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Home Brew Towers
#1
Howdy all!

Field Day is fast approaching, and I think that Sean (KF7NAY) is the only one that is currently "signed up" to bring a tower of any sort. I know he's working hard on putting the finishing touches on it so it will be ready for its' big debut!

I'd really like to get some kind of additional tower (Or towers) set up for Field Day. Thus, I've been brain-storming inexpensive ways to get another tower up for our little get-together. Emphasis on inexpensive.

I know someone mentioned that there are a lot of trees on-site that might be suitable for hanging antennas out of. However, I'm not a great tree-climber and I've really got no way to get an antenna up in a tree - I hope someone has something lined up (Like a line-thrower or something). Trees are good for wire antennas, but they aren't the same as a tower.

This brings me to the subject of home-brew towers. I was thinking (Dangerous, I know) that it might be easy to rig up some kind of hitch-mounted monopole tower out of pipe, conduit, or some other form of tubing. My initial thought was to take some rigid metallic conduit (RMC), tack weld some guy-points on each section, secure them all together with the appropriate threaded connectors, and then put a hinge on one end and hoist the whole thing up into the air before guying it all off. This would make it easy to raise/lower and assemble/disassemble on-site.

Granted, galvanized rigid metallic conduit isn't exactly cheap, but it is pretty sturdy. 2" x 10' is about $43/each at Home Depot. I'm sure that it can be had much cheaper from scrap yards and other places. $43/ft is pretty spendy, especially when new 10' sections of Rohn 25G can be had for about $120, and you'll get a "real" tower out of it.

Thoughts? I want to hear them!

This thread is primarily for "Inexpensive, temporary towers that are easily moved and set up / taken down". If you can't mount anything more than a little wire dipole off it when you're done, I'm not going to consider it as meeting my needs for this situation. There are always push-up fiberglass poles and the like for that. :^)
W0ULF 2011+
ex KF7RJU 2011-2011
ex KC7YNP 1997-2007
Rigs: Heathkit RX-1 Mohawk Receiver and HX-10 Marauder Transmitter, IC-7410 Base HF w/AH-4, IC-2720 Mobile Dual Band, IC-V8000 Go-Bag 2m, IC-2820 base 2m/70cm (That goes to Field Day or goes in the other truck when I'm driving it), Kenwood TH-75A and Icom IC-92AD HTs.
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#2
I came up with a way to fabricate a lightwieght mast for my tower. Turns out that a stick of 1-1/2" EMT fits inside a piece of 1-7/8" .065" wall fence post. I am going to use a pair of carriage bolts per connection to make up my mast.

Something to think about Vaughn is that for the price of one stick of 2" rigid metallic you can get three sticks of 1-1/5" EMT and then connect it with a few pieces of 1 7/8" fence post. The fence post goes for about a buck and a half a foot and can be had in any length up to 24 feet. The 1-1/2" EMT is about twelve and a half bucks a stick. I got the fence tubing (.065 wall) at outdoor fence supply in Salem. As I work in Salem I can bring back whatever any one wants on my way home from work.

It all depends on what you intend to put up (weight) and how high.

I like your idea of braceing or guying it. I also like the idea of using your truck as a mount point.
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#3
Sean,

Thanks for the feedback! That sounds like a great bit of info for lightweight mast.

How sturdy is it? How much of an antenna would you feel comfortable hanging on it?
W0ULF 2011+
ex KF7RJU 2011-2011
ex KC7YNP 1997-2007
Rigs: Heathkit RX-1 Mohawk Receiver and HX-10 Marauder Transmitter, IC-7410 Base HF w/AH-4, IC-2720 Mobile Dual Band, IC-V8000 Go-Bag 2m, IC-2820 base 2m/70cm (That goes to Field Day or goes in the other truck when I'm driving it), Kenwood TH-75A and Icom IC-92AD HTs.
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#4
Good question, I will have to do the math! By the way, I have posted an album on my home brew tower project. Check it out!
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#5
At this time Mike Shelby and I are planning on bringing my tower and one of his antennas for field day. I'm still trying to figure out which
page to sign up one. Maybe later,
Mike
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#6
Hey Mike!

What size of tower do you have, and what kind of antenna is Mike S. bringing for it?
W0ULF 2011+
ex KF7RJU 2011-2011
ex KC7YNP 1997-2007
Rigs: Heathkit RX-1 Mohawk Receiver and HX-10 Marauder Transmitter, IC-7410 Base HF w/AH-4, IC-2720 Mobile Dual Band, IC-V8000 Go-Bag 2m, IC-2820 base 2m/70cm (That goes to Field Day or goes in the other truck when I'm driving it), Kenwood TH-75A and Icom IC-92AD HTs.
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#7
Hi All,
My tower is a ~50' aluminum crank up. It's made of 2 - 25ft tower sections for it
only actually raises to about 47ft due to the overlap needed for stability. It will be guyed to 3 car/truck axles with 3 steel cables adjusted by 3 come a longs to adjust
to vertical and tension. The mast is aluminum and extends about 6 ft or so above the
top of the tower. The base is bolted to a 1/4" steel plate that will be staked down
with 4 18" concrete stakes.
I believe the antenna that Mike is planning on bring is a A3S Cushcraft tri-bander.
We will need to bring or borrow a good step ladder to prop the tower up while adding the antenna and to reduce the pull needed to raise and lower the tower.
I'm sure Mike is planning on using his IC-7000 for the radio.
I have to do work on every other week end and have to check to see what my
schedule looks like for field day weekend.
73, Mike KA7HBB

ps. Mike W7RIS also has one of the home built Tennis Ball / Antenna lauchers.
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#8
Hey all!
Ted and Vaughn put in a hard four hours and we managed to erect my homebrew tower. This was mostly a dry run to work out any problems that came up. The details of the design are my own and until now were unproven.
Thanks to both of these guys! I don't have the real estate to put it up so Ted was nice enough to allow me to use a field of his and he will be doing some testing out of the tribander on top. The antenna, a Cushcraft A3, is working well in the first two bands but has problems with the third, 20m. I have a plan to try to fix it but more then likely I will have to use it as it is on field day.
Look in my albums for photos of the event. I will figure out Vaughn's advice on how to link in photos to a thread.
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#9
photo of tower

[ATTACH=CONFIG]559[/ATTACH]
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#10
Cool Sean what is the trouble with the 20m end ?
73
KC7NHT
Cyrel


PODXS 070 member #1331
EPC member #14448
PRA Board Member
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