Comm noise

I flew yesterday with an owner who pointed out that he is getting a
type of crackling noise over both comm radios. The 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. The most recent change to equipment was an audion panel
installation. The noise is not rythmic like ignition noise and does
not rise and fall with engine settings like some alternator noise. It
is not as intense as the white noise when checking squelch. It is a
type of random crackling like noise.

Any thoughts?

John Dupre'

Solar activity...Sun spots...solar flares....
Signal to noise ratio...
typical for any radio receiver.

Aircraft type? Does it on the ground? In air only, slowflight as well as
cruise speed?

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


"John" wrote in message
...
I flew yesterday with an owner who pointed out that he is getting a
type of crackling noise over both comm radios. The 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. The most recent change to equipment was an audion panel
installation. The noise is not rythmic like ignition noise and does
not rise and fall with engine settings like some alternator noise. It
is not as intense as the white noise when checking squelch. It is a
type of random crackling like noise.

Any thoughts?

John Dupre'

In article
,
John wrote:

I flew yesterday with an owner who pointed out that he is getting a
type of crackling noise over both comm radios. The 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. The most recent change to equipment was an audion panel
installation. The noise is not rythmic like ignition noise and does
not rise and fall with engine settings like some alternator noise. It
is not as intense as the white noise when checking squelch. It is a
type of random crackling like noise.

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.

--
Remove _'s from email address to talk to me.

On Aug 28, 3:12*pm, "RST Engineering" wrote:
Aircraft type? *Does it on the ground? *In air only, slowflight as well as
cruise speed?

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
* * * * --Aristotle

"John" wrote in message

...



I flew yesterday with an owner who pointed out that he is getting a
type of crackling noise over both comm radios. *The 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. *The most recent change to equipment was an audion panel
installation. *The noise is not rythmic like ignition noise and does
not rise and fall with engine settings like some alternator noise. *It
is not as intense as the white noise when checking squelch. *It is a
type of random crackling like noise.

Any thoughts?

John Dupre'- Hide quoted text -

- Show quoted text -

F33 Bonanza. Slow as well as cruise flight. I was only told about it
once we were airborne and didn't think to listen othewise.

John Dupre'

On Aug 28, 4:55*pm, Orval Fairbairn
wrote:
In article
,





*John wrote:
I flew yesterday with an owner who pointed out that he is getting a
type of crackling noise over both comm radios. *The 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. *The most recent change to equipment was an audion panel
installation. *The noise is not rythmic like ignition noise and does
not rise and fall with engine settings like some alternator noise. *It
is not as intense as the white noise when checking squelch. *It is a
type of random crackling like noise.

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.

--
Remove _'s *from email address to talk to me.- Hide quoted text -

- 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 portion is slightly bent.

John Dupre'

In article
,
John wrote:

On Aug 28, 4:55*pm, Orval Fairbairn
wrote:
In article
,





*John wrote:
I flew yesterday with an owner who pointed out that he is getting a
type of crackling noise over both comm radios. *The 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. *The most recent change to equipment was an audion panel
installation. *The noise is not rythmic like ignition noise and does
not rise and fall with engine settings like some alternator noise. *It
is not as intense as the white noise when checking squelch. *It is a
type of random crackling like noise.

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.

--
Remove _'s *from email address to talk to me.- Hide quoted text -

- 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 portion is slightly bent.

John Dupre'

That would do it on the upper antenna -- especially if it has flown
through rain. Is the antenna airfoil-shaped or one of theose
wrapped-metal, round ones? I had the latter and it eventually succombed
to moisture.

--
Remove _'s from email address to talk to me.

On Aug 29, 10:11*am, Orval Fairbairn
wrote:
In article
,





*John wrote:
On Aug 28, 4:55*pm, Orval Fairbairn
wrote:
In article
,

*John wrote:
I flew yesterday with an owner who pointed out that he is getting a
type of crackling noise over both comm radios. *The 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. *The most recent change to equipment was an audion panel
installation. *The noise is not rythmic like ignition noise and does
not rise and fall with engine settings like some alternator noise. *It
is not as intense as the white noise when checking squelch. *It is a
type of random crackling like noise.

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.

--
Remove _'s *from email address to talk to me.- Hide quoted text -

- 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 portion is slightly bent.

John Dupre'

That would do it on the upper antenna -- especially if it has flown
through rain. Is the antenna airfoil-shaped or one of theose
wrapped-metal, round ones? I had the latter and it eventually succombed
to moisture.

--
Remove _'s *from email address to talk to me.- Hide quoted text -

- Show quoted text -

Wrapped metal round antenna with a tear shaped base.

Orval, you are chasing your tail. If it does it on BOTH radios, the
probability of a dual identical fault is practically zero, especially if the
noise on #1 correlates with the noise on #2.

Sure, go ahead and shotgun the thing and then come back in here lamenting
that you spent $X amus on the problem and it is still there.

I've never seen a "wrapped metal" com antenna in my career. Can you point
me to a manufacturer and model so I can see for myself. Most of what looks
like "wrapped metal" is in fact a fiberglass soda straw with either braid or
foil inside the straw.

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


"Orval Fairbairn" wrote in message
news
In article
,
John wrote:

On Aug 28, 4:55 pm, Orval Fairbairn
wrote:
In article
,





John wrote:
I flew yesterday with an owner who pointed out that he is getting a
type of crackling noise over both comm radios. The 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. The most recent change to equipment was an audion panel
installation. The noise is not rythmic like ignition noise and does
not rise and fall with engine settings like some alternator noise. It
is not as intense as the white noise when checking squelch. It is a
type of random crackling like noise.

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.

--
Remove _'s from email address to talk to me.- Hide quoted text -

- 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 portion is slightly bent.

John Dupre'

That would do it on the upper antenna -- especially if it has flown
through rain. Is the antenna airfoil-shaped or one of theose
wrapped-metal, round ones? I had the latter and it eventually succombed
to moisture.

--
Remove _'s from email address to talk to me.

In article
,
John wrote:

On Aug 29, 10:11*am, Orval Fairbairn
wrote:
In article
,





*John wrote:
On Aug 28, 4:55*pm, Orval Fairbairn
wrote:
In article
,

*John wrote:
I flew yesterday with an owner who pointed out that he is getting a
type of crackling noise over both comm radios. *The 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. *The most recent change to equipment was an audion panel
installation. *The noise is not rythmic like ignition noise and does
not rise and fall with engine settings like some alternator noise. *It
is not as intense as the white noise when checking squelch. *It is a
type of random crackling like noise.

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.

--
Remove _'s *from email address to talk to me.- Hide quoted text -

- 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 portion is slightly bent.

John Dupre'

That would do it on the upper antenna -- especially if it has flown
through rain. Is the antenna airfoil-shaped or one of theose
wrapped-metal, round ones? I had the latter and it eventually succombed
to moisture.

--
Remove _'s *from email address to talk to me.- Hide quoted text -

- Show quoted text -

Wrapped metal round antenna with a tear shaped base.

Yup -- That's the kind that I replaced! Apparently, they last only so
long, then they get wet inside.

--
Remove _'s from email address to talk to me.