Poor radio reception

[Turbofiat124]

I have had bad radio reception on my 80 Spider for several years now. I can't remember if it happened all at once or gradually over time.

It will pick up somewhat distant stations but not crystal clear so it is working somewhat. Not as good as I think it should.

I've replaced the antenna, radio and I think the extension cable but not sure about the last one.

I even had one of those 4' long telescoping antennas.

I even tried grounding that particular antenna with a wire but it didn't seem to make any difference. So I replaced it with one of those short rubber antennas. The other day I unscrewed the antenna from the base and the reception was the same. So I'm thinking the radio is not getting a signal from the antenna.

What are the odds that the extension cable has a break in it?

Also does the antenna need to be grounded before it will work?

[DieselSpider]

The antenna should be grounded by the shield on the coax cable even if the base is not. There is a chance that the cable has a break in it or has water in it shorting it out.

What happens when you plug a replacment antenna directly into the radio?

http://www.walmart.com/ip/Scosche-RMA90 ... a/16652627

[Rambo]

When i replaced my radio the adapter that plugs the antenna into the radio broke. I bought a section of antenna cable off of amazon and its about a 1 hour job to put it in. You have to remove some carpet and the rear seat to access the wiring harness. It works better than ever.

[bluespider262]

Unplug it at the radio. You can test your antenna wire for a short by connecting voltmeter from center pin to outer shell. Should show infinite resistance. If not unplug cable from the antenna (if possible) and repeat to narrow down which component is bad.

Once you've established your antenna lead isn't shorting to the shield, make sure the center pin to car ground is also infinite resistance. Otherwise the antenna is suspect.

A grounded antenna lead is like having no antenna at all. It needs a large ground in proximity (i.e. the car itself) to "work off of." Only the shield should be grounded.

[Turbofiat124]

The antenna should be grounded by the shield on the coax cable even if the base is not. There is a chance that the cable has a break in it or has water in it shorting it out.

What happens when you plug a replacment antenna directly into the radio?

http://www.walmart.com/ip/Scosche-RMA90 ... a/16652627

So how is the shielded wire grounded? Through the radio?

I didn't have a chance to look at the problem while I was off on my long weekend. Too much yard work, pressure washing the house, etc.

[DieselSpider]

The antenna should be grounded by the shield on the coax cable even if the base is not. There is a chance that the cable has a break in it or has water in it shorting it out.

What happens when you plug a replacment antenna directly into the radio?

http://www.walmart.com/ip/Scosche-RMA90 ... a/16652627

So how is the shielded wire grounded? Through the radio?

I didn't have a chance to look at the problem while I was off on my long weekend. Too much yard work, pressure washing the house, etc.

Depends on the antenna mount but usually by the radio and the antenna base mount. If you get a powered antenna it should have a ground strap and stabilizer arm too.

[Turbofiat124]

Well today I investigated why my Spider had such poor radio reception. I'm not 100% sure what the problem was, all I know is I installed a new antenna and I can now pick up WIMZ in Knoxville radio station (100 miles from here) which I couldn't do before.

Initially I could only pick up local stations but the reception was sometimes poor into valleys and when I unscrewed the mast from the base, it made no difference in reception.

First getting the radio out. I lost the pullers that came with this radio but was able to unlock the tabs by inserting some welding rods between the radio and housing and kept messing with it until it unlocked.

I initially thought the extension cable may have had a short in it but when I pulled the radio out first, the cable looked new so I must have replaced it at some time or another. When I unplugged the antenna extension cable from the radio, I lost reception.

Then I removed the bottom of the backseat and the panel the tops folds down into it to get to where the antenna plugs into the extension cable. Seems like connectors where the plug together were not making contact because afterwards I was able to pick up a Knoxville station although not the best reception. My guess is perhaps when I laid the top down, it tugged on the connectors. This time I wrapped plenty of electrical tape around both just in case.

I also discovered some corrosion where the mast screws into the base.





The new antenna has a telescoping mast so it will probably be better than the rubber antenna I was using.

I also put some antiseize compound on the threads, hoping this won't happen again.

So either the corrosion was the problem or where the antenna plugs into the extension cable was not making good contact. Or both.

[DieselSpider]

The rubber ducky is usually considered a metro area antenna while the telescoping mast will be best for long range reception. With that amount of corrosion and no really visible center lead its amazing you were getting much of any reception at all.