If you are in a hilly area, far from TV transmitters or have a large number of TV sockets you may have issues with weak DTV signal causing breakups and loss of reception. One potential solution to this is to install a TV Masthead Amplifier or a Distribution amplifier. In this article I’ll discuss the types of RF Amplifiers used for Digital TV.
What’s the Difference Between a TV Booster and a TV Amplifier?
They’re all basically the same thing. These devices all take Digital TV signals from your antenna and increase the signal level so that you can get better reception. Here’s some names you may hear them called:
- TV Signal Booster
- TV Signal Amplifier
- Masthead amplifier
- Masthead booster
- RF Amplifier
The key thing is that they take signals on the Australian VHF and/or UHF TV bands and boost the signal level.
Masthead amplifiers, as the name implies, are typically installed on pole or mast that holds your TV aerial. The idea of this is to have it as close to the antenna as possible so that the amplifier receives the best quality, highest strength signal it can. A cable is connected from the antenna that loops into a grey weatherproof box holding the amplifier circuitry. A cable comes out the other side of the masthead amp which then goes to the splitter and sockets in the house.
Masthead amplifiers typically have F sockets for cable connection and are fastened to the pole with a large cable tie. They are powered by what’s called phantom power. This is where low voltage electrical power, either AC or DC, is sent up a TV cable from a socket to power the unit. This means it doesn’t have to have a separate cable to supply power.
For information on how to install a Masthead Amplifier for Digital TV see the How to Install a Signal Amplifier for Digital TV tutorial article.
Distribution amplifiers are very similar to Masthead Amplifiers, except typically they’re installed in the ceiling or some other communications cupboard. Distribution amplifiers typically have higher amplification and better quality than Masthead Amplifiers, although these days many masthead amplifiers do call themselves Masthead Distribution Amplifiers(denoting better quality). They are typically used in large installations where there are more than 6 TV sockets. They connect into the system in a similar way to Masthead Amplifiers, with a cable in from the aerial and a cable out to the splitter connecting with F connectors. Some older Distribution amplifiers have integrated splitters.
Distribution amplifiers can be powered in a couple of different ways. They can use phantom power, where the power is sent from a plug pack via one of the TV sockets. They can also have their own power supply plug pack that goes directly in the amplifier. You will sometimes see dedicated power sockets installed in ceilings just for this.
AC or DC?
Where a TV amplifier is powered by phantom power via a TV socket on the wall, there are two types of power supplies that may be used either DC or AC. The type you have to use will have to match the requirements of the amplifier as some will only take one or the other. You also need to ensure you are using the right voltage. Kingray Amplifiers typically use an 18V supply, with older ones requiring AC but most newer Kingray amplifiers use DC. If you don’t have the original manual, packaging or installation guide the easiest way to find out what you need is to open the amplifier enclosure. The weatherproof box will open with a clip, although some will have another metal box inside you’ll need a screwdriver to open. Marked somewhere on the circuit board will be a voltage and current type, DC or AC. You can then purchase a suitable power supply if required.
Another thing to consider when buying an amplifier power supply is to make sure you get the right connector type. Most homes use PAL BG sockets for TV, so to plug it in you’ll need a PAL Male plug on the power supply. If you use F sockets then you’ll need an F type. I have also seen in some cases where installers have run the wire from the plug pack to the injector box into the area behind the socket inside the wall to prevent it being unplugged. In this case they would typically be using F connectors.
Drawbacks of Amplifiers
There are reasons why you shouldn’t use an amplifier where you don’t need to. Amplifiers introduce a point of failure. They can be susceptible to lightning damage, even if it’s not a direct hit. A nearby lightning strike can be enough to fry them. Also amplifier power supplies can fail or get unplugged or lost. The other issue is that you can have too much signal. Too much signal can introduce reflections and other interference issues in your cabling. So for these reasons I’d only use an amplifier if you need to due to weak reception in your location.