Antenna grounding plate
Thread Starter
Melting Slicks
Joined: Dec 2016
Posts: 3,193
Likes: 184
From: Central Bucks County, Pennsylvania
Antenna grounding plate
I’m reassembling some things under the rear clip on my 71 and I’ve come upon the wedge shaped piece of Aluminum or Aloe-mini-im that’s about 3”X5”X7”, strap attached and a hole in the middle for the antenna cable to go through.
I know it’s called the antenna ground. The one I removed has over-spray paint and some undercoating. Does that crap have to be removed or it won’t work correctly? I don’t understand it’s purpose, it does have a strap that is bolted to the frame. Essentially isn’t that the same as any regular steel bodied car just without a strap? Is the hidden agenda of this plate like a huge washer?
I know it’s called the antenna ground. The one I removed has over-spray paint and some undercoating. Does that crap have to be removed or it won’t work correctly? I don’t understand it’s purpose, it does have a strap that is bolted to the frame. Essentially isn’t that the same as any regular steel bodied car just without a strap? Is the hidden agenda of this plate like a huge washer?
Le Mans Master
Joined: Jun 2019
Posts: 5,472
Likes: 2,180
From: Loveland
I think it adds to the surface area of the antenna for reception. Just make sure all of the connections are grounded where they are supposed to be grounded and NOT grounded where they are not supposed to be. This includes the coax cable. Make sure the cable center wire test for continuity from the antenna to the radio. Test for 0 continuity from the center wire and the braided wire.
Last edited by kodpkd; Jul 31, 2021 at 08:21 PM.
Le Mans Master
Joined: May 2003
Posts: 8,877
Likes: 3,556
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
It will work fine with paint on it. A "normal" metal bodied car uses the body panels as a ground plane.
Since the very first Corvette rolled out in 1953- when they figured out the new spaceage fiberglass didn't conduct electricity- the engineers had to figure a work around. Most notable was the sparkplug wire shielding.
The plate electrically simulates the real earth with a conducting plane. Helps with the reflecting/receiving of the radio waves.
For FM -the groundplane should be almost 30" in diameter ( a quarter wave or 1/4 of the full FM wavelength - the same length as the antenna mast) being about the size of a garbage can lid. The engineers decided to connect the ground plane to the chassis to compensate for the less than ideal size.
So- one of the reasons reception of the radio in a Corvette is not that great.... I've solved the problem with sidepipes!!!
Richard
Since the very first Corvette rolled out in 1953- when they figured out the new spaceage fiberglass didn't conduct electricity- the engineers had to figure a work around. Most notable was the sparkplug wire shielding.
The plate electrically simulates the real earth with a conducting plane. Helps with the reflecting/receiving of the radio waves.
For FM -the groundplane should be almost 30" in diameter ( a quarter wave or 1/4 of the full FM wavelength - the same length as the antenna mast) being about the size of a garbage can lid. The engineers decided to connect the ground plane to the chassis to compensate for the less than ideal size.
So- one of the reasons reception of the radio in a Corvette is not that great.... I've solved the problem with sidepipes!!!
Richard
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,209
Likes: 9,347
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
I was wondering why I've never had good reception, I though it had something to do with the body being fiberglass. Glad I was right
Thread Starter
Melting Slicks
Joined: Dec 2016
Posts: 3,193
Likes: 184
From: Central Bucks County, Pennsylvania
I have a thin sheet of stainless (14”X14”) . If I drilled out a hole for the antenna cable coupler to go through and laid that with the OE plate, and of course keeping the ground - will this help any? Although I kept the original radio, I’m installing a Custom Sound brand stereo radio. I replaced the two upper dash pad speakers and installing next a speaker bar across the very rear of the storage area, if this matters any (?)
Le Mans Master
Joined: Jun 2019
Posts: 5,472
Likes: 2,180
From: Loveland
I have a thin sheet of stainless (14”X14”) . If I drilled out a hole for the antenna cable coupler to go through and laid that with the OE plate, and of course keeping the ground - will this help any? Although I kept the original radio, I’m installing a Custom Sound brand stereo radio. I replaced the two upper dash pad speakers and installing next a speaker bar across the very rear of the storage area, if this matters any (?)
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