Yeah, that's what I thought. Thx.


"Dave Platt" wrote in message
...
I have a friend who hates dogs (was badly mauled as a child I think) and
is
building a radio-signal transmitting device that activates those electric,
remote control, dog-punishment collars, and sets the voltage way high, too
(some have more than one power setting). Even though there are multiple
models, they all work on the same frequency (he says) and the transmitter
he's building will work in conjunction with a 1000watt (pep) amp through
an
antenna that is mounted high on a mountain with the main lobe aimed at a
nearby city of 2 million.
I don't know what to think about this guy.

I think he's trying to do something which is more than a bit
ill-considered, as well as nasty, certainly capable of causing pain to
dogs who never did him any harm at all, and possibly capable of
causing innocent people to be hurt (what if a touchy dog goes berserk
as a result of being continually shocked at a high setting, and bites
or otherwise injures someone?).

I think he ought to find a healthier way to deal with his dislike of
dogs. It might save him from having to face a big fine from the FCC,
and lawsuits from dog owners or other injured parties.

Is it possible for this thing to
work at all?

Not, I think, in the simplified way you are suggesting that he's
talking about.

For one thing, these devices do not all use the same frequency. I
checked the FCC Part 15 registrations for the remote collar
transmitters sold by Innotek - many of them use 433.92 MHz, but there
are other frequencies used as well (295.0 and 318.0 MHz).

The first of these frequencies is a commonly-used ISM-band frequency
which is used by many license-free devices, including garage door
openers, wireless outdoor thermometers, and so forth. Imagine the
interference he's likely to cause if he tries this stunt!

There are a bunch of other technical problems with what you say he's
suggesting. I won't go into details.

What's more, using this transmitter would be a violation of several
FCC rules and regs even if he has an amateur license (it would be
"broadcasting" which is specifically forbidden). If he doesn't have
an amateur license, more the worse for him!

Then he says he has plans to beef up the amplifier and shock
dogs all over the eastern seaboard.

... and if he does that he'd probably exceeding the 1500-watt legal
limit and setting himself up for another violation.

What's more, I think he's greatly underestimating the effective range
of such a system, even with a kilowatt. Those remote training collars
are deliberately designed to have a limited receiver sensitivity, so
that one person's transmitter doesn't zap dogs down the block and so
that they're less likely to be false-triggered by other ISM-band
transmissions. Add to that the fact that 433 MHz signals are very
much on a line-of-sight-plus-reflections basis, and even a kilowatt
isn't going to give him significant coverage out past the radar
horizon.

Not a joke.

Just a really bad idea, I think.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
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