Indoor Attic Antenna for High Def Dish Network tuner

[cousinvinny]

I believe I need an HD antenna (in attic) so I can pull-in local channels in HD.
I live in the northeast and I am < 10 miles from the antenna field per www.antennaweb.org. Three towers transmit WGBH (2), WCVB (5), WHDH (7),
WSBK (38), WFXT (25), WLVI (56), WBZ (4), and WGBX (44). I realize that these stations do not have HD equipment yet so they they transmit an upconverted / upscaled / manipulated signal which is digital but not true HD. My understanding is that Fox (for NFL games) will boost up their national feed and my local Fox carrier will pass that true HD signal to me. I am hoping that this signal will be a 16:9 HD signal (720P or 1080I) that will be crystal clear on my HDTV via my local HDTV antenna in my attic. Is this accurate?

My attic is on the second floor and does not have any insulation on the roof.
I do have an air conditioner air handler in the attic.
I need to point the antenna ~ magnetic north since the eight stations I want to pull-in range in degrees from 357 to 3. I am basically looking to 'split the difference'.
Sound good?

I have run RG6 QS cable; this will connect my antenna to my Dish Network HD tuner.
The run is ~ 130 feet. What is the max run for RG 6 QS for an antenna run?

Will a Channel Master 4248 eight-bay bow tie antenna (60 mile range) work well and compensate for the fact that the antenna is in the attic? I am concerned with decibel loss from being inside. The 4221 (45 mile range) would work but I figured Bigger is Better as they 99 44/100 of the time with antennas. Input?

I was considering a Yagi style antenna (directional) but it may be hard to fit.
Will I comprimise alot with the non-directional Bay Bow Tie antenna?

Thanks.

Cousin Vinny

[mjw357]

Hi Vinnie, not familiar with HD in particular but I will answer what I can.

Pointing the antenna north would be the logical place to start, always some fine tuning involved.
Really no limit to how long you can make your run, with you being about 10 miles from everything I would think signal strength won't be an issue. If you were further away from the source you might need a line amp.
The biggest issue you would normally have in this type installation is ghosting, but since you say it is digital this shouldn't be a problem.
Bowtie vs yagi, again, I don't think you need near as much antenna as you have.

[Al42]

Originally Posted by cousinvinny

I believe I need an HD antenna (in attic) so I can pull-in local channels in HD.

To an antenna there's no difference between HDTV, normal TV and two-way radio on the same frequency (other than polarization). You may need an antenna, but don't buy the "HDTV antenna" hype.

I am hoping that this signal will be a 16:9 HD signal (720P or 1080I) that will be crystal clear on my HDTV via my local HDTV antenna in my attic. Is this accurate?

Again - whether it's HD, digital or anything else, the frequency and the amount of signal/noise ratio you need are the only determining factors. Even with HDTV you will probably still need a signal that's at least 75-100uv above the noise for a noise-free picture.

My attic is on the second floor and does not have any insulation on the roof.
I do have an air conditioner air handler in the attic.

Keep the antenna away from it. Don't even have the antenna "looking over" it. Best is if you can place the antenna so that the AC stuff is behind it.

I need to point the antenna ~ magnetic north since the eight stations I want to pull-in range in degrees from 357 to 3. I am basically looking to 'split the difference'.
Sound good?

Depends on the horizontal beamwidth of the antenna. You need at least 15 degrees. Since most antennas of the type you're looking at are closer to 45 degrees, that shouldn't be a problem.

I have run RG6 QS cable; this will connect my antenna to my Dish Network HD tuner.

Dish TV is at satellite frequencies. The tuner has a discrete "local antenna" input?

The run is ~ 130 feet. What is the max run for RG 6 QS for an antenna run?

130 feet of RG6 has an attenuation of ~8.3db at 500 MHz. That's about 85% of the signal lost. You'd need a decent preamp at the antenna, or 8db more gain at the antenna than you think you need.

Will a Channel Master 4248 eight-bay bow tie antenna (60 mile range) work well

That would depend on the actual antenna gain.

and compensate for the fact that the antenna is in the attic?

If there's no metal on the roof there's nothing to "compensate" for. If there is, nothing can compensate for it.

I am concerned with decibel loss from being inside.

Being behind dry wood? No loss. Being behind shingles? None if theye's nothing metallic in them - more than an antenna can compensate for if there is.

I was considering a Yagi style antenna (directional) but it may be hard to fit.

For channel 2 it'll be about 5 feet across and about the same in length.

Will I comprimise alot with the non-directional Bay Bow Tie antenna?

A channel 2 bow tie? Figure about 12 feet wide and, for 8 elements, 10 feet high - minimum. Small you-can-hold-it-in-two-hands bow tie antennas are for UHF only and, then, aren't that good on the lower (below about 40) channels. A bow tie element (one "tie") would be about 50" across and close to a foot high for channel 2. And they aren't off-the-shelf antennas.

[kb2vxa]

Hi Cuz,

The greater Boston area reminds me of the famous (among broadcast engineers) Baltimore Experiment which clearly showed the superiority of COFDM over 8VSB which the FCC ultimately rammed down our throats. It's a long story, but it demonstrated the fragile nature of this type of HDTV modulation in an urban environment.

While "your milage may vary" it is highly recommended that a high gain outdoor antenna (with rotor if needed) mounted clear of obstructions be used with a high quality, low loss downlead. Due to it's "all or nothing" nature you have to feed the TV with a strong, clean signal, the slightest disruption such as multipath (reflections which cause ghosting on NTSC analog) propagation causes the dreaded blue screen.

FYI, Europeans have far fewer problems with COFDM, made in USA but died a horrible death when big money lobbied.........
Frackin' pay per view politics!

[Al42]

Originally Posted by kb2vxa

The greater Boston area reminds me of the famous (among broadcast engineers) Baltimore Experiment which clearly showed the superiority of COFDM over 8VSB which the FCC ultimately rammed down our throats.

Sort of like Crosby FM stereo and CBS frame-sequential color.

[CODE03]

I recently upgraded my TV to a HDTV unit, and I'm using the same old outside TV antenna that I put up to get my locals when I went with Dish Network.

That antenna pulls in the HD and digital signals from the local stations just fine, with no problems at all.

I was going to buy one of those 'HDTV' antennas, but I was also advised to just use what I have, and it works great.