High SWR’s with other antennas besides stock

Discussion in 'CB Radio Forum' started by cdavis188, Apr 24, 2024.

  1. cdavis188

    cdavis188 Road Train Member

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    So I was given a brand new 2025 Cascadia by my company. On the stock CB antenna, I have low SWR’s (at least on my Cobra 29 LX), but it’s a stock CB antenna so it really isn’t good for range. I bought a mirror mount and coax and i’ve tried two different antennas. On my 29 LTD, the SWR meter just pegs full to the right regardless of tuning on the antenna. My 29 LX is better but it still sits above 2. I first tried the Stryker SRA-10 i got with the bundle but regardless of how much i cut the whip, i got high SWR’s and ended up getting frustrated and tossed it thinking it was just a junk antenna. I got a FireStik earlier today since i’ve never had a problem with their antennas…same thing. Regardless of where i set the tunable tip at, my 29 LTD pegs full right and my 29 LX sits just above two. I’ve had other Cascadia’s and have never had this problem. I have an antenna mounted on the passengers side mirror but that’s strictly an AM/FM antenna whip, nothing to do with a CB radio and it works just fine.

    About ready to just toss all this stuff in the trash. I’ve already spent a good $250 all together just to get piss poor results
     
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  3. gentleroger

    gentleroger Road Train Member

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    I had the same problem with my 2018 Cascadia. I ran the stock for first couple years because After a lot of effort I finally got it right, but I don't know how or why. Then it unfixed itself, again, I don't know why.

    I haven't made plans to try anything but the stock antenna on my new 2025 because I don't want to spend the time and money spelunking around for a solution. I think the problem is the mirror mount itself, but that's outside my wheelhouse.
     
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  4. Timin770

    Timin770 Road Train Member

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    I see threads on this forum about the need for bonding on the Cascadia. I don't have a Cascadia but apparently bonding is supposed to help. If I got bad results on several different reputable antennas, I'd begin to suspect another problem
    BTW get good quality coax
     
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  5. Xcis

    Xcis Medium Load Member

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    When the SWR is 3.0 or higher, that indicates your antenna ground plane is at fault. This is not an antenna tuning or coax problem.
    .
    . What you want to do is interconnect the large metal components of the truck to form one large antenna ground plane for radio frequency purposes. How you do that is, for example, to connect a short flat strap [similar to a battery ground strap] from bare metal of the door to bare metal of the cab frame. Your goal is to connect the door, cab frame and chassis frame in sequence to form one large metal mass for RF (radio frequency) purposes. You need short flat straps not regular wires.
    .
    . Do NOT go from the door directly to the chassis frame because the long length will act as an additional antenna.
    This has nothing to do with electrical grounding.
     
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  6. Night Stalker10

    Night Stalker10 Road Train Member

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    Don't use the SWR function in the cobra 29's, they are useless. Since you're getting two different SWR readings from both radios on the same antenna, that proves my point. Buy a good external SWR meter with a jumper coax cable, and do the bonding that has been mentioned. Then see what the real SWR is on your antenna system. Hopefully you haven't cut too much off the antennas, otherwise they won't work for the CB band if they are too short.
     
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  7. Diesel Dave

    Diesel Dave Last Few of the OUTLAWS

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    IMG_6144.jpeg Not trying to put you on the spot, but did you put the nylon washer back on the right spot on the mount ?
     
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  8. gentleroger

    gentleroger Road Train Member

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    Yup, even ruined a pair of pants chasing after the suckered when I tried a new antenna.
     
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  9. cdavis188

    cdavis188 Road Train Member

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    no i didn’t. Switched it around and no effect
     
  10. cdavis188

    cdavis188 Road Train Member

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    I’m beginning to think it’s the mount i bought, or it’s just my radios giving erroneous information. I’ve had it connected to the stock antenna all morning and SWR’s were where they were supposed to be at. For no obvious reason a few hours later they’re back up over two according to my radio, and i never touched it
     
  11. Ridgeline

    Ridgeline Road Train Member

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    What kind of mount?

    Most likely the grounds - RF - don't exist with the new system.
     
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