FlightAware Discussions

Mast ideas?

My antenna is currently mounted on a jury-rigged PVC pipe support that sticks out of an upstairs window then up via a T-connector and more PVC pipe, placing the antenna barely above and outside of the gutter on the south side. That’s as high as I can get it with that setup due to weight and unweildiness. My own roof effectively blocks the north and another nearby 2-storey house’s firewall blocks much of the east. (To the west and northwest there are hills and mountains: not much I can do about those.) My antenna’s about 5.5 meters high by my reckoning.

I’m unable to access my roof to put the antenna up topside so the only way to get it higher would be to put it on a mast, at least 7 meters long, mounted on a re-enforced concrete fence post near my house with wall mounts, which I already have. They can accommodate from 1 to 2 inch masts. The longer the mast the better up to 10 meters or so as there are also some 3-storey houses not far away whose roofs I’d also like to try to “see over” if possible.

The mast would have to be strong enough to be self-supporting and not need guying in moderate breezes as I don’t have room for guy wires: the fence is only 1 meter from the house on the south and is just on my side of the property line so I’d only be able to guy the mast on the east and west sides anyway. It would also have to be easy to lower quickly by one person in case of higher winds or thunderstorms (I live in typhoon alley.) A telescopic pole of some sort would be ideal, I think, but all I’ve found are carbon fiber fishing poles that collapse or “un-telescope” from the weight of the antenna and LMR400 almost as fast as I extend the sections (I just tried one yesterday using a temporary mount for the pole.) I think some sort of locking mechanism would be necessary to prevent that. I haven’t been able to find any proper masts either, not even shorter ones.

Wondering if anyone has any ideas for something I could use as a mast?

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They only thing I can think of that might be suitable for use is your situation, is telescopic flagpoles. Only problem might be cost. Weather enthusiasts use it to mount the anemometer and wind vane.

Have you looked at this company? Telescoping Fiberglass Push-Up Masts - Max-Gain Systems Inc
I haven’t used them, but they’ve got a good review on eHam.
I have read about building a collapsible mast yourself, but it’s a lot of work.

I buy 6m lengths of thin wall 40mm steel tube. I’d get longer, but that’s what is available.
if it’s pivoted at the bottom, is can get a bit awkward to erect for one person depending how much weight is at the top.
These tubes are bottom mounted only and un-guyed. I don’t have tornadoes to deal with, but one is out in the open and fully exposed.

And don’t forget that the wind load can be reduced by hiding the coaxial cable inside the pole, 40mm thick-walled pvc (4m + 1.5m in my case)

I’m using something similar to this.
https://www.homedepot.com/p/Mr-Longarm-Pro-Lok-23-ft-Adjustable-3-Section-Extension-Pole-2324/100177392?MERCH=REC--searchViewed--NA--100177392--N&

I have it shoved into a j-pole mount with a little bracing on that mount, but the pole is self supporting. It’s held up to some decent winds so far, but if a hurricane is coming, i’ll take it down and leave my alternate antenna up that’s just on the jpole mount.

That’s exactly what I was thinking of. Unfortunately they’re not sold in the Philippines. Maybe I can find a telescopic fruit picking pole or something.

The only metal tubing I’ve seen here is 6 foot lengths of 1/2 inch stainless steel which is neither long enough to get the antenna higher than it is nor wide enough for my antenna mounting brackets. :frowning:

Russians tied their antenna to a baloon to gain height. :slight_smile: :wink:

http://russianpatents.com/patent/232/2320058.html

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You must be able to do more than that.
Scaffolding tube?
Any metal merchant will be able to supply steel tube.

I’ve finally found something I can use, a 10 meter tree saw with telescopic pole. It’s meant for pruning trees but the saw’s removable and can be used as a hand saw as it has a handle too. The pole by itself extends to 9.45 meters and appears to be double locking going by the photos. It looks like it has both locking clamps and stove bolts with wing nuts.

I’m also going to replace the LMR400 coax I was planning to use with lighter weight and thinner LMR240. It has more loss than LMR400 but may be easier to manage and won’t put as much strain on the antenna’s SMA connector or the mast. Besides, LMR240 is what FlightAware recommends on their shopping list for assembling a PiAware flight tracking system. Handling that LMR400 is like handling a cold, stiff garden hose.

These are quite expensive even second hand but would be ideal

Clark portable mast

or

image

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Just a follow-up: I got a pruning saw with a very good-quality telescopic 6-section aluminum-alloy pole with clamps between sections that can be locked in place using wing nuts. The pole’s maximum length is 8.4 meters but I think I won’t extend each section quite all the way and reserve 15cm or so for increased strength between sections. It’s pretty heavy, probably around 7-8kg, so I plan to guy it as well as I can to take some strain off of the screws that hold the two v-type wall mounts onto the fencepost so they don’t work loose and pull out if there’s a breeze. I got a guying kit that will work but I also had to order (import) a guy wire clamp for the mast which will take most of October to arrive. Hopefully I can get my antenna higher than nearby houses in December, around 7.5 meters or so, and increase my range. (The say screws onto the end of the pole and also has a handle so it can be used as a hand saw.)

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Troll’s long endurance Aerostat system is designed to receive, monitor, record and transmit HD video, voice and data to the limits of Line of Sight (LOS)

http://www.commsurveillancesys.com/persistent-aerial-surveillance
PAS-Aerostat-Trailer1

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Helium is expensive. Lost He eventually leaves Earth due to solar winds.

Hydrogen cheap. To generate hydrogen, aluminum (wire or metal shavings) is needed and alkali. We should not forget about the observance of safety techniques when working with hydrogen and boiling alkali.

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Methane’s cheaper. All that’s required is beans, broccoli and cabbage. Throw in some pickled eggs for increased production. :smiley:

Water electrolysis works too. I did it, the oxygen generating terminal (+) is a pain, it gets eaten up by the O- and OH- radicals.
Electrolysis of water - Wikipedia
When I was kid, i did it with kitchen salt. I have created Chlorine gas without thinking, luckily I didn’t poison myself, that weird gas color was kind of worrisome to me.
In both cases you need a pump to pressurize that balloon with hydrogen.

Heavier than air.

Also, hydrogen for passengers might be bad. That accident in the photo was due to the balloon static electricity sparking when was suddenly grounded by the landing mast wires, in rain.
A permanently attached balloon, with permanent grounding, would have no such sparks. However many localities might have something against such balloons.

I had my antenna installed in a tree until this year. Then, after three years in UV light, the supporting cable broke off and it fell on ground. I was too lazy to find a good way to raise it up in the tree again.
Funny, at 3 meters above ground where it is now, I still get good results.

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No it itsn’t.