RamAirRckt

[MOD EDIT]
This thread was created to discuss the possible methods to increase the range of the '98-00 LS/GS factory wireless alarm system. Information contained within is to be regarded as suspect and unproven until posted otherwise. Any modifications you do you make at your own risk.
-PureDrifter
[/mod edit]

My 98 GS4 is too, gotta be right on top of the car to make it work. My 94 Fleetwood was same, the reciever was under the rear package shelf. Add a longer wire for antenna and range increased dramatically.

Mixed bag about longer range, easy to open in the house and leave car unlocked unknowingly when keys are in your pocket.... Or in my Buick's case, pop the trunk!

RamAirRckt

Probably increases the ground plane which will help a LOT on the radiation efficiency of the antenna on the key fob.

But the RX antenna needs to be found and tuned.

PureDrifter

iTrader: (10)

there's no external antenna, you would have to crack the unit open and change the internal antenna length, to one that is a whole fraction of the wavelength of the primary frequency of the remote.

PureDrifter

iTrader: (10)

I've had a couple ideas on modifying the oem alarm range on my list for some time, maybe i'll get to it eventually lol.

RamAirRckt

Most of the time the antennas are a joke, just a very simple piece of wire inside the housing or a trace on the PCB. If you can get it away from the metal around it the better, but sorta hard when the antenna may be in the trunk! That is why GM puts it near the package shelf (under the back window) and it has some limited access to the outside.

RamAirRckt

Just fired up the Spectrum Analyzer. My 98 GS4 remote is on 314.5 MHz.

PureDrifter

iTrader: (10)

very close

the FCC ID HYQ1512V (for most '98-00 keys, LS and GS) shows a listed frequency of 314MHz.

so the ideal 1/4λ antenna would be 8.94inches long.
1/2λ is ~17.89inches, but may result in an antenna with too much resistance for a direct connection.

some LX450 owners did a similar mod on their cars, but they had external antennas to modify. edit-nvm, those cars had port-installed RS300 alarms, totally different setup using an external wire antenna.

wish i had more time for it at the moment, but i'm kinda loaded atm

Lavrishevo

iTrader: (1)

Considering all the time and trouble, why not do an aftermarket two way pager alarm. I had this on my Mustang and it was a great setup. Up to 1 mile range and the FOB would tell you if the locks were locked, trunk was open, if the alarm had gone off while you were at work or at the mall, etc.

Here is an example of a couple of products:

http://www.amazon.com/Python-991-Res...704809&sr=8-13

http://www.amazon.com/Viper-5704-Res.../ref=de_a_smtd

PureDrifter

iTrader: (10)

because the factory alarm works great aside from the range, integrating aftermarket alarms into a car wired up like the later LS' is a pain if you can even find a shop to tackle the job, and carrying around a fob plus your key is annoying.

Kansas

Is this thread really only about the range of the keyless entry? I'm confused since the title say's "alarm range".

The keyless entry range on my 2000 LS400 seems about the length of a football field - 100 yards ... and I mean yards - not feet. The keyless entry range on the 90 LS400 I had for many years was far less - maybe 10 feet on a good day.

PureDrifter

iTrader: (10)

for wireless range, alarm=keyless entry.

Maybe yours is so high because you're out in kansas and there's nothing to get in the way? lol mine is usually only good to 20ft in the open.

Lavrishevo

iTrader: (1)

He did say his 99 was 10 feet and his 2000 was upwards of 300 feet. I'm still under the impression it would be easier to replace the factory setup if the range is so poor. Much of it depends on what a person wants. Remote start in a hot climate like my own is a wonderful feature, especially when you have kids.