A lil swr knowledge

Discussion in 'CB Radio Forum' started by craig_sez, Oct 2, 2016.

  1. bored silly

    bored silly Road Train Member

    Joined:
    Jul 1, 2016
    Messages:
    2,714
    Thanks Received:
    656
    0
    that radio mount is a option I've never really thought about...I'm thinking about it now....thanks
     
  2. craig_sez

    craig_sez Road Train Member

    Joined:
    Sep 5, 2013
    Messages:
    5,569
    Thanks Received:
    2,711
    Location:
    novascotia,Canada
    0
    Just to show you that unless your radio draws almost nothing,ciggy lighter socket aint the best plan..
     

    Attached Files:

    bored silly Thanks this.
  3. craig_sez

    craig_sez Road Train Member

    Joined:
    Sep 5, 2013
    Messages:
    5,569
    Thanks Received:
    2,711
    Location:
    novascotia,Canada
    0
    Just a piece of alum i found at the shop..Cleaned it,cut the corners off it so i dont stab myself in the head,paint n clear coat..Mount it the the liter lips are wide enough to angle the radio dials n screen at me..Dont wanna scratch the inside of the truck so ill also get a few of those lil felt pads that go under chair legs...When i move outta the truck4 bolts and done..
     

    Attached Files:

    bored silly Thanks this.
  4. bored silly

    bored silly Road Train Member

    Joined:
    Jul 1, 2016
    Messages:
    2,714
    Thanks Received:
    656
    0
    depends on how many amps that export radio draws as to weather you can run it off a cigarette lighter plug or it needs to run direct off the batteries.the bigger radios draw more amps to run them......
     
  5. bored silly

    bored silly Road Train Member

    Joined:
    Jul 1, 2016
    Messages:
    2,714
    Thanks Received:
    656
    0
    you definitely don't need 6 ga. wire to run a barefoot 955 when 8ga.will get the job done just fine....dawg . go by everything mark tells you. makes no difference to me one way or the other.
     
  6. rabbiporkchop

    rabbiporkchop Road Train Member

    Joined:
    Feb 9, 2012
    Messages:
    9,677
    Thanks Received:
    6,525
    Location:
    Wapwallopen, Pa
    0
    Check this out..
    Any wire will have inductance and therefore, inductive reactance. The longer the wire, the higher the inductive reactance and the higher the opposition is to the flow of RF current. The fatter or larger the wire, the lower the opposition to the flow of RF current. The effect is similar to the DC resistance of a wire. The longer the wire, the higher the DC resistance will be. The fatter the wire the lower the DC resistance for the same length wire. There is an important 'however' that we must consider. First, when RF is applied to the conductor, the RF travels only on the surface of the conductor. Surface area is the important factor here, not the diameter or thickness of the conductor. Another major difference between DC and RF current has to do with wavelength. The wavelength of DC current is infinitely long. This is not the case for RF. When the XL (inductive reactance) is measured along the length of a wire, the magnitude of XL (the opposition to RF current flow) varies from very low to very high values. It continues to alternate between low and high values in cycles that have a direct relationship between the length of wire and the frequency. DC resistance, on the other hand, has no cycle. It simply increases linearly with the length of the wire.

    When measuring XL, its value is very high when the length of the wire is around one-quarter wavelength long. Increasing the length wire to one-half wavelength, returns XL to a low value.

    [​IMG]
    The length of the wire does not have to be very long for this effect to be observed. For example, at 28 MHz an 8' ground wire (or any wire for that matter) is approximately one-quarter wavelength long. If this 8 foot long ground wire connects your 10 meter rig to your ground system, the ground wire may actually prevent RF from traveling to ground. This is an UN-GROUND!

    Why? As illustrated above, the inductive reactance of wire that is one-quarter wavelength long is very high and impedes RF current flow (thus the term - impedance).

    On other bands, where the length of the wire is not an odd multiple of a quarter wavelength long, the inductive reactance (XL) is at some intermediate value.
     
  7. bored silly

    bored silly Road Train Member

    Joined:
    Jul 1, 2016
    Messages:
    2,714
    Thanks Received:
    656
    0
    Well I need about a ft.and a half of 4 ga. Welding cable with a Anderson connecter on one end and the lugs on the other end so I can run it off my radio straight down to my power cell i need this asap as in now... can ya help me out with that one ???
     
  8. craig_sez

    craig_sez Road Train Member

    Joined:
    Sep 5, 2013
    Messages:
    5,569
    Thanks Received:
    2,711
    Location:
    novascotia,Canada
    0
    I hate with a passion that i only KINDA understand this stuff..
    Lol my luck when im about to take my last breath ill get the TAAA DDAAA moment..
     
    rabbiporkchop Thanks this.