Struggling with Extending CoAxial Cable For a Sensor

[Avo Mk8]

I can't locate 2.5c-2v Coaxial Cable. Could I upsize coaxial?

2.5c-2v cable (Japanese numbering system) appears to be standard 75ohm CCTV cable.
I'm more familiar with the RG numbers used in UK

http://www.prolog.com.hk/images/Download/JIS%20Coaxial%20Cable.pdf

I think any 75ohm co-ax will do the job, but I guess you are looking for similar diameter

Mini RG-59 cable is 75 ohm and a similar size to yours. I think it has good enough electrical characteristics for your use, but a tinned steel core rather than copper, don't know if that matters in a vehicle!
I guess you don't need a whole reel? RS PRO Black Unterminated to Unterminated Mini RG-59 Coaxial Cable, 75 Ω 3.6mm OD 100m | RS Components - https://uk.rs-online.com/web/p/coaxial-cable/6655833

eBay to the rescue: RG59 Mini Cable | eBay - https://www.ebay.co.uk/itm/232842324054

I suggest soldering a joint (carefully!) is the way ahead!

 

[artistwantab]

Thank you.

This is what I needed. I will give it a chance and hopefully it works.

 

[Jim_e_Jib]

I'm wondering if there might be a limit on the length the cable can be extended to - is it possible to move whatever the sensors connect to closer to them and extend the outputs of that?