Whar did you use copper pipe?

Not certain if the ones at Lowes are fence poles but galvanized fence poles from Rona/home depot should work no? The corner 10' poles are the strongest. They go for around $10 each. Dont buy the horizontal poles they are the weekest. Quite the antenna you have there!
No they aren't fence posts. I think they are painted steel (thin steel) poles. They cost about $6 US. Even at $10 Canadian, I think the fence corner posts are a step in the right direction...Thanks!

You should go with 1-1/4" emt electrical conduit.That won't bend.

You should go with 1-1/4" emt electrical conduit.That won't bend.
Many thanks. That's just what I did. For $11 US I got a 10 ft 1 1/4" EMT electrical conduit section, got out the trusty hacksaw and made two very strong masts. They do weight a little bit more, but in this case that's a good thing. Thanks again for the suggestion!

http://www.digitalhome.ca/forum/picture.php?albumid=113&pictureid=561

I am planning on installing 17 ft of steel masting (1 1/2 - 2" diam.) up the side of the house, 16 inches away from the wall. It will braced at the bottom and to the wall at about 13 ft high.

The edge of the roof (at the eave trough) is 17 ft from the ground.

I will be placing my DYI b4b antenna with 36" x 36" reflector (total weight about 3 lbs) at the top of the mast...

My question is how high above the edge of the roof (at the eave trough), which as mentioned, is at 17 ft from the ground, can I extend the masting without any lateral supports, wires , or brackets etc, above this 17 ft level?

By the way, no, a tower, attic, or roof install are not options...

thanks

I've had a VHF/UHF Radio Shack local reception antenna with about a 5 foot boam, on a 12 feet 1 1/2 inch mast, mounted to side of the house and extending 10 feet above peak of roof with no guy wires, for over 15 years and still going strong. So I don't think u'll have any probs if ur extending around 12 to 14 ft with 2 inch mast. Just make sure ur mounting brackets r rated for ur installation.

Yeah, youre probably safe at 10 to 12 feet above the edge of the roof. Of course it depends on factors like how much wind load of your antenna build. You do want to make sure that if it does break, it doesnt land on any power lines.

gordono911;

Ok, the consensus seems to be a max. of 10 ft freestanding, or more precisely 10 ft above the last bracket support holding the mast to the wall....although Raybel does not seem too confident in this 10 ft length, they would much rather sell a $500 tower...and didn't have confidence in his own $120, 30 ft telescoping pole (2" diam)!

What is the positioning, number, and spacing of all your wall brackets, and that relative to the joints in the masting. A mast totalling 30 ft, at least in my case, requires 2 joints (for connecting 3 - 10 ft lengths).

Also, need to know how much overlap at the joints, this is very critical!

Are you turning it with a rotator, of leave it fixed position...


thanks

300ohm:

yes, the wind actually seems to be the critical variable, I noticed even an antenna with no reflector, offers enough resistance to air flow to cause stress, and sway...

I can only think of limiting this variable with guy wires, however this removes the option of changing the antenna and testing often as I would have to mount the roof each time, also, you can only guy it from the mast to the roof at two points on the side of the roof, in the opposite direction you're in air!

Re. power lines, that's impossible to guarantee, just like in any other suburban area, the lines are all around, and everyone has there own set up anyway.

I checked the local bylaws, there are none! Also, checked with the power company, they said don't worry about it, anything is possible... Wow, that's safety for you... I guess grounding the antenna becomes even more important here...

after reviewing summarily all previous posts, I do not recall seeing the following idea, which a local installer suggested to me today...

He said he has installed masts right thru and out the peak of the roof, supported from inside the attic (onto the joists, & trusses), then sealed from outside. The balance of the equipment is then mounted onto the outside part of the mast, rotor, etc...

I thought he was joking at first, but no!

Sounds interesting, but worry for water infiltration at the base...

How's the best way to join two 10 ft length of EMT (1 1/2") for masting...


Also, what about using tubed aluminum for the upper (last 10 ft) of mast, is this strong enough, certainly very light...

EMT is galvanized, meaning that there are very specific techniques used, so if you want the pieces welded you require a skilled welder with breathing apparatus and know-how.

Another option that doesn't involve welding is to have the lower piece be wide enough to allow the upper piece to slip inside it. Leave about a foot of the upper piece inside the top of the lower one and drill two holes to put galvanized steel bolts through.

Balm, EMT is not your best choice. EMT is soft metal, its meant to be easily bendable. Aluminum pipe is good, but expensive.
I used 12 feet of Galvanized steel pluming pipe. It is on the peak of the roof with 2 supports attached about 5 ft up, leaving 7 ft above. I used Stainlees steel muffler clamps from CanTire, had to replace the clamps that came with the antenna for a bigger size. The top part has two 4228's, the lower part another one. Wind loading hasn't been an issue. I like your idea of going thru the roof and supporting below. The hole can be sealed just like the existing 9 holes in the roof for vents and pipes.
Plumbing pipe is readily available in 20ft lengths, at any and every plumbing supply. And they'll deliver, for a fee, since they deliver to job sites almost every day.

before running a pipe thru the roof from the attic, which also involves going up on the roof every time something happens, I will try running the pipe up the side of the house.

re. the EMT, I agree I don't need more work in joining them , and they are heavy and expensive ...over 20$ a section at the hardware

So, I finally went to my local metal and scrap yard where I get my major construction project supplies, and found all kinds of choices for posts and the proper reflector wire mesh by the way...all at half the usual store rip-off pricing...

I'm thinking of using the first 13 ft, into the base, out of some sort of 1 7/8" steel or galvanized tubing, then sliding a 15 ft length of 1 6/8" aluminum tubing into the galvanized - the aluminum is very light, but I don't like the sway in the last 10 ft of it which will be above the last wall mount - anyone who says 10 ft of free piping, made out of any material, doesn't bend or sway, is either using 3" or more (which I doubt), is not in any wind (which I doubt), or is taking a chance, doesn't want to know, and waits until something happens befoire changing ideas (which is most likely!) -

I would try to make it telescoping with bolt inserts, then I can raise it, turn it, lower it, whatever, all from my second story window...

after reviewing summarily all previous posts, I do not recall seeing the following idea, which a local installer suggested to me today...

He said he has installed masts right thru and out the peak of the roof, supported from inside the attic (onto the joists, & trusses), then sealed from outside. The balance of the equipment is then mounted onto the outside part of the mast, rotor, etc...

I thought he was joking at first, but no!

Sounds interesting, but worry for water infiltration at the base...

I was thinking about that too. I'm glad you mentioned that an installer suggested it; I thought I might be nuts.

My idea is to put a slightly larger diameter pipe through the roof, support it to the trusses, and seal it up with roofing tar. I would put the rotor under the roof and the antenna mast through the pipe that goes through the roof. I would use a piece of hose that clamps watertight to the mast and extends down over the fixed pipe ( not clamped ); a bit of grease might me helpful to allow the antenna to rotate freely. I would run the coax up the mast and then down the inside of the mast. The opening at the top of the mast would need to be sealed with the coax running through it. Some potting compound would work fine or maybe just a larger diameter cap. The advantage of this for me is that the rotor is warm and dry and will not collect ice. In my previous setup, I had to climb a 50' icy tower to chip the ice off the rotor.

In my case, the roof is readily accessible from the garage and is the same height as the rest of the house's roof. If it should leak, then it would only drip on my car; I'm not so concerned about that. The garage placement is also directly over my house's main ground point, so I would have an easy grounding solution.


Hmmmmm, that's sounding better by the minute :rolleyes:

1-1/4" or 1-1/2" EMT would be plenty strong as long as its supported properly and the unsupported part does not exceed 5 or 6ft or so.(anything smaller than 1-1/4" would be chancey)
The couplings that are used to join EMT are not very strong.
There are 2 different types 4 screw sleeve type or compression type.
If you were able to support it either side of the coupling it may be OK.....but I would'nt use it otherwise.

http://i14.photobucket.com/albums/a321/wee-haggis/coupling1.jpg
http://i14.photobucket.com/albums/a321/wee-haggis/coupling2.jpg

Plumbing pipe is readily available in 20ft lengthsTerrific stuff for toughness - they refer to it as "Schedule 40 Black Iron" pipe and it is sometimes the only thing left standing after house fires or earthquakes, heaven forbid.

I would not depend on the threaded couplings in such a vertical pole use as an antenna mast - the threads will break down and your antenna will eventually fall down, and that Black Iron pipe is quite heavy so if it fell on something there would probably be big damage. That's why I'd not only install the threaded couplers as you would in plumbing but also then weld them to the pipe at their collars. You'd definitely want to paint the whole mast thoroughly with a couple of coats of rust paint before putting it up.

techluvr;

The sleeve idea sounds like it must be done perfectly. I discounted your version because in my mind anything that is allowed to move cannot allow for a guaranteed impermeable joint (that is between the sleeve pipe and the pipe contained within)... just thinking out loud!

I hate playing with the roofing, we had so many leaks after a brand new roof, had to have sealed and resealed. Even several reputale contractors had problems in this area due to the poor design and numerous joints... anyway that might be my second choice

stampeder:

OK here's an update....I purchased a 15 ft (1 3/4" dia. 1/8" wall) aluminum tube and a second smaller aluminum tube 15 ft (1 1/4" dia., 1/8" wall), to insert into the previous - probably allow 2ft overlapping.

I have tried installing a DYI bracket, made one 90 deg. angle at the house wall, extended outward toward the mast with a piece of flat bar, and terminated at the mast with another 90 deg. angle (thru which I will put the u-bolt to grip the mast). This forms a U-shape (looking from the top down). The extension is more than 16". I used quite heavy duty iron for the brackets, (1" wide x 1/8" thick), still the whole bracket tends to bend or torque when trying to bend it from the mast end...maybe I will need to use the channel master wall mounts- which are supported on the wall from two directions forming V shape to towards the mast...

Another problem, not sure, I found what I thought to be the wood wall studding to lag bolt the bracket to the house wall, I even undid the gyproc inside to locate it, measure up. Then I slowly ratcheted in a 3/8", 6" long wood lag bolt with washer. As I went in I didn't feel any hollow, however when arrived at the end, the bolt keeps turning. Shouldn't it not turn any more when tight. I know I didn't break the bolt, and I know I can't pull it out with my hands pulling all I can from the bracket. I wonder what happened, did it go thru and thru the wood, can a lag bolt just turn in the wood when thru, or did it go thru some other type of wall material...


Now really not sure what to do, leave that one and add another, take that one out, put larger, longer one, or move to another location...

The only place on the side of a house that I would consider lag-bolting a tower bracket would be on the roof's end-joist, but that's just me.

A lag-bolt that turns freely seems very odd - do the threads on the lag bolt go all the way to the cap, or is there a smooth section? It might be that if yours aren't fully threaded to the cap they are in as deep as they can be on the smooth part and the thickness is past where the threaded portion is. No fun trying to get those out! :eek: