In article . com,
wrote:


There are only 2 types of RF supression wi resistive and inductive.
The latter is often referred to as "magnetic" and is widely available,
but it doesn't seem to work any better than the resistive type. A
significant amount of igniton noise comes from the connection between
the plug and the plug wire, and grounded metal shields over the boots
can help here. There are wire kits with these boots, mostly for German
cars, or they can be made with metal tubing slipped snugly over the
metal bases of the plugs.

I recommend getting a copy of the ARRL Hints and Kinks for Radio Amateurs
book... get one of the mid-fifties editions and there is a whole section
on eliminating ignition noise with homebrew shielding over the plug wires
and shield cans over the distributor.

I agree that with modern resistive wires, things will be a lot better. Back
in the fifties, plug wires were normally copper. Often folks would buy it
on long rolls and terminate it in the shop themselves. Today, plug wires
have a conductive element that is conductive plastic, usually a nylon with
carbon in it, and the wire itself has a few kilohms of resistance. That,
combined with a modern coil design, means you get less high frequency ringing
after the initial spark impulse which cuts way down on the noise.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

N8N wrote:

Just to clarify, he's talking about an Avanti here; having an
all-fiberglass body, suppressing ANY source of noise is of utmost
importance.

I did not realize it was an Avanti. In that case, I think I would be
worried less about noise issues than making sure the radio antenna had
a proper centerpoise, because it can't use the metal body. The more
_signal_ you get, the more noise you can live with.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

63Avanti wrote:
now this is interesting,
I remember fabricating for my neighbor's '62 Ford a metal can with
braided shielded wires to cover his distributor and cables out to the
plugs. I no longer knew when he drove out of his driveway by watching
the patterns on my TV (UHF).

Now for the question.
Any one know if these boots, if self-fabricated, are essentially a
CYLINDER, grounded by contact with the engine block?


On piston-engined aircraft the plugs, wires, and magneto
distributor caps are all metal and are grounded. The shielded cable is
grounded at the mag end and the plug end. There's no ignition noise
from such a setup.

Go he http://www.sacskyranch.com/eng67.htm

Dan

63Avanti wrote:

On Oct 29, 6:06 pm, wrote:

A significant amount of igniton noise comes from the connection between
the plug and the plug wire, and grounded metal shields over the boots
can help here. There are wire kits with these boots, mostly for German
cars, or they can be made with metal tubing slipped snugly over the
metal bases of the plugs.

now this is interesting,
I remember fabricating for my neighbor's '62 Ford a metal can with
braided shielded wires to cover his distributor and cables out to the
plugs. I no longer knew when he drove out of his driveway by watching
the patterns on my TV (UHF).

Any one know if these boots, if self-fabricated, are essentially a
CYLINDER, grounded by contact with the engine block?

Yes. I made some from conduit that extended about 2" above the plugs.
I found it didn't mater whether or not the tops were covered with
metal, but I applied a bead of silicone RTV to prevent the sharp edges
from cutting through the wire insulation. I slit the bottom of each
tube lengthwise to make it easier to press it easier to press around
the hex part of the plug.

"63Avanti" wrote in message
ups.com...
best anti-RF ignition wiring TYPE

background:
I am getting my vintage AM/FM Delco reconditioned with the intent of
getting that "cruis'n feeling" I will also add non-vintage sound
deadening, and other electrical/static improvements noted here and
elsewhere. Thanks for the help.

Check www.magnecor.com for EMI-reducing spark plug wires.

That's the same outfit that told me they could supply 7mm wires but only if
I wasn't putting the stainless shielding back in place.

Brooksie

"Bob M." wrote in message
...

"63Avanti" wrote in message
ups.com...
best anti-RF ignition wiring TYPE

background:
I am getting my vintage AM/FM Delco reconditioned with the intent of
getting that "cruis'n feeling" I will also add non-vintage sound
deadening, and other electrical/static improvements noted here and
elsewhere. Thanks for the help.

Check www.magnecor.com for EMI-reducing spark plug wires.

In article , (Scott Dorsey) wrote:
In article . com,
wrote:


There are only 2 types of RF supression wi resistive and inductive.
The latter is often referred to as "magnetic" and is widely available,
but it doesn't seem to work any better than the resistive type. A
significant amount of igniton noise comes from the connection between
the plug and the plug wire, and grounded metal shields over the boots
can help here. There are wire kits with these boots, mostly for German
cars, or they can be made with metal tubing slipped snugly over the
metal bases of the plugs.

I recommend getting a copy of the ARRL Hints and Kinks for Radio Amateurs
book... get one of the mid-fifties editions and there is a whole section
on eliminating ignition noise with homebrew shielding over the plug wires
and shield cans over the distributor.

I agree that with modern resistive wires, things will be a lot better. Back
in the fifties, plug wires were normally copper. Often folks would buy it
on long rolls and terminate it in the shop themselves. Today, plug wires
have a conductive element that is conductive plastic, usually a nylon with
carbon in it, and the wire itself has a few kilohms of resistance. That,
combined with a modern coil design, means you get less high frequency ringing
after the initial spark impulse which cuts way down on the noise.

They also sold spark plugs with built in resistors.

greg