HDTV Antenna for Converter Box?

Question

I recently bought a digital converter box for my old analog television (32 inch). We do not have satellite or cable subscription but we have a old outdoor antenna on top of the roof hooked up to the converter box.

I found out after scanning and tunning the channels that we only get a few local channels in the area from the digital converter box. Before we receive all the channels from our local area with the outdoor antenna. Does anyone know if a HDTV anntenna is required to get all their local channels or can you use your old outdoor antenna ?. Why doesn't my old outdoor antenna get all the channels when connected to the converter box ? It did before.

Answer 1

Your old analog antenna mounted on the roof was designed to receive specific frequency ranges that were/are being used for broadcast TV.

The new digital broadcasts are -not- all within the same frequency spectrum your antenna was designed to receive.  Some are, but not all.

Getting a HDTV antenna is merely a new antenna designed to receive the new frequency range of HD broadcasts, and should work better than your existing roof top antenna.  Some have automatic tuners built-in to electronically modify the physical length of your antenna collection area to adjust for the various frequencies.

Think of using a CB radio antenna for your FM stereo; it will pick up some stations but not all - and not as good as a FM antenna.  Or an AM Loop antenna.

The "piece of metal" that is an antenna is very important for reception principles, typically engineered to be in 1/4 wavelength divisions of the transmitted signal.  Too long or too short and your signal reception suffers immensely.

Answer 2

Your old TV antenna should work just fine, if the connections are are good and it is aimed the right way. (the front has the short elements)

Enter your latitude and longitude into the spaces provided in the web page below (there are links in the fine print at the top to help you figure out your latitude and longitude).  When you do that, the web page below will give you a lot of information on the digital tv stations in your area, including their transmit power and direction.

Use that info to make sure your antenna is aimed in the right direction to get the stations you are missing.  A few degrees can be the difference between receiving a weak station and not.

It might be that the stations you are missing aren't transmitting digital yet. Or, they maybe transmitting at low power until a new transmit sight is built or something.  Antenna web is another source for similar information.

Answer 3

There is no such thing as an HD or DTV antenna. It is a piece of metal, it doesn't care what the signal is, analog, digital, Morse code, anything. It just needs to be properly tuned, oriented the correct way, and offer enough signal quality for desired results. There are better and worse antennas.

An antenna needs good enough performance to exceed a threshold known as the digital cliff. DTV is basically all or nothing. If you get a clean picture for analog it should work just fine for DTV. If your analog picture is somewhat fuzzy DTV may be difficult. If analog is poor DTV will not work.

There's a few things that can be happening.

1. Your antenna is only good enough to give you a signal you find adequate for watching analog TV, but isn't enough for DTV.

2. The stations are not transmitting the DTV signal from the same place. This happens quite a lot.

3. The stations' DTV signals are weak, this happens too, and should be corrected after the analog shutdown.

4. The band in use may be different. Digital TV is not "on top" of the analog, it is on completely different channels. If you have  a VHF only antenna for example and the DTV stations are all on UHF it probably won't work very well. Most DTV stations are in UHF. An analog station on channel 7 might have it's digital on channel 40, or vice-versa.

5. They may not be on the air yet. Most stations have their digital up and running, and have for some time. But some haven't yet done it.

If none of the above, either the box or connection is defective or you have connected it incorrectly.

You can try this, go to http://antennaweb.org

You need only enter a zip code. Uncheck to the two option boxes. It will give you a reasonable idea of what is happening with the stations in your area. You can also look them up in the FCC database at http://www.fcc.gov/mb/video/tvq.html