From: Henry Howard <>
>
> At 12:05 AM 1/15/05 +0000, you wrote:
>
>>>using the shield as ground and then double wire the
>>>other microphone leads (if one line were to break I would have a
>>>backup feed).
>
>
> That is the primary purpose of the 4 wire (also known as star quad)
> cable.
The primary purpose of star quad is to minimize unwanted noise or signal
loss. It has nothing to do with redundant wires for breakage. In fact,
as I've pointed out if any of the wires break the inductance shifts
drastically for the worse. Replace cables with broken wires. Or repair,
as almost always the break is at the solder joint in the connector.
> The double wire is not to insure against breakage, but the inner conducto=
rs
> are wound within the jacket in opposite directions such that a
> signal from outside the cable (like crossing a power cord) will
> be induced equally in both wire in opposite phase so that the
> interference is cancelled out.
Star quad winds the 4 inner conductors twisted the same way. Exactly the
same sort of method as a twisted pair core, except there are 4 wires
involved. The wires maintain their order around the circle throughout
the length. No crossover. It's that the star quad reduces the loop size
of the system that is the key. Effectively the two signal directions
follow the same path, down the center of the cable.
Walt
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