QDA4-45 Distribution Amp Combiner

Type: RF Modulators , Accessories
Part Number: 5092-001
Size: 8.500 wide x 1.750 high x 6.000 deep
Weight: 1.100
Distribution: AV over RF

Where to Buy

QDA4-45 Data Sheet
QDA4-45 Product Manual
Combiner Comparison Guide

  • qda4-45 Front View
  • QDA4-45 Backnew.jpg

More about RF Modulators

Modulation in its most basic definition is the mixing of two sinusoidal signals. The RF modulator takes an input signal and outputs a modulated signal to be transmitted as a video channel to any number of connected TVs. RF Modulators are used to distribute video in widely diverse installations, including stadiums, arenas, office buildings, college campuses, houses of worship, sports bars, and restaurants

About QDA4-45 Distribution Amp Combiner

The Contemporary Research QDA4-45 is an amplified RF combiner that can switch between one or four inputs, with adjustable amplification up to 32 dB of gain.

Related Equipment & Software


Contemporary Research offers a variety of product accessories to necessitate or enhance the functionality of AV products.

Full Description & Specifications

The Contemporary Research QDA4-45 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 included Contemporary Research RKU universal rack mount kit or optional RK1 single rack mount kit or RK2EZ dual rack mount kit. The units are wholly designed and manufactured in the USA.

  • 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 50 dBmV
  • Wide-band, low noise amplifier
  • Low power, draws less than 8.5 watts
  • Compact metal enclosure, mounts in 1 RU using the RKU, RK1, or RK2EZ rack mount kits

Distribution: AV over RF

  • Size:8.5” [216mm] wide x 1.75” [44mm] height (1RU) x 6.0” [153mm] deep
  • Weight: 1.1 lbs [500g]
  • Enclosure: Durable metal enclosure, rack mountable.
    • Tip: mounting adjacent to CR dual-channel QMODs can blocks air flow

Front Panel:
  • Input Selection, 1 or 4 inputs, Green LED indicators
  • RF Gain Selection with LCD display, 0-25 dB for four inputs, 1-32 dB for one input

Back Panel:
  • Inputs: 4 F Connectors
  • Amp Out: 1 F connector
  • DC Power: Power 2.1 mm coaxial jack (inside center conductor positive), 700 mA maximum, 11.5 to 12.7 VDC, 12 VDC typical
    • Tip: Use included 12 VDC power supply, do not share DC power with other DC supplies (voltage is often 13V and above)

  • Max Input Level: 45 dBmV
  • Combiner Isolation: 38 dB typical, 30 dB minimum, 57 - 861 MHz
  • Return Loss: 30 dB typical

  • Input 1 only: 1-32 dB gain, low noise, linear performance through 861 MHz
  • All Inputs: 0-25 dB gain (7 dB loss from combiner)
  • Max Level: Maximum level 50 dBmV
  • CTB: Composite Triple Beat -75 dB, 132 channels at +30 dBmV per channel
  • Noise: Noise Figure 4.5 typical
  • Return Loss: 20 dB typical

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