: OTA Mounts, Towers, Rigging Hardware



recneps77
2008-10-13, 06:13 PM
Radio Shack in the U.S. still has chimney mount kits, and in Canada some folks have been finding them at Princess Auto stores, although those aren't posted online in their catalogue.
Yeah, I got mine at princess auto like 8 months ago. They're "surplus" though, so they're volatile stock that may or may not be at a given store.

shmish
2008-10-24, 01:28 PM
I have a question about grounding.

stampeder
2008-10-24, 01:53 PM
Hi shmish, here's the thread about grounding to post your question in:

http://www.digitalhome.ca/forum/showthread.php?t=62265

uglydukwling
2008-10-26, 12:51 PM
I live on a heavily wooded site in sw Ontario about 45 miles from Detroit and 55 from Cleveland. Incidently, there are also wind farms in every direction except south (Cleveland). It's easy to imagine wild reflections off those moving blades, but I havn't actually heard about them being a problem. With a roof-mounted antenna, about 30 feet above ground, I usually get fair reception on analogue, but digital isn't quite good enough to keep a picture.
It looks like I'm going to need a tower. The problem is going to be installing and servicing it. My bucket truck will get me up 40 feet, but that isn't high enough to see over the trees. Going higher means climbing, and I'm too old for that.
Does anyone have any ideas for a hinged or telescoping tower that will let me work from ground level? I believe someone on this forum said that the hams had come up with some ingenious solutions. Anyone know of any links?
My other problem is that the best site for the tower may not be right beside the house. There are more accessible spots ( less dense trees and no overhead wires) further from the house. How worried should I be about signal losses if I need to use another 100 feet (or 200) of cable? Also, are there any grades of coax suitable for direct burial?

stampeder
2008-10-26, 02:55 PM
uglydukwling if you google "tilt over tower antenna" you'll see a bunch of them on the market that HAMS use that would be suitable for even the biggest VHF OTA antennas, and you'll see some DIY tilt overs too. :)

Regarding the length of coax, you should try to buy RG11 for such a long haul and a really strong preamp like a Winegard AP-8275, which you can read about in the Preamps thread.

roger1818
2008-10-27, 09:56 AM
uglydukwling, How new is your ATSC tuner? If you are suffering from multipath interference, a tuner with a 6th Gen decoder chip (especially the LG chip) will make a huge difference. Check out the ATSC Tuner & Converter Boxes (Non-Recording) (http://www.digitalhome.ca/forum/showthread.php?t=42186) thread for more details.

uglydukwling
2008-10-28, 05:56 PM
I don't have any specs on the tuner, but the set is about a month old. a Toshiba Regza rv53ou.
Reception of analogue signals is definitely much better than the 7-year-old analogue set it replaced, so I see what you mean by a newer tuner making a difference.
I've been experimenting with antenna aiming and I think I've found the right direction for Cleveland. I'm usually able to lock into a digital signal on every channel that identifies itself as being digital. Surprisingly. not all of them do. Reception should be good in that direction. There are fewer trees, and on the other side of them there's a clear line of sight across L Erie. No windmills either.
Detroit is probably a lost cause until I move the antenna. I started trimming branches until I realized that in a direct line between the antenna and Detroit, about 50 feet from the antennna, I was looking at a 3-foot diameter maple trunk, with more trees beyond it. If I'm going to go to the trouble of moving the antenna to look around that tree, I might as well raise it at the same time and improve things as much as I can.

99gecko
2008-10-29, 03:24 PM
... Incidently, there are also wind farms in every direction except south (Cleveland). It's easy to imagine wild reflections off those moving blades, but I havn't actually heard about them being a problem.
See this about DTV and wind farms:
http://www.digitalhome.ca/forum/showthread.php?p=547760&post547760

intravino
2008-10-30, 10:12 AM
Hi Guys,

I don't know if I am posting in the right thread. On the High Def Forum, I asked a few guys about my problem with receiving WVNY-DT and with their analysis and my tests, It looks like I have a problem with a other channel on the same frequency ch13 VHF. On guys said to put two 10y13s side by side to cancel the other channel. He said the two antennas has to be 52 inches apart, that is fine.

My question is : He mentioned something about balun phasing, I googled this and checked here on this forum and I found almost nothing. Does he mean that the 2 baluns have to be a match pair?

Also, I read somewhere that the baluns have to be installed the same way on the antenna outputs.

Thanks,

Intravino

stampeder
2008-10-30, 11:10 AM
intravino, the balun from one antenna may look exactly as the balun from another antenna, but if you connect them together you have a 50/50 chance of getting the connections "in phase" (the signals work together properly) or else they will be "out of phase" (the signals will cancel eachother out). If you connect them and the signal is awful, just switch the leads on one of the baluns to get them working together properly. :)

intravino
2008-10-30, 12:07 PM
Cool, Thanks Stampeder.

On the subject of baluns. I read on threads here that some users prefer the interior baluns to the ones that are supplied by Channel Master.

When I purchased the 10y13s, Delhi does give exterior balun with their antennas.

Also, I don't have a idea how I could mount 2 10y13s on my 40 ' tower. Right now the Delhi mounted to a J tube clamped to the tower.

They have to be 52,33 inches a part I think.

Does anyone have a idea?

Thanks,


Intravino

stampeder
2008-10-30, 12:12 PM
Some new antennas come with a built-in balun so that you just hook up coax directly to it, and other new antennas come with screw leads for attaching a balun. I don't have a preference except to say that I've seen people attach external baluns in a very sloppy manner causing them to come loose or break with time.

My advice is to just make sure that if its a separate balun just follow all the steps in this thread to waterproof and secure it tightly so that it never fails.

stampeder
2008-10-30, 12:15 PM
intravino, since you're in Beloeil, Quebec and having the Channel 13 interference problem, lets go over to the South Shore thread and discuss it there because other people in your area will probably also have the same problem. :)

http://www.digitalhome.ca/forum/showthread.php?t=53296

Cottager
2008-11-01, 08:49 PM
Hi stampeder. I am considering stacking a second 4228 as you recommended (if I can find one). Can you suggest how to best weatherproof the splitter that will be used to combine the antennas?

Thanks!

stampeder
2008-11-02, 12:10 PM
Cottager, here's a much better alternative to using a splitter when stacking CM4228s:


get about 4 feet of 300ohm twinlead (the old fashioned stuff)
connect both antennas with it, leaving about 2 inches of extra length
measure the length of that twinlead connection as exactly as possible
mark the exact middle of the length
cut and strip the 300ohm twinlead at that middle point
temporarily attach the balun to those twinlead ends (as the unison point of the output from both antennas)
connect your coax downlead to the balun
test by watching TV on a distant analogue station
if the reception is great your antennas are in phase and you can solder, twist, or crimp the twinlead ends to the balun and cover it with roofing tar or heavy duty electrical tape
if the antennas are out of phase your reception will be horrible
fix that by simply switching the two conductors on just one of the output leads as it joins the balun and the other twinlead
test again, and it should be fine to permanently attach the balun as shown above

intravino
2008-11-02, 12:24 PM
Hi Stampeder,


If I would like to stack two 10Y13s Horizontally, could I use the same method with the 300 ohms twin leads?


Thanks,

Intravino

stampeder
2008-11-02, 12:35 PM
Yes, it would work exactly the same, so just be careful about testing if the antennas are in phase before you permanently connect them and the balun together. :)

Also intravino with the interference problems you've described in the Quebec South Shore thread I think you should try to use shielded, foam filled 300ohm twinlead for more protection.

Cottager
2008-11-02, 08:32 PM
Thanks stampeder. That sounds relatively simple. However, I am a little puzzled by the following statement that can be found in the hdtvprimer website under "Ganging Antennas"

"The doubling of the output power is equivalent to a 3 dB increase in the signal. If the combiner is 90% efficient then a 2.5 dB gain is seen. Note the dichotomy:

If the antennas point in different directions, there is a 3.5 dB loss at the combiner.
If the antennas point in the same direction, there is a 2.5 dB gain at the combiner.

This is a 6 dB swing. 3 dB of this is just the adding of the second antenna, but the other 3 dB is from the combiner becoming a much more effective device."

I understand how adding a second antenna pointed in the same direction doubles the gain - that is a gain of 3 dB. What I don't understand is where the second 3 dB of gain comes from. How can a splitter become more efficient and go from introducing loss to adding gain?

If that is in fact true, is there any advantage using your system, 300 ohm twinlead, over a splitter? I assume that there will be 3 dB of gain with the twinlead system vs. 2.5 dB of gain using a splitter, so using twinlead will add an extra 0.5 dB of gain.

Am I missing anything else?

Thanks again.

Cottager

pablito1755
2008-11-08, 10:32 PM
Hi:

As I've mentioned elsewhere, I'm in the middle of pre-wiring my new home and was wanting to double check what I'd need from an OTA perspective. I've not yet had the time to research and decide on which antenna or rotor (if needed) I should get. I'd just like to cover all bases for wiring for now.

So from what I've read forums though, it would seem I need at least a combo UHF/VHF antenna as we have channels 2, 7, 11 and 27 in the Moncton area. If I go with a combo, all I need is one RG6 coax? If I went with 2 separate antennae, I should run just 2 RG6?

Given that one of the transmitters (CBAFT) is roughly 90 degrees to the remaining transmitters, I might need a rotor (the furthest transmitter is about 31 Km if that matters). If so, what wire(s) should I run to power and control the rotor? I'd be home running everything to the utility room before making my way back to the living room if needed. Is this a practical approach for rotor control?

Thanks,
Paul

stampeder
2008-11-08, 10:40 PM
Paul, when you buy a rotor as a full kit with the controller it contains all the wiring you'll need, including the base set that stays with your TV and powers/controls the rotor.

With a combo antenna you will have just the one RG6 drop. 2 antennas means combining the VHF and UHF output up on the mast into 1 drop downwards.

I think with a combo on a rotor you should be just fine. :)