Contemporary Research QDA4-45 RF Distribution Amp Combiner is an amplified RF combiner that can switch between one or four inputs, with adjustable amplification up to 32 dB of gain. Designed for QMOD HDTV applications, the QDA4-45 can receive an RF feed from QMOD modulators or QCA9-33 Active Combiners. Inputs can be switched between one or four inputs, with selectable gain. The compact QDA4-45 mounts in a single rack space using either the Contemporary Research RK1 single rack mount kit or RK2EZ dual rack mount kit. The units are wholly designed and manufactured in the USA.
 
Features
Switches between one input or four input combiner
Adds up to 32 dB gain for one input, 25 dB for 4 inputs
Front-panel gain adjustment and LCD level display
Provides a maximum output level of up to 71 dBmV
Wideband, low noise amplifier
Low power, draws less than 8.5 watts
Compact metal enclosure, mounts in 1 RU using the RK1 or RK2EZ rack mount kits

Applications
Combine up to 4 QMOD Modulators
Combine 4 QCA9-33 Active Combiners for 36 channels
Use as launch amp for RF system
Use as booster amp to merge QMOD channels with existing 50 dBmV analog modulator systems