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Base A-99 and Neighbors?

Discussion in 'CB Antennas' started by 338_MtRushmore, May 19, 2017.

  1. 338_MtRushmore

    338_MtRushmore
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    I just installed an A-99 on my camper. It has a push up pole, but I don't have a tool to raise it at the moment. I tested it out at roof level, and the vswr was acceptable so I transmitted voice. I was blown away by the very loud and crystal clear talkback on my stereo. At 5 watts ssb I don't hear anything. 7 watts makes a little noise, and 40 is loud as heck through the old stereo.



    Will raising it 10 to 20 feet above the roof make a huge difference? Are modern electronics less prone to interference than my 70's pioneer?
     

  2. 2RT307

    2RT307
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    Raising it should help,but you'll probably need to get some ferrite chokes for the speaker leads. New stuff is bad too, and some of it is worse than your old Pioneer. :)

    73,
    Brett
     
  3. 338_MtRushmore

    338_MtRushmore
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    I will see if I can get it raised today. I'm kinda doubting that chocks would help on the speaker wire because it only happens when the stereo is powered on. Doesn't that mean it is getting into the receive section and being amplified?
     
  4. sp5it

    sp5it
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    You get into amplifier stage. It means, that you radiate rf all around.
    Make choke balun at the feedpoint. Use grounding. Should improve.
    Mike
     
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  5. 2RT307

    2RT307
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    I used to come over my nephew's guitar amp, and I would whisper "you suck" when he practiced. He actually thought it was pretty funny! :D

    73,
    Brett
     
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  6. Steve_Buckeye

    Steve_Buckeye
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    Length of speaker wire is close to harmonic frequency. Shielded speaker cable might help.
     
  7. 338_MtRushmore

    338_MtRushmore
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    I wasn't sure if a choke was needed or not, but I will try 5 wraps around 4" pvc. I suppose I will have to do some research on propper base grounding. Thanks
     
  8. undertaker

    undertaker
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    338 drive an 8 foot copper rod in the ground then just get some heavy copper wire and ground it to the push up pole use a clamp for the ground rod. I did it and it works..
    hope this helps... lowes or home depot has them.
     
  9. sp5it

    sp5it
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    Actually it is wrong way to grounding :(
     
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  10. 338_MtRushmore

    338_MtRushmore
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    Does it help with rf, or just lightning safe? There is no way I am going to try to drive an 8' rod in the campground. 3 or 4 feet maybe? I'll have to do more research on what grounding is for operation reasons vs lightning reasons.
     
  11. 338_MtRushmore

    338_MtRushmore
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    Can you elaborate or post a link to good info? This is my first base install so I really haven't researched it much. I do know there is a giant load of bs everywhere about mobile installs, so I would assume the same is true for base installs?
     
  12. sp5it

    sp5it
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    wavrider, Mudfoot and 338_MtRushmore like this.
  13. Needle Bender

    Needle Bender
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    You'll need a voltage choke, not a 5T x 4" current choke.
    Look at the choke at the base of the GainMaster, 16T x 3" because it, like the A99, has the voltage peak at the Base.
    Also, if poss decouple the metal base of the A99 from any metal mast, using painted Oak dowel or Fiberglass rod, finally, see if you can add 24" or so radials to the bottom of the A99 - 8 of them (welding rods maybe?) works well.

    You can also put a .01 ufd capacitor shorting across each set of black & red speaker terminals at the back of the stereo amplifier to help prevent the speaker wire from looking inviting to RF.

    Maybe easier to buy this and notably increase the performance.
     
  14. 338_MtRushmore

    338_MtRushmore
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    Appreciate the link. Will have to read it a few time. Thanks
     
  15. 338_MtRushmore

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    Where can I find more info on the voltage choke you are speaking of? I have had the a99 for 3 days, so I'm really not looking to upgrade for at least another 2 weeks. Also, I don't care about my personal rf interference, because I am pretty sure I won't call the FCC on myself. The 5 on 4.25 balun helped quite a bit, so maybe this voltage choke may help even more.
     

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