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6m Beacon Antenna ...

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Zaba, OH1ZAA
Mon Jun 01 2009, 12:52PM
Zaba, OH1ZAA
Registered Member #123
Joined: Thu Apr 03 2008, 02:54PM

Posts: 25
Charly/OH3KLU, there are probably many rigid commercial antennas, but not necessarily omni-directional, and not for 50 MHz -- and you pay a lot of money to get them! --- I tried to fit ½ inch titanium extensions on the OH2SIX 19 mm dipoles, but with regular hose clamps and a 16 mm OD intermediate Alu-adapter I could not get enough friction between tube surfaces to keep the construction intact. One does not make easily holes in titanium as the drill will melt on the job! --- 73, "Zaba" OH1ZAA
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Zaba, OH1ZAA
Mon Jun 01 2009, 01:10PM
Zaba, OH1ZAA
Registered Member #123
Joined: Thu Apr 03 2008, 02:54PM

Posts: 25
Apart from the mechanical aspects designing omni-pattern antennas is quite a challenge... The nice thing about a V-configuration is that the radiated field will spool rather easily around the tower. With stacked center fed and center mounted dipoles it is much more difficult to manage radiation, as the dipole legs will be partly "shunted" and almost touch the tower --- Designing for an omni pattern is intuitively pretty hard, as it is hard to oversee all the mutual effects beforehand. One needs the idea first to be able to feed it into the simulator. With offset feeding the problem is very similar as making an aluminum pipe extension to an existing tower to serve as a ground plane antenna (from the ground up). The truth is that the RF-current is not willing to continue into the thin pipe extension from the thick tower, unless one fits the end of the pipe with a top-load of crossed elements.... With the OH2SIX V-stack a similar problem exists near the feedpoint, where there is coupling between the feeder lines near the tower, and even less willingness for the current to continue through the tubular capacitors toward the main V-sections that are supposed to radiate. Even when shielding the first part of these feeders the main element tips will couple back to the shield and there will be current on the shield nevertheless... Finally a good simulator will sort it all out (with designer steering), but this illustrates the complexity of mastering mutual impedances by intuition --- 73, "Zaba" OH1ZAA/OHoMZA ---
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Zaba, OH1ZAA
Mon Jun 01 2009, 01:43PM
Zaba, OH1ZAA
Registered Member #123
Joined: Thu Apr 03 2008, 02:54PM

Posts: 25
Charly/OE3KLU, sorry about misprinting your call... 73, "Zaba"
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Joerg, OE6VHF
Mon Jun 01 2009, 03:54PM
Joerg, OE6VHF
Registered Member #947
Joined: Mon Jun 01 2009, 12:56PM

Posts: 3
Hi Charly,
as this is the UKSMG Forum I'll post in the appropriate language.
First let me congratulate you for the new OE3XAC/6m beacon. I get it with 477 in JN76XT via Tropo. For your Antenna Problem I can contribute the following:
Perhaps you know that I plan to launch a 6m voice Repeater on Mount Schöckl at JN77RE this mounth.
I also searched for omnidirectional, vertical polarized, antennas.
Because I like the ruged design of Antennas from KATHREIN I've found the following two antenna types:

Type one is a groundplane in very rugged style:

I also will use this Antenna at the 6m Repeater side.
This Antenna was mostly used at the 40Mc siren system of OE6 firefighters. You only have to cut it on the right length.

Type two is a steel Dipole which is dedicated to 4m. You can polarize it vertical or horizontal. To convert it to 6m just mount on each end aluminium lightnig-prodection-wire with some clamp stuff and cut it on the right length.


perhaps I could help you a bit.

Joerg-OE6VHF

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Charly, OE3KLU
Mon Jun 01 2009, 08:08PM
Charly, OE3KLU
Registered Member #927
Joined: Sat May 16 2009, 12:39PM

Posts: 10
Hello Joerg !
Tks fer Your Infos - i had the Kathrein GP für my 10m Beacon in my mind BUT list Price is nearly 200.- Euros for it and thats too much ... i will try a Dipol Element of an old Kathrein TV-Yagi for test maybe thats better than my 5/8 now ... this antenna works good on Ground Wave but not on ES ...

73! Charly OE3KLU

-> when i have time and found a 4m K-Dipol i will try to made it mechanical longer ... Beacon is also there for Antenna Tests ...



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Joerg, OE6VHF
Tue Jun 02 2009, 11:37AM
Joerg, OE6VHF
Registered Member #947
Joined: Mon Jun 01 2009, 12:56PM

Posts: 3
Well, ok the price isn't ham like, but it's real good quality.
Just another Antenna source you find here:


Just give him the frequency, and he will built an antenna of your guidelines for a really good price.

73's Joerg
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Zaba, OH1ZAA
Tue Jun 02 2009, 12:12PM
Zaba, OH1ZAA
Registered Member #123
Joined: Thu Apr 03 2008, 02:54PM

Posts: 25
From the 70 MHz site Forum I noticed another omni-antenna source: ..... except for the cloverleaf (Big Wheel) all these horizontally polarized solutions tend to radiate substantially into the zenith, so I would recommend a 0.6 wave stacking distance, while keeping an eye on the feed impedance. For example if the OH2SIX single V is designed for 75 ohms, it will show 50 ohms at both feed points in the 0.6 wave spaced stack --- 73, "Zaba" OH1ZAA/OHoMZA ---
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Charly, OE3KLU
Tue Jun 02 2009, 04:20PM
Charly, OE3KLU
Registered Member #927
Joined: Sat May 16 2009, 12:39PM

Posts: 10
Rehello !

Made today some Telephon Calls and now i get a 40mhz Pager GP by Kathrein - i was myself a Firefighter in my younger Years

Thanks Joerg OE6VHF for the Tip !!!

73! Charly OE3KLU

PS: Dipol from TV-Antenna i try also ...

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Chris, W3CMP
Thu Jul 16 2009, 05:30PM
Chris, W3CMP

Registered Member #190
Joined: Sun Apr 06 2008, 04:15PM

Posts: 5
Charlie:

How about a horizontal loop made from copper or aluminum tubing? Here are a couple sites to check: ;
I've made 6 meter loops out of 1/2" copper plumbing tubing using the K0FF information. I modified the antenna construction to remove the center copper tube and eliminate the tuning butterfly. Insetad of the butterfly, I used a pair of copper 1/2" couplings, (which are about 1" long) and slid one over each open end of the 1/2" copper tubing. I put a piece of 1/2" OD teflon rod in the coupling ends. I adjusted the coupling ends in and out until the antenna was resonant, and soldered them to the tube ends. I kept the teflon rod in between the couplings to add rigidity to the structure. The antenna is mounted by a flat alum. plate with 2 U-bolts holding the copper tubing to the plate and 2 U-bolts holding the plate to the mast. It works pretty well.
A final option is to go to Ebay and get a lowband vertical mobile antenna from a 42-50 MHz mobile FM unit. These units are 1/4 w/l antennas designed to be mounted on cars. The can be mounted to a tower easily. Good luck and 73. Chris Patterson W3CMP
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Stewart, G1HHO
Sun Jul 19 2009, 03:44PM
Stewart, G1HHO
Registered Member #28
Joined: Tue Mar 18 2008, 07:31PM

Posts: 4
Charly why dont you get in touch with Mike G3SED who owns Nevada amateur radio shop.He has already supplied some heavy duty 6M verticals for beacons I think he supplied them free of charge.
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