Radio antenna

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70Duster340

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My Duster was purchased from the other owner with fiberglass fenders. It had an in-dash radio/cassette player which never worked. Knowing that the AAR Cuda and Challenger T/A came with fiberglass hoods and the antenna was relocated to the rear quarter panel, is this what I need to do to get a new radio to function? Or since the hood is metal, will the antenna work in the original location as long as it is properly grounded?

Thanks
 
An antenna does not need grounding to work. If you go the rear fender mount make sure the cord will reach. I imagine you'd need 10 feet or more.

Also, if you don't want to drill a hole in the car, they make no-hole antennas.
 
There's already a hole in the fender on the passenger side front from the antenna that the previous owner had installed.
So, why did they move the antenna to the rear passenger quarter panel on an AAR Cuda if grounding wasn't the issue. I understand that the fender was metal, but the hood was fiberglass. Got any info on that?
 
Nope, sorry. I know some on stereo and antennas, but you're on your own for Barracuda specific info.
 
Will try and remember to ask a friend that restores them, but the fenders were steel, only the hood was glass. My Dart has a fiberglass hood , just like many others, no radio problem. They didn't put the antenna on the rear of A- 12's either.
 
Nope, sorry. I know some on stereo and antennas, but you're on your own for Barracuda specific info.
Well, this isn't necessarily Barracuda specific information I'm requesting. I'm just wondering why (according to the factory) that a fiberglass hood would cause a radio to not function properly. If they felt the need to move the antenna to the rear, it must have been causing a reception issue.
 
The antenna doesn't mount in the hood, so, why is that an issue? Am I missing something here? Fiberglass fenders are a different story. The earlier cars required the antenna to be grounded. Not sure on your year and model. Try running a temporary ground wire to the antenna housing to see if that helps.
 
From what I understand/remember, unlike a steel hood, fiberglass hoods don't shield the antenna from all of the RFI/EFI the ignition system puts out, so they had to move the antenna to the rear fender.

This isn't a Mopar specific thing, as both GM and Ford did this as was well on certain "one-off" models.
 
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The antenna doesn't mount in the hood, so, why is that an issue? Am I missing something here? Fiberglass fenders are a different story. The earlier cars required the antenna to be grounded. Not sure on your year and model. Try running a temporary ground wire to the antenna housing to see if that helps.
I have tried to research this. Apparently the fiberglass hood somehow created some sort of interference with the radio. Since my Duster has fiberglass fenders, and the radio didn't work when I bought the car, I want to be reasonably sure that the fiberglass fenders won't interfere with the radio I'm planning on installing.
 
I would think that you'd have issues with your antenna working well with fiberglass fenders. Antennas like a large, flat, smooth ground plane to operate at their peak. Fortunately for us, we're only receiving and not transmitting so you really don't need your antenna operating at its peak to be able to receive radio stations. Problem is that when your antenna is attached to a fiberglass fender, you're having it basically operate to its worst ability.
 
Where would you suggest I move it? The hood is metal, but the fenders are the fiberglass I'm concerned about.

I wouldn't move it if it were me. I'd rather come up with a different way to listen to music, like a hidden bluetooth receiver, than drill a large hole in a spot where it doesn't belong on one of these cars.

First try grounding the antenna. Run some temporary alligator clip leads from the antenna ground to various grounds on the body and see if your radio stations come in better. If they do, then you know you can just add a permanent ground wire as a work around for the fiberglass issue.
 
Thanks. I was intending to run a ground wire for the antenna. My concern was if the fender being fiberglass would somehow effect the radio reception.
 
I spent years working in avionics with signaling systems. The the way an antenna works is based on the frequency of the signals being transmitted and the associated wavelengths. You need a full half wave and the antenna itself is only 1/4 with the other quarter developed from the ground plane it is attached to, just the way it works. The fiberglass hoods on T/A’s and AAR’s does not provide an effective ground plane thus the antenna is located in the rear for proper function. Hope this is helpful and good luck. Note that the intensity of the spark signal can still mess up AM radio signals and often will require addition of a filter (capacitor) in the power source for proper operation.
 
There's already a hole in the fender on the passenger side front from the antenna that the previous owner had installed.
So, why did they move the antenna to the rear passenger quarter panel on an AAR Cuda if grounding wasn't the issue. I understand that the fender was metal, but the hood was fiberglass. Got any info on that?
THe fiberglass hood has nothing to do with a antenna on the metal fender. I would imagine they did it for looks more than anything. Good question though.
 
THe fiberglass hood has nothing to do with a antenna on the metal fender. I would imagine they did it for looks more than anything. Good question though.
Toolman - my experience with antennas indicates the ground plane is vital, lots of math to support that. It is a complex issue but it is the reason the antennas are on the rear.
 
I'm a retired Electrical Engineer, Marksmopar is 100% correct, the ground plane is critical period, not just a ground, the hood surface and fenders need to be metal period. Mount the antenna on rear quarter panel, or replace Fiberglass with steel.
 
I'm a retired Electrical Engineer, Marksmopar is 100% correct, the ground plane is critical period, not just a ground, the hood surface and fenders need to be metal period. Mount the antenna on rear quarter panel, or replace Fiberglass with steel.
If that's the case, how does Chevy get a radio to work on an old Corvette where the whole body is fiberglass?
 
Never owned a vette and your assumption that there no ground plane would likely be wrong. This is the laws of physics, called radio wave propagation. A mast antenna requires a ground plane. Cudamark think about it two professionals have said a ground plane is required, if I were to guess, just a guess, there's steel embedded in the fiberglass. I worked for 30 yrs developing Rf designs Transmitters 5 to 10,000,000 watts, receivers 100 khz to 10 Ghz, and antennas 100 khz to 5 Ghz.
 
Never owned a vette and your assumption that there no ground plane would likely be wrong. This is the laws of physics, called radio wave propagation. A mast antenna requires a ground plane. Cudamark think about it two professionals have said a ground plane is required, if I were to guess, just a guess, there's steel embedded in the fiberglass. I worked for 30 yrs developing Rf designs Transmitters 5 to 10,000,000 watts, receivers 100 khz to 10 Ghz, and antennas 100 khz to 5 Ghz.
I never made any sort of assumption. That's why I asked how they did it on a fiberglass bodied car.
 
I never made any sort of assumption. That's why I asked how they did it on a fiberglass bodied car.

I'm an RF technician myself who has swept thousands of antennas but I don't have experience sweeping antennas in the AM/FM range that our radios use.

The ground plane is absolutely vital for transmitting and while it's important for receiving, it's not nearly as important. In our field, we always say you need your antenna dialed in to be able to transmit correctly but you can basically receive with a coat hanger. I've tested plenty of antennas with pretty sketchy ground planes and it really just depends on the antenna, the frequency and whether or not you can manipulate the attachment to make the ground plane better.

In this case, I'm curious if @70Duster340 tried my suggestion and just ran a couple alligator clips from the base of the antenna to good grounds on the chassis to see if that would wake the antenna up and allow the radio stations to come in.
 
The antenna mount change on the E bodies is very likely due to RFI/ EMI as mentioned. Someone said the antenna does not need to be grounded. That may not be true, as this is a coax feed and it is carried out to the mounting point. That may or may not affect performance.

Frankly, with the state of AM/FM radio, especially around here, I'd just be sure to have a device with a memory card slot, and record some tunes on there and go with it.
 
Maybe....
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