: RKE Range?



caddycruiser
02-14-06, 12:14 AM
Just wondering, how far away from the car should the stock remotes function? When I got the car, I put new batteries in them, but I have to be within about 1 or 2 feet of the car for them to work...sort of like the part on the car that picks up the signal is dead. Is there an antenna?

Any ideas? This is the '95 Brougham, with the stock RKE system & theft deterrent. Probably will be replaced one day by a more sophisticated alarm & remote start, but for now, I still want to use the stock remotes.

N0DIH
02-14-06, 03:06 AM
Pretty close to right, I think on a good day I can get 10-15 feet.

The antenna is in the back window area somewhere, and from what I have read, it looks to be intentionally poorly designed for short range.

It isn't the Key FOB, it is the car side.

Katshot
02-14-06, 06:41 AM
The module is under the rear package tray. It CAN be modified to give you better performance. I'll look around to see if I can find the article but I found one years ago on the internet and it outlined a way to make a passive antenna for the module. I built one and it actually worked! It's really nothing more than a loop of wire taped to the top of the module really.
Besides that, if you don't mind looking odd, you can make a huge increase in the range by holding the remote under your chin when you push the button. The signal uses your skull as an antenna and really boosts the signal. I know it sounds weird but it really does work.

caddycruiser
02-14-06, 10:21 AM
The module is under the rear package tray. It CAN be modified to give you better performance. I'll look around to see if I can find the article but I found one years ago on the internet and it outlined a way to make a passive antenna for the module. I built one and it actually worked! It's really nothing more than a loop of wire taped to the top of the module really.
Besides that, if you don't mind looking odd, you can make a huge increase in the range by holding the remote under your chin when you push the button. The signal uses your skull as an antenna and really boosts the signal. I know it sounds weird but it really does work.

Haha...I'll have to try letting it use my skull as an extra antenna next time:cool2:

I think I know the article you're talking about, I saw mention of something over on the Impala SS board, but didn't have time to dig deeper and find it yet.

N0DIH
02-14-06, 12:56 PM
I guess it depends on what is in the skull eh?? :) Don't want to detune it too much!! Or not enough!

"You results may vary..."

caddycruiser
02-14-06, 01:54 PM
I guess it depends on what is in the skull eh?? :) Don't want to detune it too much!! Or not enough!

"You results may vary..."

LOL, then again, I have been known to use the "skeleton as an auxillary antenna" before with different boom boxes around the house...:rolleyes:

Just never thought of it with the car remotes. I'll have to start looking for that article/posts when I get a chance, and see what I might be able to do.

Like I said, ideally, I want to eventually have a much more sophisticated alarm and remote start, but until then, it's all factory stuff...

caddycruiser
02-14-06, 02:10 PM
Think I found it:
http://impala.homeip.net/impala/technical/tech.cgi?security%2Fkeyless%2Ehtml#security_keyles s


Eric Woster used the following steps to extend the range of the RCDLR: Based on a frequency of about 315 Megahertz, a quarter wave antenna length will be about 240mm or 9.5inches. You need to make a close coupled loop that matches the internal antenna loop dimensions with two quarter wave tails on the ends of the loop. In this way the extra antenna is outside of the RCDLR box.

1. Find a thin piece of stiff cardboard and cut a rectangle the size of the front surface of the RCDLR.

2. Glue (don't staple) a single 360' loop of braided 20AWG wire to the board with long ends. The ends should hang off of the cardboard by at least a foot.

3. Snip the ends of both wires to make them extend from the edge of the cardboard by 9 to 9.5 inches.

4. After the glue has dried, pull the back of the back seat out, lift the back package shelf carpet up just a little, and secure the carboard loop to the front of the RCDLR with tape or double-sided tape, and let the wire ends hang off at the top. The wire ends can be streched out and taped down or just held in place by the package shelf.

5. Reassemble.

6. This should nearly triple the range to the rear of the vehicle.

A longer antenna won't help without some fancy ground plane effects and ugly designs. Running the antenna somewhere else will increase the antenna length unless a coaxial cable is used.

A little unclear, at least to me, but doesn't sound that hard.

RMartin0018
02-14-06, 03:00 PM
With the 93 Brougham, I have to be within 10-15 feet to work consitently.

Wheer I used to work (and park), I used to have troubles with the alarm going off when ever I tried to unlock using the remote fob. I eventually just started to use the key because I was tired of people looking at me like I was stealing it... Where I always parked was right next to the exit that was triggered by the weight of the vehicle and/or magnets. Has anyone ever had this type of problem?

N0DIH
02-14-06, 03:24 PM
A dipole antenna, 468/freq in MHz = distance in inches would probably work best, supported as much as you can in freespace inside the trunk. So if 9.5 inches is the dimension, then 9.5 inches on the center conductor and 9.5 inches on the ground side (needs to be balanced) will do the trick with a good performance. We can design fancy if you want greater range....


Think I found it:
http://impala.homeip.net/impala/technical/tech.cgi?security%2Fkeyless%2Ehtml#security_keyles s

A little unclear, at least to me, but doesn't sound that hard.

caddycruiser
02-14-06, 05:05 PM
A dipole antenna, 468/freq in MHz = distance in inches would probably work best, supported as much as you can in freespace inside the trunk. So if 9.5 inches is the dimension, then 9.5 inches on the center conductor and 9.5 inches on the ground side (needs to be balanced) will do the trick with a good performance. We can design fancy if you want greater range....

Sounds cool. I'll have to play around with it a bit then.

N0DIH
02-14-06, 05:16 PM
You can download some loop antenna software at:http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=5482 and make a really good antenna.

CoupeDevilleRob
02-14-06, 08:32 PM
I once heard if you hold the remote up to a cell phone and hold another cell phone near the car you can unlock the car. The remote signal supposedly piggbacks on the cell phone call and gets sent to the car. My dad and I tried it on his 1993 Buick and it didn't work. I wonder if something like this is possible though, maybe with a newer car. OnStar can remotely unlock cars, I wonder how that works?

caddycruiser
02-14-06, 08:44 PM
I once heard if you hold the remote up to a cell phone and hold another cell phone near the car you can unlock the car. The remote signal supposedly piggbacks on the cell phone call and gets sent to the car. My dad and I tried it on his 1993 Buick and it didn't work. I wonder if something like this is possible though, maybe with a newer car. OnStar can remotely unlock cars, I wonder how that works?

Well, Onstar works by sending a specific to your car message from their satellite, via computer, which then is picked up specifically by the Onstar transponder in the car in question. Don't know the real specifics, but that's basically how it works.

Never heard of that whole cell phone thing, though...it could just be an "urban myth", so to say.

N0DIH
02-15-06, 02:11 AM
OnStar only uses GPS from satellite, nothing else. All communuication is from cellular. The GPS is sent to the call center on a data channel setup that you cannot hear. OnStar communicates to the car via the vehicle bus with commands that are sent over the air that the TCU (Telematics Communications Unit) receives and sends on the bus. The unit is powered down 9 out of every 10 minutes when the car is shut off to conserve battery power. It is a 3 watt analog cell phone up till Feb 2004, then the CDMA digital unit started to come into being. Depending on what car you have is what unit you have.

I know, I was on the design team.

No, you cannot use a cell phone to call your car and do anything with it. If you can figure out the number (just add minutes to your service to use it as a built in cell phone), you can call it, assuming you have that service, else I don't believe the cell phone provider won't allow a non OnStar initiated call.

OnStar first arrived at GM in 1997 or 1998.

Does it surprise you what sort of people lurk here? :)

Katshot
02-18-06, 08:31 AM
Think I found it:
http://impala.homeip.net/impala/technical/tech.cgi?security%2Fkeyless%2Ehtml#security_keyles s



A little unclear, at least to me, but doesn't sound that hard.

That sounds exactly like the one I did and it DID seem to help.

CADDYBLACK99
02-21-06, 01:12 PM
I found these diagrams! They are for a 2005 CTS but the technique and location appear to be the same.

RCDL LOCATION (http://www.cadillacfaq.com/stsfaq/tsb/data/tsb/04-08-52-008.pdf)

Paul

caddycruiser
02-21-06, 01:58 PM
I found these diagrams! They are for a 2005 CTS but the technique and location appear to be the same.

RCDL LOCATION (http://www.cadillacfaq.com/stsfaq/tsb/data/tsb/04-08-52-008.pdf)

Paul

Strangely enough, that does actually make some of it a bit clearer:thumbsup: