Rotatable co-phased 10m/11m base antenna

[KF5FUR]

The antennas are separated by 10ft 4in. With about 6ft of harness left over from the center bracket. The setup may dance around a bit in the wind, but not as much that it will degrade operation. I used two aluminum pool dome poles one with a "male" end that slides into the other with two "female" ends, I placed the angle bracket so that it would clamp the joint and simply mounted the antenna on either side and there ya go.



Sorry about the picture quality, I had to crop them, as my camera takes 1200X1300 pixel photos and I had lack of good places to take the pic since I could not undo the bolt on top of the vertical piece that mounts onto the angle bracket.
Post more later when I get it installed on roof

 

[RatsoW8]

Those are shortened mobile antennas. Although it was probably fun to build it's not going to perform as well as a larger base antenna or dipole antenna. What was you reason for using mobile antennas? size?

 

[KF5FUR]

Those are shortened mobile antennas. Although it was probably fun to build it's not going to perform as well as a larger base antenna or dipole antenna. What was you reason for using mobile antennas? size?

It's all I have atm, no particular reason and I would never have bought them specifically for this. I will upgrade in the future to two base antennas. I will then add a second set of horizontal pipe somehow, as I assume the base antennas are a lot heavier. But I wonder if two 102" whips will work ok, or can I find some base antennas with the same 3/8-24 thread, I can get some screw on ground planes if the antennas do not come with them, but can one big enough be found?

 

[BJ radionut]

James: You brought up radials(ground plane).
This would have been my thoughts also. Those mobile whips are going to require some type of radial system to tune and work effectively. The mounting pipe and connecting pole your using for spacing will supply some, however it may also not give the needed "reflection" required to make the antennas radiate. You must remember you are transmitting an AC signal. The mobile whip is only half, for those antennas to work correctly they require an equal second component. Mounted on a car/truck the metal body supplies this.
The vertical ground plane antenna requires tuned radials to preform this, the exception to this rule is a 1/2 wave vertical feed like a Ringo.
The shield of the feedline I will speculate will become that component.
Are you sure you desire this?

If you think about it can you make a AC light bulb radiate light with only one wire going to it?
Just my thoughts...will it work the way you are configuring the system...it might? Will it be a efficient and effective system?
All the Best
BJ

 

[KF5FUR]

James: You brought up radials(ground plane).
This would have been my thoughts also. Those mobile whips are going to require some type of radial system to tune and work effectively. The mounting pipe and connecting pole your using for spacing will supply some, however it may also not give the needed "reflection" required to make the antennas radiate. You must remember you are transmitting an AC signal. The mobile whip is only half, for those antennas to work correctly they require an equal second component. Mounted on a car/truck the metal body supplies this.
The vertical ground plane antenna requires tuned radials to preform this, the exception to this rule is a 1/2 wave vertical feed like a Ringo.
The shield of the feedline I will speculate will become that component.
Are you sure you desire this?

If you think about it can you make a AC light bulb radiate light with only one wire going to it?
Just my thoughts...will it work the way you are configuring the system...it might? Will it be a efficient and effective system?
All the Best
BJ

What about something like this for them, or is this not large enough?

 

[BJ radionut]

They need to be 8 to 9ft long to work best on 10/11m minimum 3 per antenna...but you can get by with just 1 on each....then you have 2 dipoles!
All the Best
BJ