Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!emory!rsiatl!jgd
From: jgd@rsiatl.UUCP (John G. DeArmond)
Newsgroups: sci.electronics
Subject: Re: Stereo Amplifier Jamming
Message-ID: <3774@rsiatl.UUCP>
Date: 28 Aug 90 06:48:48 GMT
References: <1990Aug27.215353.5186@murdoch.acc.Virginia.EDU>
Organization: Radiation Systems, Inc. (a thinktank, motorcycle, car and gun works facility)
Lines: 56

dg9g@maxwell.acc.Virginia.EDU (David Guercio) writes:

>I'm trying to figure out how to make an amplifier jammer, for apartment
>use.  For instance, if someone is in the next apartment and plays the
>stereo too loud, you could switch the thing on and make a horrible
>grinding noise on their amplifier until they turn it down.

>I'm assuming that the neighbor is on the same power distribution phase
>as me.

>Whatever you suggest will not have to pass the FCC or Underwriter's
>Laboratory, so please be creative.

Kinda mutually exclusive by definition :-)

One of the easist hash generators to come by is the common ordinary 
universal motor as found in vacuum cleaners or or sewing machines.
Since the normal objective is to make mechanical power with the 
minimum of sparking and intereference, some doctoring is called for.


Dissassemble the victim motor to the extent necessary to gain access to
the commutator and brushes.  Remove the brushes.  Cut enough of the 
spring from each brush such that it only lightly touches the commutator.
Reinstall the brushes.  Power the motor up and while it is operating,
slowly drip some graphite oil onto the commutator.  One drop at a time
should do it.  Allow the surface to "dry" between drops.  When you
are finished, the motor should be making those nice loooong commutation
sparks that are typical of a partially shorted commutator.  Next, if
possible, rotate the brush assembly a few degrees to find a more 
(dis) advantageous commutation angle.  The sparks should really be 
flying at this point.

Inspect the motor to make sure there are no hash bypass capacitors
across the brushes or incoming leads.  Finally, fasten a couple of
feet of insulated wire to each terminal and stretch them out to form
a dipole.  Make a mount for the motor so that it can be placed 
near to the offending wall.  It is best if you can operate the motor
on reduced voltage, as the above modifications will dramatically
shorten its life.  During operation, you may need to apply graphite
oil occasionally to the commutator to re-enhance the spark generator
effect.

As a final note, pray that your neighbor does not have a shot gun or
else pray that the FCC catches you before he does.  The above technique
should fall squarely under the legal definition of malicious intereference.
You might have a lot more luck with the guy taking him out and buying
him a beer and discussing a compromise.

John

-- 
John De Armond, WD4OQC  | We can no more blame our loss of freedom on congress
Radiation Systems, Inc. | than we can prostitution on pimps.  Both simply
Atlanta, Ga             | provide broker services for their customers.
{emory,uunet}!rsiatl!jgd|  - Dr. W Williams |                **I am the NRA**