Drew

iTrader: (58)

I know it was spliced into the factory mast antenna. It's some kind of adapter that allows some kind of radio to use the stock antenna. Beyond that I'm just guessing as to it's purpose. Anyone know why my car would have this?

simo

Check Here

Broadcast couplers allow coupling your broadcast AM/FM car radio and your 2 way radio on to the same antenna.

KITT1983

iTrader: (3)

thanks for the link simo

but version would be right for cb radios and a aftermarket pioneer? the VHF or the UHF?

how are to you doing simo?

Jeffs82TA

iTrader: (1)

isn't that one of those things that picks up a signal from a porta c/d player and transmits the signal to the cars factory radio?

Apeiron

Doesn't look like any of them would be, CB is HF.

Drew

iTrader: (58)

It's not a FM modulator, no.

A bit more info, the car it came out of didn't have any aftermarket stereo equipment, or any indicators that it ever had. There was a brass battery bolt, a 3/4" hole with a plastic grommet in the firewall, a few mounting screws in the side of the console, and evidence of two items bolted in the bottom of the hatch well. It's a 91, so it's a little late for the Smokey and the Bandit/Convoy CB craze... And a little early for the personal communication, technology boom...

Iroctopless

A friend of mine ran a portable scanner with that adaptor back in the early 90's. That way it shared the stock antenna with the AM/FM radio.
Here's a pick of almost the exact one from the '90 Radio Shack catalogue . . .

With the mobile power adaptor and antenna kit, it was fun to take with on rides, listen to police, ambulance, fire, etc.

KITT1983

iTrader: (3)

will that adapter work for a cb radio or car phone?

Apeiron

Doesn't look like it, it'd be for VHF and UHF mobile radio.

Iroctopless

Even if it did, there would be some serious complications like destroying your headunit's tuner. To split an antenna between a CB (or any transmission device) and a receiver like your tuner would pump 3 or more full watts of power right into your radio (designed for microvolts) every time you key-up (transmit) the CB!
Sharing the antenna might work if used only for listening purposes. If transmitting is involved, then each transmitting unit would required it's own antenna or a switch to isolate one from the other.
Also an AM/FM antenna makes a horrible CB antenna due to the different wavelengths involved. For a CB antenna to work properly, especially for transmitting, it must be of the correct length and tuned.

Drew

iTrader: (58)

Thanks for the links and info! I did a little searching before I posted anything and didn't find anything concrete. A few references I found were on ex cop car forums. Apparently it's an item commonly used in those applications to utilize the stock antenna. I really don't know for sure. I removed it from the car back in 1999 because the factory radio didn't get good reception and with the adapter hooked up the passengers side dash panel was hanging down. Yesterday I was digging around in one of many boxes in the garage and came across it. It'd been a few years since I'd thought about it, so I figured maybe I'd find some new info. If I really want to know exactly why it was there, I suppose I need to trace the car back to it's previous owners and ask.

In the mid 90's everyone I knew that was playing with CB's usually were using magnetic mounts, and huge whip antennas. Car phones of the time period had the tiny glass mounted stick antennas, or built in antennas. I've removed plenty of them over the years and never seen anything quite like this. Like I mentioned before, something in the car had a sizable power wire, and it wasn't an amplifier for car audio. Whatever was in the trunk was bolted to all 4 sides of the well, 6 screws across the back (2 groups of three in a V pattern), and 3 or 4 holes on the left and right side. Aside from the holes, the car was virtually unmolested when I acquired it.

Apeiron

PIN diode switches are pretty common in devices of that type, and often there's some sort of impedance matching as well.

hardon85

That looks like an FM modulator to me, I installed one in my daily driver a few years ago for my satellite radio just like this one http://www.google.com/products/catal...d=0CCsQ8wIwAA# and when the satellite radio is on I can only get one other station (so it cuts down on reception quality), I have never gotten a concrete answer on how exactly it works, I've heard that with this device it is a hard wired input (not actually broadcasting it wireless) and I've heard it cuts out the other stations so there is no interference from other stations. Anyway it looks and sounds like an FM modulator to me since it looks the same except for the connectors and you got better reception after taking it out. But the puzzling thing is I don't know back in 99 (at the latest) what product there would have been to use this other than maybe it was a high end handsfree cell phone hookup where it would broadcast the conversation over the car's speakers. Other than that I do not know because most cars had cassettes back then that you could get an adapter for to hook anything else up.

Drew

iTrader: (58)

Most FM modulators plug into the radio, and the antenna plugs into the modulator. They existed back then for CD changers like the Pioneer 6 disc in the trunk of my 91 RS which incidentally dates back to the late 80's or early 90's. LOL

This isn't an FM modulator. The cable on this thing is about 1/2" thick, and it was spliced into the stock antenna. If it were sending a signal to the radio, there would be no need for the heavy duty cable to the antenna, and the antenna base. It's fairly obvious just from looking at it and how it was installed that it's purpose is to use the antenna for another device.

Sti-co has a website. http://www.sti-co.com/ I actually started there first. Hmm...

The only mystery to me at this point is what exactly was connected to the antenna, and what were they using it for...

91phoenix

iTrader: (5)

In the 80"s and early 90's there were many options to hook a cb to the factory antenna. I know for certain that GM used them alot in there cars. The 81 Corvette I had had a CB antenna adapter in it but no CB. I took an original GM radio out of it. These cars had a special antenna. Least ways mine did. I replaced it with an originl power from a Corvette salvage yard.
I would, however, guess that that is the adapter to use a CB antenna for radio as well as CB. It isn't the same as I pulled from my car. They do not send excess power to the radio due to the electronics in the box.