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Old 12-Oct-2012, 7:05 PM   #1
Mr.B
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Please help with antenna choice. Do I actually need two? (Brossard, Montreal)

Hi,

I'm pretty new to this, so if I'm asking questions that have already been answered, sorry for that. But please guide me to some threads that already discuss these issues.

So I'm willing to cut the cord, I've done my research and here's my report (http://www.tvfool.com/?option=com_wr...2df9c08b833b57)

There are a few things that are not clear to me so I'm kindly asking for help, pleeeease .

I'm interested in receiving the channels in GREEN and YELLOW and I'm willing to install the antenna on the roof. Money is not a problem in antenna selection since I'm willing to get the right one from the beginning .

Now the questions ...

1. I do not know how to choose an antenna based on the info on the report. Can someone make any suggestions please?
I figured I can subtract the Pwr from the NM and in case the result is negative I need an antenna with enough gain to compensate for that in order to end up with a positive value. Is that the way it really works?

2. I've read that too much gain can actually "break" the channels that actually don't need gain at all (e.g. the ones that are just a few miles away). So by getting an antenna with enough gain to receive the channels that are far (70miles) is there any risk that I might "break" the channels that are close here in Montreal? So in the end the question is how do I choose the antenna that provides the right balance in order to get the close and far channels with good quality as well.

3. The last question is the one that puzzles me the most. I want to receive both bunches of channels that you see on the map (NW - 15,21,19,12,10 and SE - 22,14,32,43,13). Do I need two antennas for that? Or is there an antenna that can receive both? I know I could use a multi-directional, but is it strong enough? Or I need to get 2 directional

Thanks a lot guys in advance for your comments and keep the site alive.
It's a a great resource and great help!
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Old 13-Oct-2012, 4:07 AM   #2
GroundUrMast
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1. The thread, http://forum.tvfool.com/showthread.php?t=109 provides several examples of how to use the data in your TV Fool report.

2. Yes, too much signal power can overload a tuner. You may be close to that point if you selected a deep fringe, high gain antenna. But you don't need a high gain antenna, so let's not worry about that happening in your case.

3. A compact antenna such as the RCA ANT-751 will receive best from the direction it's pointed. But it also receives fairly well from the opposite direction. It's not extremely directional and has modest gain. My suggestion would be to point an ANT-751 at 168° compass. You should expect to see the distant signals from the US stations while the strong local signals would still be received through the back of the antenna.
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Old 13-Oct-2012, 2:34 PM   #3
Mr.B
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Thanks GroundUrMast, that looks like a great antenna.
One question left though. The antenna range is 40miles (according to specs) but the US channels I'm interested in, are listed as 70miles away. Is it going to pick them up?

If the answer is yes, can you also give me a short explanation why please?
And after you say (hopefully) YES, in the next minute I'll order it :P.

Thanks again for answering. I really appreciate you taking the time to do this.
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Old 13-Oct-2012, 3:08 PM   #4
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Mileage estimates are the product of the sales department. A few reputable companies tend to make conservative estimates. Others make obviously exaggerated claims (150 miles is hard to believe under any circumstance).

The TV Fool data is based on the transmitter power, terrain and other known, relevant facts. Someone 10 miles from a transmitter, blocked by terrain may not be able to get a useable signal with even the largest antenna... You have open, clear terrain between you and the transmitters. Notice the 'LOS' path indication. You have a high noise margin for most all signals that are LOS. You don't need a huge antenna.

Cheers
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Old 14-Oct-2012, 2:01 AM   #5
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Awesome news !
There's one more thing I've just realized I need to ask.
My internet, phone and TV are all through (one) cable, one ISP and I actually have a connection outside where I could hook into by installing a combiner.

Now the question is if there's any problem if I'll be using the same cable or I have to use a separate cable from the antenna. Are the signals going to "clash" somehow? I'll be using mainly one TV and occasionally two.

Just in case I'm not clear here's the configuration I'm thinking:
Antenna+ISP --> combiner--> one coax into the house --> splitter --> 1 output for Internet+Phone and 1 output for TV.

In case I can do this and I need an amplifier please suggest one. And if even remotely you think I might need one (e.g. for when I'll use 2 TVs) I'll buy it just in case it comes handy one day.

PS. Let me know if there's any way I can get back to you or the website for all the help. You don't know how much I appreciate it. Thanks.
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Old 14-Oct-2012, 3:56 PM   #6
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Don't mix cable and OTA TV

Cable TV systems are 'closed' which means no signal is supposed to escape into the air. This allows them to use frequencies assigned to licensed over the air services including life safety services such as police, fire, aviation, military, etc. The cable network also uses the same frequencies that OTA TV broadcasts on. So, you don't want to hook an antenna to a cable service signal, you'll cause harmful interference. You'll also find the cable and OTA TV signals will interfere with each other, leaving you with no cable or OTA, or at least significantly degraded.

You can disconnect the cables that feed the two sets from the existing cable splitter. In fact, if the internet and phone service are delivered by the same modem, and it's the only device that will remain active on the cable connection, you can disconnect the splitter from the cable service and use it for distributing your OTA signal. Just run the one and only cable connection directly to the internet/phone modem.

The end result needs to be, cable service fully and completely separate from the OTA system.

I would try a non-amplified install to begin with. Use a 2-way splitter if feeding two TVs. Splitters with more ports have more loss. (Why add extra loss?)

If you prove the need for an amplifier, it needs to handle strong signals. The best place for an amplifier is close to the antenna. Amplifiers are only capable of compensating for losses on the output side of the amplifier.

If you where going to feed four or more TVs, I'd suggest a Channel Master CM-3410 if you already own an appropriate passive splitter. Channel Master also offers the same amplifier with a built in splitters in 2, 4 & 8 output configurations. (CM-3412, 3414 & 3418)

Unused splitter ports should be terminated using F type 75Ω terminator caps

Last edited by GroundUrMast; 14-Oct-2012 at 3:58 PM.
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Old 15-Oct-2012, 3:53 PM   #7
Mr.B
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Ups, my bad. I forgot to mention that I want to use the same cable after I cancel my TV service and the phone also.
So in the end there will be only Internet on the coax. Now, in that case, can I use the same cable?

FYI, I've ordered the antenna. But I've tried so hard to find a data sheet online to figure out the antenna gain but no luck. I'll be needing that in case I'll use an amplifier. To do the math . So is there a way to find that out?

And just for my curiosity, how come you've recommended this antenna when at the same time in the excel file from this thread (http://forum.tvfool.com/showthread.php?t=109) you're saying: *Antenna Gain* "Get this value from the manufacturer's data sheet. If they won't provide this, you'll want to consider a vendor who will."

Don't worry I've done my research on the antenna and it's a great one, it has amazing reviews, so I don't doubt it, it's just that I was curious how were you able to spot this exception.

Thanks again
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Old 15-Oct-2012, 4:16 PM   #8
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Exception to the rule

In the case of the ANT-751, it fits a niche due to it's physical form factor and size. Also, there's a lot of real world experience that supports this particular antenna's quality and capability. I wish I had more vendor provided data than I do, however, I can use a conservative set of numbers (1 to 3 dB gain H-V/UHF) and see through experience that my estimate is close.

(On the other hand, there are plenty of other RCA branded antennas that may work as well as the equivalent products from other vendors, but because vendors like Antennas Direct, Antennacraft, Channel Master & Winegard do a better job of documenting their products, I lean their way.)
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Old 15-Oct-2012, 4:29 PM   #9
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Don't mix cable and OTA TV

Even if the only subscribed service on the coax is internet, You have to assume the cable company is still sending signals on all the frequencies that will conflict with OTA transmissions.

FWIW: The newer cable system topology sends every thing as data, modulated on multiple carrier frequencies ranging from a few MHz to over 1000 MHz. By digitizing all of their 'products' they can apply encryption to control which customer can receive which program or service. They no longer need to filter out premium frequency ranges as was done back in the analog days.

Please, keep the coax that carries cable company 'service' isolated from your OTA TV coax system.
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Old 16-Oct-2012, 8:37 PM   #10
Mr.B
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Thanks a lot!

I'm waiting for the delivery . I'll let you know as soon as everything's installed. And hopefully there won't be anymore questions .
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Old 18-Nov-2012, 9:43 PM   #11
Mr.B
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Hi GroundUrMast,

as promised just wanted to let you know that I got the antenna installed it and it's all great. Almost .
Well reception is great, it's just that if I point it at 168°, towards US I'm not getting one of the local channels (15.1) that I actually really want. And I'm also not getting all the US channels, but I do get a few (don't remember exactly which), so it's great. So I ended up pointing it towards 313° so I can get all the local channels OK. Like this I'm not getting any US channels except PBS for which the quality is very poor. Almost unwatchable.

So this only proves that I need an amplifier. I will get the one that you recommended and try to point it towards US again and see what's the outcome in that case.

Please let me know, when you have time, if the amplifier that you mentioned is still a choice considering what I've just told you.

Thanks again !
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