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From: cabbie@chinet.UUCP
Newsgroups: mod.telecom
Subject: Re: range of car alarms
Message-ID: <8610310650.AA21844@ucbvax.berkeley.edu>
Date: Wed, 22-Oct-86 05:03:39 EST
Article-I.D.: ucbvax.8610310650.AA21844
Posted: Wed Oct 22 05:03:39 1986
Date-Received: Fri, 31-Oct-86 14:35:33 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: chinet!cabbie@ucbvax.berkeley.edu (Richard Andrews)
Organization: chi-net, Public Access UN*X, Chicago IL
Lines: 30
Approved: telecom@xx.lcs.mit.edu

>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