Home        Store        Docs        Blog

Fathom-X on coax?


I am planning to connect the BlueROV2 to a 500 m coax on a winch. What are my chances on succes with the Fathom-X beeing able to communicate through this cable?

(Rusty) #2

Hi Mikxie,

This should work just fine! The Fathom-X communication module is published to work well over coax.


(Tim) #3

I have been wondering about this myself. So in other words twisted pair is not necessary?

(undersearobotics.com) #4

Are you sure? Twisted pair is “balanced” electrically while coax is “unbalanced”. Normally you would need to use a pair of baluns (like these: https://www.cctvcamerapros.com/ProductDetails.asp?ProductCode=VB-2VS ) to electronically match the two cable’s impedances.

(Rusty) #5

The Fathom-X is based on the “HomePlug” technology, which is designed to go through active AC power lines, which are usually really messy, not twisted, and have a lot of noise. Coax or twisted pair will maximize performance, but are not required unless you’re trying to achieve very long distances.


(Marcus) #6

Yes, it will work! We do this using RG59 cable over 100 metres with no noticeable difference in quality. You just need to make sure you get stranded coax, which (here in Australia at least) not easy to find. Using solid core, which is most common, will not last long with all the twisting required. We use a custom waterproof stranded RG59/dual power conductor cable.



The cable is intended for this: https://www.eiva.com/Files/Billeder/Site_Images/GalleryImages/Website-ScanFish-picture.jpg

I think it is strong enough for the BlueROV2

(Kevin) #8

Wow, that’s some serious equipment! I’m looking forward to seeing that in action.


I am having trouble when I try longer cables than app 200 meters, any way to boost the signal?

I am able to control the ROV, but video is lacking >20 sekonds or not getting through at all.

(Marcus) #10

what sort of coax is it? I’m not sure if it’s possible to boost the signal.

Do you have any other conductors in the cable assembly? I only ask, because you could control the ROV (without video) over the spare conductors (Control will work fine over standard power cables, no need to be coax), and run a separate analog camera (composite or HD- AHD/TVI) over the coax-you’d need an additional display to watch the feed though. Quality of the feed will depend on what conductors you have and what camera you choose, but these formats should be ok over 200m (composite for sure, HD-AHD/TVI maybe not).

Let me know if you need coax with additional conductors as I may be able to help.