digital tv reception

#1
I have an antenna in my attic and my reception with the converter box is just so-so. I was wondering if I put my antenna on the roof and added an amp booster, if my reception of borderline channels be improved? Don
 

Jason Fritz

Administrator
Staff member
#2
I have an antenna in my attic and my reception with the converter box is just so-so. I was wondering if I put my antenna on the roof and added an amp booster, if my reception of borderline channels be improved? Don
Hi Don,
Antenna boosters are generally considered bad for DTV and HDTV reception. Amplifers/boosters will help boost the broadcast signal, and at the same time, magnify signal "noise" , cancelling out the benefit of the boosted signal.

With that said, every DTV reception situation is unique, so I wouldn't rule out trying an inline booster all together.

I'd recommend buying one from a store with a good return policy, just in case reception doesn't improve after the install.

You also mentioned moving your antenna on the roof? This should drastically improve your reception. Some of the building materials (such as metal and electrical conduit) inside of attics can limit reception of broadcast signals. If your current antenna is already rated for outdoor use, it'll be a pretty cost effective means to help improve your signal reception.

Keep us updated if you can with whichever route you decide to go.
 

bugz71

DTVUSA Jr. Member
#3
I would have to agree, I have heard that boosting is not good for HDTV either and I would never personally try it. But it might just work in your case. I am not sure I would try it but it is up to you.
 

Sparks

DTVUSA Member
#4
Antenna Location - Antenna Amplifiers

I live in a rural area so I would have never considered trying to receive a TV signal without the booster. I have distances of up to about 75 miles to some of the stations broadcast towers. Without the booster, antenna amplifier or what ever name that you wish to use. I would only get one TV station instead of the fifteen digital stations that I now get. If the TV stations in this area follow their plans we will have even more channels to view after February.

I have seen and tried amplifiers that did not make a difference in reception quality. I have seen some where the reception was better without the amplifier. I always try to use a quality product such as Winegard or Channel Master to get a device that works properly. These companies also have some cheaper signal boosters that are not all the great. There is probably other companies with excellent products.

If you live in or near a city where you have some channels with a very strong signal and you also have some stations available that would come in better with the amplifier. A booster could over amplify the stronger local channel. You could use a separate antenna without a booster for the stronger signal. You could then flip a switch to change antennas or you could put a splitter combiner on the two antennas. The problem with a standard combiner is that it may degrade your signal. Power splitter combiners are available that will do the same job without the signal loss. The powered ones would plug into a wall outlet.

Normally with a booster that is rated to amplify no more than 15 dB. It will usually not cause a problem with the near by stations with the strong signals. That way you can keep it on one wire on one antenna and not have to suffer the signal loss or expense associated with splitters and combiners. Most TV transmitting towers are set up to put the signal over the nearby receivers so as to not produce to much signal strength to them. The FCC does not intentionally allow transmitters to block other TV and radio signals that are considered to be in your local area.

If you set out to buy a booster or for that matter an antenna you first need to determine what channels you want to get. There is no point in buying equipment that is designed for channels you will never get, especially if it costs more money. Stations or other channels may become available in the future. At the same time antennas do not last forever.

With digital TV the actual channel number is probably not the same number that your tuner indicates. Channel 11-1 is not necessarily on channel 11.
An example of this is that my local analog channel 11 is of course channel 11, at least until February of 09. The same program on digital channel 11-1 and their new channel 11-2 is really broadcasting on channel 38 if I recall correctly. The TV stations signal includes information to the digital tuner to tell it that 11-1 & 11-2 is really on 38. My DTV box is automatically locked into 38 for the 11s. If I turn my antenna toward another city with there is another channel 11. That channel 11 will be on yet another channel say 42. So to get that channel 11-1 I would have to do a scan for the DTV box to locate it on 42. When I turn back to the original channel 11. I have to do another scan to again get channel 11 on channel 38.

I will also mention that this is exactly the way it works with my Channel Master converter box and with my Sanyo 19 " HDTV. Even when I do not do the scan for the other city both of them will sometimes change frequencies all by themselves. It is then necessary to do another scan to get what I want.

My Zenith DTT901 can be set to both of the channel 11s in the two different directions. With the 901 I can have two or more channel 11-1, 11-2 and so on. The 901 box knows the difference and which is which so I can view either one of them that I select without any additional scans. Obviously, I may only get a signal on the one that the antenna is pointing at.

The point of this is that you may need to select antenna equipment for the real channel numbers that is not necessarily the number indicated on your tuner. An antenna designed for say channels 8 through 59 will normally do a much better job pulling in the stations within that range than with a larger antenna. A bigger antenna designed for channel 2-83 would not normally do as good a job of pulling in the signal of the same channels that are between the 8 and 59. By bigger I am referring to more elements on the antenna to get the addition channels.

Here is an example of a partial list of channel numbers for the Rockford Area.

Rockford Area HDTV Channels
Station WREXDT Channel 13-1 RF Channel 54 Network NBC
Station WREXDT2 Channel 13-2 RF Channel 54 Network CW
Station WTVODT Channel 17-1 RF Channel 16 Network ABC

RF stands for Radio Frequency and in this case it indicates the actual broadcast frequency.

I do not live in Illinois. This is from a list that I found on the internet for Chicago area digital TV channel frequencies at http windycityhd.tv . You should be able to find something for your area on the internet. If not you can certainly find out from the engineering department of the stations that you wish to watch.

UHF and digital signals are not like the analog VHF signals that are just about everywhere if it is there at all. One end of your roof may be a better place for the antenna to get a good signal than the other end of the roof may be. The best way to find this out is to take a Field Strength Meter set for the stations that you want to get and then find where the signal is best. Since a meter of this type starts at about $135 you may prefer to move the antenna around some holding it in your hand before you install it. To just put it on the roof will not necessarily be a location for the antenna to even get a signal.

To find out if a new antenna and/or antenna booster will probably work. It is not really necessary to try it to see if it works. The engineering departments with the TV and radio stations know where there signal is going. Some of them list that on a map on their websites. All of them have this information available even if it is not on that stations website. This way you know what is really there to set up your equipment to receive. If they indicate that their signal is available to you it most likely is.

An example of a stations coverage map in South Dakota can be viewed at www kdlt.com/coverage.html . If your stations do not put these maps on their website you should be able to find out what you want to know or get a copy of the map by sending an email to their engineering department listed on their website.

I think that you will normally get a very fast and courteous reply. The technical people do not normally have contact with the public and they are usually very open to requests for information. Chief Engineers usually like to talk about (and brag about) what they are responsible for. Every ship had one of them and still does, just like Scotty who is the chief engineer on the Enterprise. TV & Radio stations also have people like this.

If you look at the coverage area map for the South Dakota station that I mentioned above. The tower for any area is obviously in about the center of that area. I can pretty much guarantee you that by the time you get two counties more or less away from the center of any of these Analog, Digital or HDTV signal areas. You will need a signal amplifier or booster to have a dependable TV signal.

Just in case somebody does not already know this. The new "Smart Antennas" are now available. I do not think that they are yet available for fringe area use. They can be controlled by some of the DTV boxes on the market today that have that option.

Digital and analog signals have a tendency to vary some. To keep your antenna pointed in a direction for the optimum signal strength. You may have to slightly rotate that antenna a few times a day to maintain the strongest signal possible of any one station. This is what the smart antenna is supposed to do for you automatically.

I am not recommending the smart antenna since I do not think that it has enough range to work in many peoples situations. I just wanted to point out this information since you will probably run across reference to the smart antenna.

You can see a picture of a smart antenna and read more about it at www solidsignal.com. Then just type "smart tv antenna" in the search area.

Companies that retail the antenna products do not necessarily carry every product available. It may be to your advantage to first go to the Winegard or Channel Master company web sites to read about the entire product lines that you are interested in. You can note the model numbers you are interested in and then set out to find the product best suited for your needs.

Probably the person that knows what works the best in your area is a local TV shop. Before you talk to them I would suggest that you first do some reading and learning so that you can tell if they know what he is talking about and if it is the truth. Many of them now days will tell you that an antenna will not work and you need to subscribe to a service such as satellite or cable TV. What they are really after in probably all situations is just the residuals for selling the services to you.

There are a lot of variables to consider when installing an antenna with an amplifier for it to work the best that it can function. It is very discouraging to spend the money and go through the work for all of this and then learn that it will not work properly.
 

Jason Fritz

Administrator
Staff member
#5
Great post Sparks

There are a lot of variables to consider when installing an antenna with an amplifier for it to work the best that it can function. It is very discouraging to spend the money and go through the work for all of this and then learn that it will not work properly.
and well said. Lets face it, most consumers are at a disavantage with the lack of proper equipment to test and diagnose dtv reception. I applaud the government for making an effort to inform everyone about the transition to digital television...

The next step, is helping everyone receive the dtv signals without interruption or problems.
 
#6
I agree with what is said in my experience the pre amplifiers that mount at the antenna on the mast are best, if the signal is to strong you can add a signal overload attenuator inline which will reduce the signal by 5db these are about 4.00 at radio shack. the channel master titan 7777 is best for uhf/vhf antennas I use a wine guard ap-4800 for uhf antennas or you can use the wineguard ap 2880 if you use both type of antennas stacked this has a input for uhf and an input for vhf.:)
 
#7
Antennas and amplifiers

Amplifiers should be used if you have a long cable run (over 75-100ft) or a splitter. If you receive a poor signal, then the amp is just going to amplify a poor signal. A splitter reduces the signal strength 50% to each TV. To get a better signal you can either raise the height or get a larger antenna.
Hope this helps.
 
#8
there is a difference between pre amps and distribution amps the pre amps mount at the antenna and boost the weak signals at the antenna to the tv. distribution amps only boost the signal for long runs but are noisy so they distort the signal. pre amps have noise filters so that they don't distort the signals. however if you have a transmitter closer than 30 miles then the preamp could cause problems for that transmitter.:)
 

Neil

DTVUSA Rookie
#9
Question about Distribution Amp with TV Antennas

I have a question about using distribution amplifiers for boosting antenna signals for long coax runs.

I have a new VHF/UHF antenna from RadioShack, rated for metro or suburban use, installed in my attic. I have coax cables running to 2 TVs, one 25' (no splitter) and one 53' (with one splitter at 50'). I have good reception on digital and analogue stations. I intend to add another coax cable of 100' length to reach a basement TV. Figuring such a long run needs an amplifier, but before fishing the 100' cable, I bought a Radio Shack distribution amp (15db) to install in the attic. But when I plugged the antenna input and the 25' and 53' coax cable outputs into the amp, I ended up with *no signal* at either TV. It's not the amp, because I tried a second one with the same result. And the electric supply is not the problem.

What makes this puzzling is I installed the very same model antenna and the very same model amplifier in the attic of my other house (outer suburbs), also connected to the very same cable -- 25' (no splitter) and 60' (one splitter at 50') coax. That house now has good signal, when it had poor signal without amp. So I have two houses with the very same equipment and set-up, and the first house goes from bad signal to good when I add the amp. But the second house goes from good signal to *no* signal when I add the amp. The only difference is the first house is outer suburbs (20-30 miles to transmitters) when the second is close-in suburbs (3-12 miles to transmitters). Both analog and digital signals are affected. Are there some peculiar ground rules about distribution amplifiers for boosting TV antenna signals to household jacks? Any guidance would be appreciated.
 
#11
I have a question about using distribution amplifiers for boosting antenna signals for long coax runs.

I have a new VHF/UHF antenna from RadioShack, rated for metro or suburban use, installed in my attic. I have coax cables running to 2 TVs, one 25' (no splitter) and one 53' (with one splitter at 50'). I have good reception on digital and analogue stations. I intend to add another coax cable of 100' length to reach a basement TV. Figuring such a long run needs an amplifier, but before fishing the 100' cable, I bought a Radio Shack distribution amp (15db) to install in the attic. But when I plugged the antenna input and the 25' and 53' coax cable outputs into the amp, I ended up with *no signal* at either TV. It's not the amp, because I tried a second one with the same result. And the electric supply is not the problem.

What makes this puzzling is I installed the very same model antenna and the very same model amplifier in the attic of my other house (outer suburbs), also connected to the very same cable -- 25' (no splitter) and 60' (one splitter at 50') coax. That house now has good signal, when it had poor signal without amp. So I have two houses with the very same equipment and set-up, and the first house goes from bad signal to good when I add the amp. But the second house goes from good signal to *no* signal when I add the amp. The only difference is the first house is outer suburbs (20-30 miles to transmitters) when the second is close-in suburbs (3-12 miles to transmitters). Both analog and digital signals are affected. Are there some peculiar ground rules about distribution amplifiers for boosting TV antenna signals to household jacks? Any guidance would be appreciated.
Neil,
Like Jay said, the distribution amplifier needs to be connected before the splitter. That's one of the ground rules that I know about. I've got a 40' coax run that works just fine with out an amp, but 100' will definitely require some kind of amp to boost the signal. Is there any difference between your two houses and those connections at all? How close to the antenna is the booster at both locations?
 
#12
I have a question about using distribution amplifiers for boosting antenna signals for long coax runs.

I have a new VHF/UHF antenna from RadioShack, rated for metro or suburban use, installed in my attic. I have coax cables running to 2 TVs, one 25' (no splitter) and one 53' (with one splitter at 50'). I have good reception on digital and analogue stations. I intend to add another coax cable of 100' length to reach a basement TV. Figuring such a long run needs an amplifier, but before fishing the 100' cable, I bought a Radio Shack distribution amp (15db) to install in the attic. But when I plugged the antenna input and the 25' and 53' coax cable outputs into the amp, I ended up with *no signal* at either TV. It's not the amp, because I tried a second one with the same result. And the electric supply is not the problem.

What makes this puzzling is I installed the very same model antenna and the very same model amplifier in the attic of my other house (outer suburbs), also connected to the very same cable -- 25' (no splitter) and 60' (one splitter at 50') coax. That house now has good signal, when it had poor signal without amp. So I have two houses with the very same equipment and set-up, and the first house goes from bad signal to good when I add the amp. But the second house goes from good signal to *no* signal when I add the amp. The only difference is the first house is outer suburbs (20-30 miles to transmitters) when the second is close-in suburbs (3-12 miles to transmitters). Both analog and digital signals are affected. Are there some peculiar ground rules about distribution amplifiers for boosting TV antenna signals to household jacks? Any guidance would be appreciated.
dtv is affected by noise most radio shack amps have a lot of nosie look for a amp that has less thaa 2.0 noise level. put a pre amp at the antenna instead of a distribution amp in the house. they are lower noise and help to boos the antennas ablity. also if there are close transmitters then both amps will overload the signal. go to tvfool.com put in address and attach the results to your next post I can tell you more then.:)
 

Neil

DTVUSA Rookie
#13
The amp is plugged in ahead of the splitter. The configuration goes like this: Antenna, 5' coax to amp input, two separate coax leads out from amp (2 spare outputs capped). Then one coax lead goes 25' to TV#1. The other goes 50' to splitter, then out of splitter 3' to TV#2 and 18' to TV#3. The amp is a RadioShack stock #15-2506, 1-to-4 bidirectional distribution amplifier for CATV or antenna. Rated for 4db. Website: 1-to-4 Bidirectional Cable-TV Amplifier - RadioShack.com.
 

Neil

DTVUSA Rookie
#14
The two house configurations are identical. In the house where the amp was a success (making weak signals good), it's attic antenna, 8' coax to amp input. The first coax output goes 25' to TV#1. The second coax output goes 50' to a splitter, then another 10' to TV#2. The antennas are the same model. The amps are the same model, and the coax are the same type (all using factory connections).

The house with the problem, however, is much closer to transmitters. I'm attaching the tvfool results.
 

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