Radio Antenna

SD Glenn · June 22, 2011, 06:49:10 PM

Tod and Bill, thanks for the input on my antenna problem. We got it fixed. Chet gave me some leads on checking with a volt meter, We got it fixed, thanks a whole lot.
(The radio is on its own circuit) When I started the Volt meter testing, I started with the ground on the car body and positive lead to my 12V lead to the radio, the voltmeter showed no voltage, then I started the car, immediately I had a spike of .08 volts, and the radio died. I took the switch down from the dash (I have a switch on the dash to shut off the 12V system to the radio) and dropped it on the floor, the radio came back on with the engine running. Surprised me. As I moved the switch back toward the dash the radio would die. The switch was mounted only about a foot to the left of the coil, a little further away and there is no longer a problem.(there is about 4 inches difference of where it works or not) (The coil and Ignition Key are one assemble on the back side of the dash) I reckon the RFI was putting the extra voltage input to tha radio. Thanks to everyone. IT WORKS.
SD Glenn

SD Glenn · June 19, 2011, 11:44:16 PM

Thanks Tod, I just did put in Copper Wire though out the ignition system. I will change those tomorrow and see what happens, and plugs if I can find any. Lots of luck there I am sure. lol
Later, (Happy fathers day all.)

SD Glenn

TodFitch · June 19, 2011, 05:27:17 PM

Quote from: SD Glenn on June 19, 2011, 02:24:52 PM
Where did I screw up. Bill, you have a point, but how do I fix it. OK, this is what is happening.

The radio and CD Player work great... When the car is not running. As soon as I turn on the ignition ther NO problem, working good. AS SOON as I start the engine, There is nothing, it seems to shut down the whole radio. No sound at all, even the LED display does not work right. Any Ideas will be appreciated, maybe suppressors on the generator and distributor???? There is definitely NO conection between the radio system and the car body, or the car wireing.Thanks
Has anybody done this before, curious....

BUT not the CD Player, it still is working with the car running. (another problem with that but I know what that is..When the vehicle is moving it skips tracks, radio is vertical, needs to be horizonal I think)

SD Glenn

Sounds like a lot of RFI (radio frequency interference) from the engine. Before looking at the generator which mostly puts electrical noise into the wires, I'd look at your ignition system. Are you running copper spark plug wires? That would do it right there. The reason they put resistor plugs in and/or resistor type high tension spark plug wires is to control RFI so that radios in the car can run, not so the engine runs better.

SD Glenn · June 19, 2011, 02:24:52 PM

Where did I screw up. Bill, you have a point, but how do I fix it. OK, this is what is happening.

The radio and CD Player work great... When the car is not running. As soon as I turn on the ignition ther NO problem, working good. AS SOON as I start the engine, There is nothing, it seems to shut down the whole radio. No sound at all, even the LED display does not work right. Any Ideas will be appreciated, maybe suppressors on the generator and distributor???? There is definitely NO conection between the radio system and the car body, or the car wireing.Thanks
Has anybody done this before, curious....

BUT not the CD Player, it still is working with the car running. (another problem with that but I know what that is..When the vehicle is moving it skips tracks, radio is vertical, needs to be horizonal I think)

SD Glenn

Wm Steed · June 18, 2011, 12:10:17 PM

You might encounter a lot of trouble trying to operate a modern AM-FM/CD radio in your 6v positive ground car.
Up to about 1963, when alternators started to be the standard charging system, vehicle chassis were not well grounded. Most vehicles built from about 1963 have whats called a BONDED chassis. That meaning that the entire chassis/body is well connected to stop the generator/alternator from radiating a signal to the atmosphere to interfere with general TV and radio broadcasting.

People that have been working on old cars for a long time will recall all the "suppressors" that old cars had on the generator, fuel gauge, etc., so you could hear the radio when the car was running.

As a general rule... the "chicken wire" in the tops of '36 and earlier cars work very good as an antenna, that is on AM radios. I have never tried to use the chicken wire for an antenna on an AM/FM radio.

The 12v aux battery you have to run your AM/FM/CD will last for hours/days before it needs charging. I would not suggest you hook the 12v up to the frame/chassis to use as a common ground... Run two wires from the battery to the AM/FM unit. If you get a lot of static in the AM/FM when the car is running you will have to install suppressors on the generator, etc.... Bill

SD Glenn · June 18, 2011, 01:04:05 AM

I stopped by the local Harley Davidson shop today. They had an antenna that fits behind the fairing on there Bikes and works very well there, should work on a Plymouth then Right? Haven't looked into where to install it yet, maybe under the sunvisor, Maybe?

SD Glenn

plym_46 · June 16, 2011, 12:31:08 PM

get a cheapie universal antenna and mount it under your running board.

TodFitch · June 16, 2011, 02:22:33 AM

Quote from: SD Glenn on June 16, 2011, 12:04:45 AM
Thanks Tod,
One more thing.... The CD/Radio is hooked to a 12V Battery in the trunk and not grounded to the car body at all, only the 12V Battery, negative ground. What happens if the Antenna system completes a ground to the car body with the positive ground?
Thanks,
SD Glenn

As long as there are no wires connecting the 6v car power to the 12v radio power there should be no problem. Two separate circuits, just happen to use the body/frame as a return path for each.

SD Glenn · June 16, 2011, 12:04:45 AM

Thanks Tod,
One more thing.... The CD/Radio is hooked to a 12V Battery in the trunk and not grounded to the car body at all, only the 12V Battery, negative ground. What happens if the Antenna system completes a ground to the car body with the positive ground?
Thanks,
SD Glenn

TodFitch · June 15, 2011, 11:32:20 PM

In 1933 and I assume other years, the car came factory wired for a radio antenna by having a lead attached to the chicken wire that ran down the passenger side windshield post. Not sure how well it actually worked... And it would be better for AM than FM which they did not have back then.

If I recall correctly, 1930 was the first year for the all steel body. If your 29 is wood framed then I'm not sure how well it will work as each seam in the body needs to be making good electrical contact to have the body act as one big ground plane. I guess it is worth a try.

SD Glenn · June 15, 2011, 10:17:38 PM

I have installed a CD Player/Radio in my 29 Plymouth coupe. I installed it behind the seat in the storage box, along with the speakers. My question is: Is it possible to hook up the "chicken wire" in the roof to use it as the antenna? Or what would be the best way/or kind of way, to hook up an antenna so it isn't seen? Any ideas?
Thanks,
SD Glenn