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  1. #1
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    Default This question goes out to the technical guys here

    Ok...

    I have read on the forum here under different post/threads where some are dissappointed with the lack of sensitivity that their radar detector gave them when coming across a LEO. I have also read where some say their radar detector is good for pickup at 2miles or greater.

    I am familiar with how "two way radio" works meaning you can have 2 radios/transcievers that are from the same factory/batch/production line and usually 1 will have more output power. At the same time the reciever sensitivity is better/hotter than the 1 next to it. In other words each radio is unique.

    If this is true, is it safe to say that some leo's radarguns are transmitting at different tx power levels and this would explain the "deafness" of some peoples detectors, not to mention if detector has a "hot " reciever?

    Thanks
    Jim

  2. #2
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    Default

    Well there is more to consider then what you had posted.

    Police radar guns are directional. So the officer has his gun pointed out his rear window and you approach from the front, you're not going to detect that the officer is there until you're almost ontop of him.

    When I used radar I didn't bother with the instant on feature. I used a hand held and it was on the trasmission hump facing downwards until I picked it up to point it at a car.

    Again, if it was pointed this way, you wouldn't receive the signal until you were very close to the officers car.
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  3. #3
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    What Roy posted is by far the most common thing we get on here. People have a couple of encounters like that and start to question their detector. Every encounter is different, and this is what most people are seeing when they think they have poor range. Then one day they get like a straight line 2 Mile encounter, and they're like "WOW".

    But to answer your question, yes. Two of the same brand of detector will have slightly different sensitivity. This might be more prevalent in radar detectors than some other hardware, because microwave circuits are sometimes difficult to manufacture with good repeatability.

    The same goes for radar guns. If you look at the TX power specs, they are very loose, for example 10-50mw. This is because the gunn diode used to generate the microwaves is also difficult to manufacture with good repeatability, and the loose specs allow them more flexibility to deal with this.

    The slight differences in detector sensitivity and gun power will usually not be very noticable under normal operation...

  4. #4
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    awwwww...

    Excellent points on both radarroy(from leo perspective) and jimbonzzz(engineer?).

    I am more used to a portable two way radio transmitting in (omni) all directions, as to where uwave are pretty much directional with feedhorn(dont know what the front to back ratio is) so your detector won't pick up until (pretty much) too late. Your busted LOL.

    As for the 2 mile range, that is my point exactly as stated earlier "when they think they have poor range".

    Thanks for the clear up guys.

    Jim

  5. #5
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    Quote Originally Posted by radarroy
    When I used radar I didn't bother with the instant on feature. I used a hand held and it was on the trasmission hump facing downwards until I picked it up to point it at a car.

    Again, if it was pointed this way, you wouldn't receive the signal until you were very close to the officers car.
    That's a good point also for those "I passed him and only had K 1" situations...

  6. #6
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    along those lines... what are the lowest-power Ka-band guns like?

    In an area of Tennessee, I drove by two motorcycle cops using some kind of handheld instant-on gun.

    I was around 500ft away and can clearly make out the first cop shooting, and "following" cars with his radar gun, but got no alert from my Whistler 1793, which I know for sure picks up Ka-band very reliably at that distance...


    I passed the speed trap at the speed limit, and I noticed how they were shooting. They aim perpendicularly at a target, pull the trigger (at which point my detector goes off Ka 3/9) and follow the car for about 5 seconds (thus efffectively targeting from the rear) and then seek out a new target.


    I was pretty surprised that being shot sideways at a 2-car distance I was only able to pick up such a weak alert.


    Can radar guns be turned down to such low power levels that they're only detectable / usable in that short a range?

  7. #7
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    Quote Originally Posted by jdong
    Can radar guns be turned down to such low power levels that they're only detectable / usable in that short a range?
    No, radar gun transmit power is fixed and cannot be adjusted or changed, except for some photo radar used overseas.

  8. #8
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    Quote Originally Posted by jimbonzzz
    No, radar gun transmit power is fixed and cannot be adjusted or changed, except for some photo radar used overseas.
    We have licensed and unlicensed (spread spectrum) microwave radios that we use, that are in the 5 and 10 GHz range. We can power up/down either by a potentiometer(using a tweeker-small screwdriver) or computer controlled.

    You are saying that they would not turn down power on the guns, or are you saying the guns do not have a potentiometer to tweek on? :wink:

    reason I ask this jimbonzzz ( and I do value your opinion) is sometimes I have to be right on top of the leo to get full strength reading and it fades very quickly as we separate, so it leads me to believe that "someone" has tweeked on the gun for minimal TX power out.

  9. #9
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    Quote Originally Posted by jimbonzzz
    Quote Originally Posted by jdong
    Can radar guns be turned down to such low power levels that they're only detectable / usable in that short a range?
    No, radar gun transmit power is fixed and cannot be adjusted or changed, except for some photo radar used overseas.
    Are there any handheld guns that would output a significantly lower power level compared to others? in a way that would severely reduce detection range of approaching traffic when targeted in the fashion I described? Or is simply shooting radar at the rears of passing cars already enough to really weaken detection?

  10. #10
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    Quote Originally Posted by jdong
    Quote Originally Posted by jimbonzzz
    Quote Originally Posted by jdong
    Can radar guns be turned down to such low power levels that they're only detectable / usable in that short a range?
    No, radar gun transmit power is fixed and cannot be adjusted or changed, except for some photo radar used overseas.
    Are there any handheld guns that would output a significantly lower power level compared to others? in a way that would severely reduce detection range of approaching traffic when targeted in the fashion I described? Or is simply shooting radar at the rears of passing cars already enough to really weaken detection?
    Some guns are more power than others. Shooting at the rear of the vehicles as you describe could possibly explain what you experienced. The way the trap is set up would make much more of a difference than different powered guns.

 

 

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