V1 not detecting speed signs
#31
07-11-2007, 12:20 AM
The signs are FM-CW and the V1 is not supposed to detect them.
Mike Valentine said it best:
1) The speed sign may employ an FM-CW modulation technique to sense the direction of vehicles in its field of view. This feature is used to isolate departing from oncoming traffic. The V1 does not recognize FM-CW modulation as a valid police radar signal and tries to reject it. FM-CW is allowed for license-free "Part 15" devices by the FCC. FM-CW is not allowed for police radar. There are numerous traffic-volume sensors using FM-CW spread all around metropolitan areas these days that detector owners would rather not produce an alert. Otherwise freeway driving (in Cincinnati, at least) would be very annoying. It's a good thing that the V1 rejects FM-CW modulated signals.
2) The speed sign may have drifted out of the police radar band from aging or temperature. "Part 15" devices are somewhat notorious for this behavior. Automatic door sensors and Doppler security sensors are both "Part 15" devices, too. Few automatic door sensors use FM-CW because of the added expense. The speed sign devices can afford the added cost of including the FM-CW modulating hardware.
END OF THREAD!!
Mike Valentine said it best:
1) The speed sign may employ an FM-CW modulation technique to sense the direction of vehicles in its field of view. This feature is used to isolate departing from oncoming traffic. The V1 does not recognize FM-CW modulation as a valid police radar signal and tries to reject it. FM-CW is allowed for license-free "Part 15" devices by the FCC. FM-CW is not allowed for police radar. There are numerous traffic-volume sensors using FM-CW spread all around metropolitan areas these days that detector owners would rather not produce an alert. Otherwise freeway driving (in Cincinnati, at least) would be very annoying. It's a good thing that the V1 rejects FM-CW modulated signals.
2) The speed sign may have drifted out of the police radar band from aging or temperature. "Part 15" devices are somewhat notorious for this behavior. Automatic door sensors and Doppler security sensors are both "Part 15" devices, too. Few automatic door sensors use FM-CW because of the added expense. The speed sign devices can afford the added cost of including the FM-CW modulating hardware.
END OF THREAD!!
#32
07-13-2007, 04:58 AM
I just bought one today. Had my 8500 x50 stolen a few weeks ago out of the Z. That's not very assuring that I need to recalibrate it if it sits out at only 100+??!! Does it have to be sent in to be recalibrated?
I'm too lazy to take out the V1 every time. Anyone know if the V1 will fit into a 996 glove compartment? Probably should have asked before I bought it.
I'm too lazy to take out the V1 every time. Anyone know if the V1 will fit into a 996 glove compartment? Probably should have asked before I bought it.
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