Bel RX75 PLUS problems

**Horsie** · 10-30-2007, 12:59 PM

"I'm not a happy camper"

I live in Romania (Europe) and on my brand new Mercedes ML 420 CDI
I've installed a brand new and expensive Radar detector.

Here, the police radars are OLD and are working only in K band.
My old Bel 975 pro was the best !

Using the Autoscan function I've passed by one of this radars with
"only 180 Km/h", so... I'm not a driver anymore !

It seems that for some reason my detector considered the radar as a
false alarm ! I've seen the officer at ~ 10m distance and I was
steering at my expensive and "dead" radar detector !

Yes, it is working, but only in Highway mode...
I've tested the functions after they "cut my licence"...

So.. WHY ?
WHY me ?

**MEM-TEK** · 10-30-2007, 07:00 PM

Originally Posted by Horsie

"I'm not a happy camper"

I live in Romania (Europe) and on my brand new Mercedes ML 420 CDI
I've installed a brand new and expensive Radar detector.

Here, the police radars are OLD and are working only in K band.
My old Bel 975 pro was the best !

Using the Autoscan function I've passed by one of this radars with
"only 180 Km/h", so... I'm not a driver anymore !

It seems that for some reason my detector considered the radar as a
false alarm ! I've seen the officer at ~ 10m distance and I was
steering at my expensive and "dead" radar detector !

Yes, it is working, but only in Highway mode...
I've tested the functions after they "cut my licence"...

So.. WHY ?
WHY me ?

Hi Horsie,

Welcome to the forum! I am sorry to hear about your bad experience and loss of your license. The RX-75 Plus's Autoscan mode only filters out pairs of X band door openers. It is not supposed to have any effect on K band at all. I guess you are sure that you were not hit with laser, so the only thing I can think of is that the officer's K band radar was NOT tuned to operate within the FCC allocated bandwidth for K band. It is possible that the officer's K band radar was malfunctioning and out of tune, or that the officer's K band radar was deliberately de-tuned to operate just outside of K band's bandwidth to make it undetectable. I don't have a clue what the laws are like in Romania, but perhaps you need to do some research and find out if it is required that police radar guns be periodically tested and if they are required to operate within the bandwidth for K band. Hopefully some fellow Romanians here on this forum can help you out as well.

Best Regards,

--Michael

**Horsie** · 10-31-2007, 01:27 AM

Yes, maybe it was out of range

It was detected as K Band in Highway mode, but not detected in Autoscan Mode

For X band fake alerts it is the City mode with different options.

From the detector's manual:

Highway / AutoScan / City Switch
The “City” button selects the RX75 PLUS’s
sensitivity. We recommend the “AutoScan”
mode for most driving.
The RX75 PLUS’s exclusive AutoScan
mode provides long-range warning, with
minimum false alarms. In this mode, the
RX75 PLUS’s internal computer continuously
analyzes all incoming signals and
intelligently adjusts the sensitivity –
eliminating the majority of false alarms.

You can also select conventional
“Highway” and “City” modes. When driving
in urban areas where annoying X-band
intrusion alarms and door openers are
common, City Mode can be engaged to
lower X-band sensitivity and reduce X-band
alerts. Full sensitivity is maintained on all
other bands. You can customize the RX75
PLUS’s City Mode sensitivity. See the
Programming section for details.

**ziddey** · 10-31-2007, 03:20 AM

That's terrible to hear. How soon can you get back your license? That said, it'd be cool if there were 420 cdi's in america. sounds like a lot of grunt! Hope you can enjoy it again soon

**Horsie** · 10-31-2007, 05:38 AM

I'm walking 3 months from now on and I have to take a driver exam... (I have to brush my driving legislation).

420 CDI is a great car, BUT the problem is stopping the 2.5t beast.

I will put Brabus brake next month.

€ · 10-31-2007, 08:11 AM

Originally Posted by MEM-TEK

(...)The RX-75 Plus's Autoscan mode only filters out pairs of X band door openers. (...)
--Michael

I see you use this theory very often... But this theory is weak since one door sensor is looking inside and one outside of the building. The difference in signal levels should be in such case about 12-24dB! How long then detector can search second sensor, if is already seeing and ignoring first one (stronger one) - quarter a mile?! It's completely out of sense!

I've sent you a patent number (4,630,054) few months ago where everythin is explained with autoscan. It's very enlightening :wink:

(It shows also that detector first receives signal and only just then interpretes what frequency it is. So narrowing band or renounce from some copletely can't increse detector's sensitivity. Ask Michael B. why Whistler do not use narrow Ka for european users. Sorry for this offtopic.)

**ziddey** · 10-31-2007, 03:18 PM

Originally Posted by Horsie

I'm walking 3 months from now on and I have to take a driver exam... (I have to brush my driving legislation).

420 CDI is a great car, BUT the problem is stopping the 2.5t beast.

I will put Brabus brake next month.

ahhh makes a lot more sense it's only 2.5t. I was thinking it was really 4.2l cdi.

**SmaartAasSaabr** · 10-31-2007, 05:58 PM

2,5 t means 2.5 tons!

**ziddey** · 10-31-2007, 06:00 PM

Originally Posted by SmaartAasSaabr

2,5 t means 2.5 tons!

i am an idiot.

**MEM-TEK** · 10-31-2007, 06:57 PM

Originally Posted by €

Originally Posted by MEM-TEK

(...)The RX-75 Plus's Autoscan mode only filters out pairs of X band door openers. (...)
--Michael

I see you use this theory very often... But this theory is weak since one door sensor is looking inside and one outside of the building. The difference in signal levels should be in such case about 12-24dB! How long then detector can search second sensor, if is already seeing and ignoring first one (stronger one) - quarter a mile?! It's completely out of sense!

I've sent you a patent number (4,630,054) few months ago where everythin is explained with autoscan. It's very enlightening :wink:

(It shows also that detector first receives signal and only just then interpretes what frequency it is. So narrowing band or renounce from some copletely can't increse detector's sensitivity. Ask Michael B. why Whistler do not use narrow Ka for european users. Sorry for this offtopic.)

My theory is based on about 6 months worth of testing. Belscort also has another patent for detecting a radar signal buried well within the noise floor. In Highway mode, my STi would steadily yet faintly detect X band door openers located over a hill. Yet in Autoscan mode my STi is able to start blocking alerts for the X band door openers before I have crested the hill such that the door openers are a distant line-of-sight. This made me wonder if Autoscan was decreasing X band sensitivity for just a single X band signal. I have tested this as well since my cell phone, when powered off and charging, emits a continuous 10.5MHz X band signal. I placed my cell phone as far away as necessary such that my STi would just continuously detect it in Highway mode. The distance was around 30 feet. I then switched my STi to Autoscan mode. There was about a 1 to 2 second delay, but my STi then started to continuously detect the signal. I don't know the specifics about how Belscort is making the Autoscan magic work to filter out even extremely weak pairs of door opener signals. All I know is that it works as I have reported.

Happy Halloween!

--Michael