The Difference Between High Gain, Boosters and Amplified TV Aerials
| Reuben Howe
When it comes to TV reception, you want the best aerial for the job. There's few things more mundanely irritating than putting your feet up in your camper, RV, or just sofa at home and then having to get up to muck about with an aerial for 10 minutes before you can relax.
Despite an array of modern wireless tech, from Bluetooth to Wifi and mobile phone signals, digital TV transmission hasn't changed in years. This is partly to its credit as a stable system, but also has resulted in a number of gadgets and gizmos being invented to try and maximise this now old-fashioned transmission.
3 main developments to maximise TV signal are High Gain devices, Aerial Boosters and Amplified Aerials.
What is high gain, and how does it compare to using an aerial booster or an amplified antenna? Let's demystify these 3 TV enhancing tools!
1. High Gain TV Aerial
All aerials have an amount of "Gain". Gain affects an aerial's effective range.
Overall, gain simply extends the range of an aerial in one particular direction, by "stretching" the volume of reception.
Imagine having a rubber band on a table, then pulling opposing sides at once. This is a demonstration of what high gain does to an aerial signal:
Low Gain TV Aerial:
As you can see, the rubber band rests in a circle shape. But, when I pull the ends to extend how far away the rubber band can reach, the sides get pulled in!
This is because the same amount of rubber band has to cover a larger vertical distance, so cannot also cover the same amount of horizontal distance as before.
A High Gain aerial "stretches" the signal on the same way I did the rubber band.
Yes, the maximum distance increased from around 10cm to around 14cm, but it also made the coverage much thinner.
So, a high gain aerial inherently becomes a directional aerial, too. Since adding gain makes the aerial reach further, but only in one specific direction.
High Gain can be achieved through the actual physicality and engineering of the wire and panels in an antenna unit, without needed extra components. For example the DTA600 achieves 8dBi of gain with no extra requirements than the DTA240, which achieves only 4dBi.
2. TV Antenna Booster
A "booster" is another way to get more juice into your aerial and potentially improve results.
An aerial "booster" (or "aerial amplifier") is an attachable unit usually acting as an adapter between your aerial and your decoder device (Set Top, TV, etc).
The booster can't just add a load of power and give you perfect results, as increased reception sensitivity is subjective.
You might want someone to use a megaphone when they're a football pitch away from you, but not so much when they are in the same room...
In the same way, boosters can sometimes cause more trouble than they are worth.
Even television antenna amplifier isn't made specifically for your specific aerial, transmitter and decoder which can cause incompatibilities and mistakes. Since TV systems rely on specific waves, using a booster which is not suited for your system can actually kill your reception rather than improve it.
3. Amplified Aerial
The final option, then, is to use a pre-constructed amplified aerial. Unlike a standalone booster or amplifier, which attaches as an adapter for an existing system, an amplified aerial is built with the amplifier internally.
This means less cables, and the aerial is guaranteed to be supplied the correct amount of power to actually reliably increase signal reception with no risk of ruining any of the sensitive systems like a booster can.
An amplified aerial will need power, or draw it from the coaxial in some cases, so does have that extra requirement when compared to a High Gain aerial which focuses on physicality and antenna design alone.
But, for the little extra power you do supply, an amplified aerial can become 5 or 6 times as efficient. This means you can get clear signal from further away from a transmitter, or in an area relying on reflected signals.
The DTA300, for example, goes from resting at 3dBi gain unamplified to 28dBi gain amplified!
Choose High Gain and Amplification When You Need It
The differences shown between high gain, boosters, and amplified aerials make it important that you decide based on your individual use-case. It might be you wouldn't benefit from a booster as you have multiple other signal sources nearby, or you wouldn't benefit from high gain as you aren't sure which direction the transmitter is in.
The most important thing to remember is energy is that your antenna system is like the rubber band, and expanding the range will always draw from somewhere else! Sometimes this is needing voltage and power supplied, sometimes it is restricting the reception in all other directions.
That trade-off is vital to understanding how high gain, boosters and amplified aerials achieve the same goal in different ways.
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