This is a car radio aerial coax cable connector designed to re-terminate a standard 5mm diameter car aerial antenna coax cable. It is consists of 4 parts that allow an existing cable to be shortened or re-terminated to accept a male jack plug. It can be fitted either by soldering the centre conductor or by careful assembly.

The assembly procedure is:

Insert the cable through the black nylon outer sleeve, then through the brass bullet shaped sleeve.

Using a sharp craft knife carefully remove 20mm of the outer PVC coax cable insulation.

Pull back the braided outer shield and then remove 18 mm of the inner insulation.

The connector then needs to be assembled in such a way to ensure the inner conductor makes good contact with the centre terminal, and the braided outer shield makes good contact with the outer brass sleeve.

You must ensure the braided cable is isolated from and does not contact the inner conductor.

The brass sleeve can then be pushed into the black nylon outer sleeve so the connector is held securely together by a friction fit.

The assembly procedure can be a bit fiddly, especially in situ, but it does often allow a replacement aerial to be fitted without the need to replace or re-run the original coax lead to the radio which often involves removing interior trim and carpets.