Sidebar Sidebar
  • You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Click here to find out how to win free radios from Retevis!

Twin X-Mount Dipole Idea

wavrider said:
You can use 3/4 wl .75 for phasing it will work the same as the 1/4 wl as far as impedance matching but it will be a longer distance so you will have more length of coax to be bale to position the antenna where you want it.
Click to expand...

Thanks. I'm trying to find a vendor that I can buy RG 59/U and going through my options. Velocity factor is crucial in making this antenna work. The second dipole has to fire 1/4 wavelength after the first for it to be a rotating dipole/circular propagation.
 
300/27.285 MHz times .82 vf=7.394 feet (7 feet 447⁄64 inches)
That's what got for RG 59/U with a .82 vf factor. This is for 1/4 wave coax cable length.
Anybody care to differ?

246/27.285 MHz times .82 = 7.393073117097306 meters/24.255 feet (24 feet 31⁄16 inches) or
6.05625 feet 1/4 wave
?????!?? Which one?????
 
Last edited:
Last edited:
binrat said:
That's not worth it. No get off of the net and go build....oh pics are a must. Have fun. ;)
Click to expand...

LOL!
Waiting for the parts to come in.
I may just get a regular 75 ohm Co-Phase harness and a 9 ft jumper instead if paying Copper $124 for a official Maco circular polarization harness.
Decision: I"ll buy the 75 ohm co-phase harness and 9 ft jumper from Star Electronics for $29 and save &95. :)
Correction; bought the harness and jumper from Amazon and saved $20 more bucks than Star's website
 
Last edited:
  • Like
Reactions: 1 person
Question. Won't feeding two antennas halve the wattage output in half?
Question 2. If antenna is orientated horizontally,can ground plane radials be added to lower take off angle?
Question 3. If the antenna is mounted on a horizontal boom, can reflector elements be added to affect gain in desired direction?
I guess I'll learn more when I get my CP Antenna book.
 
Last edited:
http://www.worldwidedx.com/cb-antennas/28913-circular-polarized-antenna.html
HomerBB it would be nice to see you build one of these antennas. According to the previous thread I posted,if you where to do a beam antenna,it says that you can set the gamma for the vertical and horizontal separately. On my antenna project I might use fishing line to support the horizontal elements. To offset halving the power into both elements,a doubling of power would need to be addressed. Since my CRE-8900 keys 10 watts am, I have descent power to make this thing work. A small amp could be used to offset the loss. It's just 3db
 
Just a thought here. I ordered a 1/4 wave 75 ohm RG59/U co-phase harness with PL-259 connectors and a 50 ohm 1/4 wave 9' jumper with PL-259 connectors. I have a MFJ-915 RF choke with ferrite beads inside and 13 ft of coax inside. I was wondering if I can coil up the co-phase harness legs and 50 ohm 1/4 wave jumper. I'll have to look it up to see how much to coil up the 75 ohm harness.
 

Attachments

  • image.jpg
    image.jpg
    286.3 KB · Views: 6

dxChat
Help Users
  • No one is chatting at the moment.
  • dxBot:
    Greg T has left the room.
  • @ BJ radionut:
  • @ BJ radionut:
    EVAN/Crawdad :love: ...runna pile-up on 6m SSB(y) W4AXW in the air
     +1
  • @ Crawdad:
    One of the few times my tiny station gets heard on 6m!:D
  • @ Galanary:
    anyone out here familiar with the Icom IC-7300 mods


      Top Bottom
      Back