STi-R Plus - moved from behind grill, holy cow!

blue dragon

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Thats interesting, since my STiR is behind an aftermarket all plastic grill on my X5. I dare not move it out into the open though here, its almost as bad as Virginnia
 

monkeyf15

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Where are you? If they're not illegal, what's the worst that could happen? :)
 

Qui-Gon

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Where are you? If they're not illegal, what's the worst that could happen? :)
He's from Canada, one of the eastern provinces where CM's are illegal. :(
 

wolfpacal

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Thats interesting, since my STiR is behind an aftermarket all plastic grill on my X5. I dare not move it out into the open though here, its almost as bad as Virginnia
Onterrible is a 1000x's worse than Virginia!!!
 

swampbread

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Thanks for the post OP. I may someday step up to such a fancy system, so this is good to know.

Which genius told you to put it behind the grill? You should never install behind the grill. The antenna needs a clear and unobstructed view to perform at its peak. What you did is well ...
Newbie, I really don't think you should be criticizing anybody's install of anything after your LJ install post...
 

The Stig

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I installed like a bowss. Sat on a chair and dropped da cash on da table and got that xxxx done for me u feel me homie? Didnt even have to move a finger u nah mean? just like a bow$$ playa.
The global language on this forum is English, not sure what all that's about
 
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monkeyf15

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While my range improved significantly when I moved from behind the grill, it could have been a lot worse. My wife has a 2012 X5, and there's really no good place to mount it and still be relatively stealth. I mounted her 9500ci antenna on the windscreen for exactly that reason, but rd's aren't illegal where we leave. Sorry, but don't sweat it too much. At least it's an M3 antenna, right?

Merry Christmas to everyone!
 

sk911

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I've always been thinking with these remote detectors that I'd rather install the antenna high up behind the windshield vs. behind a grill or bumper. It seems to me that other than being 100% exposed (outside the car) that the top windshield location is the next best location.

Sure I understand in some cases this is not possible (aesthetics, etc.) but it is what it is...
 

radarinator

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On the Vette, I just moved my STiR+ receiver from behind a plastic shroud (which was between the grille and radiator), to just behind the open grill. (the grill can't be removed without front bumper removal, so that's where
I had the RD installer put it originally). I just had the radiator upgraded for a supercharger install, and the guys who put in my supercharger moved the STiR+ to where it now has a view of the road. Ive had it less than a week, but so far, a marked difference in detection.

Today, I was on the fwy and got a big Ka kit. OK, where are you, CHP? An 1/8mi goes by, and there he is, getting onto the fwy, in the opposite direction. I figure he was on the overpass, making a left onto the fwy on-ramp when I got the first hit. I thought this was an impressive off-axis detection.

The original install was terrible. He used glue and the whole unit came loose and was just flopping. The timing was almost perfect, though, as the supercharger install involved the exact area to move the unit, and it seems to have really improved detection. Plus, with line-of-sight, I now have a chance at laser detection too. ;)
 

Nine_C1

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And yes, it's always better to be behind a solid flat vs. an uneven surface that can reflect the radio waves.
I'm still newb to all of this but after speaking to an escort rep I did find out that a partial obstruction can be more damaging to sensitivity then a full on behind the bumper obstruction
^^^ Good advice.

Glass and Plastic are both low loss mediums (an intervening substance through which something else is transmitted) so long as neither has any RF blocking metallic content.

The potential issue with either is with irregular shapes or varying thickness or density. In order for the antenna in your detector to function with maximum efficiency, the microwave wavefront presented to the aperture (mouth) of the horn has to be as flat and uniform in shape as possible. While microwaves pass easily through most glass and plastic, both materials will create a phase shift (or delay) to the signal as it passes through. What that does is distorts or fragments the wavefront presented at the mouth of the horn antenna which creates phase errors which cancel out some of the signal strength as it is passes down to the base of the horn where the signal is concentrated for presentation to the microstrip connection. Or to put it simply, a fragmented signal will lower the gain of your horn antenna reducing detection range.

Honeycomb or slotted grills are therefore much worse than solid flat plastic since the solid flat material creates a uniform phase shift leaving the wavefront effectively unaltered.

Here is a plot of what a fragmented wavefront would look like (left) as opposed to a uniform wavefront (right).

fragmented wavefront.JPG


Now some detectors have a plastic bubble (condenser) lens in front of the horn.....so how does that help as opposed to hinder considering what we just learned above? Well first the bubble has a uniform bend and thickness to it so it does not fragment the wavefront. The purpose it serves is to compensate for the shortened horn(s) inside the detector which have sharply tapered sidewalls due to their abbreviated length (they are made artificially short to fit inside the detector). By shortening the horn this acute sidewall taper causes the RF wavefront to bulge as it passes down into the horn which also creates phase errors that lower the gain of the horn, so the bubble lens bends the wavefront the other way and thus cancels out the bulge created by the acute sidewall taper of the short horn(s) used inside our detectors.

PRO-300 Lens.JPG


Likewise, virtually all radar unit antennas today also use a condenser (plano convex) lens for the same reason.......so they can shorten the horn antenna without sacrificing gain (or range).

stalker_patrol_kband_antenna_10630949.jpg
 
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GoDuke

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Nine is a radar ninja
 

Chieflpc

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Thanks for all the posts I'm trying to figure out placement on a 328
 

gpb

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lay3r3

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I was reading today on another forum about the V1's being set inside and above the maplight/mirror section on M5's and M6's. Apparently there is a healthy amount of space up there and, for radar, a relatively clean sight of the road. I have to look at mine but the question would be, is there enough headliner and glass between it and the road to make that a good option. If only a guy had the stuff handy to go through a test all these configurations :)
 

PointerCone

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