Increasing Keyless entry transmitter range

[Infinitiguy19]

I hear about many who suffer from short range keyless entry systems. But more importantly the 1994-1996 Q45, 1992-1997 J30 and G50 (Forget the correct years). The owners manual specifies 49 FEET as the keyless entry transmitter working range. But as we all know whats said on paper is far different than reality in most cases. The antenna used on the J30 and Q45 is mounted on the back of the window and shares the radio antenna.

Can we at least make the keyless entry transmitter work at 49 feet or more?

Would one more antenna on the car help the range?

Can the car phone antenna be used as antenna for the keyless entry?

Is the transmitter or car antenna at fault for the short reception?

In the owners manual it also says that this device (keyless entry):

Operation is subject to the following
two conditions: (1) This device may not
cause harmful interference, and (2) this
device must accept any interference
received, including interference that
may cause undesired operation of the
device.

Does any of the new technologies affect the OEM keyless entry system?

Can the antenna in the remote be enhanced?

Please no discussions of buying and using aftermarket keyless entry systems.

[Q45tech]

Things taught is BSEE courses.Double distance requires a quadrupling of Tx power output, or 6 db gain increase at antenna, or narrow tuned low noise preamplifier between antenna and receiver. A 1db NF preamp IC in front of 5 db oem Rcvr can give you a net NF gain of 3.5 or 1.5x the stock distance.

315 MegaHertz is usual frequency
http://www.maxim-ic.com/app-notes/index.mvp/id/3395


The main problem is usually 315 MHZ signal pollution casued by dozens of near range on frequency systems causing desense of receiver [intermodution].

[qship96]

Range on mine dropped significantly after tinting windows, down to maybe 30 feet.......yet oddly when I stand on my balcony at beach condo {24th floor/250 ft above ground} I can hit the lock button and see parking lamps blink and unlock doors/roll down windows so car is cooled down by the time I get to it.Explain that one?

[Infinitiguy19]

Well I know when it comes to setting up wireless computer networks the router is set at the highest point of the building. By doing that the signal will filter down to the rest of the computers at a far greater range than setting the router on the first floor of a multi floor building. I am not sure how that is but after shadowing the IT person in charge of my middle school network I learned that.

yet oddly when I stand on my balcony at beach condo {24th floor/250 ft above ground} I can hit the lock button and see parking lamps blink and unlock doors/roll down windows so car is cooled down by the time I get to it.Explain that one?

Could it be that there is less interference at the your condo VS elsewhere?

I think like I just stated above with the wireless network that the same applies to you. I am guessing you have metallic tint?

I would like a better answer than what I can provide as to why that happens to you Qship.

Thank you for the link and all the information Q45Tech!

[Q45tech]

315 is almost 8 times larger wavelength than 2450 MHZ wireless router.
For those that were born without a sensitivity to electromagnetic quanta in these frequencies...........EM field theory is a useful subject.

If something [glass film] attenuates light by blocking a portion with metal particles, hopefully you see that it affects other signals in the spectrum.

Light and radio waves are the same thing just different frequencies.

[Infinitiguy19]

Thanks for clearing that up Tech.

http://picasaweb.google.com/lh/photo/mC ... directlink

http://picasaweb.google.com/lh/photo/Cz ... directlink

http://picasaweb.google.com/lh/photo/ty ... directlink

http://picasaweb.google.com/lh/photo/U0 ... directlink

http://picasaweb.google.com/lh/photo/sf ... directlink

http://picasaweb.google.com/lh/photo/AG ... directlink

http://picasaweb.google.com/lh/photo/sM ... directlink

http://picasaweb.google.com/lh/photo/MB ... directlink

No getting away from the fact that Alpine supplied the alarms for the J30. Can't find any evidence of that on the 1994-1996 Q45 keyless entry control unit. Thats not a bad thing though because I read that Alpine supplies alarms to BMW as well. http://www.nicoclub.com/archives/oem-af ... parts.html.

I will sell or trade the key FOB because Jspout (The person I got the keyless entry parts from) said the remote and control unit were the same FCC ID. When I received I the parts I checked to be sure and he was wrong. The remote show ends with a 73 and I need one that ends in a 72.

And Qship these topic here may help explain a little eaiser why your keyless entry works better from a taller building: http://action.publicbroadcasting.net/ca ... 59610.page
http://ezinearticles.com/?Improve-The-R ... &id=268916

They also say soldering a wire to the antenna part of the transmitter will help range, Any truth to that?

If so what part is the antenna?
(My guess is the silver tiny sardine can on the 5th picture to the far right).

They also say using a bigger gauge wire for the antenna will help a little (Less resistance)?

[Q45tech]

Ideally at 315 MHZ an antenna should be a 5" rod [1/4 wave length]........the impedence match changes with deviations +- from 5". Inductance [coil] is series to lengthen the effective length and a capacitor to shorten an overly long than 5".

The wire can be bend into angles.

I would expect the hand transmitter is already optimized whereas the receiver antenna may need some work............maybe a mast or tower up from roof center to gain elevation if you decide not to add a low noise preamplifier.