Can I make a 6&10m dipole

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KM4SJS, Mar 25, 2016.

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  1. KM4SJS

    KM4SJS Ham Member QRZ Page

    So my paper has ALOT of scribble on it. My question is as follows:

    Can I build a 6&10meter dipole be it a wire dipole or pipe dipole...?

    I have a 6m wire up roughly 30' which seems to have a 1:2 swr (going off of the swr meter on the ts-2000). And I have a 10m pipe dipole (aluminum to copper element) up roughly 25' which I seem to be having a problem with the swr with... One day it'll tune 1:3- 1:5 then some days it won't tune at all (I'll just get the CW error message off of the 2000).

    I have a tower that I will be putting up in the very near future however I would still like to have a wire or pipe with both bands on it on the opposite side of the house.

    Any suggestions or ideas and or equations would be greatly helpful!!

    73
     
  2. KM4SJS

    KM4SJS Ham Member QRZ Page

    Here is the one for 10m... Should i have insulated the aluminum with small pieces of PVC at the mast?
     

    Attached Files:

  3. WB5YUZ

    WB5YUZ Ham Member QRZ Page

    Sorry. Cross posted.
     
  4. K5VV

    K5VV Ham Member QRZ Page

    Use your 10m pipe dipole. Add wires for 6m to make it a fan dipole. Connect the wires to the same feedpoint (or to the pipe very close to the feedpoint), then let the wires drop down a bit on the ends. Support the ends of the wires with something non-conductive -- rope or PVC pipe. Wind may cause issues if you use rope.

    It will look something like this.
    upload_2016-3-25_11-43-1.png

    My estimate is each half of the 10m (pipe) is 100 inches, and each half of the 6m (wire) is 60 inches. Adjust the 10m for SWR first, then the 6m wires. You should get <1.3:1 on 10m and <1.8:1 on 6m.
     
  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    If it's fed directly with coax and no balun and the mast is electrically common to one side of the dipole, those would be two mistakes.

    The mast should not be electrically common to either side of the dipole, so an insulator there to prevent that contact is helpful. A balun at the feedpoint would also be helpful.

    Can't tell from the image if there's a rotator on that mast or not, but there should be; otherwise you have an antenna that works in two directions but is quite lossy in two others.
     
  6. KM4SJS

    KM4SJS Ham Member QRZ Page

    wonderful. thank you gentleman. I did make the mistake in having everything basically touching the mast... I will eventually be putting up my tower and converting over to just 1 or 2 wire dipoles in each direction if not offset them to the NE/SW & NW/SE.. we shall see how tomorrow goes. That antenna has been taken down and I started to dismantle it but the bugs and loss of light got to me... Can't quite have a spot light on with all of these blind mosquitos/ flies we have here coming off of the lake...

    and no, there is no rotator on the mast. just the mast mount...
     
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Having a dipole for the 'higher bands' like six and ten meters without a rotator, you're missing out on about one-half of what you could be working.

    On the 'lower bands' like 40m and 80m, it's not as bad since relatively low antennas aren't very directional. But on the higher bands, they surely are.

    Nothing should be touching the mast.
     
  8. KM4SJS

    KM4SJS Ham Member QRZ Page

    Would a Cross 2 element pipe dipole work with a rotor? Same feed point, 2 Differnt length elements one on top of each other or both at the same center point? Or would a 2 element beam work
     
  9. WA4SIX

    WA4SIX Ham Member QRZ Page

    Look up a "Turnstyle antenna"

    Ed
     
  10. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    First, I'd recommend buying an antenna handbook or three.

    But secondly, crossed dipoles need a phase shift network between them to avoid having the feedpoint impedance reduced by a factor of two. But a 'turnstile' certainly works, and for a single band you only need a section of coax to do the phase shifting and maintain the impedance.
     

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