Antenna Adapter Has Additional Box, Wire

Hi - I've purchased a Car Head End unit from China, and it's arrived with zero documentation. One of the devices in the box is what appears to be an adapter to change the Mercedes European antenna connector to the Motorola tubular style on the back of the radio. That's good, because I need to do that. But it also has an unmarked rectangular box in the middle of the cable, with an unlabelled blue wire coming out of it. Here's a picture: Anyone want to advance a guess as to what the blue wire does? I'm guessing it's a booster of some kind, but I am certainly open to any and all suggestions. I know less than everyone on this forum. Please save me from having to prove it. Thanks, all - Charlie

The blue wire is likely a power antenna lead. The small box is probably a signal amplifier.My ex once told me I have a perfect face for radio.

Well, if the box is a signal amplifier, then something has to power it. Which would make the blue wire a likely candidate; except that they should have followed a normal color code. I was wondering if anyone had seen a device like this. It has me puzzled. I don't want to apply 12 volts, have it go directly through the antenna into the radio and fry it. >Charlie

I guess I could measure resistance between the wire and the center antenna tip. If its a dead short that would tell me something, I guess.

Went onto Google and looked for pictures of car antenna amplifiers. Most had a red wire, but a few were blue. Perhaps the color codes are different in the domestic Asian market.

You need to power the blue wire with the blue or blue white of your new radio. It is similar to a Metra 40eu55 if you need clarification.

Thanks much! I'll go search out the meta product. >Charlie

Depending on the vehicle...VW and Audi if i recall, the antenna amplifier was powered via the antenna cable. This was done internally in the OEM radio. Aftermarket radios typically don't have that setup, so the aftermarket came up with a cable adapter to power the amplifier.

The legend on the top of the unit identifies the blue wire as CAM-LINE. I'm guessing that they mean a constant 12 volts line voltage to power a camera. I'll throw it on the bench later tonight, run some power into it and start measuring voltages. I'm attaching an image of the legend on the top of the unit. All commentary gratefully received. I'm very much in learning mode. Thanks - Charlie

Connector E, pin 10, ANT