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The Contemporary Research QDA4-45 is an amplified RF combiner that can switch between one or four inputs, with adjustable amplification up to 50 dBmV. You can add up to 32 dBmV gain for one input, and 25 dB for four inputs. Designed for QMOD HDTV applications, the unit 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. This compact unit mounts two-across in a single rack space using CR RK1 and RK-2 rack kits (available separately), and can be mixed with QMOD HDTV modulators using the same rack kits.
QMOD HDTV modulators
QCA9-33 active combiner
Switches between one input or four input combiner
Adds up to 32 dBmV gain for one input, 25 dB for four inputs
Adjusts RF gain from front-panel controls and LCD display
Provides a maximum output level of up to 50 dBmV
Wideband, low-noise amplifier
Low power, draws less than 8.5W
Compact metal enclosure, mounts 2 across in 1 RU using RK1 and RK2 rack kits (available separately)
Made in USA
Use the QDA4-45 as a 4-channel, 45 dB amplifier for larger RF applications
Combine up to four QMOD modulators
Combine four QCA9-33 active combiners for 36 channels
Use as launch amplifier for the RF system
Use as booster amplifier to merge QMOD channels with existing 50 dB analog modulator systems
In the Box
Contemporary Research QDA4-45 RF Distribution Amplifier & Combiner
PS12-1 1A 12 VDC Power Supply
Limited 2-Year Warranty
Table of Contents
Input Selection: 1 or 4 inputs (green LED indicators)
RF Gain Selection with LED Display: 0 to 25 dB for four inputs, 0 to 32 dB for one input
4 x Input F connector
1 x Amp out F connector
1 x DC power input (2.1 mm coaxial jack, inside center conductor positive)
38 dB typical, 30 dB minimum, 54 to 860 MHz
Input: 30 dB typical, 13 dB in single input mode
Output: 17 dB typical
Input 1: 0 to 32 dBmV gain, low noise, linear performance through 860 MHz
All Inputs: 0 to 25 gain (7 dBmV loss from combiner)
Maximum Output Level
Composite Triple Beat
-60 dB, 134 channels at +44 dBmV per channel
1 x Power LED
2 x Green LEDs for input selection
11.5 to 13 VDC, 12 VDC typical 700 mA maximum
Durable metal enclosure, rack mountable
Dimensions (W x H x D)
8.5 x 1.75 x 6.0" (216 x 44 x 153 mm)
1.1 lb (500 g)
Contemporary Research QDA4-45 RF Distribution Amplifier & Combiner Review