In a message dated 98-02-28 14:06:57 EST, you write:
> I am sure I missed this before, but I would like to install a good
> modern radio/cd/tape etc. in my 1963 TR4 . Can I purchase positive
> ground radios, or do I have to "mess" with Dr. Lucas ?
> Thanks, this a great group !
Dennis, I went throught this is '91. I did a lot of research and came up with
three ways to get some sounds. Here they are in no particular order of
importance:
1) Get a "period" positive ground radio. This would probably be a tube type
radio with a switch that will allow positive or negative grounding. There are
disadvantages to this in that most "period" radios were AM only and tape decks
did not come in until the '70's. Also if the tubes go bad, it is very
difficult to get new tubes - no-one makes them anymore. But, there was a
thread on this list which gave a line to several companies who have radios for
LBC's for sale. One of those companies might have a modern radio which has
been converted for positive ground use.
2) Convert the car to negative ground. DANMAS from the list has a good
article on this at the VTR website (www.vtr.org). This is not difficult to do
and if done correctly cannot even be seen by looking at the car. Conversion
also eliminates any problems with other modern accessories.
3) Buy an inverter to invert the battery voltage on the radio circuit from
positive to negative ground. Basically what this does is isolate the radio on
its own electrical circuit - a circuit that looks like a negative ground to
the radio. This is what I did because I wasn't on the list and did not
realize how easy it would have been to convert the whole electrical system
over to negative ground. Biggest problem I had was designing a seperate
source to feed current to the radio when the ignition was off. Modern radios
need a small amount of current to maintain the memory for the station presets
and the clock, which they all seem to have. To get this constant trickle of
current, I inserted a small "gel-cell" battery in the circuit - between the
inverter and the radio. I mounted the inverter and the gel-cell underneath
the dash over the passenger's legs in the footwell. It can't be seen at all.
The whole thing works fine, but it cost about $125 for the inverter and the
gel-cell.
So, its your choice. Probably the easiest thig to do is convert the car over
to negative ground. If you do it right, it will not even be apparent that it
has been done.
If it matters - One thing I have found is that judges at meets do not seem to
mark off for the radio itself if it looks like a period radio. The radio I
put in is a JVC AM/FM cassette deck with two knobs - one for power and one for
tuning. The pre-sets are small enough so that the dash doesn't look like a
starship. I mounted two decent speakers under the bow cover behind the seats.
Sound is good even at speed with the top down. Hope this helps. If I can be
of further help - please give a shout. Cheers.
Art Kelly
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