# Digital TV antenna questions

Thread Starter

#### Chris65536

Joined Nov 11, 2019
270
Well, Comcast has pissed me off for the last time, and I am ready to cut the cable. Most of my electronics knowledge is digital, and I don't know much about antennas, so I am looking for advice. My house is 38 miles from The Sears Tower, and at a relatively high elevation (key word: relatively; this is Illinois we're talking about!). I was hoping to put an antenna in my attic, but I'm not sure if this is feasible. Obviously the roof will block the signal somewhat, but how much would this actually amount to in dB? Would a higher gain antenna make up for the attenuation from the roof? I have quite a lot of room up there, so I could get a huge one if necessary. Any brand recommendations? Thanks in advance.

#### crutschow

Joined Mar 14, 2008
27,751
Here's some info on mounting an antenna in the actic.
It says you lose about 10-15 miles of reception distance due to losses through the roof (what type of roof is it?).
This is perhaps about a 40-50% (-3dB) loss.
A higher gain antenna will help make up for that loss (as possibly also a low-noise antenna amplifier).

I would look for an antenna rated for at least 75 miles.

#### nsaspook

Joined Aug 27, 2009
8,685
Run a test cable first with a cheap passive antenna from the desired location to the TV. If you can get a few stations with that then a 'real' antenna in the spot is a possibility. Metal flashing will block the signal but normal roof building materials like wood and regular shingles won't cause excessive signal loss.

I currently use the Channel Master CM-5020 outdoors but something similar should work inside an attic.

https://forum.allaboutcircuits.com/...oshack-vu-190-tv-antenna.161631/#post-1414588

#### wayneh

Joined Sep 9, 2010
17,153
Thread Starter

#### Chris65536

Joined Nov 11, 2019
270
Here's some info on mounting an antenna in the actic.
It says you lose about 10-15 miles of reception distance due to losses through the roof (what type of roof is it?).
This is perhaps about a 40-50% (-3dB) loss.
A higher gain antenna will help make up for that loss (as possibly also a low-noise antenna amplifier).

I would look for an antenna rated for at least 75 miles.
Excellent, thank you for this information! I have a wooden roof with asphalt shingles, which seems to be not too bad.

Thread Starter

#### Chris65536

Joined Nov 11, 2019
270
Run a test cable first with a cheap passive antenna from the desired location to the TV. If you can get a few stations with that then a 'real' antenna in the spot is a possibility. Metal flashing will block the signal but normal roof building materials like wood and regular shingles won't cause excessive signal loss.
This is a great idea. I'll do the cable runs and splitter first, so I can see what I'm starting with.

#### nsaspook

Joined Aug 27, 2009
8,685
This is a great idea. I'll do the cable runs and splitter first, so I can see what I'm starting with.
You might find the best physical mount location is not the best for reception due to reflection nulls so leave sufficient cable in the attic.

#### Tesla23

Joined May 10, 2009
482
and often the easiest way to get relevant experimental results on TV reception is to ask the neighbours.

#### Reloadron

Joined Jan 15, 2015
6,064
I played this game a few years ago as the cable company argued with a local FOX affiliate station. I started by just hanging a wire clipped to a needle shoved into the back of my set. Let the set auto search and found 25 channels here in the greater Cleveland, Ohio suburbs. Problem was the station I was after was actually VHF and all I was finding were UHF. You may want to search and see what is available in your area. You may want a VHF and UHF antenna. Keep this in mind:
" In the US and Canada, the VHF television band occupies frequencies between 54 and 216 MHz and the UHF band between 470 and 890 MHz. In general, VHF channels are numbered 2 to 13 and UHF channels 14 to 51".

The term DTV (Digital Tele Vision) is merely the signal, it's still on the RF carrier. A DTV antenna is merely a selling point.

I suggest you give this a read before buying anything. It covers what I mentioned and a bunch more.

Ron

#### Reloadron

Joined Jan 15, 2015
6,064
Where I live there are no VHF channels.
I like this particular tool for finding what's available:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=9038e2fc38a796
This one is similar and very good also
https://antopusa.com/signalmaps/
Yes, and it figures the one channel I was after Fox 8 was:
WJW, virtual and VHF digital channel 8, is a Fox-affiliated television station licensed to Cleveland, Ohio, United States. Its second digital subchannel serves as an owned-and-operated station of the classic TV network Antenna TV.

The only VHF channel of all of them.

Good link to see what is around.

Ron

#### crutschow

Joined Mar 14, 2008
27,751
The term DTV (Digital Tele Vision) is merely the signal, it's still on the RF carrier. A DTV antenna is merely a selling point.
And it's strictly advertising hype.
Both analog and digital TV signals modulate an RF carrier
The modulation spectrum is different (the analog modulation has distinct frequencies as shown by a spectrum analyzer, while the digital modulation looks more like white noise), but there is absolutely no difference in the antennas that receive either signal.

#### Reloadron

Joined Jan 15, 2015
6,064
And it's strictly advertising hype.
Both analog and digital TV signals modulate an RF carrier
The modulation spectrum is different (the analog modulation has distinct frequencies as shown by a spectrum analyzer, while the digital modulation looks more like white noise), but there is absolutely no difference in the antennas that receive either signal.
That covers it so a DTV antenna is just an antenna.

Ron

#### nsaspook

Joined Aug 27, 2009
8,685
Thread Starter

#### Chris65536

Joined Nov 11, 2019
270
The term DTV (Digital Tele Vision) is merely the signal, it's still on the RF carrier. A DTV antenna is merely a selling point.
I was looking at some of the outdoor ones on the Channel Master website. Interestingly, their "digital" antennae (LOL) cost $30 less than the regular ones, and they seem to have less VHF gain and a little more of the UHF. They also have a "Stealth50", which for$30 total might be worth a try. I think I have a fairly good receiving situation, with all on my stations in the same direction, and nothing at all behind me.

#### Ylli

Joined Nov 13, 2015
1,053
A caveat if you are thinking of putting a high gain antenna in the attic (or elsewhere for that matter). Gain is produced by making the antenna more directional - the higher the gain, the smaller the useful beamwidth. If all the stations you want to receive are in the same direction from your locaion that is not a problem. But if some are on a heading of 30°, other at 90° and still others at 330°, you would need to be able to rotate the antenna. Look at that TVFool site mentioned above and see where all your receivable station are located.

Thread Starter

#### Chris65536

Joined Nov 11, 2019
270
All my strong stations come from either John Hancock at 125 degrees, or Sears Tower at 127. Milwaukee is 110 degrees to the left, and 20 miles farther.

#### KeepItSimpleStupid

Joined Mar 4, 2014
5,088
My Samsung "Smart TV" doesn;t know how to handle an antenna rotator.
Options:
Erase all and add
i think you can delete them.

Scan and add is MISSING.
Tune by physical channel # is missing too.

#### crutschow

Joined Mar 14, 2008
27,751
they seem to have less VHF gain and a little more of the UHF
That may be because more of the digital channels are on UHF than the analog channels were.

#### wayneh

Joined Sep 9, 2010
17,153
That may be because more of the digital channels are on UHF than the analog channels were.
Yes, you want to spend the money on UHF performance. I don't even have a VHF station to choose.