Nomenclature Chart; Description; Installation; Adjustment - Ericsson MASTR II Maintenance Manual

LBI-30766 COMBINATION NOMENCLATURE
2

DESCRIPTION

The MASTR® II Station Auxiliary Receivers are available
for mounting in MASTR II Base Stations or in MASTR II
Multiple Receiver Stations. The Auxiliary Receiver consists of
a 2-rack unit shelf with space for the receiver RF circuits, the
oscillator/multiplier, the IFAS and MIF assemblies together
with a System Board and a 10-Volt Regulator Board. 13 VDC
is required to power the shelf.
In MASTR II Base Station applications (Options 9538-
9541), power for operating the Auxiliary Receiver is provided
by the Base Station Power Supply. These options also include a
19B226307 Overlay Harness. Refer to the Interconnection Dia-
gram listed in the Table of Contents.
In MASTR II Multiple Receiver Station applications,
power for operating the receivers is provided by a power sup-
ply designed specifically for this station. Refer to LBI-30731.
Operating an auxiliary receiver in voting systems where no
external power supply is available requires the use of the
19C31 1855G1 Power Supply. This supply is mounted on the
rear panel of the receiver. No service speaker should be used
with this supply.
The Auxiliary Receiver can be supplied with an Antenna
Matching Unit (Options 9536 or 9537). A phone connector is
used for interconnecting the receiver and AMU. When the re-
ceiver is not used with an AMU, a coaxial cable
(19A129312G4) fitted with an auxiliary UHF antenna connec-
tor is provided. Refer to the Installation Instructions listed in
the Table of Contents.
The Auxiliary Receiver System Board accommodates sev-
eral option boards either individually or in combination. Op-
tion boards that plug into jacks on the System board include
the Voting Tone Board (19C320880G1) used in Receiver Vot-
ing Systems or the Squelch Operated Relay (SOR)
19C320913G1, used in external control applications.
A Secur-it Tone Notch Filter (19C328328G3), used in Tone
Remote Systems, mounts on the side of the receiver system
board chassis. A Line Response Compensator Board
(19C328328G2) is available for use in Voting Tone Systems.
This compensator provides means for adjusting the audio re-
sponse at the receiver end of a telephone line. A third version
of this board (19C328328G1) includes both the tone notch fil-
ter and the line response compensator.
A Channel Guard Decode Board (19D417261G6) may be
plugged into the System Board at P908 and P909. A Tone Re-
ject Filter (19C320627G1) is used with the Channel Guard De-
code Board to prevent the CG tone from being fed into the
telephone line. The filter attenuates below 203.5 Hertz.
The 13-Volt DC input to the 10-Volt regulator is fused. A
Light Emitting Diode (LED) is provided on the front panel of
the receiver to indicate when power is applied. A power ON-
OFF switch is provided on the regulator board. Another LED
on the front panel indicates carrier activity. The receiver chas-
sis swings out for servicing.

INSTALLATION

The Auxiliary Receiver is installed directly above the sta-
tion power supply in MASTR II Base Stations. The
19C321150 Antenna Matching Unit is located directly above
the Receiver. Refer to the Installation Diagram (See Table of
Contents). Refer to the Installation Instructions in LBI-30761
for mounting the Auxiliary Receiver in the Multiple Receiver
Station.

ADJUSTMENT

The initial adjustment for the receiver includes tuning the
input circuit to match the antenna. Refer to the FRONT END
ALIGNMENT PROCEDURE IN THE MAINTENANCE
MANUAL for the receiver.
MASTR II REMOTE CONTROL STATION
ADJUSTMENT
To adjust the LINE LEVEL control R936, located on the
System Board, use the following procedure.
1. Connect a signal generator to the Auxiliary Receiver
antenna jack J2402. Set the generator to the receiver
frequency. Modulated at 3 kHz deviation by a 1000 Hz
signal. Disable Channel Guard (if present) by opening
switch S802 on the Regulator Board.
2. Adjust the LINE LEVEL control R936 on the System
Board for a reading of 2.7-volts rms (+11 dBm) as
measured at the base station audio pair.
If the receiver is used with a Tone Control Base Station,
adjust the LINE LEVEL control for a reading of 1.0-
volt rms (+2 dBm).
To adjust the VOL SET control R930 and the SQUELCH
control R2401, use the following procedure.
1. Connect an 8.2 ohm, l-watt resistor across J2401-9 and
10, located on the rear panel of the Auxiliary Receiver.
2. Connect an AC vtvm across the 8.2 ohm resistor and
adjust R930 for a reading of 2.7-volts rms on the meter.
3. Disconnect the 8.2 ohm resistor. Disconnect the signal
generator.