Easy to add OTA TV to my FTA setup?

[GrendelT]

With the Olympics coming this winter and Christmas specials on terrestrial broadcast TV for the next month, I think it's time I put up a good outdoor antenna.

My current FTA setup consists of a 1m Ku dish, DiSEqC motor, single feed LNB, and microHD receiver.

Is it possible to integrate an OTA antenna to my FTA setup so I don't have to make another long run of coax, or is another run inevitable?

Thanks in advance...

 

[jorgek]

You can try a diplexer. Ecoda is one brand. Its a special splitter/combiner. You need 1 at the OTA antenna and sat antenna cables and the other matching unit goes in the house and feed one end to HDTV and other end to sat box.
I don't have any details but you can search web for it.

2 brands of diplexers.

 

[Titanium]

Unless you have very strong terrestrial signals and don't mind loosing some signal quality on the FTA system, I would highly recommend not using a diplexer. Run a second drop if that is an option.

Quality diplexers attenuate approximately 1.5dB each inserted unit. Two diplexers are required. One to combine and another to split out.

I loose marginal terrestrial and satellite signals when using a diplexer.

 

[northgeorgia]

Are any of your OTA channels in the VHF band? If not, you might even get by with some indoor/near the window contraption (I'm thinking the coat hanger model, which I use in my room, or possibly a few runs of wire around the window frame).

 

[ftageekyyc]

I agree with Brian that diplexers can be an issue when you have marginal signal strength to begin with.

At the extreme fringe location where I use my FTA gear, I need every dB that I can get for my OTA setup.

But, in your particular location, you may be OK.

Go to the TV Fool website and plug in your location. If the channels you want to receive for the Olympics come up all green, listed as Line of Sight with double digit Noise Margin values, you may be able to run with diplexers. You will still need to make a decision about an antenna based on your location and broadcasters.

 

[jorgek]

What is marginal strength? In the digital world the signal is either there or not, marginal is for analogue transmissions which can be in the noise and still viewable.

 

[Mr Tony]

marginal to me would be its stable right now but if you add any item to the line that may drop the signal below viewable.
As example I had a station 72 miles away that was stable during the day (every now and then it would glitch) but it required a direct line. If I added a splitter or even a barrel connector it would go out constantly during the day (night was fine)

 

[ftageekyyc]

Yep, if I tried to add anything beyond what I have right now in the way of a splitter or diplexer I would lose channels.

I suppose one could say temporal or weather dependent instead of marginal.

Based on the TV Fool report for seven channels at my location, I get one channel consistently where noise margin calculations accounting for cable length etc. suggest I have a negative value by the time the signal gets to the tuner. I also get two channels that are way down the 2 Edge almost into Tropo ranking in TV Fool. We don't generally watch them, but we them see regularly when surfing by.

Sometimes they are there, sometimes they aren't. Mostly on a seasonal basis, and occasionally diurnal in different seasons.

Next year when I put up a tower I will add a second antenna for VHF and spend some time optimizing the installation.

 

[GrendelT]

Ok, so if I make a second run of coax, should I just run that coax right into the TV and change input on the TV when I want to change source?

FWIW, here's my TVFool site survey: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=46aeb226217b1e

---

Also, what's better an attic-mounted omni-directional near the peak of the roof (but inside the attic) or an exterior omni about 10ft lower but outside?

 

[mmewrench]

I think that noise threshold is the issue. That's why ota is more likely to drop out during the day, when there is a higher noise level. Anything that introduces digital noise to the system, will increase the dropouts.

 

[ftageekyyc]

You may want to start a new thread in the OTA section. Rerun your TV Fool at 15 or 20 feet, somewhere around the height you might want to locate your antenna, and state which channels you prefer.

The best choice for your needs will depend on what channels you want to receive. The odds are good you can get the top 4 channels on your TV Fool report with an old set of rabbit ears indoors. Since NBC are the Olympic broadcaster - you might be happy with that.

 

[FaT Air]

I'd be tempted to try a ANTENNACRAFT Model 5646 aimed to the southwest. You're all UHF except for that Ch 7 ABC.
"I'm thinking the coat hanger model": http://www.diytvantennas.com/ (covers UHF only)

 

[. Raine]

Ok, so if I make a second run of coax, should I just run that coax right into the TV and change input on the TV when I want to change source?

Also, what's better an attic-mounted omni-directional near the peak of the roof (but inside the attic) or an exterior omni about 10ft lower but outside?

A good example of a marginal signal would be K25LG-D, CH 25, in their TV Fool report. The noise margin for that station is 0.2, so just adding a splitter with a loss of say 2 db would make it drop below zero to -1.8, two diplexers would drop it to -3.8 [assuming a loss of 2 db each, could be more] and probably make the signal unreliable, especially in bad weather.

Making the second run of coax, I would just run it into the TV and switch inputs, if the TV is ATSC ready. Make sure that you use RG6 coax. Anything below RG6 doesn't work well for OTA signals.

Generally an outdoor antenna will work much better than one in an attic, but it depends on which direction your stations would be received from and if by lowering it 10' below the roof line your house is blocking the signals any. Say, if in your attic, the signal only has to pass through the roof itself, but if you drop the ant. down 10' on one side of the house, then signals from the other side may have to pass through the whole house itself rather than just through the roof. Hard to say really, without knowing all the specifics of direction of signals, orientation of your house in relation to those signals, etc.

 

[jorgek]

How much loss would be introduced installing the ant in the attic versus on top of the roof?

 

[. Raine]

How much loss would be introduced installing the ant in the attic versus on top of the roof?

Really would depend on what the roof is made of, but it can be a lot. Here at my house it was like night and day comparing mounted in the attic versus mounted outside. In my attic I got lousy reception but with an eaves mount only 3' above the roof line and about 5' over from where the ant. was in the attic the signal strengths were at least doubled. My roof is barn boards with tarpaper and shingles. Old construction, the house was built in 38, but new shingles just this past year.

 

[migold]

With a shingle roof, you lose about half the signal strength, as A Raine says above. Metal roof, loses much more. But, inside the roof, the antenna is less likely to be damaged in a storm. If you are within 35 miles of the transmitting tower, and not behind a hill, you should not notice the difference, unless it is a very low power station.