DTV Reception: Easy or Difficult?

[indysteve]

Some WTFDA members were recently chatting via email about DTV reception in basements, relating to receiving DTV signals during times of severe weather. While watching TV in my downstairs (basement) viewing area this afternoon, I did some experimenting with the Insignia NS-DXA1 and the Zenith Silver Sensor antenna (no amplifier). The partial basement area is completely underground in the middle of the house with no windows and at least 25 feet to the nearest outside wall (foundation).

While I live on the north side of Indianapolis, three of my semi-local DTV stations transmit from south of Indy in Trafalgar, a distance of 37 miles from my location. The three stations are:

WTTV-DT 48 with 870 kW @ 1043'
WCLJ-DT 56 with 429 kW @ 974'
WIPX-DT 27 with 165 kW @ 1017'

The first pic is the signal from WTTV-DT with the Silver Sensor sitting on the basement floor. I could not get enough signal for the other two stations with the antenna sitting on the floor, but the signal for them did get strong enough by sitting the antenna on the corner of my desk, about 3 feet above the floor.

I've also included a fourth pic showing the reception of WNDY-DT 32 with 1000 kW @ 889' with tower located 17 miles northeast of my location. This reception was with the Silver Sensor sitting on the basement floor and aimed south when it should have been aimed northeast.

Steve

[CasualOTAer]

Hi Steve,

From my experience with the Zenith DTT901 (same box), those signal levels for the two middle stations, virtual 42 and 63, are just above the hairy edge for uninterrupted reception. If the levels stay there solidly, you're OK, but if they rise and fall, you'll likely see freeze ups.

For grins, why not try putting the silver sensor in a window facing the transmitters, if you have one, that is? Otherwise, try it up near foundation level, and let us know if those the meter goes up for those stations.

In general, I've found that (UHF) ATSC reception with indoor antennas is highly sensitive to antenna location and pointing. Sometimes, an inch or two makes all the difference. But then, I have strong multipath interference, and that helps make reception vary sharply.


I've learned that non DX-ers view of DTV reception may be different from yours and mine. Some folks who'd tolerate snowy analog reception, ghosting, etc., find even occasional hiccups in the DTV audio and picture unacceptable. If you're watching a talk show, and can't hear all the talk, or are watching a golf tournament and miss the critical putt during a signal drop, that's a complete failure to such folks. I've seen this reaction from OTA-only friends of mine, and was surprised by it.

[JD4x4]

I've learned that non DX-ers view of DTV reception may be different from yours and mine. Some folks who'd tolerate snowy analog reception, ghosting, etc., find even occasional hiccups in the DTV audio and picture unacceptable. If you're watching a talk show, and can't hear all the talk, or are watching a golf tournament and miss the critical putt during a signal drop, that's a complete failure to such folks. I've seen this reaction from OTA-only friends of mine, and was surprised by it.
Hi there Casual. I'm a non-DX-er, a 100% OTA viewer, & another Marylander. I'm curious why you were surprised by OTA-only users complaints like you mentioned. Maybe you can help me get over my hatred of DTV! :-)

With analog, I had reasonable reception- meaning some minor snow and ghosting but perfect sound reception of all the DC stations, the eastern PBS, and one Balt station. Since DTV I'm lucky if I can get a complete news or weather story about 80% of the time now. Enough to make me realize why the old radio shows were such a hit. If you can HEAR something, it's 99% of the info even if you are staring at a frozen 'blockhead' . But when you hear "Residents of .. should expect very ...... so use caution." it's not really worth the electricity. :p

I'm here looking to increase my DTV reception knowledge in order to stop cursing at inanimate tv objects, and to try to stop thinking DTV was a ruse to force everyone to cable & Fios. :)

I live in a bit of a low spot about 8 miles as the crow flies from most of the DC towers, and surrounded by trees as well, so I know I'm going to need knowledge as well as experimentation and money just to get back the pre-DTV status-quo. That's annoying, but such is life.

Since your forum name is 'CasualOTAer', would I be correct that you were surprised because you've always had a non-OTA option to fall back on for the programming that was important to you? Most curious since I'm one of the DTV 'loosers' and it's SO clear to me why dropouts may as well be a power outage. :eek:

[Russ-PA]

While I'm a DX'er, I don't DX TV as a rule, so I'm more or less of a casual OTA-er myself. Just much less so than nefore digital.

To set the stage, almost all of the Philadelphia locals have their towers at just under 8 miles away. I'm at roughly 300' above sea level, the towers are somewhat less than that. In the world of analog TV, I happily did just fine with indoor rabbit ears for 25 years here, but no more.

I do not have reliable, steady solid reception of ANY of the locals any more. According to tvfool.com, the worst of these ought to be providing me with 51db of signal. And this isn't in the basement, but on the first floor. On the second floor, a similar setup gets better reception on all of the channels, but still isn't reliably solid, especially on 12.

My wife always watched more TV than I, and she's watching less than half of what she used to, in part because we no longer get channel 12 downstairs at all, and we have regular dropout problems on all of them. I also watch a lot less.

If I hold the rabbit ears up near the ceiling, I can get better reception, but I don't feel like erecting a small tower in my family room. Nor do I like TV enough to shell out $50+ a month for cable and not watch 80% of the channels ever. Same with $40 a month for satellite. And I'd have to drill holes somewhere to put an antenna outside, which I consider as a last resort.

Next stop is some kind of amplified antenna I guess...

[w9wi]

Next stop is some kind of amplified antenna I guess...

If you're only 8 miles from the towers, I think an amplifier is going to make things *worse*.

In analog, front-end overload just made the pictures washed-out & caused stations to come in on the wrong channel.

In digital, if you compress the signal to the point where the receiver can't tell the difference between level +7 and level +5 (between 87.5% and 100% power) then one out of every eight bits is going to be wrong. Error correction can fix some problems but it can't fix that many.

At your location, if you're having trouble it's probably multipath.

[Russ-PA]

There's no question that it's multi-path, and I had an idea that amplification might not be the answer. I know that channel 6 got better when they raised the power in July, but that didn't cure that problem, and 12 hasn't improved, so I'm guessing they were never granted an increase. Those two remain the worst, but I'm having frequent repeated pixellation on all of the rest, all of which have UHF actuals.

So I'm left with bad options - an outdoor antenna and the resulting holes needed in either a floor or a wall or both, or something to raise the rabbit ears up near ceiling level which my wife will consider an eyesore.

[w9wi]

There's no question that it's multi-path, and I had an idea that amplification might not be the answer. I know that channel 6 got better when they raised the power in July, but that didn't cure that problem, and 12 hasn't improved, so I'm guessing they were never granted an increase. Those two remain the worst, but I'm having frequent repeated pixellation on all of the rest, all of which have UHF actuals.

So I'm left with bad options - an outdoor antenna and the resulting holes needed in either a floor or a wall or both, or something to raise the rabbit ears up near ceiling level which my wife will consider an eyesore.

attic?

[Jim1348]

I agree that MPDI (Multi Path Distortion Interference) is the problem. One thing that I have had pretty good luck with is adding an in-line variable attenuator. By the way, I also agree with everything that has already been mentioned:

-use no amplifier

-do use low loss cable like RG-6 or RG-11 (not RG-59)

-slight location changes can make a dramatic improvement

-use a good antenna

One of the things about the variable amplifier is you might have to make changes to it when you change channels, but not necessarily. The good thing is you may find a "sweet spot" where all cahnnels come in good.

[Russ-PA]

Attic isn't an option upstairs as the access point is on the other side of the house, and the attic isn't set up for getting around. The 'attic' over the family room ( which is the only one-story part of the house ) has no direct access.

The cable is a short length so loss shouldn't be a factor. It's the RS UHF/VHF rabbit ears using the cable attached.

I've tried moving the entire thing to different corners of the room, and to other rooms, and there's either no improvement or it gets worse. Of course the best place for an antenna to face the towers would be on the far outside corner of the garage - which doesn't work either.

[larrykenney]

I live 3/4 of a mile from Sutro Tower in San Francisco, so receiving the stations from that location is no problem whatsoever (I could probably get them with a 6 inch piece of wire) but there are other stations 5 miles and 30 miles away that are not so easy to pull in with an indoor antenna.

As others have said, location is very important. Moving the antenna just a few inches horizontally or vertically can make a huge difference in signal strength. Usually going higher is better. Still I wasn't able to find a good location for all of the stations no matter where I put the antenna inside the house.

The only thing that worked was to get the antenna outside. It didn't have to be very high and didn't have to be anything special, but just getting it outside made all the difference in the world. The rabbit ears-UHF loop even worked! Materials in the home apparently were blocking the signals.

So you might try just sticking the antenna out the window to see if it makes a difference. Hang it from the corner of your eves or attach it to the gutter. I think you'll see a world of difference.

Larry
SF