1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

How to select antenna for CB?

Discussion in 'Technical Chat' started by Khaos, Jun 18, 2008.

  1. Jun 18, 2008 at 5:07 AM
    #1
    Khaos

    Khaos [OP] Well-Known Member

    Joined:
    Feb 4, 2008
    Member:
    #4570
    Messages:
    6,506
    Gender:
    Male
    First Name:
    Bryant
    Tallahassee FL
    Vehicle:
    2005 Prerunner TRD Off Road
    265/75/16 BFG A/T, 18" Magnaflow, K&N Intake Filter, Ultra-Gauge, Kobalt Toolbox, Metal Tail Light Guards, Cobra 19 and 4ft fiberglass antenna, Plasti dipped Badges/lower valance/rear bumper/grill/bullbar/ac controls, black DIN kit, JVC KD-X40, Wet Suit Seat Covers
    Well, one of the more important mods to my truck is going to be a CB radio. I'm getting it mainly for trail use and emergencies. I hate Cell Phones so you can see why I am getting the CB.

    I have already decided on the Cobra 75WXST because of its small size and reputation. Now I need to select an antenna. I don't know anything about antennas and am horrible with electronic stuff. I plan on mounting the antenna on my toolbox. I also don't want something thats extraordinarily tall. I only am looking for 2-3 miles range.

    What should I get? If anybody wants to post pics of their set up, that works to.
     
  2. Jun 18, 2008 at 7:06 AM
    #2
    jhodge83

    jhodge83 Any dog under 50# is a cat and cats are useless... Staff Member

    Joined:
    Apr 27, 2007
    Member:
    #1432
    Messages:
    27,135
    Gender:
    Male
    First Name:
    Jamie
    Moncks Corner, SC
    Vehicle:
    09 Timberland Mica DC 4WD Sport
    wat?
    i've got a 4' fiberglass k40 and i've talked a little over 2 miles away before. u can also get the mounting base that bends so u can flip it down level w/ the toolbox. thats what i did too
     
  3. Jun 18, 2008 at 7:11 AM
    #3
    camsbored

    camsbored Well-Known Member

    Joined:
    Apr 12, 2008
    Member:
    #5932
    Messages:
    185
    Raleigh, NC
    Vehicle:
    08 PreRunner DC/Sport/LB
    Kenwood DNX8120, Homelink mirror, Valentine One hardwire
    I'm no expert, but I've done some research for CBs on two trucks recently.

    If you don't mount the antenna on your roof, get a "no ground plane" antenna. This means that there is no flat metal surface beneath the antenna to help keep the transmission power horizontal.

    The antenna will need to be tall enough that it sticks up above the cab or your forward transmission will suck. How high it needs to be depends on the antenna type.

    I'm assuming your toolbox will be metal, and the antenna will be grounded to that. You'll also need to make sure the toolbox is grounded to the truck's chassis. Since the bed is plastic this is absolutely necessary. Depending on the hinges and how well the lid makes contact with the tool box you may even want to connect a ground wire between the lid and box.

    Hope that helps a little.
     
  4. Jun 18, 2008 at 7:49 AM
    #4
    c0b2a

    c0b2a Well-Known Member

    Joined:
    Feb 8, 2008
    Member:
    #4630
    Messages:
    264
    Formula: ¼λ
    Feed Point Impedance: 50-75Ω
    Bi-directional, broadside
    Minimum Height: ¼λ
    ΔTakeoff Angle: Change height


    ¼λ Antenna Length:
    Length (feet) = 234 / Frequency (MHz)
    Length (meters) = 71.25 / Frequency (MHz)


    so based on a CB freq range: 27 MHz

    234/27 = 8.666 so your gonna want your antenna length to be close to 8 1/2 feet to obtain a 1/4 wave length which will give you good trans and receive.

    I didn't get this off any site I did this the way I build my antenna's for my work radios.
     
  5. Jun 18, 2008 at 8:34 AM
    #5
    Khaos

    Khaos [OP] Well-Known Member

    Joined:
    Feb 4, 2008
    Member:
    #4570
    Messages:
    6,506
    Gender:
    Male
    First Name:
    Bryant
    Tallahassee FL
    Vehicle:
    2005 Prerunner TRD Off Road
    265/75/16 BFG A/T, 18" Magnaflow, K&N Intake Filter, Ultra-Gauge, Kobalt Toolbox, Metal Tail Light Guards, Cobra 19 and 4ft fiberglass antenna, Plasti dipped Badges/lower valance/rear bumper/grill/bullbar/ac controls, black DIN kit, JVC KD-X40, Wet Suit Seat Covers
    You got a link to that mount?

    I'm going to be buying a UWS Low profile box, all metal. How do I go about grounding the tool box? I know that probably is a noob question but I suck at electronic stuff and I admit it.

    Wow. I'm not good at math at all, so I probably never would have been able to do that. Thats a huge help!
     
  6. Jun 18, 2008 at 12:11 PM
    #6
    c0b2a

    c0b2a Well-Known Member

    Joined:
    Feb 8, 2008
    Member:
    #4630
    Messages:
    264
    feel free to add rep to me for my antenna building skills lol
     
  7. Jun 18, 2008 at 12:27 PM
    #7
    Toy4Life

    Toy4Life 668: The Neighbor of the Beast

    Joined:
    Aug 29, 2007
    Member:
    #2566
    Messages:
    4,973
    Gender:
    Male
    First Name:
    Chad
    Slippery Rock, PA
    Vehicle:
    96 Subaru Outback 2.2 5mt
    92 4Runner SR5 3.0v6 4x4(sold) 02 Tacoma SR5 TRD Offroad 4x4 (sold)
    I have a Firestik II mounted to my rear bumper. I have a 2.5-3 mile max range.
     
  8. Jun 18, 2008 at 12:32 PM
    #8
    Toy4Life

    Toy4Life 668: The Neighbor of the Beast

    Joined:
    Aug 29, 2007
    Member:
    #2566
    Messages:
    4,973
    Gender:
    Male
    First Name:
    Chad
    Slippery Rock, PA
    Vehicle:
    96 Subaru Outback 2.2 5mt
    92 4Runner SR5 3.0v6 4x4(sold) 02 Tacoma SR5 TRD Offroad 4x4 (sold)
    Here is a picture of where it is mounted.
    [​IMG]
     
  9. Jun 18, 2008 at 9:50 PM
    #9
    mikesdoublecab

    mikesdoublecab LT Chase Truck

    Joined:
    Jun 15, 2008
    Member:
    #7334
    Messages:
    6,006
    Gender:
    Male
    First Name:
    Mohawk Mike
    Glendale, CA
    Vehicle:
    01 Tacoma DoubleCab V6 Prerunner
    Engage Offroad custom LT kit with King coilovers and bypasses, Deaver J59 leaf packs with custom 8 inch shackles and Bilstein 7100 12" travel shocks, 16x8 Eagle Alloy 137s, 285-75-16 BFG KM2s, custom front bumper and skid, Procomp H911 foglights, custom rear bumper and spare tire carrier, bed bar, Engage Offroad custom chase light rack, Icom V8000 radio
    im running a 3' fiberglass antenna so as to clear the parking garages... got it mounted on my bedbar and i get a few miles on it...

    im also running the 75WXST due to the compact size... great radio...

    [​IMG]
     
  10. Jun 18, 2008 at 10:07 PM
    #10
    hail-bop Command

    hail-bop Command Well-Known Member

    Joined:
    Feb 11, 2008
    Member:
    #4692
    Messages:
    205
    Vehicle:
    I Don't Crawl I Haul A$$!
    LOL, This one mad me laugh!:D

    The best antenna that can reach the greatest distance for the low watts a stock CB radio will put out is a Willson 500 Magnet mount with a ground plaine kit... I would also consider the Cobra Classic LTD they are really good radios that are built tough and get a great signal range.

    You might also wanna look in to getting a Linear Amplifier (10 Meter). On a clear summer morning you will be able to hit some 'Skip' and be able to talk over 1000 miles away...
     
  11. Jun 19, 2008 at 12:36 PM
    #11
    ANDYTACOMA

    ANDYTACOMA NOMAD

    Joined:
    Sep 21, 2007
    Member:
    #2760
    Messages:
    270
    Vehicle:
    2006 access cab trd offroad 4x4 black sand pe
    fog light mod /parking light mod /after market stereo /bed lights/yeasu ft8700/uniden bct15

    "The best antenna that can reach the greatest distance for the low watts a stock CB radio will put out is a Willson 500 Magnet mount"
    I am going to respectfully disagree magnet mount antennas suck.The best antenna is a nmo style mount (ground plane is better) as long as the surface its being mounted to is metal (conductive). Why does the equation the other member wrote make you laugh? He hit it right on the nose.

    "You might also wanna look in to getting a Linear Amplifier (10 Meter). On a clear summer morning you will be able to hit some 'Skip' and be able to talk over 1000 miles away"
    THIS IS ILLEGAL DO NOT DO IT
    The only people who are allowed to use a linear amplifier are amateur radio operators (on the appropriate bands) . We are licensed from the FCC. You could possibly cause damage to yourself , others and your equipment.


    FYI
    here is an interesting article to read about CB a violator and the cost involved

    The Commission ordered that, pursuant to Section 503(b) of the Act and Sections 0.111, 0.311 and 1.80(f)(4) of the Commission's Rules, "CB Shop and More is liable for a monetary forfeiture in the amount of $7,000 for willfully and repeatedly violating Section 302(b) of the Act, and Section 2.803(a)(1) of the Rules."

    http://www.arrl.org/news/stories/2008/03/26/10025/?nc=1
     
  12. Jun 19, 2008 at 12:49 PM
    #12
    ANDYTACOMA

    ANDYTACOMA NOMAD

    Joined:
    Sep 21, 2007
    Member:
    #2760
    Messages:
    270
    Vehicle:
    2006 access cab trd offroad 4x4 black sand pe
    fog light mod /parking light mod /after market stereo /bed lights/yeasu ft8700/uniden bct15

    :D

    very good!

    here are some other helpful hints and rules when building/designing antennas. These were borrowed from a ARRL Technician class book


    The basic rule is in antenna construction is "Longer the wire, the lower the resonance,shorter the wire the higher the resonance."


    234 / Frequency in MHz = Length in Feet

    A vertical antenna is a 1/4 wave antenna and is half the size of a dipole. It's highly common because of its space saving characteristic. It is found everywhere from the antenna on your FM Stereo system to your walkie-talkie





    468 / Frequency in MHz = Length in Feet


    A dipole is a 1/2 wavelength antenna. To create a dipole you must determine the following:
    1st.) What frequency band
    2nd.) What the wavelength is at that frequency.
    3rd.) How long a 1/2 wavelength is in feet or meters at that frequency.
     
  13. Jun 19, 2008 at 1:31 PM
    #13
    hail-bop Command

    hail-bop Command Well-Known Member

    Joined:
    Feb 11, 2008
    Member:
    #4692
    Messages:
    205
    Vehicle:
    I Don't Crawl I Haul A$$!
    Because the equation is way over kill... 99% of people are not going to know what they are looking at.:)

    As far as magnet mounts 'Sucking' thats your opinion, The wilson 5000 with a ground plain kit is a REALLY good antena IMO its able to handle alot of wattage and your RF Calibration is always perfect... Which means no power is being wasted or kicked back in to the finals of your transmitter, which will eventually burn it up it....

    Amplifies are illegal on Citizens Ban radios, yes but what's not illegal with anything These days... As far as causing harm to your self? Give it a rest, a low frequency like 27mhz is not going to doing anything with power pumping through it. The danger starts when you start climbing to the high frequency range because the higher the freq is the the more directional it becomes and RF burn becomes a real factor... But not on 27mhz, LOL

    Talking skip is fun and is not illegal.
     
  14. Jun 19, 2008 at 5:23 PM
    #14
    MikeS.

    MikeS. Well-Known Member

    Joined:
    Jun 10, 2008
    Member:
    #7207
    Messages:
    288
    Far Eastern WVa
    Vehicle:
    2008 DC LB 4x4 in Speedway Blue.
    Undercover bed topper, Nerf style step bars, Python alarm, Ham radio with 250 watt amp and chrome wheel well bling.
    1/4 wave length antenna is great for mobile CB use. A great antenna is the 102" whip. Problem is a 102" whip (8.5') antenna is a pain in the arse. Thus the other shorter CB antennas use a coil and a stinger to approximate a 102" whip.

    Personally I use a Wilson 5000 mag mount on the center of my DC. I would prefer to run a thru the roof mount but I can't bring myself to punch a hole in a brand new truck. If it wasn't such a long run to the frame I'd run a ground wire from the antenna to the frame.

    I run a Cobra SSB rig that has been peaked and tuned to put out a 4 watt dead key carrier on AM.

    I've been messing with CBs since 1973, my 1st was a Cobra CAM 89, which I still have BTW.
     
  15. Jun 19, 2008 at 5:38 PM
    #15
    rpoint16

    rpoint16 Well-Known Member

    Joined:
    Sep 2, 2007
    Member:
    #2588
    Messages:
    575
    Gender:
    Male
    Tempe, AZ
    Vehicle:
    2008 double cab, 4X4, V-6, TRD. Super White.
    OME 885 coils & front shocks, with TT top plate, Total Chaos UCA, Rear OME extended shocks, Rear TSB, Rear Toytec AAL, trimmed the saber-tooth-tiger-long-ass mud flaps. 17" XD Revolver rims, 265/75/17 BFG AT KO's. Ripped out the crappy FM Modulator & installed a PA-15-toy interface. OEM bed matt.
    Not meaning to change subjects too much, but how do the hand-held radios compare.

    I know absoutley nothing about CB's.
     
  16. Jun 19, 2008 at 5:50 PM
    #16
    Ridgerunner

    Ridgerunner Well-Known Member

    Joined:
    Mar 14, 2008
    Member:
    #5269
    Messages:
    3,615
    Gender:
    Male
    First Name:
    Frank
    San Francisco
    Vehicle:
    2001 prerunner doublecab limited
    2001 with; cat-back twin exhaust,elbow mod, Westin bullbar with Hella550's, Snugtop XTR camper shell, TRD off-road 2x4-black beauty.
    My old specialty...wanna "really get out" your transmit? 102" stainless steel whip bumpermounted and a gutterclip on your roof. When you're out in the wide open unclip that sucker and let it ride straight up for max range of 5-10 miles!
     
  17. Jun 19, 2008 at 5:50 PM
    #17
    MikeS.

    MikeS. Well-Known Member

    Joined:
    Jun 10, 2008
    Member:
    #7207
    Messages:
    288
    Far Eastern WVa
    Vehicle:
    2008 DC LB 4x4 in Speedway Blue.
    Undercover bed topper, Nerf style step bars, Python alarm, Ham radio with 250 watt amp and chrome wheel well bling.
    IMO not very well unless you can attach an outside antenna. Most don't put out the max legal of 4 watts. For trail use they do ok.
     
  18. Jun 19, 2008 at 5:56 PM
    #18
    Ridgerunner

    Ridgerunner Well-Known Member

    Joined:
    Mar 14, 2008
    Member:
    #5269
    Messages:
    3,615
    Gender:
    Male
    First Name:
    Frank
    San Francisco
    Vehicle:
    2001 prerunner doublecab limited
    2001 with; cat-back twin exhaust,elbow mod, Westin bullbar with Hella550's, Snugtop XTR camper shell, TRD off-road 2x4-black beauty.
    I should add that it is imperitave to "match" your antenna to the transmitter otherwise prolonged mismatch can burn out the final coils in radio rendering it useless. Your radio dealer should show you how to do it...if you need I will explain it to you here:)
     
  19. Jun 19, 2008 at 6:33 PM
    #19
    MikeS.

    MikeS. Well-Known Member

    Joined:
    Jun 10, 2008
    Member:
    #7207
    Messages:
    288
    Far Eastern WVa
    Vehicle:
    2008 DC LB 4x4 in Speedway Blue.
    Undercover bed topper, Nerf style step bars, Python alarm, Ham radio with 250 watt amp and chrome wheel well bling.
    Absolutely you must match the antenna to the transmitter. This is known as SWR. 1:1 is perfect, anything below 1.5:1 is good.
     
  20. Jun 19, 2008 at 7:58 PM
    #20
    Khaos

    Khaos [OP] Well-Known Member

    Joined:
    Feb 4, 2008
    Member:
    #4570
    Messages:
    6,506
    Gender:
    Male
    First Name:
    Bryant
    Tallahassee FL
    Vehicle:
    2005 Prerunner TRD Off Road
    265/75/16 BFG A/T, 18" Magnaflow, K&N Intake Filter, Ultra-Gauge, Kobalt Toolbox, Metal Tail Light Guards, Cobra 19 and 4ft fiberglass antenna, Plasti dipped Badges/lower valance/rear bumper/grill/bullbar/ac controls, black DIN kit, JVC KD-X40, Wet Suit Seat Covers
    I have no idea what that means. I fail at electronics.

    Someone wanna just give me a link to what I need to pare with the Cobra 75WXST? :)
     

Products Discussed in this Thread

To Top