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I'm sorry...

Subject: I'm sorry...
From: (Mark Jurras)
Date: Fri, 9 Jun 1995 10:21:13 -0400
I'm Sorry to continue this thread but I don't want misinformation about
something I commented on be taken as fact.

Recently, said:

> A normal short circuit in the radio system would only happen if  the _radio
> hot lead_  touched ground. With the radio on a different circuit and a
> different _reference to ground_ because of the second  battery installed,
> _any_ part of the new circuit met any differing voltage. For example, some
> radios carry chassis ground at the speakers, all do at the antenna. There is
> simply more places and opportunities for a problem to happen, as in _every_
> piece of hardware and wire involved in the second system,  and if it does,
> you have the potential of melting more wires, the radio, or even exploding
>  either of your  batteries.

I guess I wasn't too clear with the poor ASCII art. With the setup I
proposed the radio would see the car chassis as negative ground. This
way radio, speaker and antenna grounding are normal. The only abnormal
voltage would be the power lead to the radio. It is 12V more positive
than the chassis just like a negative ground car. The rest of the car
wiring is 12V more negative than the chassis. If the radio power lead
touches a hot wire from the car wiring you have 24V and the FUSE blows.
Remember I said "don't forget the fuse"

I used a second battery to get my point across. Actually a modern DC-DC
converter is a better choice. It can be placed near or attached to the
radio so the radio hot lead need only be a few inches long. And you
won't here the "whine" unless you are a follower of this thread.

> You comment about originality not being maintained if you go to neg.
> ground....Well, first, you are putting in a non-original radio, and then
> proposing putting in a whole second battery and wiring that
> raises the question...which has more impact on originality, an invisible
> wire-switching job and a little soldering inside the tach, or adding wires,
> batteries and hardware???

Just because a change is invisible the car is still not original.
Anyway If you recall the beginings of this way too long thread a poster
said that he did not want to convert the car. I just assumed that it
was for originality. That is why I won't convert my car.

Comments Welcome!

- -Mark      = =o&o

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