: OTA Mounts, Towers, Rigging Hardware
sorry to keep at this, but I looked at the Circuit City antenna/mast tripod roof stand. It appears quite sturdy, but have no way of determining the steel's gauge
It opens up at 100% (fully) to 29 1/2" distance from leg to leg to leg.
My question is are these supposed to be used opened up to 100%, or can it be installed partially opened up for an adjusted distance from leg to leg to leg, say less than 29" (I assume indeed so, and thats what makes this model "adjustable") ???
2009-11-21, 05:59 PM
I personally wouldn't deploy a tripod in a situation where the legs couldn't be fully separated.
why would they make them go to 29", this wont fit the standard 16", or 12" joist multiples...:confused:
2009-11-21, 08:51 PM
Tripod mounts aren't always used on wood-framed roofs. Regardless, the standards for spacing of beams in a roof vary by region and application. It would be impossible to create a "one size fits all" tripod solution.
When it comes to designing a mount, I believe the primary design requirement would be the ability to manage the load it's expected to handle. And this may not necessarily facilitate leg spacing that's in line with the beam spacing on most framed roofs.
It would be impossible to create a "one size fits all" tripod solution.
I understand what you are saying, but in this case "the size fits NONE". I have never seen a roof with joists at this multiple. From what ive seen tripods are commonly used on framed roofs, they are even advertised as such.
It would be no more difficult to design and fabricate this tripod as a function of 32", or 48",
just my opinion, guess thats why SCC unit is so cheap! ;)
Wades 3ft tripod is 32" base
Wades 5ft tripod is 44" base
2009-11-21, 11:16 PM
Wade products are made in Brantford, Ontario. So it wouldn't surprise me that their tripod mounts are made to work well in this market...
the 32" is good, but again, the 44" doesnt make sense
2009-11-21, 11:31 PM
Balm, considering your location, I'd probably go with a tower solution if possible. You're near the St. Lawrence River, which means your elevation is likely close to sea level (i.e. "low"). You'd probably want to get Ottawa (for stations not available in Montreal) and Vermont--both locations of which may not be reliable with a roof solution that's near sea level. Is a tower solution possible for you?
I prefer towers, as they aren't invasive to your roof structure, channel lightning energy away from the home, offer more wind load capacity over tripods (helpful for multiple antennae), typically allow higher mounting, don't allow antenna/rotor/preamp equipment to become buried in snow, and can be erected in more advantageous locations on your property.
2009-11-21, 11:36 PM
Balm, like I said, the design starts with managing wind and weight load; not for optimal joist spacing. And as mentioned, it's easy to reinforce a roof frame to support a tripod (assuming the roof isn't finished on the interior). If you can work a tape measure, hammer and saw, you're mostly there already. If the roof structure is finished on the inside (i.e. no attic with exposed beams), you'll likely want to consider an alternative mount.
2009-11-22, 04:24 PM
I've been meaning to scan these for a couple of years :rolleyes: but here are pics of the instruction sheets for the old Radio Shack 3' Duty Antenna-Mast Tripod (http://www.user.dccnet.com/jonleblanc/images/rs_15-516_tripod.jpg) and the Radio Shack Chimney Ratchet Mount (http://www.user.dccnet.com/jonleblanc/images/rs_15-839B_chimney-strap.jpg) that are no longer available new in Canada.
These will help you understand how similar new products work.
thank you, thats excellent!
2009-11-22, 11:34 PM
The thing about the Chimney Ratchet Mount illustration is that they show the upper and lower straps too close together (I guess to keep the size of the picture down) so plan on at least about 2 feet or more between them if possible.
2009-11-23, 08:44 PM
My neighbors house is about 5 ft higher than my antenna,his house peak is about 25 feet away.Next door to him is a another house peek about 10 feet higher,that would be about 40 feet away.So likes i dont have that clear line of sight, which could be giving me the ghosting problem.Going to Home Depot to pick up another 10 feet of mast to raise the antenna.I think i might need some guy wires with that set up that high.
I have a CM3679 and a CM 4220 combo,mounted now to a 10 ft mast using
1 1/4" conduit.I am hoping to add another 5 ft to have a clear "line of sight".I am using a joiner for the conduit(mast) and its attached to a chimney.The weight of the mast is touching the roof and i have it straped around the chimney.I was thinking to put "guy wires"(4) onto the mast using eyehooks drilled through and attached to 2 steel pipes(plumbling vents) and also attached to a deck roof,which has 2x6"s.That would put a guy wire in each direction,N S,E&W Sound reasonable?
2009-11-24, 12:12 AM
Please take care about the masting material. I used a piece of EMT (conduit) with swedged end only to find that with a consistent wind from the West blowing over the Rockies into Calgary, my EMT mast developed a curve. The TV reception wasn't much affected but I changed it out with a Radio Shack (The Source) 10' foot replacement and that cured the problem (no more curved features in the mast).
Your "line of site" idea sounds to be a much better one! :)
2009-11-24, 02:04 AM
So you didnt use "guy wires"?? How high is your mast?
2009-11-24, 08:02 AM
valkryie, I've seen many long mast runs reinforced with guy wires that have failed. They may not necessarily fall down, but they tend to warp or buckle eventually. Further, you should never let the mast rest directly on a roof--it should be supported with a block of wood.
2009-11-24, 01:14 PM
I have a piece of 2x4 under it already,so you think 15 feet is too high?
2009-11-24, 01:56 PM
A standard 2x4 will disintegrate unless its been heavily waterproofed - for that kind of base I use treated lumber that has been stained and coated. The 4"x4"x1' piece up on my roof now has been up there for a few years (in the Vancouver rain!) and its fine.
2009-11-24, 04:28 PM
No I hadnīt used guy wires with a 10ī mast with good supports placed 20 inches apart as this gave me sufficient support. The recommendation that I read was that guy wires are needed for distances of greater than 10ī above the uppermost mast support. I have since added another 5 feet over that and lowered the entire assembly but havenīt really noticed any problem using proper masting material. I think that if I was using 2 by 10 foot masts (one above the other), then I would definitely need to use guys. If the distance between supports is increased, then further stability can be gained. My support for the chimney style straps is a welded steel frame and is very strong for supporting the mast. I plan to add a satelite dish next year to the same welded steel frame. The frame has four feet which I had bolted into the two A frames that support the roof of the house. The bolts almost pass through the entire A'frame thickness. The uppermost UHF antenna (PR9032) has a tendency to sway in a strong breeze.