Newsgroups: comp.risks
X-issue: 5.68
Date: Fri, 27 Nov 87 12:33:09 EST
From: mnetor!utzoo!henry@uunet.UU.NET
To: RISKS@kl.sri.com
Subject: Re: Garage Door Openers

> An Army spokesperson denies that the Army is radiating anything that 
> would lock up these receivers.

What they may actually have said, or meant to say, is that they are not
radiating anything that *should* lock up those receivers.  Much consumer
electronic equipment is cheaply (in both senses of the word) designed and
is very vulnerable to interference from signals that theoretically it should
ignore.  Things like ham-radio transmissions interfering with TV reception
are often the fault of the TV set, not the perfectly-legal-and-proper radio
transmitter.  The problem actually is not restricted to consumer equipment;
things like police radars are often rather unselective as well.

Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,decvax,pyramid}!utzoo!henry