20' mast without guy wires?

[pcampbell]

I found out the maximum antenna mast height here is 42' at my residence. This puts me at about 17' above roof level. All the TV masts I see are steel and 10' length maximum. We do not have much wind here. I'm wondering if a long length of aluminum rectangular tubing (or circular... they also have "pipe" available in sched 40 or 80) would work, such as a 1.5x1.5" 1/8" thick. By extending the length of tube that is BELOW the roof line, and perhaps adding more brackets (3, or 4, instead of 2), would this hold up? I would be looking to go as light as possible, without sacrificing strength or stiffness.

I haven't considered about putting the OTA HD TV antenna on this, as well as UHF radio antenna.

[WHT]

I've never used 1½"x1½" square tubing, only the 2½". And that has twice the bend strength of 2½" round tubing. In theory, two brackets would work, but in practice you need a third middle one as at a certain distance (depending on the length above and length between the two brackets), you get some oscillation between the two brackets.

[CDX825]

Square tubing is allot sturdier then round that for sure. I would try to stay with one big piece rather than multiple pieces if your not going to guy it. So long as your UHF antenna is not a RF Celwave Super Stationmaster you should be good. :shock: :lol:

[exobyte]

But there's a catch with square tubing: round tubing has less drag, so it wouldn't have to be as strong.

I'm not sure how much, though. Maybe the square tubing more than makes up for the added drag, but you'll still have to mount it "deeper" if it's square and not round.

[pcampbell]

thanks for the replies. I noticed that my TV antenna mast is pretty flimsy feeling. Any guidelines for length of Tube below roof level vs above? I would probably look into buying a single 21 or 24' piece. Doesn't seem like 1.5" is much more $ than 1".

I am dealing with 3 antennas... UHF GMRS is a homemade directional Yagi but right now mounted low, the repeater is pretty close and I don't think I need it high (going about 7 miles with 25 watts and a pretty clear shot...) haven't tested it YET, waiting on a few pieces of that puzzle still. I also have it on the side of the house that the radio is on (opposite side that this large mast will be), so that my coax there is only about 10' in total length. I might look into pointing to another repeater further away in which case I'd at least want to test mounting it on this mast.

Next, TV antenna. I've got a Winegard HD-1080. Very small compared to what you think of typically but I would not want to put it at the top of the mast. Could probably go just above roof level to keep the weight and high drag stuff low.

Then the wireless - probably going to be a Pico or Nano. This is really only experimental and play at the moment but I am looking into setting up sort of wireless internet co-op. Not sure if there would really be any interest in this area :oops:

[jp498]

If you use galvanized pipe instead of tubing, you'll be all set. HD/Lowes have schedule 40 galvanized conduit pipe for about $30 for 10 feet and each piece is a good 30+ pounds of heft. This will be nice and strong. We have used it for mounting to the side of water towers and on regular towers with standoffs. Round is easier to get hardware for clamping antennas to. Now, once it's 17' above your roof, how do you plan to service it? Rohn 25 tower you can climb and it will be probably be about $15/foot. That could do the height OK if the next to top section is attached to the house.