Discussion in 'Ham Radio Discussions' started by KN4DQE, Feb 10, 2020.
WRT the Aluma tower ... make certain you know what you're getting. When I was shopping for a tower, I looked at them. I wanted something in the 50-foot range and it had to fit my budget. I've forgotten the model number and price, but in the end the 50-foot Aluma that fit my budget would only meet full wind spec fully guyed. And I didn't want to have to deal with guying the tower.
I spoke with someone from Aluma at Hamvention about the tower, and I -know- I heard him say that they ship to Florida for free. But when I asked about that via email later on, he denied ever saying that. Suffice to say, shipping would not have been free.
I have no doubt that its a good product. It just didn't meet my requirements at the time. I ended up increasing my budget substantially and got a steel crankup that meets wind specs without guying.
They're definitely not cheap. The 40' tower was quoted around $3200. Of course I have nothing to compare that to (so please feel free to provide some feedback).
Might help, might not.
Re the birds, a fake "owl" atop the antenna mast (above the beam) often helps. At least, it has for me and some others I know.
However I've also heard that some birds are pretty smart and it doesn't take them long to figure out that owl isn't moving, so they come back anyway. The ones that are more effective have motion and sound, which means running a power line to them; they turn their "heads" and make owl noises via an internal speaker. Like this:
SUNNIER Plastic Fake Owl Decoy to Scare Birds Away Scarecrow Bird Repellent Pigeon Repeller with Motion Activated Scary Flashing Eyes + Frightening Sound to Keep Control Squirrel Rabbits Away Garden
Problem is, most of those are cheaply made and battery powered, so unless you install a solar cell or a small power line, they'll go dead fairly quickly and I don't know how long the plastic lasts in high UV exposure -- maybe "not long." However, there are better ones that cost more money and likely last longer and are more effective.
That's pretty pricey.
A Tashjian WT-51 is 51' extended, 22' retracted, all galvanized steel with a very heavy duty Fulton winch, and is $3550 brand new.
It is also rated for Florida hurricane force winds per the latest ANSI/TIA specifications and will support more than the Aluma tower will.
You would have to pay for transportation, but that can often be arranged for reasonable cost if you don't mind waiting a few weeks.
Aluma towers are basically yard ornaments. Sorry, but I would never invest in one of those. Tashjian makes far superior towers and if I'm paying nearly the same price, it's a no brainer.
Aluminum? For a tower?? Uhm . . . . NO!
I "see" that wind loading information Steve noted, but I would really check that out very carefully. Most ham towers simply don't meet the hurricane wind specs Florida requires. I have an 89 foot US Tower Heavy Duty Crank Up and it doesn't come close to meeting the required specs. I got around that by telling the local building permit fellow (my city required a permit) that we have plenty of warning regarding hurricanes and I would crank the tower down. I also had my PE certify that not even God could blow over my tower when cranked down. Got the permit, no problem.
Now the wind requirements are expressed as an “ultimate” wind. From what I’ve read, converting back to “basic” or “design” wind is complicated but is roughly done by multiplying by 0.8. So 80 mph basic is about 100 ultimate.
The wind maps for my county are detailed down to fairly small areas because the westerly wind varies so much by local topography. At my house the ultimate speed is 115 (92 basic), but just a few miles to the west or north it goes up. In the mountains above timberline it can be as high as 225 mph. (Counties here are large. Mine is larger than Delaware and there are eight larger).
Florida wind speed maps online show 180 mph basic (225 ultimate) along the populated lower coasts! Yikes!
37 feet will work fine for 20 and above. As you know it is low for 40. However, FWIW, my 40 meter antenna is a dipole with the feed point also at 37 feet. While I don't bust pileups with it I can (with 500 watts) work all continents. Your location is better than mine
Funny part is, you won't find any amateur radio antennas rated for hurricane force winds any higher than Category 1, which is 74-95 mph. Category 5 is >157 mph and I don't know of a single amateur radio antenna rated for anything close to that.
So, the tower might withstand it, but parts of your beam could land in the next county.
So basically I need to confirm the rate wind speed is valid for my location (which shows to be 130 / 140 MPH in Orange county).