Cb setup tips. All help/info welcome

Discussion in 'CB Radio Forum' started by PotholeMcBounce, May 11, 2021.

  1. Meteorgray

    Meteorgray Heavy Load Member

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    Craig, I saw your video. It was very good, and it does show that an antenna analyzer can yield information that a simple SWR meter cannot, especially resonance.

    But as you noted in the video, many experienced operators find that an antenna analyzer is not really necessary for tuning mobile antennas. Most folks get good performance by adjusting antennas for good SWR values, because doing so generally also indicates acceptable overall performance relative to tuning the antenna.

    A $300 antenna analyzer is more needed when constructing base station antennas with all their potential variables, while a $30 SWR meter will get the job done for relatively simple mobile applications, IMHO.
     
    Timin770 Thanks this.
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  3. craig_sez

    craig_sez Road Train Member

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    I agree it will work if you nust want a few miles on a basic set up and dont really care...
    What if your spending more $ on your mobile set up?
    If anyone spends a few hundy on radio the $ for good coax,pl259's a decient ant and bracket/antenna then im friggin #### well sure im gonna get the most bang for the $ spent and protect my investment...
    When the #'s become worlds apart as you see in my vid then your basically shortening your tx/rec,radio life and range..
    You dont go out and buy a porche,lambo,mustange or a brand new western star and just take it to buy grocerys do you...
     
  4. craig_sez

    craig_sez Road Train Member

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    No bolting a bracket for an antenna on a mirror arm bracket doest always ground an ant..Dirt,rust,plastic bushings are usually an issue...Thats why you bond...
    When you bond you can get by with electrical wire but rf needs surface area to travel and awg wire just dont cut it..When you run long lengths of awg wire from ant bracket to frame,now your adding electrical length to your antenna..Now that you added length your tune is way down in freq range where its more than likely your radio cant go....Look up the term bonding..
    Now mounting on back of the cab,almost pointless,its chokeing tx/rec of antenna especially when pulling a dry box or reefer..Yes even with the tip above the cab which means 90% of your antenna is being blocked....It affects your ground plain and you get reflect plus most signal is lost between cab and trl...Its like putting blinders on a race horse..Most of signal is now going out to your left and right and very little in front and less to the rear....I have tried it,noticed a huge diff and saw it on a field strength meter...Yes it will work but poorly.....
    Now if you have a mid roof cab and haul a flat bed,different story..
     
  5. Meteorgray

    Meteorgray Heavy Load Member

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    Craig, in your video I see that you've got the SWR at good values, but the resonance (x) you seem to not be satisfied with, or perhaps the Ohms or return losses as well.

    Could you not adjust that 102" antenna with the 10" riser to tune better than that in order to achieve your goal? If you did, then what values did you settle on with your 102" setup that you talk with in your truck? IE, SWR, X, Ohm?

    I've been told by experienced folks that a good SWR, ie at 1.5 SWR or lower, generally indicates an antenna in good tune, although not necessarily "perfect" tune in terms of the resonance or Ohm values or etc, but that perfection is a relative thing in terms of juggling the various values (SWR, Ohms, Resonance) particularly on such an imperfect ground plane/counterpoise/second-half-of-the-antenna, AKA a big truck.

    Thanks!
     
  6. Ridgeline

    Ridgeline Road Train Member

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    You guys are funny to read.

    well resonance and/or swr being perfect doesn’t mean the antenna is actually working.
     
  7. craig_sez

    craig_sez Road Train Member

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    No one said perfect..Just better than the standard 1.5 swr...Someone mentioned that if swr is good so is resonance ect and im just showing its not..
     
  8. craig_sez

    craig_sez Road Train Member

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    Well actually those #'s are sitting still and my antenna sitting at about a 40ish degree lean....Those #'s in general get better as antenna sits more up rite with wind load..
    As my ant sits now its more tuned to ch 1 or 26.965 area at highway speed..
    I was in to much of a rush to get it on ant working and now the pinch bolt of the riser is sized....Cant adjust my whip unless i cut it,not doin that...
    I got a stainless bracket being made and my breedlove stud sittin ready to go along with a new 7ft skip shooter and my last new lmr 240 uf coax..

    Usually when setting up i woulda shoot for r=50 and x = 0 my rl as high as possible(yes its backwards) the l and c # on bottom right as near to zero as well as possible but this phase stuff is just not sinking in..
    Keep in mind to that as you move your values are gonna change to cause of what your driveing over,around,through..Ex....As wind hits the whip it changes the shape of antenna makeing it electricly longer therefore dropping your tune freq..Hard to adjust for that cause its a constant change ut i have tried to allow some for that..
     
  9. Meteorgray

    Meteorgray Heavy Load Member

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    Well Ridge, that's a good point, but what do you advise the average Joe to do when he gets a new antenna and wants to make sure it's going to perform well in regards to protecting his radio and, as you say, determine that "the antenna is actually working."

    I would suggest the use some sort of meter to get the basics right, with the SWR meter providing the essential guide, and an antenna analyzer providing the more detailed solutions. Then, it's off to the races with actual usage and seeing how far you can communicate amongst all the variables, which are especially numerous when moving down the road.

    And Craig, thanks for that. Your experience shows that even if a perfect tuning job is achieved on a mobile unit, as the rig moves on the road, things start to go awry with the tuning values due to antenna flex in the wind, field variations in the traffic, ground characteristics of the road and underlying earth, and etc and etc. Striving for perfection makes more sense for a base station compared with the fluidity of mobile applications.
     
    handlebar Thanks this.
  10. craig_sez

    craig_sez Road Train Member

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    True but i still keep wanting to better what i have so i keep watching and learning..
     
  11. jdchet

    jdchet Medium Load Member

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    I think what we're talking about here is the difference between those of us who just want a simple radio to communicate with at reasonable distances versus folks that have taken the communications hobby out on the road with us. What seems to be missing concerning the folks in the former group is a basic understanding about antenna systems. This begins to rear it's head when they start to migrate to the latter group! You witness many installs going down the road and just shake your head. How many center loaded antennas have we seen out there with the loading coil WAY below the the roof line of the vehicle? How many Stryker and similar big radios hooked up to an absolutely horrible, to the naked eye, antenna system? I agree with @craig_sez , if you're going to start investing many hundreds of dollars on a radio or radios, some tools to protect it/them would be prudent. That along with acquireing some knowledge regarding you're radio system.

    It would be nice to work for a guy like Mr @Ridgeline who knows this stuff inside and out, but I'm not moving again and I hear he's a prick (his words!) to work for! LOL! Too deep into the "back 9" of my career to run my ### off anymore!

    JD
     
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