Re: Spread Spectrum Decoys

[Matthew J Ghio <mg5n+@andrew.cmu.edu>]

> Part of the "hunt and destroy vs. cost to deploy" equation thread about
> spread spectrum networks was forwarded to me. How about putting several
> cheap noise generators on the air as decoys? This might tip the cost
> balance in favor of the network.
>
> The Julieboard Direct Digital Synthesizer board, which only needs numbers
> fed to it from a PC printer port or microcontroller output, can be bought
> wired and tested for $125. Production in volume should be cheaper. So who
> is hunting down transmitters and killing them, and risking a confrontation
> with an armed opponent, for this paltry sum?

Decoys would be easy to build, just build a cruddy receiver, tune it to
a dead station, add an amplifier, and retransmit the noise at another
frequency, and presto, you have a decoy.  Incredibly cheap to build,
(nothing more than a few transistors, capacitors, and resistors, which
don't have to be good quality either); the most expensive thing would
probably be the power supply.  Since the signals would be encrypted,
they wouldn't know static from data (well, they could probably figure it
out if they tried, it just depends on how much effort they want to put
into it).

As for the Julieboard, $125 sounds a bit steep.  If we build the boards
ourselves, it could be done a lot cheaper.  Making rough guesses, we
would need: 8088 (or similiar capacity chip): $2-3.  Small amount of
low-power static RAM (16K or less): $5   eproms: $2-3   UART or
something similiar: $2-3  cpu clock, transistors, TTLs, logic gates,
other paraphinelia to interface CPU to transmitter: $??  Transmitter and
receiver: <$10.  (This is USA $$$ btw...  also I haven't been following
the electronics market too closely lately so correct my guesses if
they're wrong.)  The only problem is finding people experienced enuff to
build the boards.