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Re: Radio communication

To: Bryan Savage <basavage@earthlink.net>
Subject: Re: Radio communication
From: Ralph Forsythe <rf-list@centerone.com>
Date: Fri, 14 Feb 2003 18:04:30 -0700
At 03:52 PM 2/14/2003 -0800, Bryan wrote:

>Ralph, I wonder if the metal car, supported by insulators, develops a 
>charge when the
>round insulators are spinning 2,000 - 3,000 RPM inside a partially 
>confined space?

Potentially, I suppose, sure. :)  Actually a metal car will definitely 
build up a charge at those speeds, that's why aircraft have wires about 
3-4" in length hanging from the trailing edge of the wings and ailerons, 
with the ends (conductors) fanned out.  This helps dissipate the static 
into the air so the avionics don't freak out - and this technology is 
decades old.  Actually that's about the first thing I'd try on this 
subject, just to rule it out.  Also couldn't hurt to make sure the power 
coming into the radio is filtered reasonably well.

Beyond that, if someone's willing to stick a backpack in their car with the 
transmitter stuck on key with an antenna pointing up somewhere while they 
do a run down the salt, I think some trial and error diagnosis with signal 
measurement equipment would improve the results dramatically.  I envision a 
pack with a 2m ham radio, and a small 12v battery good enough to keep it 
keyed for 10 minutes or so - this rules out vehicle power interference as 
well, and the ham radio vs something like a CB lets you legally alter the 
power output to see the effect it has.

Could just be crappy antennas too.  You'd be amazed how much of a 
difference quality equipment and solid connections make when a little 
stress is applied to the components.  Maybe I'll go snag some parts and rig 
up a test bed, could be entertaining... :)

- Ralph

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