Mary Robinson is all about real-world information on the switch to digital television signals. The success of the DTV switch will depend on regular folks understanding new technology and getting it running in their homes. Ms. Robinson is weighing in on those nitty-gritty details, sharing her enthusiasm for TV-signal technology with those who are less technically inclined. She’s developed an expertise through years of hands-on experimentation, pulling in signals from the rooftop of her Texas home. Now she’s a resource for consumers struggling with the digital switch. We discovered Mary right here on TVWeek.com, where she reliably dispensed information in the comments section of this story, First Digital TV Converter Box Wins Government Approval about the digital switch. Let’s keep the conversation rolling!



Digital Transition Answers

So Simple Any TV Fool Can Use It

August 18, 2008 12:21 PM

I have been made aware of a most useful Web site for calculating the possibility of receiving digital television stations. TVFool.com contains a lot of useful information interpreting and analyzing just how much signal strength there will be near ground level at any address that is input to the search engine.

TV Fool will create a list of all stations that it computes are receivable at any address that is entered. A list can be created for analog signals, digital signals or a combination of the two. The list can be further configured for stations before or after the digital transition.

The list will include the station’s call sign, the actual broadcast channel, the virtual broadcast channel for digital stations, the network affiliation, the effective radiated power of the transmitter, the estimated signal strength near the ground at the input address, the distance to the transmitter, the true compass direction to the transmitting antenna, the magnetic compass direction to the transmitter for ease of aiming the antenna, the height necessary for minimal useful signal strength and the antenna height needed for “line of sight” reception of the signal. This very detailed chart is a good estimate of the anticipated successful signal reception.

Go to TV Fool’s signal locator page to find stations available for any given address.

Be aware that the signal strength values are listed or given in negative numbers. This means the lower numbers are actually the stronger signals. For an example: A station with an expected signal strength of -30 Db would be a stronger signal than a station with an expected signal strength of -85 Db.

I find that the listing of stations is more current that those listed on the Antenna Web site, although I did find that TV Fool lists only stations that are licensed or have approved applications, and not those that have applications pending.

Along with the signal locator, TV Fool offers the most detailed coverage maps I have found anywhere. The coverage maps give a color-coded overlay of estimated signal strength onto a Google map, a Google satellite image or a hybrid of both. Any station call sign can be input for a search of the coverage of the station’s signal, and you can choose analog or digital signals for the station.

The color codes can be interpreted as follows: White: Watch out for signal overload if using an amplifier. Red/Yellow/Green: Generally stronger signals that may be received with an amplified indoor or medium-gain attic or outdoor antenna. Cyan: Weaker, but still usable signals that may require a high-gain outdoor antenna and possibly a signal amplifier. Purple: Signals that are quite weak and may take some effort to receive.

I have found TVFool.com to be a fun and informative Web site, and I believe a lot of good information can be extracted from it if you are having difficulty receiving digital signals.


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Comments (10)

Beth Ventrone:

Help! I just installed my converter box. I turned it on and programed my romote controll to scann all the stations. I only recieve three stations. I tried rotating my antenna, I even bought a signal booster but nothing changes.I get channel 12 , 69, 63 and that is all. I do also have a statelite dish but it is seperate from my local stations . Any other suggestions I am already desparate .

mary... the at lady:

Hi Beth,
I rellay need some more information before I can help you figure out what tweaks may need to be made to help you get the stations you are missing. You can be sure I will help you if I can. First off, there are lots and lots of channel 12s, 69s, and 63s in the US.
I will ask you to be a bit more specific for me. If you possibly can, I need to know...

1. What are the call signs of the stations that you got before hooking up the converter box. The stations on analog.

2. What city do the stations you get come from? What is their city of license?

3. Where are you located in relation to that city that the stations come from, and how far away are you?

4.What kind of antenna are you using? If you can, describe it for me. Is it an outside antenna? Or is it a table top or attic antenna?

I need as much information as you can get me. Also, if you can go to tvfool.com and input a couple of the call signs in the online coverage maps page of that site, find about where you think you live on the map or hybrid option, please describe for me color that covers where you live for the digital stations.

If you can get me that information, I will see what I can do for you. It would also help me to know if you live in an apartment building or single family home and what the terrain is like around you.
The more information, the better I will be able to help you out.
Please post back, we will take it from there.

Bob Schwaninger:

I recently bought a Durabrand DTV1307. We use it in our garage with "rabbit ears" only. It was fine until the digital transition. When I attempt to pick-up local "digital" stations, the TV screen is blank except for the statement "low digital signal". Is this a "operator error" or do I need a new antenna? I also tried connecting an RCA converter box #DTA800, but that only made it worse.

Thank you,
Bob Schwaninger

mary... the cat lady:

Well, let's see what I can come up with...
Not knowing what market you are in or what channels you were getting before, I will have to try to guess what is going on.
The first thing that comes to mind is that maybe some of your stations have switched channels. That is going to happen a lot as stations move to their final DTV facilities. I would expect this to happen more if the stations were moving from VHF to UHF.
One other thing off the top of my head is that some of the stations are doing a final tweek of the transmitters for full power operation, and this may take a few days to work out.
If you will post back and let me know what DMA (market or city) you live in, I will do some research to see if I can give you some definitive answers.
What channels were you getting before? Are you getting any channels now? Give me as much info as you can, and I will be glad to help out. Please include call signs of the stations, it will help a lot.

Jim Thompson:

Hi, I sure hope somebody can point me in the right direction.I have a hd tv I use direct tv hd box for ota signal connected to my 40 ft tower ant. Before 2/17/2009 I received at least 12 different digital stations some from the north some from the south since 2/20/2009 NOTHING. Did my ant go bad, is it my receiver? how my tv see the channels. Jim (Everyday I clear the channels and re scan still no luck)

mary... the cat lady:

Wow Jim,
Let's see if I can give some pointers as to what to look for...
First, I want you to know that I am jealous of your 40 foot tower set up. I would love to have something like that. Congrats on a nice rig.
First thing that comes to mind is are you using a pre-amp at the antenna. If you are, most all pre-amps that I know of do not let a signal through if they lose the power supply. That would be my first suspect. Some power supplies have a LED light to show that they have power. If you do not have power, check the breaker or fuse to determine if it is blown, and that is the reason for the power supply failure. Do you have a television that you could hook directly to the antenna, even an analog one, that could help determine if you are getting signal down into the house? If you are using a pre-amp, what kind is it, and how long has it been in service? I really hope you are not using one from Radio Shack because the quality is severely lacking. They are prone to going out after only a few months service, especially in the heat. Get a Channel Master or Winegard pre-amp.
If you are getting signal into the house, then I would suspect the Direct TV box. Call customer support and report to them that you are getting signal into the house.
The next thing I would check is the signal meter for the Direct TV box. Does the box show to be getting signal?
Moisture in coax connections can kill a signal. If the braided shielding or center conductor gets corroded, you will lose all signal. That happened to me a while back. I now use a good grade di-electric grease to help maintain a good connection, as well as seal most connections with RTV or at a minimum electrical tape.
A simple thing that can happen is that the rotor can get off sync with high winds. Has that happened recently? Rotate the antenna due north to see if it is still synchronized. If not re-sync.
I know that Channel Master sells stand alone power supplies for their pre-amps. So if you have one, and indeed your power supply is the culprit, then all you will have to do is order one.
But the first thing I would do is check to see if you are getting signal into the house. That wil determine what direction you need to go from there.
Do you have any stations nearby? If you do, check to see if you are getting signal behind the pre-amp if you have one, and if you have no pre-amp, check the signal coming straight off of the antenna.
I hope this helps. Please post back with your findings, and let me know if I can do anything else for you, OK?

Jim Thompson:

Thank you for answering my S.O.S. I do have a pre amp with a led light (a winegard)it's lit.I did hook up the tv to the antenna after the pre amp.I received analog ststions from about 40 miles away.So would the problem be the direct tv box that I was using to get hd?. I don't use the direct tv service just the decoder for ota.My rotor does not work,When the antenna man was here we just pointed in the direction to get the most channels and locked it in place.If I got a converter box would that do the same thing as the dtvhd box? Jim Thompson

mary... the cat lady:

Hey Jim,
Since you were using the Direct TV box just for OTA HD, and your digital channels just suddenly disappeared, and you were still able to get analog channels clearly, then I would suspect the Direct TV tuner has gone bad.
The converter box would do much of the same thing as your Direct TV HD tuner would do, except that it would not be in HD, only stanadard definition. That being said, it would be an inexpensive way to determine if it is the Direct TV tuner that is bad.
If you can get your hands on a converter box, just hook it up to the antenna and then to the TV to see if you are getting digital channels. If you are, then that would answer the question.
However, one more thing that I would suggest is to hooking the Direct TV box up to your TV another way if you can.
What I am saying is that if you have it going to your TV via a HDMI cable, then try hooking it up with component cables, or try just hooking it up to the TV with A/V cables. Just try different ways of getting the signal to the TV. My cable box is a HDTV box, but if I wanted to I could hook it up to a TV just using coax. It would not be in HD, but it would still tell if the tuner was doing its thing.
Are you sure that the antenna hasn't moved? It probably has not, but I just want you to make sure. Even though the motor on the rotor doesn't work, doesn't mean that the rotor won't turn in a a good wind, and the antenna has to be pointed pretty much exactly right to be able to recieve UHF signals from 40 or so miles away. Please check it closely.
The first thing that I would do after checking the direction of the antenna would be to see if someone you know has a converter box that you could borrow for a while to see if indeed the channels come in.
In case that the converter box works, then I would suggest that you go ahead and order your coupons and purchase two boxes to have as back-ups in the event that you purchase another HD box, or to use in the interim. Even if you had coupons at one time and they expired, you can re-order coupons to replace them thanks to the stimulus package.
I hope this helps, and I would really like to know how this all turns out, so please post back and let me know.

Jim Thompson:

Mary you are one very smart cat lady. I ordered the converter box coupon,bought the box hooked it up and wa la. I'm back to getting all the former channels plus one.There not in HD I'll just have to look for a old sat hd box to get ota hd.Couldn't have done it with out you. You were purrrrfect thanks, Jim

mary... the cat lady:

That is so sweet. Thank you, and I am glad I was able to help.

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