Comrex DH20

Comrex's newest DSP technology delivers better and more reliable sound quality. The DH20 delivers the deepest and most stable hybrid null, ensuring maximum isolation between the send and caller audio. That means no echo and no "bottom of the barrel" sound.

In addition, they've added selectable automatic gain control (AGC) and caller ducking. With AGC, each call will be delivered to your equipment at the same level. Caller ducking reduces the caller's audio level when the announcer speaks, providing a more "controlled" environment. There's also a speaker amplifier so you can connect a speaker directly to the unit and monitor callers without headphones. 

Features

• The world's best, most affordable digital hybrid
• DSP digital technology ensures the very best audio quality and the deepest, most reliable hybrid null
• Easy to install, simple to operate
• Built-in speaker amplifier
• Balanced audio in and out
• Mic or line input
• Selectable AGC ensures every caller is at the same audio level
• Selectable caller ducking
• Selectable auto-answer/auto-disconnect compatible with most telephone central offices including loop current interruption and busy/reorder tones
• Remote control and status
• Automatically accepts all worldwide voltages
• Worldwide compliant, including FCC, CSA, CE and CTR21

Specifications

Connections

• Caller Output: XLR male, 0dBu nominal, adjustable, balanced, 50 Ohm impedance
• Aux Output: XLR male, 0dBu nominal, adjustable, balanced, 50 Ohm impedance
• Telco Line: RJ-11 connector, POTS line or analog extension from a PBX or dry line (no DC offset voltage)
• Telco Set: RJ-11 connector
• Remote: DB-25 Female
• Remote Send Input: 0dBu nominal, adjustable, unbalanced, 20k Ohm impedance
• Remote Caller and Aux Output: 0dBu nominal, adjustable, unbalanced, 50 Ohm impedance
• Control Inputs: Remotely activate any of the following functions with a switch closure to ground: On, Off, and Monitor Mute
• Status Outputs: Remotely check the status of the hybrid using the On and Off status outputs. Status outputs are open collector outputs rated at 30VDC and 40mA maximum
• Monitor Output: 1/4" stereo jack: Tip=+phase, Ring=ground, Sleeve=ground, 1W output into an 8 Ohm load
• Send Input: XLR female, Mic/Line selectable, -55/0 dBu nominal, adjustable, balanced, bridging, 20k Ohm impedance

Telephone Transmit

• Nominal send input of 0 dBu referenced to -15 dBu onto the telephone line
• Frequency Response: 250 Hz to 3.5 kHz, ±1dB
• Signal to noise ratio: >56 dB
• Distortion: <0.2%

Telephone Receive

• Nominal telephone line level of -15 dBu referenced to caller output of 0 dBu
• Frequency Response: 250 Hz to 3.5 kHz, ±1 dB
• Signal to noise ratio: >56 dB
• Distortion: <0.2%

Mix-Minus

• Caller-to-Send separation: 50 dB nominal
• Tail time: 32 milliseconds

Controls

• On/Off Buttons
• Volume Up/Down Buttons

Status LEDs

• On Status, Off Status
• Send Audio Presence
• Caller Audio Presence

Adjustments

• Send Input Level
• Caller Output Level
• Auxiliary Input Level
• Auxiliary Output Level
• Burst Adapt Select
• Mic/Line Select
• Caller Boost Select
• Momentary/Latching Select
• Auto Answer/Disconnect Select
• Caller Control Select (0, 6, 12, or 18 dB)
• AGC Select
• Auto Mix-Minus Select
• Aux Mix Select

Null

• Send-to-Caller separation: 55dB nominal
• Tail time: 32 milliseconds

Power & Physical

• Power: IEC Type, Auto Adjusting 100-240VAC, 2A, 50/60Hz, 30W
• Size: 17.125" L x 10.125" D x 1.75" H (43.6 cm x 25.7 cm x 4.44 cm)
• Weight: 6.35 lbs (2.88 kg)
• Operating Temperature: 32-100° F (0-38° C)
• Humidity: 0-80 percent

 

Product Manual

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