Motorola Astro Digital Spectra Digital Spectra Plus Basic 6881076c20 E Manual

							Chapter 3 Basic Theory of Operation
3.1 Introduction
The following theory will help isolate the problem to a particular board. Using circuit board 
replacement as the basic service approach maximizes the working time of the radio.
3.2 General Overview
The ASTRO Digital Spectra and Digital Spectra Plus radios are wideband, synthesized, fixed-tuned 
radios. The ASTRO Digital Spectra is available with VHF, UHF, and 800 MHz bands. The ASTRO 
Digital Spectra Plus is available with VHF and 800 MHz bands only. All ASTRO Digital Spectra radios 
are capable of both analog operation and ASTRO mode (digital) in 12.5 kHz, 20 kHz, 25 kHz, or 30 
kHz bandwidths.
The ASTRO Digital Spectra and Digital Spectra Plus radios consist of seven major assemblies, six of 
which are in the main radio chassis. They are:
 Control Head Assembly (Dash- or Remote-Mount) — is connected, directly or remotely, to the 
front of the transceiver by the interconnect board or remote interconnect board and control 
cable. This assembly contains a vacuum fluorescent (VF) display, VF driver, microprocessor 
and serial bus interface.
 Power Amplifier (PA) — contains antenna switch, directional coupler/detector, and amplifier(s).
 Front-End Receiver Assembly — contains pre-amplifier, preselector, mixer, and injection filter.
 Radio-Frequency (RF) Board — contains receiver IF amplifier, demodulator, synthesizer logic 
and filtering circuitry, and digital receiver back-end integrated circuit (IC).
 VCO/Buffer/Divider Board — contains voltage-controlled oscillator (VCO), divider, receive and 
transmit buffers.
 Command Board — contains power control/regulator, digital-to-analog (D/A) IC, serial bus inter-
face, and audio power amplifier (PA).
 VOCON (Vocoder/Controller) Board (Digital Spectra radio) — contains the microcomputer unit 
(MCU), its associated memory and memory management integrated circuit, and the digital-sig-
nal processor (DSP) and its associated memories and support IC.
For the ASTRO Digital Spectra Plus radio, the VOCON board architecture is based on a Dual-Core 
processor, which contains a DSP Core, an MCORE 210 Microcontroller Core, and custom 
peripherals. The board also contains memory ICs and DSP-support ICs. 
						

							February 3, 20036881076C20-E
3-2Basic Theory of Operation: Analog Mode of Operation
3.3 Analog Mode of Operation
3.3.1 Receive Operation
When the radio is receiving, the signal comes from the antenna/antenna-switch on the power 
amplifier board to the front-end receiver assembly. The signal is then filtered, amplified, and mixed 
with the first local-oscillator signal generated by the voltage-controlled oscillator (VCO). The resulting 
intermediate frequency (IF) signal is fed to the IF circuitry on the RF board, where it is again filtered 
and amplified. This amplified signal is passed to the digital back-end IC, where it is mixed with the 
second local oscillator to create the second IF at 450 kHz. The analog IF is processed by an analog-
to-digital (A/D) converter, where it is converted to a digital bit stream and divided down to a baseband 
signal, producing digital samples. These samples are converted to current signals and sent to the 
digital-signal processor (DSP)-support IC. The DSP-support IC digitally filters and discriminates the 
signal, and passes it to the DSP. The DSP decodes the information in the signal and identifies the 
appropriate destination for it. For a voice signal, the DSP routes the digital voice data to the DSP-
support IC for conversion to an analog signal. The DSP-support IC then presents the signal to the 
audio power amplifier on the command board, which drives the speaker. For signaling information, 
the DSP decodes the message and passes it to the microcomputer.
3.3.2 Transmit Operation
When the radio is transmitting, microphone audio is passed to the command board limiter, then to 
the DSP-support IC where the signal is digitized. The DSP-support IC passes digital data to the DSP 
where pre-emphasis and low-pass (splatter) filtering are done. The DSP returns this signal to the 
DSP-support IC where it is reconverted into an analog signal and scaled for application to the 
voltage-controlled oscillator as a modulation signal. Transmitted signaling information is accepted by 
the DSP from the microcomputer, coded appropriately, and passed to the DSP-support IC, which 
handles it the same as a voice signal. Modulation information is passed to the synthesizer along the 
modulation line. A modulated carrier is provided to the power amplifier (PA) board, which transmits 
the signal under dynamic power control.
3.4 ASTRO Mode of Operation
In the ASTRO mode (digital mode) of operation, the transmitted or received signal is limited to a 
discrete set of deviation levels, instead of continuously varying. The receiver handles an ASTRO-
mode signal identically to an analog-mode signal up to the point where the DSP decodes the 
received data.
In the ASTRO receive mode, the DSP uses a specifically defined algorithm to recover information.
In the ASTRO transmit mode, microphone audio is processed the same as an analog mode with the 
exception of the algorithm the DSP uses to encode the information. This algorithm will result in 
deviation levels that are limited to discrete levels.
3.5 Control Head Assembly
3.5.1 Display (W4, W5, and W7 Models)
The control head assembly for W4, W5, and W7 models has an 8-character, alphanumeric, vacuum 
fluorescent display. The anodes and the grids operate at approximately 34 Vdc when on and 0 Vdc 
when off. The filament operates at approximately 24 Vrms. The voltage for the display is generated 
by a fixed-frequency, variable duty-cycle controlled “flyback” voltage converter. The switching 
frequency is approximately 210 kHz. The internal microprocessor controls the voltage converter, 
which provides approximately 3.7 Vdc to the vacuum fluorescent (VF) driver and approximately 2.4 
Vrms to the VF display. 
						

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Basic Theory of Operation: Control Head Assembly 3-3
3.5.2 Display (W9 Model)
The control head assembly for a W9 model has an 11-character, alphanumeric, vacuum fluorescent 
display. It needs three separate voltages to operate: the cathode needs 35V to accelerate electrons 
to the anode; the grid needs 40V to totally shut off current flow; the filament needs 3.8 Vrms at 80 
mA. These voltages are obtained from the transformer on the display controller board.
3.5.3 Vacuum Fluorescent (VF) Display Driver
This VF display driver receives ASCII data from the VOCON board, decodes it into display data, and 
then scans the display with the data. Once properly loaded into the display, data is refreshed without 
any further processor action. The display driver is periodically reset by the actions of transistors that 
watch the clock line from the microprocessor to the display driver. When the clock line is held low for 
more than 600 milliseconds, the display driver resets and new display data follows.
3.5.4 Vacuum Fluorescent (VF) Voltage Source (W9 Model)
Voltage for the VF display is generated by a fixed frequency, variable-duty cycle driven, flyback 
voltage converter. An emitter-coupled astable multivibrator runs at approximately 150 kHz. The 
square wave output from this circuit is integrated to form a triangle that is applied to the non-inverting 
input of half an integrated circuit (IC).
During start up, the inverting input is biased at 3.7V. A transistor is on while the non-inverting input 
voltage is below 3.7V. This allows current to flow in a transformer, building a magnetic field. When 
the triangle wave exceeds 3.7V, the transistor turns off and the magnetic field collapses, inducing 
negative current in the transformer.
This current flow charges two capacitors. As the voltage on one of the capacitors increases beyond 
35V, a diode begins to conduct, pulling the integrated circuit’s inverting input below 3.7V. This 
decreases the cycle time to produce the 35V. The 41V supply is not regulated, but it tracks the 35V 
supply.
Similarly, the ac supply for VF filament is not regulated, but is controlled to within one volt by an 
inductor on the display board.
3.5.5 Controls and Indicators
The control head assembly processes all the keypad (button) inputs and visual indicators through 
the microprocessor. Some of the buttons double as function keys for radio options. All buttons are 
backlit to allow operation in low light. Refer to Chapter 1. Introduction (page 1-3 and page 1-5) for a 
functional description of each control switch, button, or indicator.
3.5.6 Status LEDs
These LEDs are driven by the display driver as though they were decimal points on the VF display. 
Level shifting transistors are required for this since the display driver uses 39 Vdc for control signals.
3.5.7 Backlight LEDs
The microprocessor operates the backlight LEDs. A transistor supplies base current to the individual 
LED driver transistors. The driver transistors act as constant current sources to the LEDs. Some 
backlight LEDs are connected to a thermistor. This circuit allows more current to flow through these 
LEDs at room temperature and reduces current as the temperature rises. 
						

							February 3, 20036881076C20-E
3-4Basic Theory of Operation: Power Amplifier
3.5.8 Vehicle Interface Port (VIP)
3.5.8.1  Remote-Mount
The VIPs allow the control head to operate outside circuits and to receive inputs from outside the 
control head. There are three VIP outputs that are used for relay control. There are also three VIP 
inputs that accept inputs from switches. See the cable kit section for typical connections of VIP input 
switches and VIP output relays.
The VIP output pins are located on the back of the control head below the area labeled “VIP.” These 
connections are used to control relays. One end of the relay should be connected to switched B+, 
while the other side is connected to a software-controlled on/off switch inside the control head. The 
relay can be normally on or normally off depending on how the VIP outputs are configured. The 
function of these VIP outputs can be defined by field programming the radio. Typical applications for 
VIP outputs are external horn/lights alarm and horn ring transfer relay control.
3.5.8.2  Dash-Mount
The VIP outputs are driven by a serial-to-parallel shift register. The output transistors are capable of 
sourcing 300mA current. Primarily, these transistors control external relays. The relay is connected 
between the collector and switched B+.
Each VIP input transistor is connected to a dedicated input port through transistors used for input 
protection. These VIP inputs are connected to ground with either normally open or normally closed 
switches.
3.5.9 Power Supplies
The +5V supply is a three-terminal regulator IC to regulate the 12V SWB+ down for the digital logic 
hardware.
3.5.10 Ignition Sense Circuits
A transistor senses the vehicle ignition’s state, disabling the radio when the ignition is off. For 
negative-ground systems, the orange lead is typically connected to the fuse box (+12V).
3.6 Power Amplifier
The power amplifier (PA) is a multi-stage, discrete-transistor RF amplifier consisting of the following:
 Low-level power controlling stage
Drivers
 Final amplifier
 Directional coupler
 Antenna switch
 Harmonic filter
3.6.1 Gain Stages
The first stage buffers the RF signal, filters harmonics, and acts as a variable amplifier. All of the 
amplifying stages are matched using transmission lines, capacitors, and inductors and are supplied 
with dc from either A+, keyed 9.4V, or 9.6V sources. Following the last gain stage, PIN diodes switch 
the signal flow either from the antenna to the receiver, or from the last gain stage to the antenna.  
						

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Basic Theory of Operation: Front-End Receiver Assembly 3-5
3.6.2 Power Control
A directional coupler and detector network controls power. It senses the forward power from the last 
gain stage and feeds the detected voltage back to the command board control circuitry, where it is 
compared to a reference voltage set during power-set procedures. The dc feed voltage is corrected 
and supplied to the “controlled” stage of the power amplifier. Circuitry on the power amplifier board 
controls the gain of the first stage and is proportional to the dc control voltage.
3.6.3 Circuit Protection
Current and temperature sensing circuitry on the power amplifier board feed sensed voltages to the 
command board for comparison. If the command board suspects a fault condition, it overrides the 
power control function and cuts the power back to a level that is safe for the conditions.
3.6.4 DC Interconnect
The ribbon cable connector carries sensed voltages for power and protection to the command board. 
It also carries A+ feed to the command board for distribution throughout the internal transceiver 
chassis and carries control voltage from the command board to the power amplifier board.
The rear battery connector carries A+ from the battery to the power amplifier board. The red lead 
goes directly to the A+ terminal on the PA board. The black lead from the battery connector ties to 
the chassis, and connection to the power amplifier board is made through the board mounting 
screws.
A+ ground connection for the internal transceiver chassis is through the RF coax ground connectors 
and through the mechanical connection of the power amplifier heatsink to the rest of the radio. 
During test conditions in which the power amplifier assembly (board and heatsink) is physically 
disconnected from the rest of the radio, it is acceptable to rely on the coax cable connections to carry 
ground to the internal chassis.
3.7 Front-End Receiver Assembly
The receiver front-end consists of a preselector, a mixer circuit, and an injection filter. The receiver 
injection (1st local oscillator) comes from the VCO assembly through a coax cable. The injection filter 
is either fixed-tuned or tuned at the factory depending upon the bandsplit. The output of the filter is 
connected to the mixer.
The preselector is a fixed-tuned filter. The receiver signal is fed to the preselector from the antenna 
switch in the PA for the 800 MHz radios, or the preamp output for VHF and UHF. The signal is then 
sent to the mixer integrated circuit where it is connected to the mixer transistor. The receiver injection 
is also fed to this point. The mixer output is at the 1st IF center frequency of 109.65MHz. This signal 
is sent to the 1st IF on the RF board through a coaxial cable.
3.8 Radio Frequency (RF) Board
The RF board contains the common synthesizer circuits and dual IF receiver and demodulation 
circuits. A 4-pole crystal filter at 109.65MHz provides first IF selectivity. For HRN6014D, HRN6020C, 
HRN6019C, HRN4009D, HRN4010C, and later RF board kits, two 2-pole crystal filters provide first 
IF selectivity at 109.65MHz. The output of the filter circuit is fed directly to the custom digital back-
end circuit module. An amplifier (at 109.65MHz), the second mixer, the second IF amplifiers (at 450 
kHz), the IF digital-to-analog converter, and the baseband down-converter are part of the digital 
backend circuit module. The digital backend circuit module also converts a 2.1MHz reference to a 
2.4MHz clock for the DSP support circuit module. 
						

							February 3, 20036881076C20-E
3-6Basic Theory of Operation: Voltage-Controlled Oscillator (VCO)
Synthesizing for the first and second VCO is performed by the prescaler and synthesizer ICs. These 
ICs are programmed through a serial data bus from signals generated on the VOCON board. A dc 
voltage, generated on the command board, sets the synthesizer’s reference oscillator frequency of 
16.8MHz. This voltage is controlled by the digital-to-analog converter (D/A), and is the only element 
of the RF board requiring alignment.
The second local oscillator runs at 109.2MHz (low-side injection), and consists of a VCO that is 
frequency-locked to the reference oscillator. Part of the local oscillator’s circuitry is in the prescaler 
IC.
A clamp and rectifier circuit on the RF board generates a negative dc voltage of 4 volts (nominal) for 
increasing the total voltage available to the first VCO and second local oscillator’s VCO. The circuit 
receives a 300 kHz square wave output from the prescaler IC, then clamps, rectifies, and filters the 
signal for use as the negative steering line for the two VCOs.
3.9 Voltage-Controlled Oscillator (VCO)
3.9.1 VHF Radios
The voltage-controlled oscillator (VCO) assembly utilizes a common-gate FET in a Colpitts 
configuration as the gain device. The LC tank circuit’s capacitive portion consists of a varactor bank 
and a laser-trimmed stub capacitor. The inductive portion consists of microstrip transmission line 
resonators. The stub capacitor serves to tune out build variations. Tuning is performed at the factory 
and is not field adjustable. The varactor network changes the oscillator frequency when the dc 
voltage of the steering line changes. The microstrip transmission lines are shifted in and out of the 
tank by PIN diodes for coarse frequency jumps. A third varactor is used in a modulation circuit to 
modulate the oscillator during transmit.
The VCO output is coupled to a transistor for amplification and for impedance buffering. The output 
of this stage passes through a low-pass filter where the signal is split into three paths. One path 
feeds back to the synthesizer prescaler; the other two provide injection for the RX and TX 
amplification strings. The receive injection signal is further amplified and passed to the RX front-end 
injection filter. The transmit signal goes to an ECL divider, which divides the signal by two. The signal 
is amplified and buffered and then injected into the transmitter’s low-level amplifier.
A 5V regulator provides power to the divider. All transmit circuitry operates from keyed 9.4 volts to 
conserve current drain while the radio is receiving. A transistor/resistor network drives the PIN 
diodes in the VCO tank. These driver networks provide forward bias current to turn diodes on and 
reverse the bias voltage to turn the diodes off. AUX 1 AND AUX 2 lines control the PIN diode driver 
networks.
3.9.2 UHF and 800 MHz Radios
The VCO assembly generates variable frequency output signals controlled by the two steering lines. 
The negative steering line increases the tuning range of the VCO, while the positive steering line 
affects the synthesizer control loop to incrementally change the frequency.
The VCO generates a signal in the required frequency range. For UHF and 800 MHz radios, this 
signal is fed to the doubler/buffer circuit which, in turn, doubles the VCO output frequency and 
amplifies it to the power level required by the TX buffer and RX mixer. A PIN diode switch routes the 
signal to the TX port when the keyed 9.4V is high. Otherwise, the signal is routed to the RX port. The 
VCO assembly’s synthesizer feedback output is the same as the doubler output frequency.
3.10 Command Board
The serial input/output IC provides command board functions including buffers for PTT, channel 
active, squelch mute, busy, and data transmission, and logic functions for switched B+, emergency, 
reset, and power control. 
						

							6881076C20-EFebruary 3, 2003
Basic Theory of Operation: VOCON (Vocoder/Controller) Board 3-7
The regulator and power control circuits include an unswitched +5V discrete circuit and the regulator/
power control IC, which produces both switched +5V and 9.6V. The unswitched +5V source is used 
as a reference for its switched +5V source. Filtered unswitched +5V is used for the microcontrol 
circuits. Switched +5V and 9.6V are controlled by a digital transistor from the serial input/output IC. 
The power control circuitry receives power set and limit inputs from the digital-to-analog IC, and 
feedback from the RF power amplifier. Based on those inputs, the power control circuitry produces a 
control voltage to maintain a constant RF power level to the antenna.
The reset circuits consist of the power-on reset, high/low battery voltage reset, and the external bus 
system reset. The reset circuits allow the microcomputer to recover from an unstable situation; for 
example, no battery on the radio, battery voltage too high or too low, and remote devices on the 
external bus not communicating. Communication in RS-232 protocol is provided by an IC which 
interfaces to the rear accessory connector (J2).
3.11 VOCON (Vocoder/Controller) Board
The VOCON board, located on the top side of the radio chassis, contains a microcontrol unit (MCU) 
with its flash memory, DSP, and DSP-support ICs. The VOCON board controls receive/transmit 
frequencies, the display, and various radio functions, using either direct logic control or serial 
communication to external devices. The connector J801 provides interface between the encryption 
module and the VOCON board for encrypting voice messages.
3.11.1 ASTRO Digital Spectra
The VOCON board executes a stored program located in the FLASH ROM. Data is transferred to 
and from memory by the microcontrol unit data bus. The memory location from which data is read, or 
to which data is written, is selected by the address lines.
The support-logic IC acts as an extension of the microcontrol unit by providing logic functions such 
as lower address latch, reset, memory address decoding, and additional control lines for the radio. 
The VOCON board controls a crystal-pull circuit to adjust the crystal oscillator frequency on the 
microcontrol unit, so that the E-clock harmonics do not cause interference with the receive channel.
The vocoder circuitry on the VOCON board is powered by a switched +5 volt regulator located on the 
command board. This voltage is removed from the board when the radio is turned off by the control 
head switch.
The DSP IC performs signaling, voice encoding/decoding, audio filtering, and volume control 
functions. This IC performs Private-Line/Digital Private-Line (PL/DPL) encode and alert-tone 
generation. The DSP IC transmits pre-emphasize analog signals and applies a low-pass (splatter) 
filter to all transmitted signals. It requires a 33MHz crystal to function. An 8 kHz interrupt signal 
generated by the DSP-support IC is also required for functionality. This device is programmed using 
parallel programming from the microcontrol unit and the DSP-support IC.
The DSP-support IC performs analog-to-digital and digital-to-analog conversions on audio signals. It 
contains attenuators for volume, squelch, deviation, and compensation, and it executes receiver 
filtering and discrimination. The IC requires a 2.4MHz clock to function (generated by the digital 
back-end IC) and is programmed by the microcontrol unit’s SPI bus.
3.11.2 ASTRO Digital Spectra Plus
The VOCON board, located on the top-side of the chassis, contains a Dual-Core processor, which, in 
turn, contains a DSP Core, an MCORE Microcontroller Core, and custom peripherals. The board 
also contains memory ICs and DSP support ICs. 
						

							February 3, 20036881076C20-E
3-8Basic Theory of Operation: VOCON (Vocoder/Controller) Board
The VOCON board controls receive/transmit frequencies, the display, and various radio functions, 
using either direct logic control or serial communication to external devices. The connector J801 
provides an interface between the encryption module and the VOCON board for encrypting voice 
messages.
The VOCON board executes a stored program located in the FLASH ROM. Data is transferred to 
and from memory by the microcontroller unit data bus. The memory location from which data is read, 
or to which data is written, is selected by the address lines.
The vocoder circuitry on the VOCON board is powered by two regulated voltage supplies: 3.0 Vdc 
and 1.8 Vdc. These regulated supplies are powered by a switched 5 Vdc regulator located on the 
command board. This 5 Vdc supply also powers some vocoder circuitry. This voltage is removed 
from the board when the radio is turned off by the control head switch.
The DSP Core inside the Dual-Core processor performs signaling, voice encoding/decoding, audio 
filtering, and volume control functions. This core performs Private-Line/Digital Private-Line (PL/DPL) 
encode and alert-tone generation. The DSP Core transmits pre-emphasized analog signals and 
applies a low-pass (splatter) filter to all transmitted signals. The Dual-Core processor requires a 
16.8MHz and a 32 kHz clock to function.
The DSP-support ICs perform analog-to-digital and digital-to-analog conversions on audio signals. 
They contain attenuators for volume, squelch, deviation, and compensation. The receiver interface 
IC requires a 2.4MHz clock to function (generated by the digital back-end IC) and is programmed by 
the microcontroller unit’s SPI bus. 
						

							Chapter 4 Test Equipment, Service Aids, and Tools
4.1 Recommended Test Equipment
The list of equipment contained in Table 4-1 includes most of the standard test equipment required 
for servicing Motorola mobile radios, as well as several unique items designed specifically for 
servicing this family of radios. The Characteristics column is included so that equivalent equipment 
can be substituted; however, when no information is provided in this column, the specific Motorola 
model listed is either a unique item or no substitution is recommended.
Table 4-1.  Recommended Motorola Test Equipment
Motorola
Model NumberDescriptionCharacteristicsApplication
R-1013_* or
R-1370_*SINAD Meter
SINAD Meter with RMS 
Vo lt m et e rw/o RMS audio voltmeter
w/RMS audio voltmeterReceiver sensitivity 
measurements
R-1074_* Fluke 87 Digital 
MultimeterTrue RMS metering, 200kHz 
frequency counter, 32-segment 
bar graph with backlit displayRecommended for ac/dc voltage 
and current measurements
R-1151_* Code Synthesizer 2, 
ExpandedInjection of audio and digital 
signaling codes
R-1377_* AC Voltmeter 1mV to 300V, 10-Megohm input 
impedanceAudio voltage measurements
R-1439_ or
R-1440_
(See 
Table 4-2 for 
plug-in elements)BIRD Wattmeter
BIRD WattmeterPower range: 100 mW to 100W, 
2MHz to 1GHz,
UHF-F connector
Power range: 100 mW to 100W, 
2MHz to 1GHz,
N-female connectorTransmitter power 
measurements
R-1611_ Dual-Channel 100Mhz 
Oscilloscope (Agilent)Two-channel, 100MHz 
bandwidth, 200 M sample rate/
sec., 2MB memory/channelWaveform measurements
R-2600 Series System Analyzer This item will substitute for items 
with an asterisk (*).Frequency/deviation meter and 
signal generator for wide-range 
troubleshooting and alignment
S-1339_ RF Millivolt Meter 100µV to 3V RF
10 kHz to 1GHzRF-level measurements
S-1348_ DC Power Supply, 
Programmable0-20 Vdc, 0-5 Amps current 
limitedBench supply for 7.5 Vdc
SLN-6435 Audio Isolation 
TransformerAudio measurements (audio PA 
must NOT be grounded) 
						

							February 3, 20036881076C20-E
4-2Test Equipment, Service Aids, and Tools: Service Aids and Recommended Tools
Table 4-2 contains a listing of the plug-in elements that are available for the BIRD wattmeters listed in 
the 
Table 4-1.
Table 4-3 contains a listing of non-Motorola test equipment recommended for servicing mobile 
radios.
4.2 Service Aids and Recommended Tools
Refer to the tables in this section for a listing and description of the service aids and tools designed 
specifically for servicing this family of radios, as well as the more common tools required to 
disassemble and properly maintain the radio. These kits and/or parts are available from the Motorola 
Parts Division offices listed in the Replacement Parts Ordering section located on page A-1of this 
manual.
Table 4-4 lists recommended service aids common to both ASTRO Digital Spectra and ASTRO 
Digital Spectra Plus radios. While all of these items are available from Motorola, most are standard 
shop equipment items, and any equivalent item capable of the same performance can be substituted 
for the item listed.Table 4-2.  Wattmeter Plug-In Elements
Power25-60MHz50-125MHz100-250MHz200-500MHz400-1000MHz
5W --- 01-80305F21 01-80305F29 01-80305F38 01-80305F46
10W --- 01-80305F22 01-80305F30 01-80305F39 01-80305F47
25W 01-80305F15 01-80305F23 01-80305F31 01-80305F40 01-80305F48
50W 01-80305F16 01-80305F24 01-80305F32 01-80305F41 01-80305F49
100W 01-80305F17 01-80305F25 01-80305F33 01-80305F42 01-80305F50
250W 01-80305F18 01-80305F26 01-80305F34 01-80305F43 01-80305F51
500W 01-80305F19 01-80305F27 01-80305F35 01-80305F44 01-80305F52
1000W 01-80305F20 01-80305F28 01-80305F36 01-80305F45 01-80305F53
Table 4-3.  Recommended Non-Motorola Test Equipment
Model NumberDescriptionApplication
Agilent 8901_ Modulation Analyzer Reference oscillator deviation and compensation 
measurements
Weinschel 49 30 43 30 dB RF Attenuator For tests that require a modulation analyzer or 
wattmeter