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I want to install a radio in my 67 BJ8, which is earth positive. Since I couldn't find an earth positive radio I am buying a new radio and a power inverter. My questions are is there an antenna that I can install that does not require cutting a hole in my precious car (possibly something that attaches to the rear bumper) and how do I attach it to the power source other than directly to the battery?
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Radio for BJ8
- Thread starter Bragor188
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wim janssen
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Concerning the antenna: I have it installed underneath the right hand door at the chassis. It fits perfectly!!
Greets
Wim
[ 09-03-2003: Message edited by: wim janssen ]</p>
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<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Jon12:
If your car has a positive ground why couldn't you hook up the pos. to ground and neg to pos.?
Sorry about the stupid question, Jon<hr></blockquote>
Jon,
On most available modern electronic devices they are setup for negative ground. This means that the metal radio chassis (can) is permanently connected to the negative power terminal of the radio.
If you tried to install this radio in a positive ground car which has a hot negative terminal, there would be a direct short circuit from the neg. battery supply terminal thru the metal radio can to the positive side of the battery.
There are a couple of ways around this. One is to insulate all of the radio metal from ground (the car metal) with insulated radio mounting hardware. This still presents the problem of having the antenna shield connected to the wrong polarity. With this method it is very easy for the metal radio chassis (can) to become accidentally grounded & burn something up.
The second method uses an electronic, transformer isolated DC to DC converter which effectively reverses the battery pos & neg connections to the radio & prevents problems.
Lastly, many people convert the car from positive ground to negative ground so that all modern negative ground accessories may be connected without problems.
D
If your car has a positive ground why couldn't you hook up the pos. to ground and neg to pos.?
Sorry about the stupid question, Jon<hr></blockquote>
Jon,
On most available modern electronic devices they are setup for negative ground. This means that the metal radio chassis (can) is permanently connected to the negative power terminal of the radio.
If you tried to install this radio in a positive ground car which has a hot negative terminal, there would be a direct short circuit from the neg. battery supply terminal thru the metal radio can to the positive side of the battery.
There are a couple of ways around this. One is to insulate all of the radio metal from ground (the car metal) with insulated radio mounting hardware. This still presents the problem of having the antenna shield connected to the wrong polarity. With this method it is very easy for the metal radio chassis (can) to become accidentally grounded & burn something up.
The second method uses an electronic, transformer isolated DC to DC converter which effectively reverses the battery pos & neg connections to the radio & prevents problems.
Lastly, many people convert the car from positive ground to negative ground so that all modern negative ground accessories may be connected without problems.
D
Chaps
Lots of them available in the UK. Most of the more upmarket Radiomobiles have a polarity switch so you can select Positive or negative earth.
I don't know what shipping to the US would cost, but I bought my radiomobile (LW/MW) for ÂŁ20 UKP.
Well worth investigating I would have thought.
I'll look out some Companies for you.
PS I really wouldn't go down the converter route. A friend of mine did this and ended up with a fried harness, due to a short. With a car like a Healey vibration and bumps and crashes over uneven road surfaces are inevitable. Either convert to negative or get a dual polarity radio unit.
Cheers
[ 09-04-2003: Message edited by: BEEJAY7 ]</p>
Lots of them available in the UK. Most of the more upmarket Radiomobiles have a polarity switch so you can select Positive or negative earth.
I don't know what shipping to the US would cost, but I bought my radiomobile (LW/MW) for ÂŁ20 UKP.
Well worth investigating I would have thought.
I'll look out some Companies for you.
PS I really wouldn't go down the converter route. A friend of mine did this and ended up with a fried harness, due to a short. With a car like a Healey vibration and bumps and crashes over uneven road surfaces are inevitable. Either convert to negative or get a dual polarity radio unit.
Cheers
[ 09-04-2003: Message edited by: BEEJAY7 ]</p>
I bought a nice period-correct, positive ground Blaupunkt radio from a chap in Germany who restores old radios, Klassik radio or something similiar. It should pop up on an internet search.
I would avoid the inverter route, they tend to whistle during operation and it is not a very pleasant sound.
I would avoid the inverter route, they tend to whistle during operation and it is not a very pleasant sound.