The CM-BH4W is a portable, battery powered 4 wire communication unit for use in a multitude of TV and radio broadcasting applications. This uses audio transformers at its input and output, providing galvanic isolation from outside interference, ensuring your communications are loud and clear, every time. In 4-wire mode, the unit acts as a 2-way intercom, with input audio routed to the headset earpiece, and microphone audio is routed to the output upon pressing the talk button. The output level is maintained at +2dBu peak level by a built-in AGC. In IFB mode, the input audio is routed to the output, and is interrupted by the microphone signal when the talk switch is pressed. The talk switch can easily be converted from momentary to latching operation to suit your application. A low battery warning LED flashes when the 9V PP3 battery has depleted to 6V, giving plenty of notice to swap the battery. In addition, the CM-BH4W automatically switches off when the headset jack is removed, and the low power circuitry gives up to 150 hours use from a single alkaline 9V PP3 battery. Transformer balanced inputs & outputs.
Product Features
Transformer balanced inputs & outputs.
4-wire and IFB modes.
Low battery warning indicator.
150 hours from a single 9V PP3 battery.
Typical Applications
Used in TV studio floors, sports grounds and arenas by presenters and cameramen to produce content and to hear talkback.
Product Category
Belt Packs
Technical Specifications
Mic In to Line Out
Mic Input Impedance: 1k5Ω Unbalanced for 200Ω dynamic microphone
Limiter Input Threshold: -60dBu
Line Output Level: +2dBu
Line Output Impedance: 150Ω Transformer balanced
Line In to Headphone Out
Line Input Impedance: >10kΩ Transformer balanced
Input Gain/Volume: Adjustable off to +10dB
Maximum Input Level: +24dBu
Maximum HP Output Level: +7dBu (ref 9V battery voltage, <1% THD, 100Ω load)
Minimum HP Impedance: 100Ω
Connections
Line Input: 1 x XLR 3 pin female socket (balanced)
Line Output: 1 x XLR 3 pin male plug (balanced)
Headset (CM-BH4W): 1 x ¼” (6.35mm) mono unbalanced jack socket
Equipment Type
CM-BH4W: Belt-pack 4-wire headphone amplifier
Physical Specification
Dimensions (Raw): 12.5cm (W) x 6.7cm (D) x 4.8cm (H)
Dimensions (Raw): 4.9” (W) x 2.6” (D) x 1.9” (H)
Dimensions (Boxed): 23cm (W) x 13cm (D) x 8cm (H)
Dimensions (Boxed): 9.1” (W) x 5.1” (D) x 3.1” (H)
