OTA project plan, opinions please.

20-Jun-2011, 12:56 AM

Hello,

i'm working on my setup for OTA and i'd like some opinions please.

Here are my coordinates;

http://www.tvfool.com/?option=com_wr...001bdbd1aecae8

Where I want to mount it:

In the attic, I know that I may lose channels in red but I'm ok with that.

Hardware:

For up to 4 tv's;

http://importbestbuys.com/catalog/mo...tv-p-2254.html

CM-7777 pre-amp.

Questions:
Is this sufficient
I want UHF OTA and my traditional cable running on 1 cable... How can I accomplish this? (I heard something about a diplexer, is that right?)

Thank you very much for your responses

John Candle · 20-Jun-2011, 11:34 PM

The tvfool radar report does not show up. It says , The page you are trying to access does not exist.

GroundUrMast · 21-Jun-2011, 12:23 AM

from your previous post...

http://www.tvfool.com/?option=com_wr...001bdbd1aecae8

GroundUrMast · 21-Jun-2011, 12:41 AM

Satellite systems are different from cable, OTA signals can be inserted with the appropriate diplexer. An inexpensive diplexer will not accomplish the task on a terrestrial CATV network. Mixing OTA and terrestrial CATV network signals on the same coax is technically possible but almost always ill-advised. The most critical concern is that you can quite easily transmit interfering signals on aircraft, fire and police frequencies. The cable network is a closed system and can therefor use frequencies assigned to over the air services including life safety services. My advise is, don't risk interfering with life safety services.

On a practical level, most cable networks use QAM and NTSC modulation, the OTA transmissions use ATSC and NTSC modulation. This is why your television setup menu has a selection for 'air' and 'cable'. In addition, the cable network can use channel assignments which do not align with the over the air assignments. The result is that you will not likely find a setting on your TV that will give you the ability to tune both cable and OTA channels without reconfiguring the tuner setup and possibly re-scanning each time you switch modes.

If you are willing to invest in cable grade signal processing equipment and commercial grade test equipment, it's technically possible to convert ATSC to QAM and then insert the QAM into a cable grade signal stream... Can you afford an investment of thousands of dollars per channel plus thousands of dollars of test equipment? And be responsible for any interference you cause?

An A/B switch at the TV is far more practical for most viewers.

Presuming I copied the correct TVFR link...

Most of what I'm about to say is based on your attic being a satisfactory location for OTA reception...

Click on the "Pending Applications - All Channels" radio button and you will see that several of the post digital transition stations will be using high-VHF channel assignments. A UHF only antenna will not offer reliable reception of those channels. You could choose a two antenna solution using the 8-bay panel antenna plus a high-VHF antenna such as the Antennacraft Y5713. You could go with a single combo antenna such as the Antennacraft HBU-33 (or larger) or a Winegard HD7694P (or larger).

If you choose an 8-bay panel antenna, double check the pricing on Antennas Direct DB-8, Antennacraft U-8000, Channel Master CM-4228 and Winegard HD-8800... I am a bit skeptical of the gimmick hinge in the antenna you linked to.

I'm not convinced you will need a preamp. If you do, I would be worried that the CM7777 would overload. An Antennas Direct CPA-19 or Winegard HDP269 would be a better choice for a single antenna setup. For a two antenna system, the Antennacraft 10G221 has dual inputs (UHF/VHF) with high input capacity.

John Candle · 21-Jun-2011, 4:42 AM

There are opinions , and then there is the truth. GUM is telling you the truth , cable Tv is a Closed System the signals are transmitted With In the cable lines and uses the same frequencies as broadcast television and police and fire and airport and other communications. Connecting the Broadcast VHF and UHF channels from the antenna in with the same channels that are being used in the cable system ~~ well your Tv tuner will not like it. And the cable system signals will go through the antenna system coax to the antenna and be transmitted by the antenna. It will be Zero fun , so use two separate coax systems to prevent from happening. DO NOT connect active cable and antenna on to the same coax at the same time. The Winegard HD7694P VHF high band / UHF combo antenna pointed at about 146 true , 161 degree magnetic compass and you will receive the American digital stations and Canada digital stations. I recommend mounting the antenna on the roof for strong reception of the American and Canada stations. Here is where to buy the HD7694P antenna in Canada , http://www.canadapost.ca/shopper/sea...negard+hd7694p

John Candle · 21-Jun-2011, 5:18 AM

Here is how to aim Tv antennas , http://www.kyes.com/antenna/pointing/pointing.html . Read and understand about , REAL Digital Broadcast Tv Channels , Virtual Digital Broadcast Tv Channels , Analog Broadcast Tv Channels , http://forum.tvfool.com/showthread.php?t=695 , The switch from analog to digital of America and Canada is the same , the dates are different. Here is information of the Canada transition that is happening now , http://www.tvtechnology.com/article/105462 , http://www.tvtechnology.com/article/117022 , http://www.digitalhome.ca/forum , http://www.saveandreplay.com , http://www.trentondistributors.com , http://www.friends.ca , http://www.crtc.gc.ca/eng/home-accueil.htm . Here are some but not all , free Tv guides , http://www.canada.com/entertainment/...ion/index.html , http://tv.yahoo.com , http://tv.entertainment.excite.com , http://www.tvzap.com , http://television.aol.com , http://www.titantv.com , http://www.zap2it.com

21-Jun-2011, 11:58 AM

Thank you so much for all of this information.

So i understand that classic cable will broadcast anywhere it can, including back out the antenna. On the other hand, if i were to subscribe to a satellite TV service, a Diplexer would do it correct?

About the pre-amp = How can one be overkill? I was under the impression that it cleans the signal before sending it to the TV's, it's possible to clean out the signal entirely or can the signal be too strong for the tv?

About the Antenna, John Candle, any particular reason why you recommend the Windegard HD 7694 over this one that I linked below? I'm only going on the specs that i can compare between the two but maybe i'm missing something?

Regards,

Flixxx

Dave Loudin · 24-Jun-2011, 2:03 PM

I would suggest reading the Signal Analysis FAQ that's linked to near the top of your report. It does an outstanding job of explaining the concepts involved.

Now, to your questions in detail:

1) Why the Winegard antenna instead of the multidirectonal 8-bay?

Three reasons: First, you don't need a "multidrectional" antenna. See how all your channels are grouped together? The Winegard's performance will be perfectly adequate. Second, the specifications for your 8-bay were sloppily written. It is a UHF channel design, but UHF is 14-69, not 2-69. You will have a channel 10 and a channel 12, and those are outside of the design range for the 8-bay. Third, the signals are predicted to be strong to very strong in your area. You do not need a high-gain antenna for adequate performance of your system.

2) How can a pre-amp be overkill?

A pre-amp does not "clean" a signal, just raises the level of all signals and noise that enter it. As with any electronic device, the pre-amp will add a little noise to the signals that pass through it, so in reality the ratio of signal to noise and interference is actually a little worse with a pre-amp than without it. Pre-amps are used to overcome losses in the cables and splitters.

Yes, signals can be too strong for a preamp or tv tuner. Excessively strong signals overload the initial stage of either device, causing the strong signal to appear all over the spectrum in the device, knocking out reception of other channels. You may have encountered this behavior with inexpensive FM radios in the past.

Instead of buying a pre-amp, you may be better off buying a distribution amplifier, like the CM-3414.

3) Classic cable

We are telling you that classic cable should never end up being radiated by a home antenna. Cable is a closed system, meaning the signals stay in the cables between the cable company's head end and your TV set. Since the signals are never "in the air" cable companies can use frequencies not otherwise reserved for TV broadcasting. As GroundUrMast said, some of the frequencies used by cable are the same as used by aircraft and public safety agencies.

If you try to connect both your antenna and the cable TV feeds together with a splitter, the cable's signals will route both to the TV and to the antenna, which will then radiate those signals - a very bad thing.

John Candle · 24-Jun-2011, 6:49 PM

Yes satellite and antenna can on the same coax cable. The HD7694P is the antenna to use because your location has both UHF and VHF high channels 7 thru 13.