Re: Radio static/Defroster

[STEADIRIC@aol.com]

>Another data point: it is signal strength dependent.  I'll be on Route 4 in
>Durham NH listening to Maine Public Radio or WGBH in Boston, and turning on
>the defroster will trash the reception.  If I then switch to WUNH, whose
>antenna I am then right under, the static almost disappears.  It's not being
>masked by volume - even if they are playing something quiet this is apparent
>.  So, dear listers, if you have any knowledge of RF arcanery, what's up? 
>Seems to me that putting the defroster into an electrical circuit is causing
>it to interfere in the antenna's ability to pick up a clean signal.  Is this
>how radio works?  can the defroster "out-antenna" the regular antenna, or
>sheild it?  Is it acting as a diffraction grating/prism?  Could there be
>some sort of filtering that would help, i.e. a small inductor in series with
>the defroster, and/or a high quality capacitor to ground right at its
>connections?

First off when your directly under (or within 2 miles) of a broadcast 
"Stick" (Tower for those not in the biz...) your actually getting a 
greatly REDUCED signal (On the order of 70db...) Because of antenna 
polarization patterns.  I think that you have some problem with the 
antenna and ground plane because what your describing is a Faraday shield 
..... The other thing that you might look at is your alt, it's voltage 
reg and it's diodes.... If it is passing ANY A/C it would be reradaited 
by the defroster grid and it might just be powerful enough to mask you 
antenna... (Think Jammer here Joe...)

>Is this quest doomed to failure? 

It just might be... But I'd look at the alternator.......


Later!


Eric Fletcher
'87 5KCSTQIA2RSR2B
St. Louis, MO

STEADIRIC@aol.com