Selecting the proper signal amplification for rural TV reception.
Once the proper antenna is selected for rural TV reception the next step in the process is signal amplification. Proper signal amplification is more important than most people realize. The first thing to understand is this. Signal amplifiers do not make the antenna work better. Proper signal amplification can improve the results but the performance of the antenna remains the same. The function of signal amplification is to boost the signal the antenna is producing to compensate for signal loss created by getting the signal from the antenna to the TV(s). This is called "signal attenuation" This includes the length of coax cable between the antenna and TV(s) and signal splitters.
Here are a few things you should be aware of when it comes to signal amplification.
- You can't amplify a signal into existence that the antenna is not receiving.
- Too much signal amplification can be just as bad for reception as not enough.
- Signal amplifiers are not created equal.
There are two specifications you should look at when selecting a signal amplifier.
- The amount of signal amplification produced by the amplifier. More isn't always better.
- The amount of "noise" added to the signal during the amplification process. 1 -3 dB of noise is excellent. The lower the noise figure the better. This is especially true in rural areas. If the amplifier doesn't state the noise figure save your money.
The amount of signal amplification a signal amplifier produces is referred to as "signal gain". The gain of the amplifier is measured in decibles (dB). The higher the gain number the more amplification the amplifier produces.
The "noise" figure is also measure in decibels (dB). the lower the "noise" figure the better. For TV reception in rural areas the amount of "noise" produced by the amplifier becomes a critical factor.
Below are a few examples of proper signal amplification for rural TV reception.
When supplying 1 TV or 2 TVs using a 2 way signal splitter I recommend the LNA 200 preamplifier. This preamplifier produces 18 dB avg. of signal gain with an ultra low 1 dB noise level. Signal splitter cause signal loss. The more times the splitter divides the signal the greater the signal loss becomes. This is not a bad thing as long as proper signal amplification is in use. Remember the function of the amplifier is to get the signal from the antenna to the TV(s) without loosing signal strength while adding minimal noise to the signal. Signal amplifiers for rural TV reception located near the TV do little good when compared to a preamplifier located near to the antenna.
In the example above there is a 2 way signal splitter in line. The 2 way splitter causes a 3.5 dB signal loss when inserted in line. It doesn't matter if the second port of the splitter is connected to anything, or it the TV is on or off, the signal loss still occurs. It's called "insertion loss".
Now consider the coax cable from the antenna to the TV. Using a quality solid copper RG 6 coax cable a 100 foot length of coax cable will cause as much as 5 dB of signal loss. More if an inferior coax cable is in use.
Best performance is obtained when the signal amplification in use is 5 dB to 10 dB greater than the loss that occurs between the antenna and TV(s).
Lets add up the signal loss from the example above.
100 feet of RG 6 solid copper coax cable 5 dB.
One 2 way signal splitter 3.5 dB.
Total 8.5 dB of signal loss between the antenna and TV.
The recommended LNA 200 preamplifier provides 18 dB of signal gain resulting in a plus 9.5 dB. That's perfect for the best possible TV reception in rural areas.
When supplying 3 to as many as 8 TVs in rural reception areas in addition to the LNA 200 preamplifier I recommend the LNA 100 ultra low noise signal distribution amplifier. This unit provides 20 dB of signal gain with only 1 dB of noise. The LNA 100 installs in line just before the signal splitter on the antenna side of the splitter. Take a quick look at this > and then come back.