ACCURATE ELECTRONICS INC
Practice Section 104001C Rev B January 2014
PO BOX 1654 97075-1654 8687 SW HALL BLVD 97008 BEAVERTON OR USA 503.641.0118 FAX 503.646.3903
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.
7
Note: If the TMS does not provide an impedance setting that matches
impedance selected on the module, re-option the module as necessary for a
proper impedance match during this procedure. Then, when this procedure
is completed, reset the module’s impedance as required.
3.
Send test tone at 1004Hz and 2804Hz at the CLR-specified transmit
input level toward the distant facility-side end. Have personnel at
that end measure the received levels, subtract the 2804Hz level from
1004Hz level, and report the result.
4.
Set to IN the proper combination of XMT EQL DIP switches that
approximates as closely as possible the reported difference, i.e., the
amount of equalized gain required, as specified in Table 4.
TABLE 4.
Equalized Gain Settings from Cable Loss Data.
1004 Hz – 2804 Hz
Difference
Amount of Equalized Gain Required
0.0 to 0.2 dB
0.0 dB
0.3 to 0.7 dB
0.5 dB
0.8 to 1.2 dB
1.0 dB
1.3 to 1.7 dB
1.5 dB
1.8 to 2.2 dB
2.0 dB
2.3 to 2.7 dB
2.5 dB
2.8 to 3.2 dB
3.0 dB
3.3 to 3.7 dB
3.5 dB
3.8 to 4.2 dB
4.0 dB
4.3 to 4.7 dB
4.5 dB
4.8 to 5.2 dB
5.0 dB
5.3 to 5.7 dB
5.5 dB
5.8 to 6.2 dB
6.0 dB
6.3 to 6.7 dB
6.5 dB
6.8 to 7.2 dB
7.0 dB
7.3 to 7.7 dB
7.7 dB
4. CIRCUIT DESCRIPTION
4.01 This circuit description is intended to familiarize you with the 104001C
Prescription Line Amplifier for engineering and application purposes only.
Attempts to troubleshoot the unit internally are not recommended and may
void your warranty. Troubleshooting procedures should be limited to those
prescribed in Section 7 of this practice. Refer to the 104001C block diagram,
Figure 1. of this practice, as an aid in following this circuit description.
Note: The transmit and receive channels of the 104001C module are virtually
identical. Therefore, the description in paragraphs 4.02 and 4.03 applies to
both channels.
4.02
A transformer is used at each port (input and output) of each channel to
interface external circuits. Switch-selectable taps on the external-circuit side
of each transformer afford a choice of 1200, 600, or 150-ohm balance
terminating impedance on both sides (facility and terminal) of the module.
The internal-circuit side of each transformer is protected by a silicon voltage-
transient suppressor that limits transient voltages to a safe level and provides
surge protection. In addition, both transformers are center-tapped to derive
balanced simplex leads.
4.03
Signals entering each channel’s input port are coupled across the input
transformer and applied to the LEVEL ADJUST circuit and GAIN AMP.
The level adjust circuit is controlled by the channel’s front-panel
GAIN/LOSS and LEVEL switches. These switches allow selection of 0 to
24dB of gain or loss in 0.1dB increments. Signals at the output of the GAIN
AMP are applied to and active slope-type amplitude equalizer consisting of
the EQUALIZATION ADJUST circuit and EQL AMP. The
EQUALIZATION ADJUST circuit is controlled by the channel’s front-panel
EQL switches. These switches allow selection of 0 to 7.5dB of gain at
2804Hz (re 1004Hz) in 0.5dB increments. Signals at the output of the EQL
AMP are applied to the POWER AMP, which drives the output transformer.
4.04
The 104001C can be optioned to provide 25mA of internally generated
sealing current to metallic facilities on the facility and/or terminal sides of the
module, to accept externally generated sealing current from the far ends of
the facilities on both sides of the module, to derive normal simplex leads on
both sides of the module, or to provide bypassed (straight-through) simplex-
lead signaling via a path separate from the transmit and receive transmission
paths. Each of the 104001C’s two internal sealing-current sources has a
“ZAP” feature by which a greater amount of sealing current is provided for a
few seconds when power is initially applied to the module.
4.05
When the internal sealing-current source on the 4001’s facility side is
selected, sealing current is fed to the external 4wire facility though the
transmit output port (pins 41 and 47) and is returned to the module through
the receive input port (pins 7 and 13). When the internal sealing-current
source on the 104001C’s terminal side is selected, sealing current is fed to
the external 4wire facility through the transmit input port (pins 40 and 55)
and is returned to the module through the receive output port (pins 5 and 15).
When the externally supplied sealing current option is selected on either side
of the module, the center-tapped leads of the receive and transmit
transformers are connected together. This creates a return path that allows
the module to accept sealing current from an external source at the distant
end of the external facility. The third option setting provides normal simplex-
lead derivation at the module’s facility-side and/or terminal-side ports. When
optioned for bypassed (i.e., straight-through) SX-lead signaling, an additional
switch optioned selects either normal (RCV IN SX to RCV OUT SX and
XMT IN SX to XMT OUT SX) or reversed (RCV IN SX to XMT IN SX and
RCV OUT SX to XMT OUT SX) straight-through signaling.
4.06
The 400C’s facility-side (receive input and transmit output) transformers
are connected to both bridging and opening bantam-type test jacks, while the
terminal side (receive output and transmit input) transformers are connected
to opening bantam type test jacks only.
4.07
The Power Supply on the 104001C is simple series voltage regulator
that uses a zener diode as reference source. A series diode in the negative
input battery lead protects the circuit against reversed input-power
connections, and a transorb between input battery and ground limits high-
level supply transients to a safe level.
5. MECHANICAL OUTLINE
5.01
See FIGURE 2.
6. SPECIFICATIONS
Note: Transmit-channel and receive-channel specifications of the 104001C
are identical.
6.01 Electrical
Terminating impedances (all four ports):
1200, 600 or 150 ohms, balanced, switch-selectable
Flat Gain or Loss:
0 to 24dB of gain or 0 to 24dB of loss,
in switch- selectable 0.1dB increments,
with gain or loss selected via switch option
increments, prescription-set
Deviation from gain or loss setting indicated by front-panel switches:
+0.25dB maximum, re 1000Hz
Maximum Output Level:
+10Bm
Total Harmonic Distortion: less than 1% at +10dBmoutput level