Page 1 of 10
Model 104003C
January 2014
This document contains proprietary information and is supplied for identification, maintenance, engineering evaluation or inspection purposes only and shall not be duplicated or disclosed without written
permission of: ACCURATE ELECTRONICS INC By accepting this document the recipient agrees to make every effort to prevent unauthorized use of this information.
Prac_104003C0_RevA.pdf
Contents:
Section 1. General
1
Section 2. Application
1
Section 3. Installation
2
Section 4. Circuit Description
6
Section 5. Mechanical Outline
6
Section 6. Specifications
6
Section 7. Testing and Troubleshooting
7
Section 8. Maintenance
7
Section 9. Warranty
7
Section 10. Condensed Alignment Procedures
8
Figure 1. Circuit Description
10
Figure 2. (see Figure 5.)
Figure 3. Hypothetical Circuit Employing 104003C
Line Amplifiers
2
Figure 4. 4Wire Circuit Employing DX signaling
2
Figure 5. Module Switch Locations
4
Figure 6. Preliminary Alignment Procedure –
No Equalization
8
Figure 7. Final Alignment Verification –
No Equalization
8
Figure 8. Preliminary Alignment Procedure –
with Equalization
8
Figure 9. Final Alignment Procedure –
with Equalization
9
Table 1. Installer Connections to 104003C
3
Table 2. Transmit and Receive Channel
Equalized Gain Optioning
3
Table 3. Loopback Frequency Selection
4
Table 4. Loopback Level Selection
4
Table 5. Test Procedure
10
1. GENERAL
1.01
The Accurate 104003C Line Amplifier with Loopback module provides
switch-selectable level control, equalization, and impedance matching in
both the transmit and receive channels of a 4wire voice-frequency
transmission facility. Additionally, the 104003C provides tone-activated or
dc-activated equal-level loopback of the facility.
1.02
The 104003C’s transmit and receive amplifiers in the 104003C may be
individually switch-optioned to provide up to 24dB of either flat gain or flat
loss in 0.1dB increments. Maximum output level of each channel is +7dBm,
with less than 1% distortion.
1.03
Equalization in both the transmit and receive channels may be
prescription-set to introduce up to 7.75dB of slope equalization from 1000 to
3000Hz in 0.25dB increments. The module’s equalized gain adjustments are
designed to provide frequency response within + 1dB over the 300 to 3000Hz
range when used on nonloaded cable facilities.
1.04
The 104003C may be switched-optioned to match 1200, 600, or 150-
ohm impedances at both the facility and terminal ports. Transformers
associated with each of the ports are center-tapped to derive balanced simplex
leads that provide for DX, loopback, and other signaling schemes that require
a dc path.
1.05
The 104003C provides loopback toward the facility for remote testing
of the circuit. Loopback may be tone or dc activated. In the tone-activated
mode, 1 of 11 loopback-activation frequencies may be switch-selected;
loopback is released in response to the reapplication of loopback tone (two-
tone-burst operation). Loopback levels of +16dB, +9dB, -16dB, or –23dB
may be prescription-set. In the dc-activated mode, the 104003C activates
loopback for the duration of a locally applied ground signal.
1.06
Auxiliary loopback relay contacts are available at 104003C’s 56-pin
connector to light an external loopback lamp or disable an associated data set
in data applications.
1.07
The front panel of the 104003C is designed so that level adjustments
can be made while the module is mounted in place. The 104003C features a
full complement of front-panel test jacks to facilitate alignment and
maintenance activities. Both bridging and opening bantam-type jacks are
provided at each port. A red light-emitting diode (LED) on the front panel
lights when the 104003C is in the loopback mode.
1.08
The 104003C incorporates an internally regulated power supply that
permits operation on –22 to –56Vdc filtered input. Current requirements
range from 30mA in the quiescent state to 65mA with both the transmit and
receive channels at maximum output. A green LED on the front panel lights
when power is applied to the module.
1.09
Surge protection in provided for the input and the output of both the
transmit and the receive channel. Reverse-battery protection and transient-
limiting circuitry are provide in each channel’s internal power supply circuit.
1.10
As a Type-10 module, the 104003C mounts in one position of a Type-
10 Mounting or apparatus case installation. In relay rack applications, up to
12 modules may be mounted across a 19-inch rack, while up to 14 modules
may be mounted across a 23-inch rack. In either case, 6 inches of vertical
rack space is used.
2. APPLICATION
2.01
The 104003C Line Amplifier with Loopback is designed for use on
4wire voice-frequency transmission facilities, where it provides bi-
directional level control, amplitude equalization, and impedance matching.
In addition, the module’s tone or dc-activated loopback circuitry allows
remote testing of the facility. Thus, the 104003C is equivalent to a 4wire-to-
4wire voice-frequency repeater with loopback. The 104003C may be used
as either a terminal or an intermediate repeater. Figure 3 shows a hypothetical
ACCURATE ELECTRONICS INC
PO BOX 1654 97075-1654 8687 SW HALL BLVD 97008 BEAVERTON OR USA 503.641.0118 FAX 503.646.3903
WWW.ACCURATE.ORG
Practice Section 104003C Rev A
LINE AMPLIFIER with LOOPBACK MODULE
MODEL 104003C