VHF Antennas?

Discussion in 'Lake Powell Recreation' started by Squirrel, Aug 28, 2017.

  1. Squirrel

    Squirrel Well-Known Member

    I have a lower end Motorola VHF radio for my Bayliner. With the new 8' antenna, it has never worked very well at any surface distance. Less than 1/4 mile it seems to work OK.
    Question; With what limited information above, what antenna gain might work best. I would like to replace the 8' antenna with a 4' unit. I plan to be on the lake 9/18 thru 9/28 and would like to solve the issue before that trip. Sq
     
  2. Grant Stevens - USBR

    Grant Stevens - USBR Well-Known Member

    Any idea why your new 8' antenna doesn't work? Common problems are a short at the PL-259 connector, you can check with an ohm meter. Sure it's not the radio, low voltage due to a bad connection is common, what are the symptoms? Post more and maybe we can get it working as is.

    Anyways, to your original question, I recently like the antenna solution posted at thehulltruth. It's a short extension to get the antenna up and away from the metal frame of your windshield (and your head), with a small 3' antenna on top. Hopefully it will work with your existing mount.



    [​IMG]

    http://www.thehulltruth.com/marine-...-difference-these-two-digital-antennas-2.html
     
  3. potter water

    potter water Well-Known Member

    Your key words were, "low end Motorola." Of course, check the connections, but a quality radio is very important. Find your local amateur radio club folks and ask them to bring a power and Standing wave Ratio meter to your boat. They will be very happy to provide you that service. It all will become clear. If a high SWR, then you have antenna and cable problems. If SWR is okay, then you have a crappy and low power radio problem. Also, your radio may be getting out, but a bad or crappy mike can cause people to ignore you. Get the radio SWR and power checked by your friendly ham radio neighbors before you muck about with changing out the 8 foot antenna. It should easily talk many miles line of sight. You see a lot of boats with the 8 foot and they are not having the problems you are. Good luck and let us know what you find.
     
    Bill Sampson likes this.
  4. GregC

    GregC Well-Known Member

    What Potter Water said! If you need to , use a magnifying glass to check the end of the cable to make sure not even one of those little tiny shield wires on the coaxial cable are touching the center conductor. Even if you have to stuff the extra wire, you should not cut the coaxial to a convenient length, as the length of the wire is almost as critical as the length of the antenna. This usually isn't a complete signal killer, but there is a "just right wrong length". The ham club guys can fix this too, if needed, and are usually thrilled to help, just for the fun of figuring out what went wrong!
    Gotta disagree w/Potter a little about the Motorolas though, while they're not my favorite, they are mostly serviceable functional equipment. I've used many brands and they aren't my least favorite. Even a puny radio will talk farther that you're talking about.

    GregC

    ps... Nan and I will be at the lake the last two weeks of Sep. Aiming for Scorup/White area. Still want to see the Battleship while there is enough water to the boat in and out.
     
    Last edited: Aug 29, 2017
  5. Squirrel

    Squirrel Well-Known Member

    ps... Nan and I will be at the lake the last two weeks of Sep. Aiming for Scorup/White area. Still want to see the Battleship while there is enough water to the boat in and out.
    I will be there from the 20th till ?? Staying at Stanton and day tripping.

    The boat is at Powell, so I won't be able to look at the antenna/radio until the 18th. Sq

    Last edited: Today at 9:34 AM
     
    Last edited: Aug 31, 2017
    Bill Sampson likes this.
  6. Squirrel

    Squirrel Well-Known Member

    So, what should the ohm reading be on an 8' vhf antenna, I can check that when I get down there on the 20th. Sq
     
  7. GregC

    GregC Well-Known Member

    Should be zero, completely open between the center conductor and the outer shell or braid.
     
  8. Goblin

    Goblin Well-Known Member

    ∞, give or take
     
  9. Squirrel

    Squirrel Well-Known Member

    So, the way I see it, unless it is "shorted" there isn't any way to check it.
    I have it loosely weaved thru the 2 aluminum roof frame supports. I will have to check those areas. Sq
     
  10. Grant Stevens - USBR

    Grant Stevens - USBR Well-Known Member

    Right, unless you can disconnect the antenna side of the cable, and most 8' fiberglass you can't, you can only check for a short, not continuity. With out a swr meter, not sure you could do much more.

    I'm concerned if you bought a new antenna, the problem may be with the radio (I'm guessing your motorola is older, for sure before yaesu/standard took over the marine division. Does it have the red distress button, that will narrow down the age.

    Bring a new pl259 connector and solder iron just in case, easy enough to cut off the old and replace it if you got a short. If you cut off the connector, again check for a short prior to attaching the new connector.
     
  11. Squirrel

    Squirrel Well-Known Member

    The radio is only 5 or 6 years old and it does have red distress button. The radio is mounted under the dash so I know it hasn't gotten wet. Sq