Re: Comm noise

On Aug 28, 4:55=A0pm, Orval Fairbairn <o_r_fairbairn@[EMAIL PROTECTED]
>
wrote:
> In article
> <2246c861-90f0-4772-9c66-e88303325...@[EMAIL PROTECTED]
>,
>
>
>
>
>
> =A0John <jdupre5...@[EMAIL PROTECTED]
> wrote:
> > I flew yesterday with an owner who pointed out that he is getting a
> > type of crackling noise over both comm radios. =A0The noise is most
> > prevalent when receiving from more distant and weaker transmitters
> > like other aircraft and not noticeabl when receiving from closer more
> > powerful transmitters i.e. the tower.
>
> > The owner has operated the aircraft with every other system turned off
> > including the alternators and has operated on individual magnetos with
> > no change. =A0The most recent change to equipment was an audion panel
> > installation. =A0The noise is not rythmic like ignition noise and does
> > not rise and fall with engine settings like some alternator noise.
=A0I=
t
> > is not as intense as the white noise when checking squelch. =A0It is a
> > type of random crackling like noise.
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> > Any thoughts?
>
> > John Dupre'
>
> I had a similar problem years ago, with one of those cheap whip
> antennas. I switched to a high-quality antenna and got rid of the
> problem.
>
> It appears that moisture had somehow entered the material surrounding
> the metal antenna and was causing arcing.
>
> --
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> - Show quoted text -

I did notice that the upper antenna is loosing some of its coating and
the exposed areas look corroded.  I would replace the antenna for that
reason alone but the owner wants some more confirmation than looks.
The lower antenna (bent whip) doesn't appear corroded although the
whip ****tion is slightly bent.

John Dupre'