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Fixed Wireless Equipment

Antennas for the Birds

One of the hazards of being a wireless ISP is that a variety of natural forces can interfere with your external infrastructure—such as antennas—wreaking havoc with your signal.

[June 17, 2003]

On ISP-Wireless in March, LL mused:

Well, here's an interesting one. We have a 19dB grid antenna facing a client. It seems that every few weeks it gets moved. We've finally concluded that "d*mn birds" are doing the following:

• Perching on the antenna (including owls perching at night)·
• Using the antenna as a favorite do-do spot·

Any bird experts out there who might shed some light on getting rid of these little troublemakers?

While this predictably generated a good deal of mirth, it also garnered serious attention.

[T commented] "They must be big birds or else really poor antenna mounts. We don't have that problem with Andrews 24 dBi grids (which have a tighter beam width) and I have seen birds on them. Have you considered changing it out for a panel antenna?"

Other solutions broke down into two camps. The first group suggested obstructing bird access in some way.

[RB suggested] "You could take a few pieces of Unistrut and fashion some sort of guard or sacrificial perch right above your antenna, so that they'll land on it rather than the flimsy grid. Won't keep them from pooping all over it though.

On the other hand, maybe if you cover their new perch with some of this stuff ["bird spike"], it will give them a little incentive to find a different rest area?"

JR also recommended bird spike, although from a different source:

"We use Bird•B•Gone 2000 (no joke). Out here in California, the hawks get pretty large and can stop a 5.8 signal quite effectively. Signal loss problems went away, after installing Bird•B•Gone. The case only cost 55 bucks."

R offered a more home-made solution:

"A half-inch diameter door spring will work. Might have to give it a little extra pull interiorly, but they won't light after trying it out several times. I did this many times in Oklahoma and Missouri because of the same problem. No more birds."

The other camp endorsed frightening—or zapping—the avian interlopers.

[AN said] "I am sure you have seen those wooden snakes made across the border. You can hold them by the tail and manipulate your wrist to make it move in a snake like motion. Get one of those and attach the back half of the snake to the grid and leave some of the front half toward the top and front if signal allows. Any movement of the antenna should make it sway back and forth. The only problem, I think, is some owls will eat snakes if given the opportunity."

JM's advice was electrifying:

"We had the same problem. We wrapped (in alternating sequence) a pair of wires supplying 110 volts to the antenna grid. One wire will be hot and the other ground. This will take care of your bird problem. They will land only once. Just make sure the wires are separated by good insulation and won't touch during rain/or high winds."

AS had a similar, if more humane plan:

"I have prevented pigeons from landing and cr*pping all over. On a ledge where they like to congregate, I mounted two wires about a quarter of an inch apart. Each wire loops back to itself, and in turn is connected to a 9 volt battery. Every time they land on the ledge and their feet touch the two wires, they make a circuit and fly way. When it rains, I disconnect the battery from my house."

—End