@Geostar: For cables entering your home, ensure that you create a "drip loop" below the entry point. This will prevent water running down the cables from travelling right into your wall. Do this even though you will use silicone around the entry point.

Keep cables as far away from the hydro service as possible. In my neighbourhood, I have seen several installs where the coax/rotor cable travels down the same conduit as the aerial hydro cable. People often forget (or aren't aware) that certain conditions can enable electricity to arc from the hydro line to other metal parts/cables within close proximity. In other words, cables don't need to be touching your hydro lines to create dangerous situations.

Work cables back from the antenna/pre-amp, leaving some minor slack to accomodate expansion/contraction due to temperature changes--but not enough slack to allow flapping in windy conditions (which can wear cables). Make sure you leave enough cable between the mast and rotor mount to allow for rotation.

Be mindful that as your coax temperature increases, so does it resistance. As such, attempt to route cables where they would be subjected to less sun or heat from furnace/fire place exhausts.

Does anyone have any experience with gable mount antennas. I would like to know if they have had problems with wind shear ripping them off the eaves or if installed correctly they perform well.

I have a CM9521A on 5 ft mast on gable end bracket. 3 ft mast from rotator to CM4221HD. Extremely stable mount for this type of antenna. I think you're ok with a total of 10 ft depending on the slope of your roof. The more slope, the more sturdy.

My stacked 4221's held quite well at 10 feet, even through I had a less than ideal separation between the upper and lower mount. There are several examples of others results in the "pimp my gear" thread as well you could take a look at.

I could not in good conscience say your results would be fine trying the same thing I did, but installed to the mount manufacturers recommendations the gable/eaves mounts work quite well.

Hi all, see photo in Post #463 of the Pimp My Gear (http://www.digitalhome.ca/forum/showthread.php?t=24755) thread. What I'd really like to know here is "will it fall down" :)

A year or so ago Yaamon installed a CM 4221 on the side of my house. It worked well, but some stations were flaky.
Recently came across a free CM 4228 and rotor, so I basically swapped out the old antenna for them. I also reran the cable so now I have 40ft of RG6 with no couplers direct to the TV (no amp).

So now I have a 4228 and rotor sitting on top of a 10ft pole, which is a 1 1/8" 'top rail' fence post from Home Depot. It does flex a little in the wind. Is movement a problem? Reception is rock solid now, although I wonder what will happen in storm...

da = distance from the antenna to the top mounting bracket

I should probably clarify that this should read:

da = distance from the centre of the antenna to the top mounting bracket

admin: Could you please modify my previous post accordingly? Thanks.

Hi all, what I'd really like to know here is "will it fall down" :)

You can see my post in the OTA Mounts, Towers, Rigging Hardware (http://www.digitalhome.ca/forum/showthread.php?p=984985#post984985) thread for the math, but I think you might want to make some adjustments.

I am assuming the 4221 was installed at the top of a 10 foot mast and you just removed it and put the rotor and 4228 on the top of that mast. The increased overall mast length and increased wind load on the 4228 could result in excessive stress at the top mounting bracket. Your options are decrease the length of the main mast or increase the spacing between the top and bottom mounting brackets.

Using the approximated corollary of the formula I posted in post #1119 (http://www.digitalhome.ca/forum/showthread.php?p=984985#post984985):

Ft = (l/db) x Fa

where:
Ft = lateral force at the top mounting bracket
Fa = lateral force at the antenna (wind load)
l = Total length of mast, including mast above the rotor.
db = distance between the two mounting brackets.

(Once again I will leave it as an exercise to the reader to prove this formula. ;))

and the assumption that for a 10 foot mast, 3 feet should be between the mounting brackets, would a good rule of thumb be that 1/3 of the total mast should be between the two mounting brackets? What do others think? Obviously there are other factors such as wind load on the antenna, but we are talking about a rule of thumb here, not an accurate calculation.

Thanks for the advice. I will try to lower the bottom mount by about 1ft and bring the whole mast down by that amount.

Guys,
I see many of you are using conduit for getting the antenna higher above the roof in 1 1/4" to 1 1/2" diameters.
I was wondering why is that?
Cheaper price maybe?
I am planning on using aluminum pipe.
Was quoted $6.67/foot

or galvanized pipe at $4.37/foot

both prices for 1 1/4" diameter.

What would the conduit price cost and is it that much less expensive?
Any Pro's/Con's for using aluminum or galvanized?

Thanks.

What would the conduit price cost and is it that much less expensive?
Any Pro's/Con's for using aluminum or galvanized?

Conduit is much cheaper, I think a 10' length will be less than $20 at pretty much any home improvement store, taxes in.

Con's for using aluminum:
- expensive
- galvanic corrosion between the alunimum pole and all of the steel hardware attached to it
- weaker than steel for a given wall thickness

Pro's for aluminum:
- easier to carry up the ladder when you install it because it's lighter

Conclusion: Use conduit

Pioneer Fan, I've moved your question into this thread that has a ton of info on EMT, aluminum, galvanized plumbing pipe, PVC, etc. for antenna mast use so have a look through and you'll get some further advice. :)

So I bought a 10' EMT segment that was labelled 1.5" and its OD turned out to be bigger than 1.5" and too big for my u-bolts to go around. I was just about to return it to the store. Then, I found an old, rusty (on the surface) pipe laying around that's 12' long and exactly 1.5" OD. This is nice because I don't think 10' was enough anyways, and I haven't found bigger segments for sale at home depot.

I started removing rust from it in a small area, so I could clamp a grounding wire, and the material underneath looked very much like copper (I should have known from the green rust...) and I remember earlier in this thread there was advice on not using copper because it's too soft and will bend easily.

But I don't really know if it's copper. It looks like it, but this 12' piece feels like it's the same weight, or lighter even, than the 10' segment of EMT (which has a bigger diameter too). Could it be some kind of harder alloy? Or is it just a regular copper water pipe. I really want to use it because it saves a trip to HD (carrying around a 10' or larger piece in a small car, sticking out the window, is a royal pain), and also because it's 2' longer than anything I saw on sale.

Whichever mast I choose, it's going to be attached to an 8' tall chimney with a channel master Z-mount, if that matters. Given that, should I bite the bullet and exchange my 10' EMT for one with a smaller diameter, or go ahead and use this 12' "copper" mystery pipe?

Schmerm - Rather than return the 1.5" pipe or take your chances with the mystery pipe, why not get some u-clamps that will fit the new 1.5" pipe?

I already made a weatherproof enclosure for my preamp and drilled holes in it specifically for the uclamps that I got, making getting new clamps an annoying option.

@monomono: A couple concerns I have with your setup:

1) How long is the mast above the top bracket? If it's longer than 10', I'd be worried. Check the recommendations by the bracket manufacturer.

2) Is that a wood stove chimney? And if so, how close does the antenna get to it?! Wood stoves exhaust more heat than most furnaces--which could impact an antenna/rotor setup close by. Your equipment may also be contaminated with soot.

3) I don't recommend tie wraps for coax/rotor cables--especially in cold climates. Most cables become stiff in cold weather. Movement (wind, rotor direction changes) can then cause chaffing of the cable--eventually causing wear than can cause failure. A high-quality electrical tape is recommended instead.

Schmerm, the density of copper is almost the same as steel, so you won't be able to tell by weight. You already broke the surface and got down to non-oxidized base metal and saw the copper, so that's probably what it is. Copper is very soft compared to steel, so you would definitely want to consider the pipe bending in a storm.

That's what I was afraid of, but will this be an issue if only 4' of the pipe is unsupported?

Hi Jase88,

1. The total length above top bracket is probably a touch over 10ft, maybe 10.5. As I mentioned it does move a bit in the wind, and I'm going to lower the bottom mount by about 1ft.

2. It's a gas fireplace which we hardly ever use, and it's a good 4 ft from the antenna

3. Thanks for the tip! I will replace the ties with tape next time I lower it.

Schmerm, without knowing exactly what the mystery pipe is made of, it's tough for anyone to really make an informed opinion. You said the pipe seems even lighter than the steel pipe, and since the density is the same, the pipe is longer, and the diameter is smaller, that means the wall thickness is would have to be thinner and therefore weaker. Can you measure the wall thickness?

I guess the easy answer is go ahead and give it a try, the worst that's going to happen is the pipe will bend. You just need to take a look at what will get damaged if that happens and decide if it's worth saving the drive back to get the smaller 1.25" steel conduit.