There are 3 types of TV signal amplifiers; preamplifiers or preamps, booster or power amps, and distribution amps.
| Type | Specs | Use |
|---|---|---|
| Preamp | High Gain, Low Noise | Weak Antenna Signals |
| Booster Amp | Moderate to High Gain | Long Cable Runs |
| Distribution Amp | Low to Moderate Gain | Replace Signal Splitters |
 ClearStream JUICE UHF VHF Antenna Amplifier
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 PA18 UHF / VHF Antenna Pre-Amplifier Kit
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Preamps increase signal power but not noise (as much). Signal improvement depends on the preamp Noise Figure (NF), and gain. Additionally, the closer the preamp is to the antenna, the better the signal improvement.
NOISE FIGURE
Noise figure is a measure of the noise an amplifier introduces to a signal. The less noise the lower the noise figure, and the greater the signal improvement. Published noise figures are often based only on the amplifier, not the preamp housing input and output connections and internal cabling loss. Noise figures vary from 2 to 4 dB or more.
FREQUENCY and GAIN
Some preamps have an adjustable gain, others are fixed gain. Gain varies from 10 to 30 dB. Most preamps cover the VHF and UHF frequency bands. Some cover VHF-Hi and UHF, some only UHF.
FILTERs
FM Trap -- Some preamps have the option to switch in an FM Trap to filter out the commercial FM radio band which is between RF channels 6 and 7 (VHF band).
The filter is needed when an FM signal is strong enough (a close FM transmitter) to overpower the preamp, preventing TV reception or reducing performance.
Some FM traps slightly reduce RF channel 6 reception (VHF).
4G/5G Filter -- Also called cell filters, these preamps have the option to filter out cellular 4G and 5G mobile communication in the UHF band. A 4G/5G filter may be needed if you're close to a cell tower.
| Parameter | Options |
|---|---|
| Frequency Band |
• VHF / UHF • VHF-Hi / UHF • UHF |
| Gain | • 10 to 30 dB • Fixed or Adjustable |
| Noise Figure | • 2 to 4 dB |
| Filters | • FM Trap • 4G/5G Filter |
OUTDOOR PREAMPs
Outdoor preamps are 2 separate units, an amplifier mounted close to or on the antenna, and a power unit inside the home that supplies power to the amplifier through the coax cable.
The power unit uses standard house current (110-120 Vac), and supplies direct current (DC) power to the amplifier through the coax cable center conductor. There can only be cable between the preamp and the power unit. Coax ground blocks and cable connectors can be used if they pass DC power (most do). Do not use splitters / combiners or impedance matchers, they block power and the power could damage them.
INSIDE PREAMPs
Some indoor antenna preamps are attached to the antenna, some are detachable (optional). Some preamps are connected in the cable between the antenna and television. The preamp power comes from house current (110-120 Vac) or a USB connection.
BOOSTER AMPLIFIERS
Booster or power amps are high gain amplifiers (20 dB or more) used to overcome long cable runs and/or signal splitter loss. Some are fixed gain, some have an adjustable gain. The amps are powered by 110-120 Vac standard house current.
DISTRIBUTION AMPLIFIERS
Distribution amps are fixed gain amplifiers (3 to 8 dB) with multiple outputs. These amps are used instead of signal splitters to overcome signal loss. The amps are powered by 110-120 Vac standard house current.
 8-Output TV CATV Distribution Amplifier
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ATTENUATORS
A very signal strong signal can overwhelm (saturate) a TV receiver, causing signal distortion (inhibits reception). An attenuator can reduce the signal to an acceptable level. Signal attenuation varies from -3 to -10 dB or more. Some attenuators have a fixed reduction, some are adjustable.
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Amplifiers |