Coaxial Cable and Antenna Problem

Thread Starter

jothom

Joined Jul 19, 2018
6
Hi all,

I have a problem with a battery powered(48v) machine. it is controlled via a wireless transmitter and therefore has receivers (multiple). The antennas for the receivers are all bolted down onto a metal panel which works fine until the panel is bolted down to the chassis, then a problem occurs, after testing its when any of the antennas connects to the chassis. The antenna connectors that fail are TNC connectors but I have also used BNC connectors in the past on the same machine and they worked fine with no problems.
The coaxial cable is 1.5m, 50ohm and has an outer braid and underneath that is has a thin aluminium layer, doing some research I found that the coax cable should be ground which I have not done as of yet, as it is shorting though the chassis do you recommend the machine chassis to be ground too. The coax cable shouldn't run parallel to other electrical wires but due to the layout of the machine its hard to avoid.

To summarise my questions:
1) Do I or Should I ground the coaxial cable? if so what end or both because i have heard problems about both?
2) Should I ground the chassis of the machine?
3) Could the fact that the cable is running with other electrical wires effect this?
4) Why does it do this to TNC and not BNC connectors
5) Am I ok to use my battery Negative terminal as a ground/earth as it is a moving machine and has no fixed earth point

Thank you for reading and I hope this makes sense,
Any other questions please feel free to ask,
 

Thread Starter

jothom

Joined Jul 19, 2018
6
Update: I ground the cable and/or the machine and it fixed the problem.

It was probably worth a try before I uploaded the question but no if anyone else has the same problem thats how I fixed it so for this reason i will not delete this post.
 
Top