[AMPS] Neighborhood RFI and Amps

[Jon Ogden]

>I am not aware of a "Bullet Proof" answering
>machine,  is there one available?  I have put fettites and
>K-Com filters on the line to the answering machine;  also
>ferrites on the AC power cord for the machine.

Problem is that most of the consumer electronics these days that fall 
under part 15 regulations are just cheap garbage.  They "must accept all 
interference...."  

Lots of phones and answering machines just are not properly shielded.  So 
even if you put filters on the phone lines, it doesn't help because the 
RF is getting into the machine itself and not through the phone line.

We had an interesting experience in college once.  We were getting into 
some cheapo phones the university had put in some offices in a building 
across the road from us.  This building was populated in significant part 
by the typical liberal/environmentalist/"all technology will hurt you" 
kind of people (I am not making that up!).  One guy started complaining 
that if we were getting into their phones and disturbing them, what were 
we doing to their bodies and their health!

So we got a guy from the nuclear radiation lab to come over with his 
field strength meter.  I was in the shack, pointed our TH-6DX right at 
the building and unloaded 1400 Watts of CW right on 20 meters at the 
building.  The field strength meter didn't move.  The guy complained that 
the equipment was obviously defective.  So the gal from our club who went 
with held her HT up to the meter and transmitted.  It moved.  But it fell 
away sharply as she moved it away.

Never heard from the guy again.

We forced the University's telecom department to put FCC spec'd phones in 
the building and we never had a problem.

Perhaps her answering machine is a cheapy.  Maybe if you bought her a 
high end one the problem would go away (I'd test it out in my own shack 
first).  Then she'd get a nice, new fancy machine, she'd be endeared to 
you and you'd never have the problem.

If you really want to screw up the phones, transmit a kilowat on 6 
meters.  Or on 915 MHz if they have one of the 915 ISM band phones! :-)

Oh that's right, that's called malicious interference! :-)

73,

Jon
KE9NA


--------------------------------------------------------------------------
Jon Ogden

jono@enteract.com
www.qsl.net/ke9na

"A life lived in fear is a life half lived."


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