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DocNo.DCP0001330 RnB 25/02/04 rev2
Operation Instruction Manua
l
1ZDM
Single Zone Desk Microphone
Features
The 1ZDM has compressor, noise gate, equalisation
controls and optional chime (one to three note).
The unit is fully monitored and complies with BS5839 part4.
Simple operation by the use of a single button Speak bar.
The unit is supplied in a sturdy plastic desk mounting case
with a gooseneck microphone fitted.
Technical Description
Microphone signals are passed to a voltage controlled
amplifier under control of a signal derived from rectifying
the stage output signals, providing 3:1 compression ratio.
The output of this stage is fed to an LED output level
display and a three-band equaliser (100 Hz, 1KHz, 10 kHz).
Power is supplied at nominal 24 VDC via separate cabling,
the phantom power on the audio + and audio - being used
for fault detection only. A regulator circuit provides 15 VDC
for powering the 1ZDM electronics.
Front Panel Features
The 1ZDM provides for the following LED indications
:
Name
Function / Description
1
OK
GREEN when no fault detected.
2
FAULT
AMBER when fault detected.
3
SPEAK
GREEN when system ready for paging announcement, FLASHING GREEN when system is
busy.
4
VU
VU meter to show audio level. VU meter is constantly active and will light in sync with audio
peaks to indicate that the audio path to the input stage is intact. This occurs even when speak
bar is not pressed.
Block Diagram
