RE: Valentine 1 stealth mounitng/laser falsing

["Mudry, Robert (CAP, AMR)" <rob.mudry@xxxxxxxxxxxxx>]

Chris,

Thanks for a thorough reply.  I can immediately rule out the heat factor.
The detector started falsing as soon as I pulled out of my driveway on a
chilly morning (7:30 am) so there was nothing near the detector that had
enough time to warm up.   I cannot think of anything else besides maybe two
pillar mounted AM/FM antenna amps (diversity antenna system).  Perhaps those
things are radiating noise that affects the laser portion of the circuitry.
Also, I just remembered that the "inside" of the CHMSL assembly is coated
with a reflective silver coating.  Perhaps that coating has something to do
with it?    

This past summer I noticed that my detector would false exactly the same way
simply by covering the rear laser sensor with the tip of my index finger.
Someone else on the list has confirmed this strange behavior.  At this point
I'm worried that simply masking the laser sensor may not fix the problem.
Is there a way to disable the laser portion of the unit while in the
test/diagnostic mode?    

Rob Mudry
'96 328is 
BMW CCA #135536
	
	Robert,

	Since "laser" or LIDAR works in the infrared spectrum, the color of
visible
	light coming through the CHMSL (center high mounted stoplight) lens
should
	not affect the falsing characteristics of your detector. In fact If
you look
	at most detectors, including the Valentine, the lens for the IR
sensor is in
	fact a very dark red.

	For a CHMSL lens to affect your LIDAR detector it would have to
change the
	wavelength of the sunlight significantly. Police LIDAR is designed
to be as
	dissimilar to bright sunlight as possible so as to be functional
during the
	day.  The lens would also have to focus the light much more as
sunlight is
	very diffuse, and a quality LIDAR detector like the Valentine should
not
	report diffuse IR scatterings. Now if the design of the lens were
correct,
	and the dye used had a significant IR emissive component, it could
cause a
	false positive, it's pretty unlikely that this combination would
occur. My
	best guess is that either heat, or an electrical circuit near te
unit are
	causing it to give false positives

	Unfortunately the CHMSL lens would seriously compromise your
effective range
	because the red dye used in the plastic reduces the transmissivity
of light
	through the lens by between 40% and 60% (rough estimate based on
past
	experience)especially becasue most red dyes absorb IR quite well .

	Also you have to remember that even under the best circumstances
LIDAR
	detectors are quite poor at giving advance warning. Unless the LED
is
	pointing directly at you but beyond effective range (1/4 mile or so
	depending on the weather), you probably wont get a warning before
the police
	have your speed. If you are lucky you will get a reflection off of a
car
	ahead of you but thats likely to only last for a fraction of a
second.

	Chris Dinsmore
	================================
	The eyes may be the windows on the soul
	But the word is the doorway to the mind
	================================

	-----Original Message-----
	From: Mudry, Robert (CAP, AMR) <rob.mudry@domain.elided>
	To: 'BMW Mail list' <bmw-digest@domain.elided>
	Date: Monday, October 12, 1998 11:19
	Subject: Valentine 1 stealth mounitng/laser falsing


	Hey Gang!

	Does anyone here on the BMW digest have a Valentine 1 radar/laser
detector
	mounted on the rear deck inside the third brake light assembly?  I
have just
	installed my V1 in such a way, and I'm getting an almost constant
rear laser
	falsing.  It seems to me that the red plastic changes the wavelength
of the
	sunlight and causes the detector to false.  (I can't wait to test
that
	theory at night)
	Also, I just spoke with some tech guru at the Valentine Research and
he
	seems to think that it shouldn't cause it to false.  The guy didn't
strike
	me as knowledgeable on the subject so before I call again I'd like
to get
	some feedback from the list.  The car is an E36, and the third brake
light
	assembly has been modified (read: destroyed) to accommodate the V1
unit.  My
	guess is that I'll have to cover the rear laser sensor and give up
laser
	protection. (if any...)  My front laser protection is obviously
already
	compromised so it's not a big deal if I lose the rear coverage.
TIA.

	Rob Mudry
	'96 328is
	BMW CCA #135536

	

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