Clear-Com HB-704 - Manual (Page 15)

H B - 7 0 2 / H B - 7 0 4 T W O - A N D F O U R - C H A N N E L H E A D - 3 - 1
MAINTENANCE
INTRODUCTION
This chapter provides maintenance information including troubleshooting tips and block diagrams.
Caution: These servicing instructions are for use by qualified personnel only. To reduce the risk of electrical
shock, do not perform any servicing other than that contained in the operating instructions unless you
are qualified to do so.
BLOCK DIAGRAM OF HB-702 TWO-CHANNEL HEADSET STA-
TION
Figure 3-4 HB-702 Block Diagram
EQ/
LIM
Headset
Mic
Sidetone
Null
Call
Light
Intercom
Volume
TW Option
Channel
Switch
Ch. A
Power
Ch. B
Call Send &
Receive
Headset
Output
Mic
Mute
Common
+30 VDC
Ground
Long Line
4-Wire
Input
4-Wire
Output
2-Wire / 4-Wire
Select
Rectifier 16 VAC Power
Ch. B
Ch. B
Ch. A
Ch. A
4-Wire
Option
Talk
RMK
Microprocessor
Talk
Latch
Disable
Call