Section 365–001–201
2
1.
GENERAL
1.1
Document Purpose
This document provides a general, circuit, installation and testing information for the Charles Industries
3650–01/03 2-Wire ETO w/LC Channel Units
1.2
Document Status
This document is reprinted to provide a general editorial update.
1.3
Equipment Function
The Charles Industries 3650-01/03 2-Wire ETO w/LC Channel Units are used in the CHarles Industries 360/363
D4 Digital Carrier Terminal to provide an interface to in-band (with no DC) signaling or no signaling special service
units such as 2-wire voice frequency extensions, data sets, or modems on a private line. The 3650–01 provides a
900-ohm balanced interface, while the 3650–03 provides a 600-ohm balanced interface. The 3650–01 is shown in
Figure 1.
1.4
Equipment Location/Mounting
This unit occupies one channel unit slot of a Charles Industries 360/363 D4 Digital Carrier Terminal Channel Bank
assembly.
1.5
Equipment Features
The 3650–01/03 2-Wire ETO w/LC Channel Units include the following features:
Termination impedance of 2.15 uF in series with 900 ohms (3650–01) or 600 ohms (3650–03) for
matching the impedance of the 2-wire port interface.
Built-in selectable hybrid-balancing compromise network of 2.15 uF in series with 900 ohms
(3650–01) or 600 ohms (3650–03)
Built-in jack (J3) to mount an optional 3690–00/10 compromise network subassembly or an optional
3690–01/11, 02/12, or 03/13 precision balance network (PBN) subassembly, and provisions (pins 41
and 46) to connect an external PBN.
Built in jacks (J2 and J4) to mount optional 3691–00 nonloaded cable equalizer and/or 3691–01 H88
loaded cable equalizer subassemblies for post- and/or pre-equalization.
Transmit and receive prescription attenuation of 16.5 dB in 0.1 dB increments.
Sealing current for internal, external or looped feed.
Carrier group alarm, ground or shorting contact, with wink for lead conditioning.
68 dB of gain transfer, eliminating the need for external VF amplifiers.
Selectable full 8-bit coding for optimum signal-to-distortion ratio.
Front-panel-accessible bantam-breaking jacks for accessing the distant (line) or local (drop) end.
2.
INSPECTION
2.1
Inspect for Damages
Inspect the equipment thoroughly upon delivery. If the equipment has been damaged in transit, immediately re-
port the extent of damage to the transportation company.
2.2
Equipment Identification
Charles Industries’ equipment is identified by a model and issue number imprinted on the front panel or located
elsewhere on the equipment. Each time a major engineering design change is made on the equipment, the issue
