View Full Version : how important is rear jammer?
gary3594
05-18-2007, 05:28 PM
I have 2 heads. I've read on various posts that LEO can't shoot laser from a moving platform such as coming from behind in his car. Is this true? My dilemma is I have a 911 and the jammer head barely fits right in front of the rear license plate and is quite obvious and breaks up the lines of the car.
Anyone know if lasers are used in the NJ, PA, NY state area? If anyone has been shot, is it from the front or back.
My reasoning is this. If they don't laser you from the rear initially, once you get the warning from the front, you slow down and shut off the jammers anyway. The rears would be also turned off in my system, and I would be going at the PSL.
If you miss seeing the stationary LEO and he shoots you from the rear, you would be vulnerable then.
Am I giving up a lot by not installing a rear sensor/jammer? I would then use the 2 heads in the front for better coverage.
Hessen
05-18-2007, 06:09 PM
Anyone know if lasers are used in the NJ, PA, NY state area? If anyone has been shot, is it from the front or back.
PA state police do not use laser (yet). Only K band radar in stationary mode.
NY and NJ use laser heavily. NYS troopers are relentless in speed enforcement, NJ is not far behind.
Someone posted here ( I believe it was the Veil Guy ) that NJ state police are targeting laser from the rear.
Yeah Dude. You can afford a 911. Pony up Bro, put 2 heads on the front and 2 on the back. :wink:
8)
erickonphoenix
05-19-2007, 12:30 AM
I thought TSiWRX had a good point. He left the rear sensor on to verify direction of hits. He knows he can't jam a rear hit but wants to know if it came from the rear. Knowledge is power.
Even if they shoot from the rear it's a logical shooting spot. Look for turns or obstructions where LEOs might hide as you pass by. Embankments and wooded enclaves with obvious track marks leading onto the interstates are good places to glance over your shoulder for a check. And don't forget feeders (frontage roads) Some local LEOs in TX like to shoot IO Ka up the entrance ramp while merging.
charles charlie charles
05-19-2007, 01:28 AM
If you can afford it, deffo put a head above your rear plate.
Carlos from Spain posted some pics of his 911 install on this board so do a search.
The decision to make is whether you want to have your plastic rear bumper cut to accommodate the jammer head. I would think that once installed it would look rather stealthy and easy for any bodyshop to repair when you sell the car.
But if you fook it up.........I wasn't here.......... 8)
Oz Striker
05-22-2007, 04:18 PM
This got me thinking about placement on my car, clearly there isnt anywhere to mount......... But waht about stcking them behind my reverse lens, circled in the following pic. It would fit in, but i would have to readjust my reverse bulbs.
But how badly would the plastic lense affect the effectiveness of the sensor?
http://i128.photobucket.com/albums/p183/oz_striker/DSC04306.jpg
http://i128.photobucket.com/albums/p183/oz_striker/My%20Car/DSC04310.jpg
http://i128.photobucket.com/albums/p183/oz_striker/My%20Car/DSC04311.jpg
But how badly would the plastic lense affect the effectiveness of the sensor?
Excellent location , I think the pick-up will not be affected but the jamming ray could be distorted if the lens is refractive , it would split it in different direction , I asked this question to Yvan/AL about placing my sensor inside an empty shell of foglamp : it is ok as long it is a ''clear'' lens/glass .
erickonphoenix
05-22-2007, 05:23 PM
But how badly would the plastic lense affect the effectiveness of the sensor?
Excellent location , I think the pick-up will not be affected but the jamming ray could be distorted if the lens is refractive , it would split it in different direction , I asked this question to Yvan/AL about placing my sensor inside an empty shell of foglamp : it is ok as long it is a ''clear'' lens/glass .
You would want to get replacement lamps for the tailights and fabricate a clear lens of the section you want to mount the jammer behind. Those tailights are segment to magnify the light inside the lens so it appears brighter on the outside.
There was an ariticle on a Stealth M5 used in the Cannonball a few years ago that had the two LPP units installed inside the rear bumber. Since the M5 was black and lenses were flush the install was virtually undetectable. I would assume you would need to pull the bumper, saw two holes and glass in mounts for the LPP so it would be rigid.
Anyways, I looked for the article but it appears the link expired.[/img]
TSi+WRX
05-22-2007, 06:47 PM
^ VERY interesting proposed setups by you guys! 8)
Indeed, Oz, I'd go the way that brother erickonphoenix recommended - replace the seemingly "smoked" sections with clear lens ones, at the *very* least (and I want to highlight the potential distortion issue cited by Eloi - we've all seen how much jammer performance is degraded by "in-vehicle" [read: inside windshield] mounting), but if it were me, and the replacement costs were not prohibitive, I truly would try to cut-out sections of that back-up light lens, and flush-mount the heads as he described for the previous Cannonball M5.
Great ideas, everyone! Thanks for sharing them! This gives me ideas of my own (i.e. cutting my own tail-lights)! :)
Oz Striker
05-23-2007, 03:49 PM
How about the following rear fog light??:
http://cgi.ebay.co.uk/BMW-E46-3-Series-2DR-Clear-Red-M3-Style-Reverse-Lights_W0QQitemZ130115200627QQihZ003QQcategoryZ103 74QQrdZ1QQcmdZViewItem#ebayphotohosting
Its clear, but the plastic has engraved lines to help refract the reverse light, which will be a problem i think.
TSi+WRX
05-31-2007, 06:23 PM
^ The fresnel pattern printed on the lens is used to specifically direct light output - and that, of course, as you said yourself, would be worrisome.
If you think back to about two decades or so ago, many automobiles were equipped with sealed-beam headlights with such line-patterns printed on their lenses. That patterning, in conjunction with the reflectors buried within the headlamp housing, focused and patterned the light for proper output.
I would be worried that the printed prisms would cause your outgoing jamming beam to be distorted.....and performance thus degraded.
fulcrum
06-04-2007, 01:38 AM
After being ........ from behind by an UltraLyte 100LL a few weeks ago, I decided that rear protection was needed.
This is how the LPP is installed in my Alfa Brera.
http://www.jammthem.com/imagePub/LaserRadarEtc/Rear_lpp1.jpg
http://www.jammthem.com/imagePub/LaserRadarEtc/Rear_lpp2.jpg
http://www.jammthem.com/imagePub/LaserRadarEtc/Rear_lpp3.jpg
http://www.jammthem.com/imagePub/LaserRadarEtc/Rear_lpp4.jpg
I tested with an UltraLyte 100LL, a Laser Atlanta SpeedLaser S and a JenOptic LaserPatrol. Results are perfect.
TSi+WRX
06-04-2007, 05:10 AM
^ Whoa! :shock: Awesome install! 8) Super-stealthy!
Just be careful - I still don't trust *any* jammer to give true JFG protection at the rear (I'd like to see how the upcoming LI will do in this respect)..... Keep your eyes open to threats, and get down to legal/semi-legal speeds ASAP after you receive the alert and verify the threat.
Conservatively, my own "rule of thumb" is that I've got about 500 ft. to do so.
Certainly, that's not enough in "hyper-speeding" situations, but for normal everyday highway commutes, where one's not too far above the PSL, that may be enough distance/time to make the difference.
Best wishes,
-A
fulcrum
06-04-2007, 05:58 AM
... Just be careful - I still don't trust *any* jammer to give true JFG protection at the rear (I'd like to see how the upcoming LI will do in this respect)..... Keep your eyes open to threats, and get down to legal/semi-legal speeds ASAP after you receive the alert and verify the threat. ...
Even getting a reading of the parked car at 200m (660ft) is very difficult. (I only managed to get a punch trough with the UltraLyte so now and then) When the car is moving and/or at longer ranges things look even better.
I improved effectiveness of the (single) jammer by 'disabling' the reflectors on the rear of my car. (These were integrated in the light units on the back) I also use the radio mute output of the LPP to disable my braking lights during a laser alarm. The next step will be auto jammer shutdown at or around the PSL. (using GPS and database)
LittleOverPSL
06-04-2007, 09:58 AM
I improved effectiveness of the (single) jammer by 'disabling' the reflectors on the rear of my car. (These were integrated in the light units on the back) I also use the radio mute output of the LPP to disable my braking lights during a laser alarm.
Nice. Care to elaborate on these two?
Asleeper
06-04-2007, 11:30 PM
Fulcrum.......NICE install, looks slick.
You can't even see it. Also, VERY interested in how you used the radio mute to disable the brake lights. I'm considering a rear head, but have the problem where I can't make it obvious that I am slowing down due to being targeted by an leo since jammers/detectors are illegal where I am.
erickonphoenix
06-04-2007, 11:56 PM
Awesome install! 8) 8) 8) 8) 8)
TSi+WRX
06-05-2007, 05:35 AM
Even getting a reading of the parked car at 200m (660ft) is very difficult. (I only managed to get a punch trough with the UltraLyte so now and then) When the car is moving and/or at longer ranges things look even better.
Excellent!
Looks like you have a way to quantitatively test your setup - that's indeed the only way you can be sure that what you have truly works. Hopefully, you will indeed get good rear-on protection for that 600-700 ft., and that it will allow you to successfully slow-to-PSL/reasonable in that span. :)
How highly curved/contoured is the rear of your vehicle? I'm not that famiilar with its side profile - perhaps that's in-part responsible for your good rear-on numbers?
I improved effectiveness of the (single) jammer by 'disabling' the reflectors on the rear of my car. (These were integrated in the light units on the back) I also use the radio mute output of the LPP to disable my braking lights during a laser alarm. The next step will be auto jammer shutdown at or around the PSL. (using GPS and database)
^ Awesome!
Here, where I live, I don't dare mess with my rear reflectors, unfortunately.
In my city, the American "red-by-sight" code is strictly enforced, and some of my friends have been ticketed after replacing their factory rear lighting with aftermarket units that do not bear such reflectors. :(
fulcrum
06-06-2007, 12:42 AM
The round shape of the rear of this car (round in both the horizontal and the vertical) makes it an easy target for a lasergun from behind. Disabling the reflectors makes big difference, but not as much as on most other cars. I don't want to install a duo head here, simply because it doesn't look good.
A leo pointing his gun at my car with the jammer on will need some time to get a reading. More than enough time for me to slow down and switch the LPP off.
The LPP has an audio mute connection. I use a relay (the normally on contacts) in series with the wires of the break lights. The coil of the relay is connected via a transistor timer/buffer stage to this mute output. This timer limits the brake light disable time to a maximum of around 3 seconds during the LPP alarm phase.
The front of the car has a duo head LPP. At ranges of 300+ ft this gives me perfect protection.
I don't know if this was ever tested, but some guns can get your speed at almost 6500ft (2km). Using a tripod it is even relatively easy to do. The LPP jammed perfectly also at this range. (single head from the rear)
There was a question about the side profile of the car:
http://www.jammthem.com/imagePub/AlfaRomeo/06brera3_640x480.jpg
http://www.jammthem.com/imagePub/AlfaRomeo/06brera2_640x480.jpg
TSi+WRX
06-06-2007, 06:22 AM
Very cool, fulcrum ! :)
Thanks for the great information on using the mute-wire for the light disable! Great tactical analysis!
Asleeper
06-07-2007, 08:59 PM
Very cool, fulcrum ! :)
Thanks for the great information on using the mute-wire for the light disable! Great tactical analysis!
a big X1......I am going to give that some serious thought.
charles charlie charles
06-09-2007, 05:53 PM
top marks mate, you are certainly a braver man than me cutting your tailgate like that!
specialchicken
06-10-2007, 03:51 PM
well i never considered rear jammers until I started seeing LEO sitting on the on ramps of freeways!!!! I have a similar problem as you, no room to fit a rear jammer so I can careful now when i pass an onramp.. I did temp mount a jammer head on the rear but a single head wasnt very effective...if i was you id test it if you can...here is a few pics i got of some LEO on a on ramp in my area;
http://i155.photobucket.com/albums/s288/specialchicken1/121022007182.jpg
http://i155.photobucket.com/albums/s288/specialchicken1/rearlaser.jpg
TSi+WRX
06-11-2007, 05:42 AM
...if i was you id test it if you can...here is a few pics i got of some LEO on a on ramp in my area;
^ Luckily, fulcrum did post previously that he was able to test his rear profile. :) Not all of us have this ability, sadly. :(
Definitely, the unique rear profile of his vehicle may already be conferring to him a higher degree of "natural protection" than what many of us may see on our own, more "traditional," vehicles - however, his own passive-protection modifications certainly kicks things up anohter level.
fulcrum
06-20-2007, 01:43 AM
IR picture which shows effect of modified reflector:
http://www.jammthem.com/imagePub/LaserRadarEtc/brera_ReflectMod1.jpg
(In this picture only the right side reflector is modified)
TSi+WRX
06-20-2007, 12:06 PM
^ NICE!!! 8)
So, does your car still have reflectors, or not? And if so, are they still red by-sight/light?
I'm very interested in pursuing this modification - however, my local enforcement is rather intense and strict with regard to tail-light "red-by-light/red-by-sight" codes; having an actual red reflector is unfortunately a true need for me.
Again, thanks for sharing! :)
fulcrum
06-22-2007, 06:05 AM
It looks as if the car has still reflectors. But the retroreflecting doesn't work anymore. I destroyed the prisma's from behind using a mini drill (Dremel)
So in the night you can see it when the car is parked, and the reflectors don't "light up"
TSi+WRX
06-22-2007, 06:32 AM
^ Ah! I see!
Thank you for your candid discussion of this as well as for the modification procedures. :)
I still don't know if I can totally get away with this in my area - however, it is definitely a good trick to have up one's sleeve, so to speak.
Thank you for your knowledge and know-how! :)
fulcrum
06-24-2007, 06:17 AM
The very best solution for the reflectors is using a IR blocking sheet in front of the reflectors. This works very much like veil, but 1000's of times more effective. For visible light you will still have fully functioning reflectors, but for 905nm IR it is as if they're painted black.
TSi+WRX
06-24-2007, 07:38 AM
^ Very interesting. I'll give this a look-see, and see if Google searches won't help me a bit on this one. :) Again, thank you for your ideas and candid discussion! :)
lacning74
02-29-2008, 10:55 AM
After being ........ from behind by an UltraLyte 100LL a few weeks ago, I decided that rear protection was needed.
This is how the LPP is installed in my Alfa Brera.
http://www.jammthem.com/imagePub/LaserRadarEtc/Rear_lpp3.jpg
http://www.jammthem.com/imagePub/LaserRadarEtc/Rear_lpp4.jpg
I tested with an UltraLyte 100LL, a Laser Atlanta SpeedLaser S and a JenOptic LaserPatrol. Results are perfect.
I plan on doing a license plate install with a slim LI head. Don't plan on cutting and recessing into the body, though.
Does the over-hang in fulcrum's install matter? Certainly, making the head flush would make it very un-stealthy. I will have about an inch of overhang from my hatch handle on my mini cooper.
TSi+WRX
02-29-2008, 11:14 AM
^ I would think that unless it is an extreme-high-angle shot, he should be OK.
The infamous Noory got burned by precisely this kind of shot (bridge), albeit at the front of his vehicle - but the physical configuration of the head placement was the same, i.e. with a little "overhang." His front plate was the "overhang" that shadowed (and thus visibly concealed) his central LPP head.
"Flush" is important for maximized performance, but in this case, I think that fulcrum's compromise was one that he could not avoid, in that stealth is of paramount importance in his particular geographic location.