LBI-31564A
Mobile Communications
DELTA - SX
136 - 174 MHz
RADIO COMBINATIONS
(NEGATIVE GROUND ONLY)
Maintenance Manual
LBI-31564
SYSTEM SPECIFICATIONS* - Cont.
DIMENSION, LESS ACCESSORIES (H X W X D)
40-60 Watts
65 mm X 260 mm X 325 mm
(2.5 X 10.2 X 12.7 inches)
65 mm X 290 mm X 325 mm
(2.5 X 11.4 X 12.7 inches)
110 Watts
WEIGHT, LESS ACCESSORIES
40 and 6O Watts
5.9 kg (13.0 pounds)
6.5 kg (14.5 pounds)
110 Watts
TRANSMITTER
RECEIVER
CONDUCTED SPURIOUS
MODULATION
- 85 dB
AUDIO OUTPUT
12 Watts with less than
3% distortion
(to 4.0 ohm speaker)
± 5.0 KHz
SENSITIVITY
Standard
UHS Preamp
AUDIO SENSITIVITY
60 to 120 Millivolts
12 dB SINAD (EIA) Method
20 dB Quieting Method
Squelch <6 dB SINAD
0.35 uV
0.50 uV
0.25 uV
0.175 uV
0.25 uV
0.125 uV
AUDIO FREQUENCY
CHARACTERISTICS
Within +1 dB to -4.5 dB of a 6
dB/octave pre-emphasis from
300 to 3000 Hz per EIA standards.
Post limiter filter per FCC and EIA
Channel Guard 8 dB SINAD
ADJACENT CHANNEL SELECTIVITY
EIA Two-Signal Method
DISTORTION
Less than 2% (1000 Hz)
Less than 5% (300 to 3000 Hz)
( @ 25 kHz channels)
( @ 30 kHz channels)
- 85 dB
- 95 dB
- 85 dB
- 95 dB
DEVIATION SYMMETRY
0.5 kHz maximum
SPURIOUS RESPONSE
- 90 dB
- 90 dB
- 80 dB
MAXIMUM FREQUENCY
SEPARATION
INTERMODULATION @ 25/30 kHz - 85 dB
136-153 MHz
17 MHz
150.8-174 MHz
23.2 MHz
MODULATION ACCEPTANCE
± 7.0 kHz
MICROPHONE LOAD IMPEDANCE600 ohms
MAXIMUM FREQUENCY
SEPARATION
POWER ADJUST RANGE
RF OUTPUT IMPEDANCE
FM NOISE
2:1 of rated power
136 - 153 MHz
150.8 - 174 MHz
17 MHz
23.2 MHz
50 ohms
FREQUENCY RESPONSE
Within +2 and -8 dB of a standard
6 dB per octave de-emphasis curve
from 300 to 3000 Hz (1000 Hz
reference)
- 65 dB
CARRIER ATTACK TIME
AUDIO ATTACK TIME
25 milliseconds
25 milliseconds
<5%
RF INPUT IMPEDANCE
50 ohms
CHANNEL GUARD TX TONE
DISTORTION
HUM/NOISE RATIO
UNSQUELCHED
SQUELCHED
- 55 dB
- 70 dB
RECEIVER RECOVERY TIME
RECEIVER ATTACK TIME
CHANNEL SPACING
200 milliseconds
150 milliseconds
25/30 kHz
CHANNEL GUARD (Optional)
Tone
67 - 210.7 Hz ( ± 0.5%) **
Digital
023 - 526 (H) code (Standard Codes)
* These specifications are intended primarily for use of the serviceman. Refer to the appropriate Specifications Sheet for the
complete specifications.
** Any tone (67-210 Hz) ±0.5%
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LBI-31564
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LBI-31564
The PA board is inserted into the radio from the top of
the frame, while the TRS board is inserted from the bottom.
There are no wires used in the basic radio. Interconnections
are provided by pins on the TRS board that mate with con-
nectors on the PA assembly. A power bus connects A+ and
A- from the front connector to the PA assembly. The PA
board is isolated from ground (floating). power is supplied
directly from the battery to the PA power output stage.
DESCRIPTION
General Electric DELTA-SX mobile radio combinations
are completely solid state utilizing microcomputer technol-
ogy and integrated circuits to provide high quality - high re-
liability radios. The DELTA-SX radio is designed for use in
vehicles having a negative ground battery system. In vehi-
cles having a positive ground battery system a polarity con-
verter must be used. Standard combinations may be
equipped with:
The radio is of single-layer con-struction with all major
modules and tuning adjustments easily accessible from the
top of the radio.
• Microcomputer Control led Frequency Synthesizer
• Up to 32 channels
Centralized metering jacks for the transmitter, receiver
and system functions are provided for simplified alignment
and troubleshooting.
• .0002% or .0005% frequency stability
• UHS Preamplifier (Ultra High Sensitivity), optional
• Tone and/or Digital Channel Guard, optional
Excluding option boards, the basic radio consists of two
printed wiring boards mounted in a cast aluminum frame.
The two boards are the transmitter-receiver-system (TRS)
board 19D901650G1 and the power amplifier board (See
Figure l). The TRS board is connected to chassis ground al-
lowing it to be used in vehicles with a negative ground bat-
tery system only. Option boards include the Channel Guard
board and VG Interface board. The VG Interface board is
used in radios equipped with VOICE GUARD.
The radio set is housed in a weather resistant case only 2
1/2 inches high. The radio is secured to the vehicle by a bot-
tom mounting plate, and is tamperproof when locked into
the plate. When unlocked, the handle can be pulled down
and the radio pulled out of the mounting plate or the top
cover removed for servicing. When pulled down, the han-
dle can be used to carry the radio.
Figure 1 - Typical Module Layout
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LBI-31564
FREQUENCY SYNTHESIZER
TRANSMITTER
The frequency synthesizer consists of a microcomputer,
electrically erasable PROM(S) (EEPROM), a frequency
synthesizer IC, transmit and receive VCO’s, and associated
circuitry. The frequency synthesizer under control of the mi-
crocomputer generates all transmit and receive RF frequen-
cies.
The transmitter consists of the exciter, frequency synthe-
sizer, TX VCO, and a power amplifier assembly. The PA as-
sembly consists of a PA board mounted along the side of the
radio next to the heat sink assembly. The PA board also con-
tains a hermetically sealed antenna relay and a low pass fil-
ter.
EFEPROM
RECEIVER
The EEPROM stores binary data for all RF frequencies,
Channel Guard tones/ digital codes, and the timing function
of the carrier control timer (CCT). The microcomputer ac-
cesses the EEPROMS and provides the correct WALSH bits
to the Channel Guard board to generate the correct Channel
Guard tone or digital code on a per channel basis.
The receiver consists of the frequency synthesizer, RX
VCO, injection amplifiers, front end, IF and limiter detector.
In UHS receivers, a preamplifier board is added in the re-
ceiver front end. Audio and squelch circuitry for the re-
ceiver is located in the system section of the TRS board.
Jacks for the Channel Guard and other structured options
are also located in the system area.
PROGRAMMING
CONTROL UNITS
The EEPROM allows the radio to be reprogrammed as
needed to adapt to changing system requirements. RF fre-
quencies, Channel Guard tones and digital codes, and the
CCT function can be reprogrammed.
Several "S" series control units are available for use with
the DELTA-SX, radio combinations.
The S-500 control unit contains an on-off volume con-
trol switch, a rotary channel selector switch for 1, 8, or 16
channels, a MODE A/B switch (optional) to expand the
channel select capability to 32, seven segment channel indi-
cators(s), a red transmit indicator, channel busy indicator
(optional), and an external tone option jack. Options that
may be used with this control unit include Type 90 and 99
tone, squelch operated relay SOR, GE-STAR encoder, and
public address.
Depending on the configuration of the radio, one or two
EEPROMS may be provided. Radios not equipped with a
MODE A/B switch will have one EEPROM. Radios with
more than 16 channels and those with the MODE switch
will have two EEPROMS.
NOTE
When programming, remember that all RF frequen-
cies must be divisable by 5 or 6.25 kHz but not both.
The S-600 control unit contains an on-off volume con-
trol switch, squelch disable switch, red transmit indicator,
and a 7 segment channel indicator. A rotary channel select
switch permits selection of up to eight- channels. A white
power on indicator is used for back lighting the front panel.
Space is provided for two optional. pushbutton switches and
two optional indicators.
The EEPROMS can be reprogrammed through the radio
front connector using the General Electric Universal PROM
Programmer Model TQ23IO. This programmer allows all
information to be loaded simultaneously.
The S-900 series control units designed specific-ally for
the DELTA class radios are highly versatile, software con-
trolled units providing numerous functions and options in-
cluding:
Alternatively, a single channel Programmer Model
4EX22A10 allows the user to reprogram the radio on a per
channel basis. This programmer requires the removal of the
radio top cover and any option boards present. A special
programming jack, J711, is provided in the radio for inter-
connections.
• Dual priority Scan
• Digita1 Volume Control
• Digital Squelch Control
• Type 90 or 99 Encode Tones
• GE-STAR Identification
Programming instructions are provided in the respective
Programmer Maintenance Manuals.
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LBI-31564
• 128 Channels in -
8 Modes of 16 Channels each
HOOKSWITCHES
or
In Channel Guard or other tone applications, a micro-
phone or handset hookswitch is supplied with the radio. The
hookswitches are equipped with a Channel Guard disable
switch.
4 Modes of 32 Channels each
• Carrier Control Timer (per mode basis)*
• Channel Guard - Tone or Digital*
• Channel Frequencies*
Placing the switch in the "up" position (towards the
small speaker symbol) disables the Channel Guard decoder.
With the switch in the "down" position, the Channel Guard
is disabled when the microphone or handset is removed
from the hookswitch.
• Home Channel Revert
• Auxiliary Relay Control
CHANNEL SELECTION
SPEAKER
Depending on the control unit used a single rotary or
pushbutton selector switch will select up to 16 channels. In
radios equipped with more than 16 channels, the control
unit contains a MODE A/B switch. The MODE switch al-
lows the user to select a second set of 16 channels (17-32).
A three by five-inch speaker contained in a molded plas-
tic housing provides an audio output of 12 watts with a
speaker impedance of four ohms. The speaker leads are ter-
minated in Vehicle Systems Plug P3 which connects to
Jl-A on the rear of the control unit.
The MODE A/B switch may be used to provide mobile-
to-mobile communications through an intermediate repeater
(repeated path) or direct mobile-to-mobile communications.
For example: channel 1 Mode A may be programmed for
the repeater frequency (repeated path) while channel l Mode
B would be programmed for the mobile receive frequency
(direct path). Judicious programming will allow selection of
repeated or direct communications paths on selected chan-
nels.
INITIALADJUSTMENT
After the radio has been installed (as described in the In-
stallation Manual), the following adjustments should be
made by a certified electronics technician.
TRANSMITTER ADJUSTMENT
The transmitter adjustments include measuring the for-
ward and reflected power and optimizing the antenna
length, then setting the transmitter to rated power output.
Next, measuring the frequency and modulation and record-
ing these measurements for future reference. For the com-
plete transmitter adjustment, refer to the Alignment
Procedure in the service section of this manual.
MICROPHONE AND HANDSET
A hand held microphone with a built-in transistorized
microphone preamplifier is available for use with the radio.
The microphone is housed in a sturdy twopiece case, and
the extendable coiled cord plugs into the microphone jack at
the k of the control unit. The plug is secured to the jack by a
retaining screw.
RECEIVER ADJUSTMENT
An optional telephone-type hand set is available for use
with the radio. The handset uses a dynamic microphone
with a built-in microphone preamplifier. The extendable
coiled cord plugs into the microphone jack on the back of
the control unit, and is secured to the jack by a retaining
screw.
The initial adjustment for the receiver includes tuning
the input circuit to match the antenna. Refer to the Front
End Alignment Procedures in the service section of this
manual.
OPERATION
*
These functions are actually performed in the radio. If
you down-load, the data is stored in the control unit.
Complete operating instructions for the Two-Way Radio
are provided in the Operator’s Manual. The basic proce-
dures for receiving and transmitting messages in mobile
combinations are as follows:
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LBI-31564
TO RECEIVE A MESSAGE
4. Press the push-to-Talk (PTT) switch on the microphone
and send the message. The red transmit light on the con-
trol unit will glow each time the PTT switch is pressed.
1. Turn the radio on by turning the OFF-VOLUME control
halfway to the right.
2. Turn the SQUELCH control clock-wise (to the right) as
far as possible. A noise will be heard from the speaker.
MAINTENANCE
3. Adjust the VOLUME control for the desired listening
level.
The use of microcomputer technology allows self diag-
nostic maintenance routines to be incorporated in the micro-
computer software. These routines are easy to run and
provide a quick analysis of microcomputer and frequency
synthesizer operation.
4. Turn the SQUELCH control counterclockwise to the left
until the noise just cuts off.
5. In multi-frequency radios, select the desired channel.
The radio is now operational.
The service section of this manual contains the diagnos-
tic routines, and other maintenance information to service
this radio. The service section includes:
TO TRANSMIT A MESSAGE
• System interconnections
• Mechanical layout
1. Turn the radio on and select the proper channel.
• Disassembly procedures
2. If a lengthy message (or several messages) are to be
sent, the vehicle engine should be running to maintain
the battery charge.
• Replacement of IC’s chip capacitors and resistors
• Microcomputer self diagnostics
• Alignment procedures for the transmitter and receiver
• Troubleshooting flowcharts and waveforms
3. Pick up the microphone and listen briefly to the speaker
to make sure that no one else is using the channel.
Pinted in U.S.A.
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