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Re: Intercom Installation problem

Subject: Re: Intercom Installation problem
From: Gramin@aol.com
Date: Fri, 21 Feb 1997 19:59:39
In a message dated 21/02/97  05:05:06, you write:

>they can work just as well as 
>transmitting antennas for any electrical noise running around in the 
>primary side of the ignition system.

Not if  the frequency ranges are different.   If the noise spectrum "running
around the primary side" is wide enough to reach the region where  leads of
this length act as efficient radiators (100Mhz up) the only way they could
affect the audio  is by saturating some non-linear element in the front end
of  the receiver.  That's much more likely from the power and rise times you
have   in the output lines  (we used to make quite good radar jammers with
spark plugs ).  If the input is just a gate, then a capacitor could be used
to  kill all high frequencies there. Might be worth trying that, but it would
be better to know the internal circuit details first, it might be an
amplifier stage !

Graham


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