Remember, anything that is transmitted can be jammed. If a person is close
to the reciever or transmitter it can be easily jammed. (I demonstrated
this to a salesman at a convention when he said "Our units cannot be
jammed" by just placing my handheld tranciever next to his reciver and
transmitting. It de-sensed his reciever so much that it could no longer
recieve it's data.) Spending huge cash on jam-proofing must have a really
good reason, and a business or home security system isn't one. (How many
B&E artists have a VanEck or other item with higher technology other than
a crow bar.) In fact, the government cant come up with a jam-proof
system.. they just transmit at Gagillion watts to overcome the jamming
signal.

On Wed, 1 Jul 1998, Brian Robinson wrote:

> It will be difficult to find a system that is both cheap and has a high
> jamming margin.  I don't the details on why you need a high jamming
> margin,  but there are a bunch of vendors selling cheap spread-spectrum
> LAN cards;  you could always just buy a few and see if they work in your
> application.
>
> There are more expensive radios made for the transit (i.e., railroads,
>  metros) market that are more jam-resistant,  but also much more
> expensive.
>
> Hope this helps.
>
> Brian Robinson
> hbrobinson@lucent.com
>
>  ----------
> From:  PICLIST [SMTP:PICLIST@MITVMA.MIT.EDU]
> Sent:  Wednesday, July 01, 1998 9:57 AM
> To:  PICLIST
> Subject:  Spread Spectrum radios
>
> There has been a few threads on these type of radios and I wanted to let
> the
> list know that in a few weeks there will be some relatively cheap systems
> available which will have very high jamming margins. This will be both
> frequency hopping and also direct sequence.
>
> If of interest please let me know.
>
> Thanks,
>
> Peter Grey
> Neosystems
> Australia
>