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  1. #1
    Petty Officer 1st Class
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    Default Can I run 2 VHF radios off 1 antenna?

    Situation: I have a 25 watt VHF radio on my boat with an 8’ Shakespeare antenna. This radio works fine. For Christmas my wife bought me a Class D Digital Selective Calling VHF radio. She felt I needed to added protection this radio offers when interfaced with my GPS chart plotter. I would like to keep both radios onboard so that I can monitor various channels simultaneously without having to mess with those scan features.

    Question #1: Can I purchase a splitter to run both radios in parallel off of 1 antenna?

    Question #2: Even if I can purchase a splitter and wire this thing up correctly, will 2 radios operate properly in parallel off just 1 antenna?

    Anyone got any experience with this… Your thoughts please???
    Keith

    1993 27' Crownline 250CR
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  2. #2
    Ensign halfmoa's Avatar
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    Doesn't sound safe to me, it sounds like a great way to fry radio A when you key up radio B. JMHO.
    People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf.


  3. #3
    Petty Officer 1st Class
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    Wow! A lot of views and only 1 reply. Hey, don't be shy. If you have any information about this that is still more than I know.
    Keith

    1993 27' Crownline 250CR
    Volvo 740 (7.4 ltr. engine)
    DP-D1 Sterndrive

    iboats.com: A boat owner's best friend... if you're fortunate enough to be on land!

  4. #4
    Petty Officer 1st Class Peter Eikenberry's Avatar
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    I would find myself a marine radio technician as ask them.
    Ike
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  5. #5
    Vice Admiral NYBo's Avatar
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    The only splitters I've found are for AIS/VHF sharing. They would allow you to transmit from only one of the units, and they cost as much as an antenna anyway. I would go for a separate antenna. This way you have redundant systems. Losing an antenna isn't that uncommon.
    Bob
    '88 Bayliner 1700 Capri Bowrider, 85 HP Force O/B, "Sea Weasel"
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    Disclaimer: Although I am a member of the USCG Auxiliary, the opinions and advice in my replies are my own and do not necessarily reflect CG or CG Auxiliary policy or regulations unless so specified.

  6. #6
    Captain
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    What you are looking for is Directional Power Combiner.
    Not a Recieve Splitter!
    They are common in the Microwave world, not so much in the VHF world.

    I searched the Pasternack Catalog and can find none for use under 500 Mhz.
    Stock prices are from $350 to $1000

    They can make one for you on request. $$$$$
    A second antenna would be cheaper.

    Try to separate the antennas horizontally by at least 10 ft. to keep the transmitter from overloading the other receiver.

    Alternately, separate them vertically.
    One directly above the other.
    Antennas radiate out the sides. Not so much straight up and down.

  7. #7
    Lieutenant Junior Grade
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    google; shakespear cs-2

    Designed specifically for this app. What brand antenna are you using?

  8. #8
    Commander chriscraft254's Avatar
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    I am no expert on this but have seen people try the splitters and it seems to never work out well. I would want to seperate antennas for back up puposes.

  9. #9
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    Quote Originally Posted by Pete104 View Post
    google; shakespear cs-2

    Designed specifically for this app. What brand antenna are you using?
    He intends to operate both radios in lieu of scanning.
    With the switch , the "Unswitched" Radio has no antenna and will not Recieve.
    If it was for dual radios, at separate locations, one at a time only, the switch would work.

    The Power combiner, or dual antennas, allows dual receive, along with dual transmit.

  10. #10
    Commander chriscraft254's Avatar
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    And having two radios is really nice, because then you can leave one on 16 and chatter on the other.

    Chris Craft 254 Seahawk
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  11. #11
    Petty Officer 1st Class
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    Options:
    - install a second VHF antenna and use 'em both.
    - sell the old radio and buy a portable.
    Personally, I prefer a portable as a second radio. It's just more versatile than 2 fixed units.
    The newer portables have amazing battery life.

  12. #12
    Senior Chief Petty Officer
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    Default Re: Can I run 2 VHF radios off 1 antenna?

    Quote Originally Posted by rfdfirecaptain View Post
    Situation: I have a 25 watt VHF radio on my boat with an 8’ Shakespeare antenna. This radio works fine. For Christmas my wife bought me a Class D Digital Selective Calling VHF radio. She felt I needed to added protection this radio offers when interfaced with my GPS chart plotter. I would like to keep both radios onboard so that I can monitor various channels simultaneously without having to mess with those scan features.

    Question #1: Can I purchase a splitter to run both radios in parallel off of 1 antenna?

    Question #2: Even if I can purchase a splitter and wire this thing up correctly, will 2 radios operate properly in parallel off just 1 antenna?

    Anyone got any experience with this… Your thoughts please???
    Answers:

    #1: No
    #2: No

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