: OTA Mounts, Towers, Rigging Hardware
2006-08-02, 12:17 PM
How do you calculate that direction?The antenna needs to be pointed at the broadcast transmitter antenna. Apart from manually moving the antenna with a TV hooked up in order to find the "sweet spot", there are several ways to calculate antenna bearing described in one of the posts in the OTA Forum Knowledge Base and FAQ. Click on my signature below to go to it.
2006-08-02, 12:43 PM
You know, I did look through the OTA FAQ http://www.digitalhomecanada.com/forum/showpost.php?p=362703&postcount=9.
I know my lat/long. I know my distances from the transmitters. The calculators can give you bearings, but I just want to know how one aims "exactly at 170 degrees using magnetic North". My compass ain't that precise.
2006-08-02, 12:46 PM
I just want to know how one aims "exactly at 170 degrees using magnetic North". My compass ain't that precise.I see what you mean now. When it comes down to the last steps of "peaking" an antenna for the sweet spot I do it the old fashioned way: one person turns the antenna while another watches the TV down below. In your case in Oakville where you'd want the best compromise between Buffalo and Toronto stations that process could take all day! :)
2006-08-03, 10:50 PM
Sorry if this is dumb, but can a mast structure be: A long pole?
A wooden fence post?
A 10' steel electrical conduit?
A green metal (chainlink) fence railing?
2006-08-03, 11:15 PM
Not a dumb question.
A 10' steel electrical conduit. ;)
2006-08-04, 09:11 AM
A mast can be anything that can hold the antenna.
2006-08-04, 11:11 AM
True, intrac, as long as it is not flexible (like ABS or PVC, for instance). My concern about wood is the longevity and the fact that there is more of it per foot of altitude, meaning higher wind load. Old plumbing pipe might have lead. I think Yaamon is right, just go to any building supply store like Rona or Home Depot and get a 10 or 12 foot length of galvanized steel pipe that the clamps of the antenna will fit around.
For gmark2000, keep in mind that no matter what you use there is the issue of grounding, which you can read about in detail in this thread. If you use a galvanized steel pipe or a retail antenna mast that is buried a few feet below the surface or into concrete... there's your ground. With non-metallic poles you will need to run a grounding wire down, and again there are details in this thread.
For 026163, you would have the same lack-of-grounding issue with a tree too.
2006-08-04, 09:30 PM
For testing purposes, I was thinking of a broomstick and a patio umbrella stand... Just to get some pre-aiming before committing to an antenna location on the roof (where it would be less conspicuous).
2006-08-22, 07:56 PM
I finally got up on my roof to install the pre-amp I bought months ago. I used a Winegard AP-8780 because I wanted more gain on UHF, but some gain on VHF for FM's. Spec says 17dB-vhf & 28dB-uhf.
The signal I was getting before the pre-amp was ok, but I wanted to split it again and again. I now have it hooked up to 2 ATSC tuners, 2 NTSC tuners and 2 FM tuners.
I have the digital tuners going through a uhf/vhf band pass splitter with the vhf side going to the fm's.
I have a 4228 pointing at Buffalo and a 4221 pointing at Toronto. They are combined using a backwards coax splitter. It turned out I didn't have the phasing quite right; the feeds on the antennas are different. And although I had the peaked separately before I combined them, I had better results tweaking them again after they were combined. I'm now using the side lobes added together for the Toronto stations by pointing the 4221 more south and I got a better result for all the buffalo stations as well.
While I was up there I did an experiment and tried 300 ohm leads from both antennas, both connected to a single bal-un. It was suggested on here months ago, but if the outcome was posted, I didn't see it. Didn't work as well as the bal-uns that came with the antennas and the coax combiner. That $11.54 I spent at The Source just went in the garbage. :(
Going to the basement analog TV, I combined in the TV2 RF output of my EVu PVR. That signal is high!! It was causing interference on a bunch of channels. First I put a 20dB attenuator on it, most of the interference went away, so I added another 12dB. That seems to have done it. I guess they make it high so you can distribute it to all 16 TVís in your house??
Anyway, I'm now pretty happy with the reception results. If only I could do something about the programming......
I'll post updated results in the forum that covers Ajax.
2006-08-23, 09:05 AM
If only I could do something about the programming......
:rolleyes: And here is me thinking the exersize is all about equipment :) does anyone actually watch the programming :)
2006-08-29, 05:49 PM
I'm new to OTA, done some reading elsewhere and gone through a lot of the forums here @ DHC, and hoping to supplement my SD BEV with HD OTA:). Already purchased a Samsung T451.
I'm planning on putting up a CM 4221 on the chimney to pull in CN Tower which should be @ 210 o from true north - not magnetic (using the tools elsewhere in these forums - thanks to those who posted the links) from my house and hopefully Buffalo as well @180 degrees. I imagine I would be aiming for Buffalo and getting Toronto on the side lobes???
I am planning to try a 1" or 1.25" electrical conduit as my mast.
But a few questions:
1) Unfortunately I have few trees to deal with but judging by the number of other houses on my street with chimney mount antennas I'm hoping I wouldn't get too much scatter. but those attennas were probably put up when the trees were saplings 50 years ago.
If anyone thinks these trees might be a problem could they please let me know. The bearings given in the photos are magnetic and declination for my house is 10.5' W so the true direction of th CN tower for me would be 15 degrees to the left of the last picture since the yard stick is pointing @ 225 degrees:
pics form my roof (http://photos.yahoo.com/ninety9gecko)
I think I have enough elevation to get direct line-of-sight to the CN Tower ~28Km if I could see through the leaves.
2) Has anyone ever tried reinforcing a mast by inserting a smaller diameter mast inside the other oneand bolting through? I have done something similar but for a clothsline set-up but it really stiffened the final product - i.e wind resistance? Not quite the same effect if fails - I can't just re-wash my busted attenna if it comes down...
I was thinking if I could clear the trees with a re-inforced mast I might be okay to go up a few more feet than I had read been recommended.
If anyone has any thoughts I'd really appreciate it.
thanks in advance
2006-08-29, 06:02 PM
99gecko, what's your location.
I'm using a CM4228 with about a 10' pipe mast on my chimney, and looking into trees.
My azimuth (from Thornhill) is about 160 degrees.
2006-08-29, 06:13 PM
99gecko you shouldn't have any problem with the trees, they all seem fairly far away, and if you do, just buy yourself a nice strong preamp.
I have an entire cluster of 70 foot trees, starting about 20feet from where my antenna is, and i can pull in CBC French at 60-70%
before you fasten your antenna to your chimney like you were talking about, u should rig it up really temporarily, maybe even have someone hold the antenna up there well you check the signals, and then you can see what the results are, and permantly mount it based on those.
i'll be looking for your results in the results folder
2006-08-29, 08:19 PM
When I put my antenna's up temporarily I was looking through a tall maple no more than 20-30 feet away and in full leaf, I am 70 miles away from TO but pulled in CBC without any problems at all, I was using an amplifier though.
2006-08-29, 09:40 PM
99gecko your view towards Buffalo looks fine. ;)
That tree towards the cn tower should not be a problem either.
With a 4221 you can use a 1.0" ID as the antenna is not that heavy. Also there would not be much wind load from the antenna.
I would bracket about 3' against the chimney and the other 7' with your antenna on top with a 1.0" ID pole.
There is no need to go with the 1 1/4" ID pole with a 4221. Puts more load/stress on the mounts so you will need extra brackets. If you were considering a 4228 then I would recommend the 1 1/4" ID pole.
There is no need to re-inforced the pole using either the 1.0" ID or 1 1/4" ID is strong enough.
Just remember to use a ground rod and ground the mast(pole) and the coax before it enters the house.
2006-08-30, 10:30 AM
thanks All for your replies (man, you were fast:cool: ),
Interac, my location is NW of Markham Rd. & hwy 7. Grand Island is at 163 degrees so with declination I would start ~ 175.
026163, thanks for the tip I had read that one earlier in this thread I believe - good ideas. results might not be coming for a couple weeks though
Yaamon, thanks for all the tips. I am actually lucky enough that where I work I have access to all the trades (plumbers, electricians, sheet metal, gas fitters, millwrights &steam fitters), so I queried a couple of electricians about grounding. Neither has actually worked with antennas, but are going to let me know about the codes (they have to pull out the book) I will post anything they say that is different than already in this thread. But one guy mentioned to me that I might want to use "isolators". He said they are an insulated ring that holds the coax away from the actual mast. Are these necessary? I just assumed I could use tape/ties to hold it onto the mast.
2006-08-30, 02:00 PM
thanks All for your replies (man, you were fast:cool: )Those guys have helped sooo many people they deserve a medal!...one guy mentioned to me that I might want to use "isolators". He said they are an insulated ring that holds the coax away from the actual mast. Are these necessary? I just assumed I could use tape/ties to hold it onto the mast.Those are also called "stand-off insulators" and have been around since the original antenna days when the wiring was unshielded twin-lead. They look like a bishop's crook or a loop-head screw with a centre insulator that you can pass the wiring through. Nowadays with shielded coax that protects from electrostatic discharge they are not needed anymore so I just use the black tape method. You'll see great info earlier in this thread about this issue.
2006-08-30, 03:12 PM
I live in a '60s era apartment building, and I want to widen the existing cable-line hole in the external wall so that I can run a second cable through it (for my antenna). But after about 4-6 inches of plaster (on both the outside and the inside) I run into some kind of barrier. I'm not sure if it's steel, or rock, or... I just don't know.
All I know is that there is a hole going all the way through that is just wide enough for one cable, and not matter what I've tried (metal and concrete drill bits, pounding with a large spike and hammer), I can't make it any wider. Any idea what I'm running into, and how to get through it? What do people normally do when they have to run cable from a dish or antenna through an apartment wall?
2006-08-30, 03:20 PM
...after about 4-6 inches of plaster (on both the outside and the inside) I run into some kind of barrier. I'm not sure if it's steel, or rock, or... I just don't know.I can't say what you've run into but in cases where I know I can pop a hole in beside another and the going is getting tough I go to an equipment rental place and get a heavy duty hammer drill. Get one of the really strong ones (unfortunately the ones you see on sale at Rona and Canadian Tire are not strong enough) and some masonry/concrete bits and you should have no trouble. I would not pound a chisel/spike into it with a hammer because it could cause fractures and/or chipping in the concrete. A hammer drill focuses the effort onto one point.
Are you allowed to do this by your landlord BTW? :eek:
2006-09-01, 08:44 AM
Those guys have helped sooo many people they deserve a medal!
It must have been because he was being too helpful. :confused: