This report is on my exploration into digital television with a Wine Guard HD-4400 semi-directional antenna and an Insignia receiver.
The antenna – a small vertical semi-directional antenna chosen for its low cost and relatively flat gain curve across the UHF spectrum – worked surprisingly well, outperforming an old outdoor antenna five times its size.
The receiver – a small square black box with sixth generation LG chipset – did a great job converting the digital signals into analog, although it lacks a pass-through feature for viewing regular analog transmissions on the television while not in operation.
Television Station Reception:
1. Any antenna not receiving a station’s analog signal will not likely receive the digital signal either.
Weak signals in analog with obvious static but in color will show up in digital. Extremely weak analog signals absent color will not show up at all in digital. For analog signals that fade in and out, the digital receiver will show a normal picture with normal audio for one moment and then freeze the picture with no audio the next moment.
2. An old rooftop antenna does not perform any better than an eight-inch loop antenna.
The old rooftop antenna works fine for analog television. The signal strength of analog stations change with rotation of the antenna going from weak to decent reception. In digital no discernible change in reception occurs with rotation of the antenna – weak stations remained weak and strong stations remained strong – performing not much better than an eight inch loop antenna.
The new semi-directional antenna did show changes in reception with rotation, including the discovery of a new television station.
3. Amplification has no apparent effect upon digital reception unlike analog reception.
Increasing the amplification of distant stations in analog improved the picture – from gray static to decent color reception. Increasing the amplification of distant stations in digital resulted in no noticeable change in reception.
The new semi-directional antenna received distant stations fairly well; and when the air was still, brought in a new station ninety miles away. Increasing amplification on the new semi-directional antenna had no discernable effect upon reception of distant digital television stations.
4. On windy days trees can redirect both weak and strong signals canceling out digital reception.
When radio waves pass through trees from a television station, the radio waves undergo a process of diffraction where parts of the signal constructively interfere becoming brighter and destructively interfere becoming dimmer. The greater the distance between the transmitter and an antenna the more the intervening trees alter the signal path requiring careful placement of an antenna for reception of distant stations.
When the wind blows – either as a breeze in summer or as a gust in winter – the moving trees momentarily become better at diffracting the signal from the television station. Even very strong signals from local stations can cancel out at the antenna resulting in loss of audio and the loss of video in the form of blocks on the screen.
I estimate that the new semi-directional antenna receives signals from one thirtieth of the area of an omni-directional antenna. This reduced area means fewer redirected signals during windy days can cancel out the direct signal from a television station; and, dropouts that once lasted four seconds on an eight-inch omni-directional antenna now last less than a quarter of a second on the new semi-directional antenna.
5. Close stations and distant stations require separate antennas.
For close television stations about fifteen miles away, I’m thinking that an inline attenuator will reduce signal strength from a directional antenna preventing the receiver from overheating. For distant television stations about seventy-five miles away, I’m thinking about adding an inline amplifier to another directional antenna – although I cannot be sure it will work.
HDTV Audio and Video:
1. Picture quality largely depends upon data rate.
The commercial stations – WCYB, WEMT, WKPT, and WJHL – and the public television stations – WEMT and WSBN – broadcast fifteen megabits per second high definition channels that look pretty good on an analog television set. The high definition channel always ends in a one, for example: 2 – 1.
The commercial stations – WCYB, WEMT, and WJHL – also broadcast four megabits per second standard definition channels that look okay, but become a little blurry when anything moves on the screen. The standard definition channels always end in a two, for example: 5 – 2.
The public television stations – WEPT and WSBN – broadcast two low definition channels splitting the four megabits per second into two equal parts. These low definition channels look okay for static unchanging pictures, but even the slightest motion reduces the picture to a grainy, blurry, blocky mess. The low definition channels end in a two or three.
The commercial station – WKPT – broadcasts three low definition channels splitting the four megabits per second into three parts. These low definition channels never look bad, but motion can become stilted or frozen for a moment, suggesting that frames get dropped.
The religious station – WLFG – broadcasts a single television channel in stretched mode. By pressing the button on the remote labeled zoom a few times the picture can be squeezed back into a more natural shape.
Also with the high definition channels on the other stations, pressing the zoom button can crop the picture removing those annoying black stripes at the top and bottom of the screen. But for the other station’s standard definition and low definition channels pressing the zoom button has no effect on the picture.
2. Apart from being digital, the audio quality of the stations didn’t change in any perceptible way.
WSBN remains the quietest station out there – doubling the length of the volume bar improved matters but you have to scale it back when changing channels. WJHL has a weather channel with nice music, but the commercials and weather alerts blast in loudly. WYCB has a standard definition channel where actors hiss like snakes because the station has over emphasized the high frequencies.
WSBN has a secondary audio program that doesn’t differ from the primary audio program. WKPT rebroadcasts a local radio station as a secondary audio program labeled French.
Additional Notes:
1. Changes in February
A few low power analog broadcasts will still continue on after the February 19, 2009 data and some digital television stations will change their frequencies – see TV Fool for details.
2. Helpful websites on HDTV
TV Fool – This site has a great list of the few stations you can get over the air. Just enter your coordinates from Google Earth or a street address.
Titan TV – This site lists the program schedules for broadcast stations by area.
HDTV Primer – This site lists antennas and their reception characteristics.
Multipath Solutions – This site presents solutions to the problem of multipath – also known as ghosting – in an urban environment.
DIY Budget HDTV Antenna – A video of a simple low cost antenna you can build yourself.
3. Antenna, cable, and splitter effects
A non-directional antenna with receiver brought in stations at the -45 decibel level.
A semi-directional antenna with receiver brought in stations at the -75 decibel level.
A fifty-foot cable reduced reception by 1.5 decibels – approximately half a block on the signal meter.
A two-way splitter reduced reception by 3.0 decibels – approximately one full block on the signal meter.
4. Time deviation by station
Not every stations broadcast has the same time as NIST Eastern Standard Time.
Measurements done by the quick look method – accurate to within plus or minus one second.
Station Deviation in Hours: Minutes: Seconds
--------------------------------------------------
WCYB -00:00:17
WEMT -00:00:01
WEPT -00:00:05
WJHL +00:00:17
WKPT -00:00:02
WLFG -05:06:39
WSBN -00:00:09
The antenna – a small vertical semi-directional antenna chosen for its low cost and relatively flat gain curve across the UHF spectrum – worked surprisingly well, outperforming an old outdoor antenna five times its size.
The receiver – a small square black box with sixth generation LG chipset – did a great job converting the digital signals into analog, although it lacks a pass-through feature for viewing regular analog transmissions on the television while not in operation.
Television Station Reception:
1. Any antenna not receiving a station’s analog signal will not likely receive the digital signal either.
Weak signals in analog with obvious static but in color will show up in digital. Extremely weak analog signals absent color will not show up at all in digital. For analog signals that fade in and out, the digital receiver will show a normal picture with normal audio for one moment and then freeze the picture with no audio the next moment.
2. An old rooftop antenna does not perform any better than an eight-inch loop antenna.
The old rooftop antenna works fine for analog television. The signal strength of analog stations change with rotation of the antenna going from weak to decent reception. In digital no discernible change in reception occurs with rotation of the antenna – weak stations remained weak and strong stations remained strong – performing not much better than an eight inch loop antenna.
The new semi-directional antenna did show changes in reception with rotation, including the discovery of a new television station.
3. Amplification has no apparent effect upon digital reception unlike analog reception.
Increasing the amplification of distant stations in analog improved the picture – from gray static to decent color reception. Increasing the amplification of distant stations in digital resulted in no noticeable change in reception.
The new semi-directional antenna received distant stations fairly well; and when the air was still, brought in a new station ninety miles away. Increasing amplification on the new semi-directional antenna had no discernable effect upon reception of distant digital television stations.
4. On windy days trees can redirect both weak and strong signals canceling out digital reception.
When radio waves pass through trees from a television station, the radio waves undergo a process of diffraction where parts of the signal constructively interfere becoming brighter and destructively interfere becoming dimmer. The greater the distance between the transmitter and an antenna the more the intervening trees alter the signal path requiring careful placement of an antenna for reception of distant stations.
When the wind blows – either as a breeze in summer or as a gust in winter – the moving trees momentarily become better at diffracting the signal from the television station. Even very strong signals from local stations can cancel out at the antenna resulting in loss of audio and the loss of video in the form of blocks on the screen.
I estimate that the new semi-directional antenna receives signals from one thirtieth of the area of an omni-directional antenna. This reduced area means fewer redirected signals during windy days can cancel out the direct signal from a television station; and, dropouts that once lasted four seconds on an eight-inch omni-directional antenna now last less than a quarter of a second on the new semi-directional antenna.
5. Close stations and distant stations require separate antennas.
For close television stations about fifteen miles away, I’m thinking that an inline attenuator will reduce signal strength from a directional antenna preventing the receiver from overheating. For distant television stations about seventy-five miles away, I’m thinking about adding an inline amplifier to another directional antenna – although I cannot be sure it will work.
HDTV Audio and Video:
1. Picture quality largely depends upon data rate.
The commercial stations – WCYB, WEMT, WKPT, and WJHL – and the public television stations – WEMT and WSBN – broadcast fifteen megabits per second high definition channels that look pretty good on an analog television set. The high definition channel always ends in a one, for example: 2 – 1.
The commercial stations – WCYB, WEMT, and WJHL – also broadcast four megabits per second standard definition channels that look okay, but become a little blurry when anything moves on the screen. The standard definition channels always end in a two, for example: 5 – 2.
The public television stations – WEPT and WSBN – broadcast two low definition channels splitting the four megabits per second into two equal parts. These low definition channels look okay for static unchanging pictures, but even the slightest motion reduces the picture to a grainy, blurry, blocky mess. The low definition channels end in a two or three.
The commercial station – WKPT – broadcasts three low definition channels splitting the four megabits per second into three parts. These low definition channels never look bad, but motion can become stilted or frozen for a moment, suggesting that frames get dropped.
The religious station – WLFG – broadcasts a single television channel in stretched mode. By pressing the button on the remote labeled zoom a few times the picture can be squeezed back into a more natural shape.
Also with the high definition channels on the other stations, pressing the zoom button can crop the picture removing those annoying black stripes at the top and bottom of the screen. But for the other station’s standard definition and low definition channels pressing the zoom button has no effect on the picture.
2. Apart from being digital, the audio quality of the stations didn’t change in any perceptible way.
WSBN remains the quietest station out there – doubling the length of the volume bar improved matters but you have to scale it back when changing channels. WJHL has a weather channel with nice music, but the commercials and weather alerts blast in loudly. WYCB has a standard definition channel where actors hiss like snakes because the station has over emphasized the high frequencies.
WSBN has a secondary audio program that doesn’t differ from the primary audio program. WKPT rebroadcasts a local radio station as a secondary audio program labeled French.
Additional Notes:
1. Changes in February
A few low power analog broadcasts will still continue on after the February 19, 2009 data and some digital television stations will change their frequencies – see TV Fool for details.
2. Helpful websites on HDTV
TV Fool – This site has a great list of the few stations you can get over the air. Just enter your coordinates from Google Earth or a street address.
Titan TV – This site lists the program schedules for broadcast stations by area.
HDTV Primer – This site lists antennas and their reception characteristics.
Multipath Solutions – This site presents solutions to the problem of multipath – also known as ghosting – in an urban environment.
DIY Budget HDTV Antenna – A video of a simple low cost antenna you can build yourself.
3. Antenna, cable, and splitter effects
A non-directional antenna with receiver brought in stations at the -45 decibel level.
A semi-directional antenna with receiver brought in stations at the -75 decibel level.
A fifty-foot cable reduced reception by 1.5 decibels – approximately half a block on the signal meter.
A two-way splitter reduced reception by 3.0 decibels – approximately one full block on the signal meter.
4. Time deviation by station
Not every stations broadcast has the same time as NIST Eastern Standard Time.
Measurements done by the quick look method – accurate to within plus or minus one second.
Station Deviation in Hours: Minutes: Seconds
--------------------------------------------------
WCYB -00:00:17
WEMT -00:00:01
WEPT -00:00:05
WJHL +00:00:17
WKPT -00:00:02
WLFG -05:06:39
WSBN -00:00:09
