New finds & the Woz!

From: Marvin <marvin_at_rain.org>
Date: Mon Oct 30 17:12:31 2000

Dwight Elvey wrote:
>
> "R. D. Davis" <rdd_at_smart.net> wrote:
> >
> > Didn't everyone build one of these, as well as AM and FM radio
> > transmitters for their own radio station, as a kid? The circuitry for
> > a TV jammer is very simple; just requires a few easily made inductors,
> > an RF transistor, antenna, resistors, caps, variable cap and batteries
> > (I used two 9V batteries in mine). The whole thing fit on a hand-made
> > PCB that was about 2" by 2" or less.
>
> Hi
> I saw an article that showed that one could put
> two junction fets together in such a manner that
> it made a negative resistance curve like a tunnel
> diode. I did this and made a FM jammer. It used:
> 1 PFET
> 1 NFET
> 1 pot
> 1 coil
> 1 tuning cap
> 1 bypass cap
> 1 battery
>
> I would think that a standard oscillator could be
> done with less transistors but it would require more
> total parts. I used to hate opera ( still do ). Most
> of this was on FM. A few blanked out signals would eventually
> cause the person listening to hunt for another channel.
> FM goes completely quite when jammed, unlike AM that squeals.

It might be added here that I very much enjoy something called ARDF (Amateur
Radio Direction Finding.) The same techniques can be used to find such
devices rather easily :).
Received on Mon Oct 30 2000 - 17:12:31 GMT