Building an antenna mast. Could this work?

[W5BRM]

Sorry pic isnt drawn to exact specs. Used MSPaint and its a PITA to get exact measurements with that

My plan is to build a semi-portable/temporary install antenna mast from 2x4x10 pressure treat wood. The idea is to create a mast that can be broken down and reassembled for field day or camping activities. Also I want to build this for my home QTH. The landlord said I could have antenna's but couldnt attach anything to the house or hang wire in the trees. I am thinking of building 2 of these so I can stretch a horizontal dipole between them or use one to hang an inverted V from it. I can feed antenna and ground straps through a window or run it out a door jamb. Want to to be disassembled as I dont to leave any wires up while I'm out traveling. I had considered building one from aluminum antenna mast but thought that me a bit too flimsy at the 30ft level plus the metal masting would play havoc with matching and such

The assembly would be something like this. take 1 2x4x10 and cut in half. Clamp 2x4x5 and 2x4x10 together. Drill holes and set 1/2 inch X 6 inch through bolts and tighten them together. Set in bucket of concrete and let set. Drill holes on each remaining peice at about 2 and 4 inches from end of each board. Assemble rest of mast as shown in pic. 4 long bolts at each area where 2x4 butt together for strength and vertical stability. Set 2 shoulder nut ring bolts or something similar for guy wire attachment at about the 25 ft level (havent worked out exactly which kind of hardware to use to attach the guy rope to)

Has anyone ever tried setting up anything like this before? Success or failure? This is what I got in my head and want to kick around the idea before i beguin physical build.

Feedback would be appreciated

[NQ6U]

I'm sure it would work, but sixty linear feet of 2x4 would be pretty heavy and difficult for one person to handle. I have had pretty good luck with ten foot lengths of steel top rail for chain link fences, which is cheap, strong and easily obtained at any big box hardware store. It works okay up to thirty feet as long as you run a couple of sheet metal screws in at each joint and guy it at the top and middle. I've been able to muscle them into the vertical position all by myself, although it is easier (a lot easier) if you have help.

[KA9MOT]

I have 48 sections of this: http://www.ebay.com/itm/18-Fiberglas...item3cd504c3bd

You have to guy it, but it is light and if you head over to Lowe's, Home Depot or Menards, you can buy 3 inch steel washers that you'd drill holes in for guy rings.


Picture of homebrew guy rings, I didn't make this one, Credit goes to Andy WY5V (He was nice enough to share):

DSC070592.jpg

[KA9MOT]

Sorry pic isnt drawn to exact specs. Used MSPaint and its a PITA to get exact measurements with that

My plan is to build a semi-portable/temporary install antenna mast from 2x4x10 pressure treat wood. The idea is to create a mast that can be broken down and reassembled for field day or camping activities. Also I want to build this for my home QTH. The landlord said I could have antenna's but couldnt attach anything to the house or hang wire in the trees. I am thinking of building 2 of these so I can stretch a horizontal dipole between them or use one to hang an inverted V from it. I can feed antenna and ground straps through a window or run it out a door jamb. Want to to be disassembled as I dont to leave any wires up while I'm out traveling. I had considered building one from aluminum antenna mast but thought that me a bit too flimsy at the 30ft level plus the metal masting would play havoc with matching and such

The assembly would be something like this. take 1 2x4x10 and cut in half. Clamp 2x4x5 and 2x4x10 together. Drill holes and set 1/2 inch X 6 inch through bolts and tighten them together. Set in bucket of concrete and let set. Drill holes on each remaining peice at about 2 and 4 inches from end of each board. Assemble rest of mast as shown in pic. 4 long bolts at each area where 2x4 butt together for strength and vertical stability. Set 2 shoulder nut ring bolts or something similar for guy wire attachment at about the 25 ft level (havent worked out exactly which kind of hardware to use to attach the guy rope to)

Has anyone ever tried setting up anything like this before? Success or failure? This is what I got in my head and want to kick around the idea before i beguin physical build.

Feedback would be appreciated

That is what they show in the 1940 something ARRL Amateur Radio Handbook. Worked then, but it would be amazingly heavy.

[WØTKX]

If guyed well, you don't need the concrete bucket at the bottom. A shallow hole of 6" or so, depending on how soft the ground is, should be sufficient to lever the base against for raising the antenna... I would recommend a shallow temporary hole for the bucket if you do use it.

A very lightweight mast guyed well will hold wire antennas very well. I have seen "maypole" style inverted Vee antennas with four 90 degree wires deployed using very whippy flexible masts.

Another whippy mast design for a single Vee is setup so the mast is curved over and loaded with tension, with the two wire elements used as the other "legs", and a single rope applying tension half way up the mast, opposite of the Vee.

Rapid single person deployment, like in two minutes or less.

[W5BRM]

If guyed well, you don't need the concrete bucket at the bottom. A shallow hole of 6" or so, depending on how soft the ground is, should be sufficient to lever the base against for raising the antenna... I would recommend a shallow temporary hole for the bucket if you do use it.

Rental property. LL wont allow holes dug

A very lightweight mast guyed well will hold wire antennas very well. I have seen "maypole" style inverted Vee antennas with four 90 degree wires deployed using very whippy flexible masts.

Another whippy mast design for a single Vee is setup so the mast is curved over and loaded with tension, with the two wire elements used as the other "legs", and a single rope applying tension half way up the mast, opposite of the Vee.

Rapid single person deployment, like in two minutes or less.

I'm trying to avoid "whippy" masting. I live in Oklahoma and the wind is always moving about. Whenever I'm home, a day doesnt go by when the power doesnt flicker because of the wind.

I know a mast has to have some flexibility or the antenna takes the brunt of the kinetic damage and breaks sooner but some of those flexables ones have too much whip to them and that makes me uncomfortable

If I WERE to get a flexible or fiberglass type mast I might get this and only deploy it to 30 feet to keep some of the rigidity at that height

http://www.mgs4u.com/Antenna-MK-8-Standard.htm

But thats getting a pretty high price and I am on limited budget. Just too many things I need to do to rebuild my station to buy 2 of those :(

[KG4NEL]

I don't know how much you can stretch your budget, but if it were me, I'd look at something like a 33' fiberglass mast kit with a base-mounted autotuner. For 100W, they're not too badly priced; you could even use cheap tape measures as a radial field if you didn't want to commit to laying radial wires down and wanted something you can pack at a moment's notice.

Those Radio Shack telescoping masts would also work as a radiating element, although they're a lot heavier than aluminum tubing or fiberglass.

I can understand the not attaching anything to the house part, but have you talked (sketched a diagram, maybe?) with the LL about what a tree-mounted antenna would involve?

[W3WN]

It will probably work, at least at first. But it's going to be heavy, and that much mass may be more than one or two people can easily manuever into a vertical position.

Check around at hamfests or online. You can find 4 foot fiberglass mast segments (interchangeable with the ones I use for the FPV), military surplus from camoflauge or tent supports, for a few bucks each. Finding 8 of them to give you 32 feet should be easy enough... and you can get guy rings at the same time (probably the same place) that will fit those mast segments perfectly.

Much easier to haul around, set up, raise or lower by yourself... and even with shipping, most likely less expensive than the way you're thinking of doing this. Wood isn't exactly cheap anymore.

[WØTKX]

I have a similar kit from this supplier, but mine is a mix of fiberglass and aluminum, this one is all fiberglass.
Mine cost me $70, bigger base plate and carry sack. Goes to 48', and it works quite well.

$58.00 plus shipping on eBay.

http://www.ebay.com/itm/12-Fiberglas...item3cd597f599

[W5BRM]

I was looking at that on ebay a while back. I'm seriously considering it. Saw a sale that had 25 4ft poles too. Almost dropped the hammer on that one but then i saw none of the poles had the reinforcement rings on the end. I see most of these do but not all of them. I'm also not a huge ebay fan but its better than Craigs List...lol

I have a similar kit from this supplier, but mine is a mix of fiberglass and aluminum, this one is all fiberglass.
Mine cost me $70, bigger base plate and carry sack. Goes to 48', and it works quite well.

$58.00 plus shipping on eBay.

http://www.ebay.com/itm/12-Fiberglas...item3cd597f599