1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

CB radio poor range

Bat21 May 15, 2017

  1. Bat21

    Bat21 Well-Known Member Supporter I am in morocco

    1,777
    72
    48
    Map
    This one really has me stumped.

    I have a CB radio in the 80 which is only really used on trips to Morocco but in the 10 years I have been going my transmission range has been absolute crap.

    My first setup was a Nissan Patrol Y60, Midland 78 CB and a springer antenna. Transmit range was <1 mile.

    This radio was then fitted to my second Patrol which was wrecked in Spain, but before being wrecked the transmit range could only get <1 mile again.

    Then in 2009 I bought the 80 and fitted the above radio to it but this time I fitted a Siro 3000 antenna which is supposed to be the dogs. Again transmit range was about 1 mile.

    Roll forward to this year and I decided to replace the radio and antenna. Radio is a Thunderpole T800 and antenna is a Mini Orbiter..... guess what the transmission range is still only about a mile.

    Tested it last night with a mate who was round and I could hear him about 4-5 miles away but he lost me in less than a mile.

    The antenna was on the front ARB but I have now moved that to the roof bars as one of the Tech guys at Thunderpole says it needs to be big up. I have even run an earthing cable from the antenna mount to the 80 body.

    WTF is going on, why can I only transmit 1 mile max in 3 different vehicles with 2 different setups.

    SWR is about 1 so that's fine too.
     
  2. Chris

    Chris Super Moderator Supporter I am in europe

    14,008
    1,520
    113
    Garage:
    Map
    There's so much here that someone could write a book about it. Ground planes, standing wave yadda yadda. It could be everything from your mike to the set itself just being a bit low on watts. Plug his set into your car and see if it reverses the problem? Could be as simple as a poor connection somewhere. You need someone to go through it bit by bit really. Earth is one thing but on bars, does it get a decent ground plane?
     
  3. Bat21

    Bat21 Well-Known Member Supporter I am in morocco

    1,777
    72
    48
    Map
    What's the difference Chris.... I thought as long as the mount was earthed that would be fine. I seem to remember back in the 80's drilling a hole In the middle of the roof of my Avenger and fitting the antenna there to get a good ground plane, but that's not an option on the LC as I have a Maggiolina up top.
     
  4. Shayne

    Shayne Well-Known Member Supporter Guru

    9,679
    2,110
    113
    Map
    Trying to imagine what you might have done wrong 3 times i wonder if you put power to the radio from the same place each time ?

    If you haven't already maybe try running both positive and negative direct from the battery ?

    Furthest i ever got with my cb is when i took it out and lobbed it across the garden :shifty:
     
    Alexandertheallright likes this.
  5. Bat21

    Bat21 Well-Known Member Supporter I am in morocco

    1,777
    72
    48
    Map
    Thanks Shayne.

    In all 3 installations the power came from the battery, to a fuse , then a switch to the radio. So a clean supply really.

    I'm thinking of using a couple of baked bean bean tins and some string as this will be more reliable.
     
    clivehorridge likes this.
  6. Towpack

    Towpack Well-Known Member I am in england

    2,339
    373
    83
    Garage:
    Map
    Assuming the radio, antenna and associated wiring is all correctly connected and not faulty then a good ground plane, or lack of it, will have the greatest affect on range and the direction of it. This is especially important if you have limited power, 4w I believe? A good 'ground' and a good 'ground plane' are not quite the same things. A side mounted antenna on a gutter or bar mount may have a good 'ground' but the radio waves will be drawn to the side of the antenna with the most metal under it so will be very directional. Mounted on the LH gutter the strongest signal will be to the right and a rear mount will give greater forward range etc etc. I recently fitted a multi band antenna to the 80 for HF use and went for a central roof mount for this reason. I also have a roof bar mount at the rear corner of the vehicle for VHF use. If I swap antennas round and run the HF from the bar mount the difference in performance, particularly directionality is very noticeable.
    As regards a power feed to the radio itself, direct to the battery every time.
     
    clivehorridge likes this.
  7. Shayne

    Shayne Well-Known Member Supporter Guru

    9,679
    2,110
    113
    Map
    I will be tackling mine again soon , my second attempt at my second cb the one that hasn't been lobbed ....... yet

    Got myself a Wilson silverload antenna this time because its top loaded which i hope will help because i want to keep the antenna fairly low .
    I believe the possibly crucial step i have skipped before now is to set the SWR whilst parked as great a distance as possible from any buildings , telegraph poles and whatnot mainly because i can't find anywhere suitable to do it .
     
  8. Bat21

    Bat21 Well-Known Member Supporter I am in morocco

    1,777
    72
    48
    Map
    Having now done some reading this 'ground plane' stuff now makes sense as thinking back all installations have had poor ground planes.

    Thanks for the info guys.... I now need to work out where to mount the antenna to create a maximum groundplane.
     
  9. Chris

    Chris Super Moderator Supporter I am in europe

    14,008
    1,520
    113
    Garage:
    Map
    Middle of roof and middle of bonnet are the best. But of course the worst places to have a bloomin antenna. So, what you can get is an artificial ground plane. They are often used on lorries with fibreglass cabs. Or in fact, Landrovers which are aluminium and consequently not so good with a mag mount. It's a sort of lumpy thing that goes at the bottom of your aerial. Winch bumper is good, but because they are coated, you don't get the earthing. As TP says, grounding and ground plane are not the same thing. You need both. Try the bumper but make sure you have a metal to metal contact on the underside where it tightens up. I have had very good results with the ARB bumper, cleaned metal and a well SWRd Siro.
     
    clivehorridge likes this.
  10. Bat21

    Bat21 Well-Known Member Supporter I am in morocco

    1,777
    72
    48
    Map
    Thanks again Chris.

    I've come to the conclusion a large surface area to mount it is needed so will try and work on that.

    I did have it on the ARB and did rub off the coating before fitting it there. It worked there but the range was poor.
     
  11. StarCruiser

    StarCruiser Well-Known Member Guru I am in uk

    6,918
    2,004
    113
    Garage:
    Map
  12. Bat21

    Bat21 Well-Known Member Supporter I am in morocco

    1,777
    72
    48
    Map
    Thanks SC.

    I am familiar with checking/setting the SWR but I haven't been doing it exactly that way I.E. not having the doors shut and doing it while close to the house.

    I'm now thinking a 6" mag mount mounted in the centre of the bonnet is going to be my best option
     
  13. clivehorridge

    clivehorridge Well-Known Member Supporter Guru I am in romania

    11,987
    2,351
    113
    Garage:
    Map
    I seem to be as well informed as most posting on this subject, but at the same time, equally as confused by the end result.

    I have a relatively short (about 1m) antenna mounted on the front ARB winch bumper bar. The earth is good through the bar (when tested using a meter) but I admit to not running a separate earth to it.

    Reception and transmission is good up to about a km, then both fade off to disappearance at about 1.5 to 2 km.

    Actually, that suits my needs, but I'm at a loss as to why it's such a short range when others are boasting 5-10 km.

    I don't want the antenna to be roof mounted because it would be destroyed the first time going offroad, as I'm plagued by overhanging trees and bushes, which I hear all the time bashing the roof rack.

    I'm considering a different type of antenna, maybe longer than the short one I have, and when changing, installing a wired earth to it, and see if there's a difference.

    There's a local guy I haven't tried yet, he's supposed to be an expert in CB installations (well he does it for a living, which must mean something) so I should take it to him for an opinion.

    Not helpful to the thread, but it shows my sympathy and empathy with the problem.
     
  14. Bat21

    Bat21 Well-Known Member Supporter I am in morocco

    1,777
    72
    48
    Map
    That was exactly what I was getting when mounted on my ARB Clive.

    I've tried everything, a Sirio High Power 3000, a Mini Orbiter both with poor results.
    I've just ordered a 6" mag mount to try in the middle of the bonnet. After this thread last night I did some research on ground planes and it now sounds like this has been my issue on all vehicles as thinking back I have never had a good ground plane.
    If the mag mount resolves the problem I will either leave it there or consider fitting a fixed mount there or on the front of the roof.

    It will be interesting to hear what he says if you do take it to him. Let me know if you do.
     
    clivehorridge likes this.
  15. Shayne

    Shayne Well-Known Member Supporter Guru

    9,679
    2,110
    113
    Map
    Just reading myself that cb antennas radiate downwards and bounce the signal off the car . Just out of curiosity i wonder if tilting your antenna on its current mount (wherever that is ?) so it leans over the bonnet/roof might increase range a little ?
     
  16. Chris

    Chris Super Moderator Supporter I am in europe

    14,008
    1,520
    113
    Garage:
    Map
    No I don't think it would Shayne.

    They need to be vertical
    Might work if you pointed the vehicle at the person you were transmitting to but think about the back side of the twig now beaming up at the sky
    Not going to be good if they're behind you

    Proper GP decent earth proper connections with a half decent set and it's all you need
     
    Shayne and StarCruiser like this.
  17. Shayne

    Shayne Well-Known Member Supporter Guru

    9,679
    2,110
    113
    Map
    Just curiosity Chris , it seems wherever it will get broken is the best place for it :icon-rolleyes: on the roof above the rear view mirror i guess would give a full 360 projection . I should have bought a no ground plane landrover antenna as i can't imagine myself ever needing more than a mile range .
     
  18. Chris

    Chris Super Moderator Supporter I am in europe

    14,008
    1,520
    113
    Garage:
    Map
    Of course
    The problem with cb is that it's a very low power thing
    4w is not much at this wavelength/ frequency or whatever it is
    Vehicles are also the worst place to have one
    In terms of range it depends on use. 1 mile line of sight is ok but 1 mile round a corner or behind a hill isn't going to work it's not just range it's path of the signal you see

    I've had more than 4 miles out of mine in tough terrain
    But this brings a problem
    Unless everyone has a set that good then you can't talk to each other
    I remember in wales a time when only JW and I could send and receive to each other across two groups
    Everyone else could hear but they just couldn't be heard

    When we were in morocco with 8 cruisers we were strung out over much more than a mile and only the people in the middle tended to hear the occasional call from the front
    We then had to relay those to the back
    With a decent set front and back then you make sure everyone sticks together and don't zig when they should zag
    It can be very dusty if you travel too close together

    I actually have a small amp for mine which I can plug if needs be. If I use it too close to people it just overpowers their sets but out in open country it's handy
     
    clivehorridge likes this.
  19. clivehorridge

    clivehorridge Well-Known Member Supporter Guru I am in romania

    11,987
    2,351
    113
    Garage:
    Map
    Will do Paul, it's a bit hectic at the moment, but when I have time to catch some breath I'll give him a bell and pay him a visit.:thumbup:
     
  20. stumog

    stumog Well-Known Member I am in england

    2,706
    260
    83
    Map
    Could we not set up something like a club band with uhf ? the SA lcc have something like it and works very well.

    They have a dedicated frequency that is for them.

    I am miles from really knowing what I am on about but could someone in the know look into it?
     
Don't like the adverts? Become a supporter

Share This Page