally Posted by jimbonzzz

No, police radar units do not leak any radar when in standby mode.

There might have been one exception: I seem to remember tales of an old Kustom unit (KR-11?) that DID emit low power radar when in standby mode to keep the patrol car speed. But that was either X or K band, and there's probably VERY few of these units left on the road today (if any). To my knowledge, no other radar units ever used such a technique.

The low Ka alerts you've experienced could happen if the radar is pointing away from you, and there isn't a lot around to reflect the radar back.

Jim

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sorry JIM i know you are the pro but i actually think some radar guns do leak a little RF power when on hold i seen this happen a few times with a stalker dual radar unit.not once but a few times
but they NEVER SHOULD LEAK ANYTHING AT ALL.

There's no point in worrying about how many LEDs light up so long as the first one comes on in time for you to do something about it.

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Originally Posted by brick

There's no point in worrying about how many LEDs light up so long as the first one comes on in time for you to do something about it.

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for me its a big deal tho :wink:

I hate to step on toes here, but I have had that happen also. I belive they do leak once in a while. On more then one occasion I have been parked or stopped next to a cop and gotten a brief brap of K or Ka. And I am 100% sure he didn't pull the trigger, there was no other car in the area to give a false etc. This has happened several times, and I didn't ever post it because I know what would be said, as it was a radar in the area, or he clocked someone etc. But I know for fact that wasn't the case.

Technically, it is impossible for a radar unit to "leak" low power radar energy when in standby. The gunn diode in the radar guns is basically fixed output power, and it is either ON or OFF.

What you guys are experiencing, I don't know. Maybe it is what Airmoore said, they have a handheld unit powered up layin on the seat. Or, maybe someone was nearby with a leaky radar detector, and there just happened to be a cop there too. Or maybe the cops have some other piece of hardware in the vehicle (GPS, satellite tracking system etc) that leaks harmonics on the police radar bands. Some radar units will emit a brief radar signal when the cop flips it on, even if they have it on hold, this might also produce a weak alert on the detector.

Jim

As I said, I know you know 1000 times more about this stuff than I do professor, I just thought it was the radar gun and wondered the same thing. :)

I passed the same sheriff today going the opposite direction. I got the Ka about half mile away over two short but steep hills. The strange thing is that during the alert I got a POP warning then it went back to a Ka alert. The alert was strong as I got close and pegged out just after I passed him. It was a busy road and he had traffic in front and behind him. This is the forth time I have been near this car with this being the strongest warning. I think I am just going to ask him what he has when I see him at the station next time. I'm very curious. I do know that the bel works though. Coming home from St. Louis I got a brief Ka (two then three bars) and slowed from about 83 to 70. Almost two miles and two sloping hills later there he was. MO highway patrol instant on! The Bel went full tilt for about 2 to 3 seconds then went quite. Got to love the range :D

Let us know what he says, I know the 2 departments that I have had it with dont' have GPS, or things like that.

There's been times I've picked up NYS Troopers when there were no other cars out there. It would be a weak signal that would get up higher (to maybe half strength), and then I would get hit with instant on (full alert) and it would go back down to about half.

How can one say it's impossible?

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Originally Posted by davekr

How can one say it's impossible?

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Re your signature, if you lost your pup recently, my sympathies.

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Originally Posted by hoosier

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Originally Posted by davekr

How can one say it's impossible?

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Re your signature, if you lost your pup recently, my sympathies.

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Thank you, people like you have helped me cope so much better... :)