The Problem Is Not In Your Set!

I have been getting calls and emails recently from several people all with the same question. It seems that they have either purchased a new DTV set or have connected a DTV converter to their old analog set and have experienced a strange phenomenon. They are getting great digital reception from all the local stations except Channel 9, WCPO DT.

Now let’s be clear. These are people who do not subscribe to cable or a satellite service. Instead, they rely on over-the-air reception to watch TV.

There is a very simple answer to this conundrum. The problem is not in their TV set. The problem is on top of the TV set or on the roof. It is very likely the antenna.

Back in the 1990s the FCC assigned new channels for DTV to all existing full-power broadcasters. In most cases these new channels were in the UHF band, i.e. Channel 14 – 68. For example CET received DTV Channel 34, WLW got Channel 35. Both are in the UHF band. WCPO got VHF Channel 10. Therein is the problem.

While you may not know it, there are significant differences in the design of antennas used for picking up UHF channels from those designed to pick up VHF channels. I won’t go into the physics. Take my word for it. So if you have a UHF antenna, either set top or roof top, and it is a “UHF only” model, it will not pick up the VHF signal from Channel 10, WCPO.

By the way, don’t let these numbers confuse you. In order to keep it simple, all digital TVs and converter boxes display the old channel analog numbers so the consumers don’t have to get used to a new numbering system. When you watch CET’s digital channel, which as I said above is really channel 34, the TV channel indicator will display good old Channel 48.

OK back to the problem at hand. I did an experiment. I live on a very high ridge just north of Harrison. On a clear day I can see some of the TV towers in downtown Cincinnati from my front window. I connected a UHF/VHF antenna to a DTV receiver and got a good picture from Channel 9 DT. I switched to a “UHF only” antenna. I got nothing.

You might ask why now? You may be using the same antenna that you used for getting analog Channel 9. The UHF antenna worked OK.

Digital signals are different in that they are either perfect or non existent. It is called the “cliff effect.” With analog signals we all have experienced a TV signal that is snowy. We put up with it until it is no longer viewable. A digital signal will never be snowy. If the TV set’s circuitry determines that it can not provide a perfect picture, it will just go to black. I think that is what is happening with our callers’ sets.

The solution is to get an antenna that is designed for both UHF and VHF. That should fix the problem. Some set top antennas have amplifiers. This can help as well. Be sure that the amplifier can be switched off. There are some instances when too much signal can cause problems as well. That’s another column.

The Problem Is Not In Your Set!

I have been getting calls and emails recently from several people all with the same question. It seems that they have either purchased a new DTV set or have connected a DTV converter to their old analog set and have experienced a strange phenomenon. They are getting great digital reception from all the local stations except Channel 9, WCPO DT.

Now let’s be clear. These are people who do not subscribe to cable or a satellite service. Instead, they rely on over-the-air reception to watch TV.

There is a very simple answer to this conundrum. The problem is not in their TV set. The problem is on top of the TV set or on the roof. It is very likely the antenna.

Back in the 1990s the FCC assigned new channels for DTV to all existing full-power broadcasters. In most cases these new channels were in the UHF band, i.e. Channel 14 – 68. For example CET received DTV Channel 34, WLW got Channel 35. Both are in the UHF band. WCPO got VHF Channel 10. Therein is the problem.

While you may not know it, there are significant differences in the design of antennas used for picking up UHF channels from those designed to pick up VHF channels. I won’t go into the physics. Take my word for it. So if you have a UHF antenna, either set top or roof top, and it is a “UHF only” model, it will not pick up the VHF signal from Channel 10, WCPO.

By the way, don’t let these numbers confuse you. In order to keep it simple, all digital TVs and converter boxes display the old channel analog numbers so the consumers don’t have to get used to a new numbering system. When you watch CET’s digital channel, which as I said above is really channel 34, the TV channel indicator will display good old Channel 48.

OK back to the problem at hand. I did an experiment. I live on a very high ridge just north of Harrison. On a clear day I can see some of the TV towers in downtown Cincinnati from my front window. I connected a UHF/VHF antenna to a DTV receiver and got a good picture from Channel 9 DT. I switched to a “UHF only” antenna. I got nothing.

You might ask why now? You may be using the same antenna that you used for getting analog Channel 9. The UHF antenna worked OK.

Digital signals are different in that they are either perfect or non existent. It is called the “cliff effect.” With analog signals we all have experienced a TV signal that is snowy. We put up with it until it is no longer viewable. A digital signal will never be snowy. If the TV set’s circuitry determines that it can not provide a perfect picture, it will just go to black. I think that is what is happening with our callers’ sets.

The solution is to get an antenna that is designed for both UHF and VHF. That should fix the problem. Some set top antennas have amplifiers. This can help as well. Be sure that the amplifier can be switched off. There are some instances when too much signal can cause problems as well. That’s another column.

DTV over-the-air, an inexpensive option

With more and more people buying Digital TV sets, some are confused about needing a cable or satellite service to receive the local stations’ digital channels In fact over a one week period I had two callers ask me about receiving digital TV channels over-the-air and what antenna they should get. Both wanted to get the new HD digital programs from the local stations in Cincinnati. Both wanted to know if an antenna, either indoor or outdoor, would be required.

Well, there is no easy answer. One caller noted that he lived about 40 miles north of Cincinnati. That distance places him within the potential coverage area but there are many other factors that can impact on his ability to receive DTV from the Cincinnati stations. In fact, the only way to know for sure is to actually install an antenna and see if it works. Another is to hire a technician with a signal strength meter. He or she can measure the quality of the signal and recommend an antenna. There are several models available that can work. There is absolutely no way to know “for sure” without actually installing the antenna.

Let me explain. An often overlooked by-product of the new Digital TV transmission format is the “cliff effect.” Simply put, the digital picture on your new DTV is either perfect or non-existent. With older analog broadcasting, the farther you lived from the TV transmitter the more the picture degraded, i.e. got snowy. Eventually it would be too bad to watch. With digital signals the new DTV tuner locks on to the TV signal and keeps the picture perfect until it no longer has enough “bits and bytes” of information to make a perfect picture. When that happens the picture vanishes. “It falls of the cliff.” From perfect to non-existent in an instant.

Since I don’t know if there are hills or buildings that might block or reflect the signal for the Dayton caller, there is no way of telling what, if any antenna, will work. We have two CET staff members who live in the Fairfield area of Butler County. While they live only a few blocks apart, one gets perfect reception from all Cincinnati DTV stations and the other gets none, no matter what antenna he tries.

As discussed in past posts, most people in the Cincinnati area do not receive local channels off the air. They subscribe to cable or satellite services and as such reception of local channels is part of the package. These individuals can also receive hundreds of other channels. As we get closer to the analog cut off date in 2009, more and more channels will be delivered in HD. Time will tell how many will choose to continue over-the-air only reception with the plethora of other options.

DTV over-the-air, an inexpensive option

With more and more people buying Digital TV sets, some are confused about needing a cable or satellite service to receive the local stations’ digital channels In fact over a one week period I had two callers ask me about receiving digital TV channels over-the-air and what antenna they should get. Both wanted to get the new HD digital programs from the local stations in Cincinnati. Both wanted to know if an antenna, either indoor or outdoor, would be required.

Well, there is no easy answer. One caller noted that he lived about 40 miles north of Cincinnati. That distance places him within the potential coverage area but there are many other factors that can impact on his ability to receive DTV from the Cincinnati stations. In fact, the only way to know for sure is to actually install an antenna and see if it works. Another is to hire a technician with a signal strength meter. He or she can measure the quality of the signal and recommend an antenna. There are several models available that can work. There is absolutely no way to know “for sure” without actually installing the antenna.

Let me explain. An often overlooked by-product of the new Digital TV transmission format is the “cliff effect.” Simply put, the digital picture on your new DTV is either perfect or non-existent. With older analog broadcasting, the farther you lived from the TV transmitter the more the picture degraded, i.e. got snowy. Eventually it would be too bad to watch. With digital signals the new DTV tuner locks on to the TV signal and keeps the picture perfect until it no longer has enough “bits and bytes” of information to make a perfect picture. When that happens the picture vanishes. “It falls of the cliff.” From perfect to non-existent in an instant.

Since I don’t know if there are hills or buildings that might block or reflect the signal for the Dayton caller, there is no way of telling what, if any antenna, will work. We have two CET staff members who live in the Fairfield area of Butler County. While they live only a few blocks apart, one gets perfect reception from all Cincinnati DTV stations and the other gets none, no matter what antenna he tries.

As discussed in past posts, most people in the Cincinnati area do not receive local channels off the air. They subscribe to cable or satellite services and as such reception of local channels is part of the package. These individuals can also receive hundreds of other channels. As we get closer to the analog cut off date in 2009, more and more channels will be delivered in HD. Time will tell how many will choose to continue over-the-air only reception with the plethora of other options.