: OTA Mounts, Towers, Rigging Hardware
2007-11-05, 05:56 PM
I have a question regarding the tower height above the eave bracket. According to the Delhi literature, one should not exceed 2 sections above the bracket. If I use four sections including the top section, my set up would put me at 24 feet. The antenna is a 4228 with rotor and CM7777 preamp. My ultimate goal is to get to 50 feet, based on TVFOOLs chart to get LOS to WNYO. Any comments or suggetions are appreciated from this group of knowledgable people.
ps I plan on using the 16 gauge tower.
2007-11-05, 06:07 PM
I plan on using the 16 gauge towerYes, 16 gauge is a must for that height. With towers we have to remember that the most severe physical stresses are on the very lowest section, and the stresses get stronger as you near the ground (10' and lower). Are you planning on using guy wires?
With a very solid concrete footing and 16 gauge metal you are okay, so then the next point of stress would therefore be at the eave bracket. If you aren't going more than about 10' higher than the eave, a simple bracket from any of the main OTA gear manufacturers will be fine. If you are going much higher without guy wires, you need to consider a very strong bracket, perhaps custom made for you by a welding or metal shop. This would not be attached to soffits, but would have to be joined to an attic end joist with deep seated lag screws. Again, with 16 gauge tower sections I think you can go up to about 40' to 50' but then you need to start worrying about what the wind will do. With a single CM4228 and rotor up there you've got a reasonably light load.
2007-11-05, 08:03 PM
Thank you Stampeder. Yes I will be using a concrete footing 4 feet deep, with the ground rod driven through the center.The base plate will be attached to mounting bolts ( J bolts in the concrete attached also to the ground rod). The bracket I can fabricate quite easily, since I am involved in heavy constuction and I do have access to engineers, for design considerations. :D
2007-12-01, 04:23 AM
Hoping I could get some insight\help\opinions on a mounting idea. I have a old satellite dish and I was thinking of using the mount bracket to mount a 4228. The mount bracket looks like this:
I want to set it up so it will bolted\screwed into the eave of the roof, right at the peak of the house\roof. The mount will be rotated so it will stick straight up and I can fit a mast inside of the tube and mount the antenna on that. I hope that gives a good picture of what I want to do. I am wondering if this would work out? I could put up to 10 bolts\screws in the base (5 on each side) of the mount so I would think it would be secure enough. I am a little worried how the mount AND the eave would hold up over a longer period of time especially in wind.
I'm not sure if anyone else has tried this or thought of trying it or not but I need to find a way to mount the 4228 without putting holes into the roof itself. Let me know what you think.
2007-12-01, 01:43 PM
Companies like Winegard and Channel Master sell the same thing as a "J Bracket" so you will be fine for using just one antenna. If you start to put long masts with several antennas and a rotor, etc. you are going way past its safety capability.
2007-12-01, 04:35 PM
I am planning to put a 4228 on it with a preamp and a rotor. The mast will not be very long just big enough to clear the roof when rotating the antenna. I am concerned about the weight of everything I guess.
2007-12-01, 05:42 PM
A satellite mount is perfect for a 4221 using a 1 1/4" pole.
To me even if you were to screw the base of the mount into the roof truss(not sure how much screws you would be able to get in only one one side pf the base because of the width) that is too much load at the base to support a rotor and a 4228.
If you were to hit that all sides of the base into the truss by supporting it in the attic I would not mount anying more than a 4228.
A rotor and 4228 that is too much weight and load at one point for support especially during the winter if there is any ice build up and encounter any high winds.
If you want to still go ahead I would remove the J arm and mount the straight 1 1/4" ID pole on to the base. Drill the bottom of the pole so it can swing forward or back to be level. At least this way the weight sits right down on the base and not putting stress on the back half of the base which will tend to lift the screws at the front.
If you look at the picture the weight of the antenna/pole will tend to push down on the back half, putting excess stress on the front of the base(tend to lift up).
This is what I did to my own base, I used a sat base with a 3' - 1 1/4"Id pole and then rotor on top. But I also used two additional tripod legs to support the base.
Hope I made sense. If you are going to do a roof mount do it right and not cut corners to save time.
2007-12-01, 08:28 PM
So how heavy is a CM rotor? The 4228 is 15lb right? What if I threw guy wires from the j mount right where the 1 1\4 pipe goes in and tie it on to the roof, would that provide enough support? Or I could bolt on legs to go from the jmount to the roof?
Yaamon do you have a picture of your setup with the satellite mount? The problem is I dont want to put something directly on the roof because it is not my roof but I think if I could mount it off the side of the roof, on the eave, just above the siding then I could get away with it. I should be able to get 3-5 screws bolts on the top and 3-5 on the bottom of the mount. Any other ideas?
2007-12-01, 10:25 PM
What if I threw guy wires from the j mount right where the 1 1\4 pipe goes in and tie it on to the roof,That's probably your best bet if you want to take a lot of the load off the J-bracket.
I'd use small-link chains from a hardware store and connect one end to the roof truss and the other end to the J-bracket with turnbuckles, so that you can loosen or tighten the support to suit. Also I'd make sure that all the metal parts you use are either galvanized, stainless, or waterproofed to prevent rusting.
2007-12-01, 10:43 PM
I think I might have some photos of the base on the roof.
Im on a tight schedule as I'm flying out to Miami and then to the British Virgin Island next week Tuesday and have lots to finish up before I leave.
Doing a 6' satellite dish install with a special brackets for dual satellite. My sister has a few jobs lined up for me. Yea I know working in the hot 84'F temp, but will be forced to drink a few beers to keep cool. ;)
If I have some time before I leave I will go in the back yard and zoom in on the mount and post the photos.
Guy wires will work, maybe you can try attaching them higher for even better support.
2007-12-01, 10:45 PM
Yaamon, do you think the small nuts&bolts on a J-bracket would hold what he wants? I've never tried it but I'd hate to see one of them fail on him.
Enjoy your trip and a few Presidentes too! :D
2007-12-01, 11:17 PM
Thanks will try my best and not to drink so much. :rolleyes:
The nut and bolts are pretty strong. As long as they dont do all the support there should be no problem.
Using the guy wires and securing it to the pole should help greatly taking the load off.
On my setup as long as you tighten all three nut and bolts it should hold strong as it does not put the stress on one bolt but all three together.
On my setup I used back the long nut and bolt through the pole and base. At the end of the pole I used the two separate ones.
stampeder I have been keeping the taste alive. One of my trips to the states I finally found and bought a case of 24 Im down to my last 6.
2007-12-02, 12:35 AM
After some searching I have found some actual eave mounts. Something like this:
Should be no reason why this mount shouldn't hold it up there nice as long as I dont put the mast up too high!!
2007-12-02, 10:39 AM
Channel master also sells wall bracket that will clear the eaves. I like using them on customers that prefer wall mount and only if they have no obstruction.
With this you have to make sure you have enough elevation and a clear view.
I use them on installs as the bottom bracket has a additional support leg to hold the weight of the pole and antenna pushing down.
Better support than what you shown, they come in 12 and 18" depth.
This customer back yard backs onto a ravine so no other houses was blocking his Buffalo view.
2007-12-05, 04:31 PM
I am feeding my CM 4228 signal into a Windows Vista media centre PC via the HD Homerun, and have a windows mobile wireless handheld I can run the RDP client on, letting me see and control the computer from on the roof. This should make the aiming process much easier, especially as a one-man job.
2007-12-15, 12:18 PM
Could we put a 10 foot length of PVC pipe at the top of the tower to get even more height?
2007-12-15, 04:58 PM
Could we put a 10 foot length of PVC pipe at the top of the towerI wouldn't use non-metallic pipe. To see why I say that, go to any hardware store and pick up a 10' length of ABS or PVC and you'll see that when you hold it out horizontally and shake it from one end that both types of plastic pipe will flex. That's a pretty good simulation of wind load, so if you put something like that up atop a tower and the wind comes up you'll more than likely be unable to get reliable ATSC signal locks from all the motion. Probably a length of galvanized 1 1/2" steel would be better, or at the very least some extruded steel antenna pipe.
2007-12-15, 08:29 PM
I'm thinking of getting a 4228 and installing it on the roof. Our chimney was removed years ago when we put on a 2nd storey :p Our house is like the tallest on the block (most are single storey houses) so height isnt an issue.
With the two options suggested here, J-mount and tripod which do you think is best for shortest pole length? (<5 ft)
I think tripod might be too much, seeing as it is 3ft already?
And I want it to be least obtrusive, so J-mount seems best (this would be the J-mount as suggested in the most recent couple posts, fastened to roof surface and aimed upwards until straight)
What do you think?
2007-12-15, 10:39 PM
I wouldn't use non-metallic pipe.Whatever the supporting rod it should be as light and strong as possible. Steel is a possibility but it seems heavy. What is the lightest least-breakable material that wouldnt waver in the wind? The antenna itself is only 65 grams and presents almost no wind load
2007-12-16, 03:48 AM
What is the lightest least-breakable materialExtruded steel antenna pipe is the answer then.