ST802414@BROWNVM.BITNET (CHRISTOPHER CHUNG) (10/14/86)
I have a car alarm that pages you when the alarm goes off. It is
supposed to be a 4 watt system that can transmit for 8 miles.
I recently tested it in a very large shopping mall parking lot.
I parked the car about 200-300 feet from the front entrance and
stood outside and had someone set it off. It worked fine. Then I
moved a few feet just inside the glass doors of the mall and it didn't
beep me when the alarm went off. I called the company and they said
that the range could be reduced to be that little.
Does this happen to all the makes of beeper car alarms or is this
a cheaply made alarm system? Is there a way to boost the range with
some kind of booster or an addition antenna (I am using my car radio
antenna)? Does this also happen to CB's and cellular phones or do
they have much higher power transmitters?
Thanks,
Chriscabbie@chinet.UUCP (10/22/86)
>I have a car alarm that pages you when the alarm goes off. It is >supposed to be a 4 watt system that can transmit for 8 miles. >I recently tested it in a very large shopping mall parking lot. >I parked the car about 200-300 feet from the front entrance and >stood outside and had someone set it off. It worked fine. Then I >moved a few feet just inside the glass doors of the mall and it didn't >beep me when the alarm went off. I called the company and they said >that the range could be reduced to be that little. > Does this happen to all the makes of beeper car alarms or is this >a cheaply made alarm system? Is there a way to boost the range with >some kind of booster or an addition antenna (I am using my car radio >antenna)? Does this also happen to CB's and cellular phones or do >they have much higher power transmitters? > >Thanks, >Chris If that is a true 4 watt rf output system then it should transmit much farther than what you are receiving now. In any transmitter system, the single most significant improvement anyone can make to their transmitting range is through antennas. Remember the CB boom? There were literally dozens of antennas to pick from, each one having its virtues and failings. The absolute worst antenna was the one that converted your regular AM FM broadcast radio antenna into a CB antenna. In answer to your question, and solution to your problem, FCC rules notwithstanding, is to replace the antenna. CB radios have a 4 watt output and cell phones have a 25 watt output (if I remember correctly). Rich Andrews ...ihnp4!chinet!cabbie
philip@axis.UUCP (10/31/86)
Your problem is a very common one with radio communications. Most large buildings (shopping centers being generaly the worst) just seem to stop dead almost all radio communications. I have had similar experiences with ham radio equipment, in one case a local repeater (less than a mile away, running 25 watts) just vanished upon entering a department store. I really don't see much hope for your system working in such circumstances. You can probably console yourself with the fact that even if you get your warning while more than a few hundred feet away from the car, by the time you get there either the car or its contents will be long gone. Philip