The store-bought 2m/70cm groundplane antenna I’ve had mounted on a broomstick inside my apartment now has a home outside where it can reach so many more places.

After some brainstorming sessions in the hardware store, thinking of methods to mount 3 sections of military surplus fiberglass poles to my balcony railing, I figured out how to lash a basic flagpole mount to the rail and use chains and safety ropes to keep it stable.

Test fit of antenna and bracket on a 2″ PVC pipe.

My biggest concern with this installation is safety. The absolute last thing I want to happen is for the pole, the mount, the railing, or anything else to fail and catastrophically hurt someone downstairs or cause any property damage. To that end, I’ve employed chains and safety ropes where possible so, hopefully, if one thing fails, not everything will fail.

For outdoors weather concerns, I’ve configured the poles and brackets so that water cannot run downward into any inverted joins. The PVC pipe at the top has a cap, and exterior walls sit on top of interior tabs. Water cannot ingress, and the bottoms are open so water can egress without issue.

The poles overlap enough that I shouldn’t need to worry about stiff winds making them walk upwards and off the tab ends; but we’ll know more once we get real weather that’s not 102°F Texas Summer. Maybe some pins drilled through will alleviate that issue, but will introduce water ingress points. I also have 3/4″ PVC jammed into the flagpole socket, and the base of the bottom pole section sits on top of that, so that way strong wind cannot make it rattle and bounce upwards off the mount.

The top end of the PL259 connector under the antenna is sealed with self-annealing rubber tape. The bottom end on the feedline is open so water can egress if there’s any capillary action. I’ll inspect the installation after the next major rain to check for ingress or worsened SWR. I’ve also added a “drip loop” in the feedline so water drips off over the balcony instead of travelling down the feedline into my window passthrough.

Flagpole mount, attached to railing with electrical conduit brackets, and secured with a safety rope in case of failure. Screws use locking washers.
Safety rope attached around pivot. This will work, assuming the pivot itself doesn’t break. Not seen: flagpole socket has a 2’x3/4″ PVC pipe inserted firmly; the fiberglass pole sits over this, ensuring it won’t pop off the mount.
More safety rope on top rail. Center knot is an Alpine Butterfly Loop, and ends are tied with double-overhand, though I’ll retie it with an improved Alpine Butterfly Bend (won’t jam under load, and easier to untie).
Top support is 5′ of 2/0 chain anchored to brackets screwed into the wood decking. Chain is tightened with a turnbuckle. There’s a link added between chain arms so the pole is still captive if one bracket fails. Note the added safety rope.
Pole installation is complicated by the overhang and rain gutter. Note the outward angle; thankfully it’s not too steep. Top of 2nd pole section is above the gutter. Note the drip loop in the RG-8 feedline.
And there it is; another 4′ above the eave. Not crazy about the off-vertical angle, but it still hears really well. I do worry about the gutter edge wearing into the fiberglass under typical wind conditions. Might wrap that with sacrificial sheet metal and hose clamps. Also need to redo the cable ties.

I’ve already tested the antenna and RG-8 feedline (essential for VHF/UHF where higher power loss in coax is a concern), and I can reach repeaters in Georgetown and Elgin. I can also hear the tower and ground control at Austin Bergstrom Airport across town. It’s better than the flexible J-Pole I have in the window. I hope to do lots of simplex and weak-signal modes soon.

All-in-all, even though I have safety concerns, it’s a functional installation.

Published by Shawn

He's just this guy, you know?

Leave a comment

Your email address will not be published. Required fields are marked *