Coax feedlines

Discussion in 'Mobile Radio Systems' started by RSTORRIE, Oct 10, 2018.

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  1. RSTORRIE

    RSTORRIE QRZ Member

    If you have multiple radios installed in your vehicle, such as my son has a 2m and 6m in a radio console. Is there an issue with zip tying the multiple antenna coax feedlines together running to the antennas mounted on the trunk using NMO mounts? He wants to clean up the wires in his car and not sure if they will cause problems being zip-tied together running through the vehicle. I could not answer it. Maybe somebody has some input on it. Thanks.
     
  2. KB0MNM

    KB0MNM Ham Member QRZ Page

    Theoretically, tying the coaxes together should do no harm. Practically, the only issue that I see would be if they are tied together so tight as to damage the dielectric ( insulating material between the center wire and braid ) of the cable(s). I would suggest that he power-off the unused radio ( 2M or 6M ) before transmitting on either one, because the transmit signal could be coupled into the receiver of the radio not transmitting. W0BG has a website that goes into detail about mobile installations, yet I doubt that this question is covered there.
     
  3. KK6YDB

    KK6YDB Ham Member QRZ Page

    I am his son he is referring to, I had just registered with this site a few moments ago. I figure it'd be easier for me to explain what I am referring to. I want to have four radios installed and one scanner. there will be different bands i.e. 2m, 6m, 70cm, and 900mhz. I was asking this question because I want to have the cables managed neatly under my headliner and have them come down the pillar in one run and use zipties to manage it. I haven't been able to find anything else online saying whether its a good or bad idea.
     
  4. W5DXP

    W5DXP Ham Member QRZ Page

    If you have common mode signals flowing on the outside of any of the coax runs, they will couple over to the adjacent cables. You may (or may not) need clamp-on ferrite beads to alleviate common mode problems.
     
  5. KD2NOM

    KD2NOM XML Subscriber QRZ Page

    Also - I recommend using velcro ties instead of zip ties if that is practical for your installation.
     
  6. AG5CK

    AG5CK Ham Member QRZ Page

    The cables coming into my shack from a couple of HF antennas and a 2m/440 antenna are zip tied together. As long as you don't let the Incredible Hulk install the cable ties it will be fine.

    You're more likely to have a problem from the antennas being so close together than how the coax is routed. You can only get them so far apart on a vehicle.
     
  7. NG1H

    NG1H Ham Member QRZ Page

    As posters above said as long as everything is installed correctly (read K0BG's site if you haven't already) you shouldn't have a problem. But it is easy also to make a mistake/have something go wrong in the future with mobile installs so YMMV. The sorta-kinda good idea about tying them together is that if you do have problems it means something is wrong somewhere and it would be a good idea to fix the actual problem rather than covering it up by separating the cables.

    Something to think about if you haven't already investigated this is that a lot of vehicles have cable runs along the floor and there is often space available.
     

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