The signal from your antenna may be too weak for use by your tuner. This may be due to the distance to the broadcast towers, the type of antenna, your location, geographic or structural obstructions, weather, splitters or the length of the cable. Amplifying the signal may increase the number of stations your tuner can access. Many amplifiers include multiple outputs for connecting to multiple devices.
Prior to purchasing a signal amplifier, make sure:
The cable is in good condition. The cable is no more than 12" longer than required. The connections are dry and in good condition. There are few, preferably zero, splices in the cable. The cable is the correct type. The cable is not run next to and parallel with electrical wires. Your antenna is of the correct type and pointed correctly.
Install the amplifier as close to the antenna as practical. This usually means installing the amplifier in the attic but some are designed for mounting on the antenna mast. The amplifier requires a power source, usually 120 volts.
THE CABLE IS IN GOOD CONDITION
The cable should be free of cracks, kinks and breaks.
THE CABLE IS NO MORE THAN 12" LONGER THAN REQUIRED
A service loop of 12" near the appliance allows for minor changes in the location of the appliance without splicing. The longer the cable, the more the signal is degraded so you want the cable to be as short as possible.
THE CONNECTIONS ARE DRY AND IN GOOD CONDITION
Wet or corroded connections will short out or block the signal.
THERE ARE FEW, PREFERABLY ZERO, SPLICES IN THE CABLE
Each splice degrades the signal so you want as few as possible. An amplifier more than makes up for the splice at the amplifier.
THE CABLE IS THE CORRECT TYPE
Use RG59, RG59U or RG6 coaxial cable. This will maximize the signal delivered to your device. If running cable underground, use RG59U or RG6.
THE CABLE IS NOT RUN NEXT TO AND PARALLEL WITH ELECTRICAL WIRES
Electrical wires give off magnetic pulses that will interfere with your antenna signal if the cable runs parallel with and next to the electrical wires. Avoid running the cable near electrical wires. If you must cross over electrical wiring, do so at a right angle.
YOUR ANTENNA IS THE CORRECT TYPE AND POINTED CORRECTLY
Look up the direction to point your antenna online. The same sites often tell you the distance to the towers and the type of antenna required in your area. If your broadcast towers are not in the same general area, you will need a multi-directional antenna. If your towers are grouped in the same general direction, you can use a directional antenna for increased signal strength. Choose an antenna designed for the distance to the towers. Note instructions for which end of the antenna to point toward the towers.
Amplifiers run about $20 and up. They are available at most electronics stores. You normally don't need the most expensive amplifiers. Cable runs about $40 for 100' and connections are inexpensive. Both are available at most hardware stores. Antennas run about $40 and up. Don't spend more than you must for the type that you need.
If you are not familiar with installing antennas, cable and electrical outlets, hire a professional. The cost is minor compared to a trip to the emergency room.
--Pat c 03:13, 19 October 2011 (UTC)