Coax within vhf microphone cable?

[KevinV]

Just about to start changing the cable on my radio, but there's a difference.
The new one is a straightforward 8-core (with a bare wire in contact with the shield), but the old one has the white in the centre, with bare copper wrapped around it (connected to orange for the plug). Being central the bare copper isn't in contact with the shielding, but does make the white+copper coaxial.
Can I ignore this? Or do I need to go shopping again, and if so, what do I shop for?
The only thing wrong with the radio is the cable, so I'd really like to fix it and spend my money elsewhere

 

[KevinV]

Anyone? Or do I just suck it and see?

 

[Bilgediver]

Anyone? Or do I just suck it and see?

Are you replacing just the cable to the mike and if so where does that plug fit in you picture on the old cable? Does it connect to the radio or the old mike.?
One thing nor clear in your pictures is where the shielding braid is connected. That is important to know and it is probably linked to one of the coloured wires.

The shielded white wire is the audio output from the mike and replaces the white in your old cable. What we need to determine is if the other colours are all used and doing what. Normally a mike has the audio out and PTT (transmit) switch as normal . Some also have channel up and down buttons . All of those functions depend on the correct earth connection to operate This earthing may all be done only utilising the shied however at the radio end it is not unusual to the common ground to be earthed and and in the case of the PTT another ground wire linked to another terminal in the radio . Studying your radio will confirm this or you may on your old wire see evidence of this.

The new cable will probably work just by connecting the colours exactly as the old wire however if the PTT does not work than that link I mentioned is required.

That link could have been made in the microphone previously if no evidence of a connection from braid to the radio then one or two of the colours may be linked to the braid in the mike.

What radio is it and what model is the mike. Might be able to find details on the web.

Hope this helps

 

[KevinV]

I'm just replacing the mic cable on a navman 7200 - I can't find anything very useful about it on the net as navman is no longer in existence.
The pictures are the mic end, but the radio end is identical - the orange (to/from the plug) connects to the bare sheath around the white. I'm guessing the white is a data wire, with the sheath being common - ve
As there isn't really any other option I have connected all the wires to the plug - fingers crossed it works - the radio isn't worth taking a punt on a possible replacement mic.
I've only managed to do the mic end today, will do the radio end another day. Then comes the "interesting" task of testing it on the bench in a workshop in rural Monmouthshire

 

[Bilgediver]

Replacing colour for colour should work. The number buttons produce tones which are generated in the mike and they probably go down the same wire as the audio. . Other wires will be used by the up down switch.
The sheath is grounded and is to protect the audio signal from external interference so the wire inside it will be the mike audio. possibly also the DTMF tones from the buttons. The other wire connected to the sheath will probably be be part of the PTT and Up Down circuit. Lets hope it works