For increased data security, the modem supports the U.S. Government developed Digital Encryption
Standard (DES) data encryption and decryption protocols. This capability requires installation of thirdparty IP compliant DES encryption and decryption software.
The standard IPSeries base station circuit board contains five (5) main sections defined below:
Input/OutputCircuitry associated with one of the following base station’s data
connectors:
RS232 Serial Port DB9 Data Connector
RJ45 Ethernet 10 Base T Interface Connection
System ControllerHouses the modem, diversity, and Ethernet circuitry. Manages the
operation of the base station’s modem providing transmit timeout
protection in the event a fault causes the base station to become
halted in the transmit mode. The system controller also handles the
loading of selected transmit and receive frequencies into the injection
synthesizer. Includes memory for storage through Electrically
Erasable Programmable Read Only Memory (EEPROM) of the base
station’s operating parameters, which are retained after the base
stations power is cycled off.
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SECTION 1: THEORY OF OPERATION
ModemsConvert data into an analog audio waveform for transmission and
analog audio from the receiver to serial data interface. There is one
(1) modem that is dedicated to the transmit operation and two (2)
modems dedicated to the receive operation. The modem dedicated
to the transmit supports a 115.2 KBPS data transmission rate on the
serial port, SLIP protocol, and a 19.2 KBPS OR 9.6 KBPS over-theair data transmission rate. Provides Forward Error Correction (FEC)
and Error Detection (CRC), bit interleaving for more robust data
communications, and third generation collision detection and
correction capabilities.
Diversity Reception
RX Injection The Injection Synthesizer board provides a highly stable local
Transmitter Consists of an exciter and a power amplifier module covering various
Receiver 1/Receiver 2/ Uses three (3) discrete receivers tuned to the same frequency.
Receiver 3 The three (3) receivers are required to support IPMobileNet’s base
NOTE
The receivers are double-conversion superhetrodynes with an
Power Supply Power supply circuitry derives the various operating voltages
Circuitry selects one of three (3) diversity receiver audio outputs for
processing by the modem by comparing the Received Signal
Strength Indication (RSSI) output from each receiver. Audio from the
receiver with the highest RSSI value is passed to the modems.
oscillator signal for the three (3) receivers. This displays a serial
data input/output interface, synthesizer, and VCO.
frequency bands in segments. A different power amplifier module is
required for each segment. The transmitter power control is included
with the power supply circuitry on the same board.
station Diversity Reception System (DRS).
: Some installations use only two (2) receivers.
Intermediate Frequency (IF) of 45 MHz. Each receiver consist of
bandpass filters, RF amplifiers, a mixer, 45 MHz crystal filter, and a
one-chip IF system. The injection synthesizer provides the first local
oscillator signal and outputs from each receiver including RSSI and
analog audio for Diversity Reception.
required by the base station. Fixed voltage regulators are employed
through the base station for this purpose.
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SECTION 1: THEORY OF OPERATION
IP4B Base Station Section Descriptions
System Controller
This section displays the Central Processing Unit (CPU)(U1), clock, and power-on reset circuitry. It
provides more processing power than required for future capabilities to be incorporated without changing
processors. Such capabilities include data encryption/decryption (DES) and remote fault monitoring. U1
features a 16-bit address bus and 128K of internal flash random access memory (RAM).
NOTE
: To enter the programming mode it is necessary to reset the switch (S1) and power up again.
CPU operations are controlled by Y3 an 18.432 MHz clock module. Capacitor (C1) and an internal
Schmidt trigger circuit inside of U1 generates the power on reset signal. The RESET* output from U1
drives a latch and decoder found elsewhere on the board.
This section displays the RAM, decoder, EEPROM, and programming power supply circuitry. U2 is a
512K x 8 bit static RAM chip, which provides temporary storage of base station configuration data while
the power is on. This is necessary in order to program the base station. U2 is controlled directly by the
address, data, and control busses from the CPU.
Chip U5 decodes the A11-A14 address bus to provide chip selects for the modem and EEPROM
memory. Chip U6 is an 8-bit latch. It latches inputs from the D0-D7 bus and lights the front panel status
indicators (
Chip U3 is a serial EEPROM, which provides 2K bits of pre-programmed data storage for the CPU. Data
is clocked out of U3 by EECLK, and back into the CPU via EEDATA.
A programming power supply is required for the flash RAM inside of the CPU, and this function is
performed by U4. This chip is a low dropout voltage regulator with a shutdown control. Resistors R22
and R21 set the output voltage. When the base station configuration data is to be stored in flash RAM,
the CPU makes VPP_ENABLE high. This turns on the regulator, producing a 12-volt output via VPP for
the flash RAM.
This section displays a dedicated processor and voltage regulator. Chip U7 is a processor, which permits
manual keyboard operation of the base station. Regulator VR2 provides 5 volts DC power for all logic
circuitry on the System Controller Board.
Input/Output
This section displays the CPU input/output circuitry. Chip U8 is an RS232 transceiver, which interfaces
the CPU to the modem via J1. From there, the RS232 data goes directly to a rear panel DB9 connector.
U8 converts 5-volt logic-level data to +/-12 volt data in RS232C form, and vice-versa. A charge pump
power supply on the chip converts the +5 volt DC power to the +/-12 volt levels required. The charge
pump uses capacitors (C28 to C31) to generate voltages.
NOTE
Modem Switching
This section displays the connector wiring and modem switching circuitry. Connector J7 is routed to the
front-panel TX, CD, and RX1-RX3 LED indicators. The base station will also accept modulation from an
external source (modem or amplified microphone audio). Transmission gate U10A switches this signal
source.
TX, CD, RX1, RX2, and RX3).
: The RS232 serial port data transmission rate of the base station is 115.2 KBPS.
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SECTION 1: THEORY OF OPERATION
Modem
This base station uses separate modems for receive and transmit functions so that full-duplex operation
may be obtained. The A0-A1 address bus in addition to the individual read (RD*), write (WR*), and chip
select (MODEMTXCS*) lines control all three (3) modems. Modem operations are timed by Y2, a 4.9152
MHz clock module.
Modem chip U14 is dedicated to the transmit operation. Data from the D0-D7 bus is read by the chip,
and then converted to a 4-level FSK analog signal, which appears on the TXOUT pin. Op amp U21B
buffers the signal, which becomes the MODEM_TXMOD output. From this point, the signal is routed to
the modulation circuitry on the Exciter Board.
Chip U14 has the ability to demodulate receiver audio, although this capability is not used in most
systems. Incoming data-bearing audio from the Diversity Reception circuitry (and selected receiver)
appears at DISC_AUDIO. The signal passes through resistor R54 and into the modem chip. Resistor
R52 and capacitor C41 serve as feedback elements, limiting both the gain and bandwidth of an amplifier
within U14. The modem chip demodulates the audio into 8-bits of data, which exit U14 on the D0-D7 bus.
Chip U14 also provides a bias voltage for the analog circuitry on the Exciter Board. This voltage is about
2.5 volts DC, and it appears on the VBIAS line. The purpose of VBIAS is to bias the Exciter Board analog
circuitry for proper operation. Please note that if this voltage is low or missing, the Exciter Board circuitry
may not work.
Modem chip U15 is dedicated to the receive operation. Incoming data-bearing audio from the Diversity
Reception circuitry (and selected receiver) appears at DISC_ AUDIO. The signal passes through resistor
R56 and into the modem chip. Resistor R55 and capacitor C46 serve as feedback elements, limiting both
the gain and bandwidth of an amplifier within U15. The modem chip breaks down the audio into 8 bits of
data, which exit U15 on the D0-D7 bus.
Modem chip U16 is also dedicated to the receive operation, although it may not be used in this
application. The operation of U16 is exactly the same as U15.
Receive Signal Strength Indication Comparator
This section displays the RSSI comparator circuitry. A series of comparators (U20BCD) simultaneous
compare RSSI1 to RSSI2, RSSI2 to RSSI3, and RSSI1 to RSSI3. Within this process eight (8) possible
results are then forwarded by the comparators to a series of NAND gates (U18ABC), which reduce the
number of results to three (3) and translates the results for an analog multiplexer (U19A). To determine
which of the three (3) results is the strongest, the following needs to occur:
For Receiver 1 to be selected as the strongest signal, both input pins on the NAND gate (U18D) must
go high (driving pin 7 of U19A). If Receiver 1 has the strongest signal, a light emitting diode
(LED)(D1) lights indicating Receiver 1 was selected.
For Receiver 2 to be selected as the strongest signal, the inverter (U17B) must go high (driving pin 6
of U19A). If Receiver 2 has the strongest signal, D2 lights indicating Receiver 2 was selected.
For Receiver 3 to be selected the strongest signal, the inverter (U17C) must go high (driving pin 5 of
U19A). If Receiver 3 has the strongest signal, D3 lights indicating Receiver 3 was selected.
SEL_RSSI is the output selected with the strongest signal. When RSSI voltage exceeds a threshold,
another LED (D4) lights. As the other three (3) LEDs, this circuit is intended as a diagnostic tool. It
provides a go/no go indication that an RF signal has been received. A pot (R74) sets the turn-on voltage.
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SECTION 1: THEORY OF OPERATION
Baseband
This circuitry amplifies the audio from each receiver, routes it through a RF multiplexer, and selects the
audio from the receiver with the highest RSSI value. The comparator circuit on the previous sheet
controls it.
There are three (3) channels of audio, with separate gain and DC offset adjustments to compensate for
performance differences in the receivers. For example, incoming audio from receiver 1 appears at
AUDIO 1. An op amp (U12D) is then amplifies the audio. A pot (R72) adjusts the gain, while another pot
(R57) adjusts the DC offset on the output. The amplifier output passes through a RF multiplexer (U19B),
then drives a low pass filter (U9) through another op amp (U12A) and through the AUDIO_OUT line,
which goes to a switch (S3) and to pin 4 of a connector (J3).
The remaining audio circuits work in the same manner.
The output from U19B also appears on DISC_AUDIO, which goes to the CPU (U1) and from there the
audio is demodulated by the modems.
Receiver Board
Please be aware that the base station uses three (3) identical receiver boards. As a result, the circuitry
Front end. Incoming signals pass through a bandpass filter (FLT4). The desired signals are amplified by
U8 and additional selectivity is provided by a monolithic bandpass filter (FLT5). Another amplifier (U7)
further amplifies the signal and the output pass through two (2) crystal filters (FLT2 and FLT3).
IF Amplifier
The incoming 45 MHz signal passes through C17, C18, and R28 which provides impedance matching to
the IF amplifier input. U6 is a super heterodyne IF subsystem. Inside the chip, the signal is applied to a
mixer. The mixer also accepts a 44.545 MHz local oscillator input. The local oscillator consists of an
internal amplifier, plus crystal (Y4) and associated components. The mixer output passes through Y3, a
455 KHz ceramic IF filter. It is amplified, passed through ceramic filter (Y2), and on to a second IF stage.
The IF output drives a quadrature detector. The phase shift elements for the detector are C20 and FLT1.
The recovered audio appears at pin 9, while RSSI appears at pin 7.
Within the RSSI circuitry, chip U6 uses a detector, which converts the AGC voltage generated inside the
chip into a DC level corresponding logarithmically to signal strength. RSSI is used by Diversity Reception
on the System Controller to select the receiver with the highest quality signal.
A filter consisting of a resistor (R21) and a capacitor (C40) provides high frequency de-emphasis for the
audio. The audio is buffered by op amp U3A. From there the AUDIO output line goes to a connector, for
hookup to Diversity Reception on the System Controller Board.
Resistor (R22) and capacitor (C41) provides RF filtering for the DC RSSI voltage. The RSSI is buffered
by op amp U3B. From there the RSSI output line goes to a connector, for hookup to Diversity Reception
on the System Controller Board.
Several sets of 455 KHz IF filters (Y3 and Y2) are available to suit receiver selectivity requirements.
will be described only once.
Should replacement of these filters be required, exact replacement parts must be used.
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SECTION 1: THEORY OF OPERATION
Receiver Injection
This displays a serial data input/output interface, synthesizer, and VCO. The I/O interface circuitry
accepts clock, serial data, and enable signals from the System Controller Board via terminal block TB1. A
lock detect (LD) status output is returned to the System Controller Board from the synthesizer. U3 is a
hex Schmidt Trigger inverter, which squares up incoming signals for reliable operation of the synthesizer
chip. This is necessary because of a cable run between the two (2) boards.
The main section of this board is synthesizer chip (U2). The device contains the key components of a
phase locked loop (PLL), including a 1.1 GHz prescaler, programmable divider, and phase detector. In
operation, the desired frequency is loaded into U2 as a clocked serial bit stream via the CLK and DATA/I
inputs. The lock detection circuitry consists of inverters U3E/U3F, diode CR3, and resistor R5. When the
synthesizer is in lock, the LD pin on U2 is high, making the LD output on terminal block TB1 high. The
EXC LD input on TB1 routes the lock detect output from the Exciter Board through diode CR3, and out
through LD. This configuration tells the CPU on the System Controller Board that it is acceptable to
process received data, or to key the transmitter when LD is high. Otherwise, if a fault in either synthesizer
prevents a lock, receive and transmit operation will be inhibited.
Other items of interest include a programming switch and serial data output. Switch (JMP1) may be used
to program the firmware configuration inside chip U2. The system controller board performs programming
so a jumper is installed in the LNVCC (operation) position instead. The EXT DATA output on block TB1
sends frequency programming data to the transmitter synthesizer on the Exciter Board.
The UHF injection signal is generated by module VCO1. This device is a wide-range voltage controlled
oscillator (VCO). A voltage on the VT input determines the VCO frequency. The voltage is generated by
the phase detector output (PD/O) of U2, which drives a loop filter consisting of R4, C19, C20, R21 and
C10. The filter integrates the pulses, which normally appear on PD/O into a smooth DC control signal for
the VCO. The output of VCO1 is attenuated by module AT1, resulting in improved VCO stability.
This section displays the DC power supplies, frequency reference, and RF output circuitry. Regulator
VR1 provides 9 volts DC for VCO module VCO1, and RF amplifier (U7). Regulator (VR2) provides a low
noise 5-volt DC output for inverter (U3), synthesizer (U2), and reference (Y1).
Reference module (Y1) provides a high-stability 10 MHz reference frequency. Y1 is a voltage controlled,
temperature controlled crystal oscillator (VCTCXO). This device also has a VC input which accepts a
control voltage from pot R23. The pot permits a slight shift in the reference frequency which enables the
three (3) receivers to be tuned precisely to the assigned receive frequency. A diode (CR2) provides
additional voltage regulation, improving the frequency stability of reference Y1.
The RF output circuitry consists of RF amplifier (U7), and power splitters (U8, U5, and U6). U7 increases
the signal level to correct for losses in the splitters. The splitter U8 provides two (2) RF outputs. One
output drives splitter U5, which provides local oscillator injection for receivers 2 and 3. The other output
drives splitter (U6), which drives receiver 1 and the PLL_FEEDBACK input on chip U2.
Exciter Board
This section displays the input/output interface, transmitter keying, and power supply circuitry. The
input/output interface is built around terminal block (TB1) and Schmidt Trigger inverters (U7). Incoming
clock, serial data, and chip select signals on block TB1 are squared up by U7. Then they are sent to the
appropriate inputs on the transmitter synthesizer (U2). The EXCDATA source comes from the receive
synthesizer on the Injection Synthesizer Board. A Schmidt Trigger chip is used here because of a cable
ran to the System Controller Board. The synthesizer returns a lock detect output to the Injection
Synthesizer Board via U6 and EXCLD.
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SECTION 1: THEORY OF OPERATION
A regulator (VR2) powers the T/R switch circuitry. When the System Controller Board makes TXKEY*
low, inverter U6D goes high, turning on transistor Q2 and FET Q1. This applies 5-volt power to the
TXENABLE output, turning on the T/R switch on the Power Amplifier Board. At the same time, transistor
Q3 conducts, grounding the KEY* input of the Power Amplifier Board. Finally, inverter U6C goes high
and turns on RF switch U1, connecting the VCO output to the Power Amplifier Board for transmission.
The power supply consists of two (2) voltage regulators. A regulator (VR1) provides 9-volt power for the
VCO. Another regulator (U11) provides low noise 5-volt power for the logic circuitry, synthesizer chip,
and analog circuitry.
Analog Modulation
This section displays the analog modulation circuitry. Incoming modem audio from the System Controller
Board appears at TXMOD, and is buffered by op amp U5C. If an external modulation source (modem or
amplified microphone) is connected to the base station’s DB9 connector, audio appears at EXTMOD.
From there the audio passes through low pass filter U10. The audio is inverted and amplified by an op
amp (U5D). It then passes on to the VCO module via VCOMOD. Pot R42 adjusts the level to suit the
VCO.
The 10 MHz reference is also modulated in order to counteract the corrective effects of the synthesizer
loop circuitry. For example, if only the VCO were modulated, the synthesizer would try to compensate for
the frequency “error,” caused by the modulation. This effectively reduces the amount of modulation
available. Modulating the reference and the VCO simultaneously deceives the loop into not
compensating for the modulation, because when the reference frequency goes high, the VCO frequency
goes high, and vice-versa.
An op amp (U9A) amplifies the AUDIO output from another op amp (U5D) and applies it to jumper block
JMP1. Pot R30 adjusts the gain of U9A. Op amp (U9B) inverts the phase of the audio and applies it to
the other side of jumper block JMP1. The purpose of the jumper block is to select the proper phase of the
audio. If the wrong phase is used, on modulation peaks the reference will swing in the same direction as
the VCO, canceling out most of the modulation. The output from the jumper block goes to the 10 MHz
reference via REFMOD.
The VBIAS input is a 2.5-volt DC source, which biases the op amps to the correct operating point. It is
generated by modem chip (U14) on the System Controller Board.
Phase Locked Loop
This section displays phase locked loop (PLL) circuitry. The 10-MHz reference (Y1), runs synthesizer
(U2), which in turn controls VCO VCO1. The main section of this board is the synthesizer chip (U2). The
device contains the key components of a PLL, including a 1.1 GHz prescaler, programmable divider, and
phase detector.
In operation, the desired frequency is loaded into U2 as a clocked serial bit stream via the CLK and DATA
inputs. The lock detection circuitry consists of inverters U6A and U6B, diode CR1, and resistor R1.
When the synthesizer is in lock, the LD pin on U2 is high, making the EXCLD output on terminal block
(TB1) high. The EXCLD output on TB1 routes the lock detect output from the Exciter Board. This
configuration tells the CPU on the System Controller Board that it is acceptable to process received data,
or to key the transmitter when LD is high. Otherwise, if a fault in either synthesizer prevents a lock,
receive and transmit operation will be inhibited.
The switch (JMP1) is used to select the supply voltage to chip U2. The UHF injection signal is generated
by module VCO1. This device is a wide-range voltage controlled oscillator (VCO). A voltage on the VT
298994.DOC Page 9
SECTION 1: THEORY OF OPERATION
input determines the VCO frequency. The voltage is generated by the phase detector output (PD/O) of
U2, which drives a loop filter consisting of R19, C16, C17, and C47. The filter integrates the pulses,
which normally appear on PDOUT into a smooth DC control signal for the VCO. The output of VCO1 is
attenuated by module AT2, resulting in improved VCO stability.
Amplifier U8 amplifies the signal and applies it to a splitter (U3). One output of U3 is connected to a
switch (U1). U1 is enabled by signal TX when the transmitter is enabled. The other output of the splitter
is connected through AT1 and provides feedback to U2.
Power Amplifier
The transmit injection signal from the RF injection section is applied to the high-powered linear amplifier
(U1) one (1) watt amplifier. The signal is then routed to the final power amplifier boosting the output
signal to 40 watts. The transmitter output power is controlled with R3. R3 controls the output voltage of
an adjustable regulator (U3). The signal KEY* enables the regulator. The output of the amplifier is routed
to transmit antenna port ANT (via SW1).
298994.DOC Page 10
SECTION 2: FACTORY TEST PROCEDURE
Equipment List
The following table lists the equipment required to perform the IP4B Base Station Factory Test
Procedure.
CHECKLIST OF REQUIRED MATERIAL FOR
PRELIMINARY TESTING OF THE IPSeries BASE STATION
NO. REQUIRED TOOLS
Calibrated Base Station System – Consisting of the following components:
(1) Appropriate version IPSeries Base Station to be tested
(2) Desktop or laptop computer configured as an Internet Protocol Network Controller (IPNC)
1
(3) Corresponding IPSeries Mobile Radio (If an IP4B base station, use IP4 mobile radio)
(4) Desktop or laptop computer with two (2) available serial ports and Microsoft Windows 95 or
greater and IPMobileNet Dial-Up Networking, IPMessage software (IPMN_INVADR.exe), and
HyperTerminal for base station installed
2
Comm Test Set (HP 8920A or B)
3
High Frequency Probe (85024A)
4
Power Supply for 85024A Probe (HP1122A)
5
Four (4) Channel Scope (Tektronix TDS 460A)
6
General Purpose Scope Probe
7
Digital multi-meter Tektronix Fluke (DMM912 77)
8
DC power supply with ammeter, 13.8V, 12 amps or more (Astron VS12M or equivalent)
9
100-watt dummy load/attenuator (Pasternack PE7021-40 or equivalent)
10
Four (4) antennas (generic mag mounts) tuned to frequency or transceiver
;
11
Serial cable DB9M – DB9F connectors (generic)
12
Input/Output (I/O) Board (IPMN p/n: 502-80081)
13
IPSeries Base Station power cable specified for use with the specific base station being used
14
Three (3) serial DB9F-DB9M Null Modem cables
298994.DOC Page 11
SECTION 2: FACTORY TEST PROCEDURE
Programming and Configuring the Base Station
This section applies to all frequency ranges of the IPSeries Base Station. Important! The base station’s
The programming procedure should be performed when it is necessary to upgrade a base station’s
Firmware or to change the operating parameters to suit client needs.
Viewing the Base Station’s Configuration Data
Step 1 At the HyperTerminal window, type in the appropriate password and press [ENTER].
Step 2 Type ? and press [ENTER]. The following example displays in the HyperTerminal
IP address must be known prior to performing the procedures in this section.
window:
Host serial = 115200,N,8,1, timeout=200
Host framing = SLIP, no split frames no status messages
tunnel = 0
TX format = new
Injection = LOW SIDE, 45MHz
channel spacing = 25000
Channel = 0
Channel Tx freq Rx freq Inj freq
Frequency=0 , 481.000000, 486.000000, 441.000000
Serial number: yyyyyyyyy
RIM address = 1
Frequency group = 1
TX quiet time = 5
Symbol sync time = 12 milliseconds, 0 extra inter-split-frame count
TX tail time = 5
Radio data rate = 19200
Max data tx time = 60 seconds
Carrier detect delay time = 1 millisecond
Station ID = ABC123
Station ID time =10 minutes
Polarity = TX+, RX+
Allow crc errors = 0
Suppress keep alive = 0
Allow base to base = 0
Timeslot status = 0
Duplicate time = 10 milliseconds
Control head grant delay = 50 milliseconds
RIM DD delay = 0 milliseconds
Retry interval = 0 milliseconds
Retry time limit = 0 milliseconds
RSSI step = 25 (=19dBm)
IPNC = 192.168.3.3
SLIP Address = 192.168.4.6
RF IP Address = 192.168.3.1
SNTP interval = 60 seconds
num timeslots = 16
timeslot period = 992ms
timeslots per voice packet = 4
noise = -128dBm
Fixed TX Delay = 0 milliseconds
Scale TX Delay = 0 microseconds
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SECTION 2: FACTORY TEST PROCEDURE
Adjustment / Alignment Procedures
Make appropriate notations of any items that require attention during this procedure. This information is
needed later during the repair process.
Startup
Step 1 Remove the base station cover placing the screws in a location where they will not be
Step 2 Connect the base station to the appropriate components.
Step 3 Power up the base station and computer. The power supply ammeter must read 1.2
Receiver Injection
Step 1 Using the HP high frequency probe verify that the receiver injection frequency is present
Step 2 Adjust R23 on the receiver injection circuit board to set the injection frequency within 10
Receiver
Step 1 Using the high frequency probe, monitor the 44.545 MHz second injection frequency
Step 2 Inject an on-frequency signal at a level of –80 dBm, modulated with a 1 KHz test tone at
Step 3 Check the receiver’s sensitivity, verifying that the SINAD is 12 dB or better at a maximum
misplaced.
amps or less with a 13.8 VDC input.
at each of the three (3) receivers by monitoring the receivers R24 surface mount pad
which lies on the 50 ohm track between P1 and C43.
Hz of the exact injection frequency. The amplitude of the injection frequency should read
approximately +5 dBm ±1 dBm.
at U6 pin 3, adjust trimmer capacitor (C22) to the center of the oscillator’s oscillation
range. The amplitude level of pin 3 of U6 should read between +5 and +10 dBm.
±5.0 KHz deviation into the receiver under test.
level of –119 dBm (-120 is typical).
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SECTION 2: FACTORY TEST PROCEDURE
Diversity Reception
Step 1Inject an on-frequency signal at a level equal to Receiver 1 12dB SINAD level, modulated
with a 1 KHz test tone at ±5.0 KHz deviation into Receiver 1.
Step 2 While monitoring TP1 with the digital multi-meter, adjust RSSI1 low adjust potentiometer
(R12) for a reading of 0.750 VDC ±10 mV.
Step 3 Increase the amplitude of the signal by 50 dBm.
Step 4 While monitoring TP1 with the digital multi-meter, adjust RSSI1 high adjust potentiometer
(R11) for a reading of 2.75 VDC ±10 mV.
Adjustments R11 and R12 are interactive adjustments, therefore continue adjustments until the DC voltage
at TP1 is 0.750 VDC for the receiver’s 12 dB SINAD level and 2.75 VDC for a 50 dBm increase from the
Step 5 Inject an on-frequency signal at a level equal to Receiver 2 12dB SINAD level, modulated
Step 6 While monitoring TP2 with the digital multi-meter, adjust RSSI1 low adjust potentiometer
Step 7 Increase the amplitude of the signal by 50 dBm.
Step 8 While monitoring TP2 with the digital multi-meter, adjust RSSI1 high adjust potentiometer
Adjustments R9 and R10 are interactive adjustments, therefore continue adjustments until the DC voltage
Step 9 Inject an on-frequency signal at a level equal to Receiver 3 12dB SINAD level, modulated
Step 10 While monitoring TP3 with the digital multi-meter, adjust RSSI1 low adjust potentiometer
Step 11 Increase the amplitude of the signal by 50 dBm.
Step 12 While monitoring TP3 with the digital multi-meter, adjust RSSI1 high adjust potentiometer
Adjustments R33 and R35 are interactive adjustments, therefore continue adjustments until the DC voltage
receiver’s 12 dB SINAD level.
with a 1 KHz test tone at ±5.0 KHz deviation into Receiver 2.
(R10) for a reading of 0.750 VDC ±10 mV.
(R9) for a reading of 2.75 VDC ±10 mV.
at TP2 is 0.750 VDC for the receiver’s 12 dB SINAD level and 2.75 VDC for a 50 dBm increase from the
receiver’s 12 dB SINAD level.
with a 1 KHz test tone at ±5.0 KHz deviation into Receiver 3.
(R33) for a reading of 0.750 VDC ±10 mV.
(R35) for a reading of 2.75 VDC ±10 mV.
at TP3 is 0.750 VDC for the receiver’s 12 dB SINAD level and 2.75 VDC for a 50 dBm increase from the
receiver’s 12 dB SINAD level.
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SECTION 2: FACTORY TEST PROCEDURE
Step 13 Inject on-frequency signal at a level of –80 dBm, modulated with a 1 KHz test tone at
±5.0 KHz deviation into Receiver 1.
Step 14 While monitoring the AC voltage at TP6 adjust audio 1 AC adjustment potentiometer
(R72) for 350 mVRMS (±1 mV).
Step 15 While monitoring the DC voltage at TP6 adjust audio 1 DC adjustment potentiometer
(R57) for 2.500 VDC (±1 mV).
The audio AC and DC adjustments are interactive, therefore continue adjusting R72 for 350 mVRMS and
R57 for 2.500 VDC until further adjustments are no longer required.
Step 16 Inject on-frequency signal at a level of –80 dBm, modulated with a 1 KHz test tone at
±5.0 KHz deviation into Receiver 2.
Step 17 While monitoring the AC voltage at TP6 adjust audio 1 AC adjustment potentiometer
(R71) for 350 mVRMS (±1 mV).
Step 18 While monitoring the DC voltage at TP6 adjust audio 1 DC adjustment potentiometer
(R58) for 2.500 VDC (±1 mV).
The audio AC and DC adjustments are interactive, therefore continue adjusting R71 for 350 mVRMS and
R58 for 2.500 VDC until further adjustments are no longer required.
Step 19 Inject on-frequency signal at a level of –80 dBm, modulated with a 1 KHz test tone at
±5.0 KHz deviation into Receiver 3.
Step 20 While monitoring the AC voltage at TP6 adjust audio 1 AC adjustment potentiometer
(R53) for 350 mVRMS (±1 mV).
Step 21 While monitoring the DC voltage at TP6 adjust audio 1 DC adjustment potentiometer
(R59) for 2.500 VDC (±1 mV).
The audio AC and DC adjustments are interactive, therefore continue adjusting R53 for 350 mVRMS and
R59 for 2.500 VDC until further adjustments are no longer required.
Step 22 Adjust the carrier detect potentiometer (R74) to illuminate a level of –116 dBm.
Receive Data
Step 1 Using a calibrated mobile radio, generate uplink data messages using the X=1400,19
Step 2 Attach an antenna to one of the base station’s receiver ports and verify on the base
command in the IPMessage Utility program.
station monitor screen (HyperTerminal) that the received message data quality are
consistently 240 and higher for 1400 character messages. Repeat test for each receiver.
298994.DOC Page 15
SECTION 2: FACTORY TEST PROCEDURE
Exciter
Step 1 Using the X=1400,19 command, generate data messages so the transmit power and
frequency can be checked.
Step 2Note the power level and then on the power amplifier circuit board adjust the
potentiometer (R3) fully counterclockwise (this will enable low power transmit operation).
Step 3 Connect the base stations’ transmit port to the HP communication test set.
Step 4 While transmitting data messages using the X=1400,19 command, adjust the following:
TCXO Y1 for minimum frequency error
R42 for ±5 KHz deviation
Transmit output power should be approximately 1mWatt. The REFMOD adjustment needs to be made
Step 5 Connect the base station to the IPNC.
Step 6 Using a calibrated mobile radio operating on the base station’s channel, adjust R30 for
This command will ping the IPNC continuously with a 500-character test message. Press [Ctrl]+C to
Power Amplifier
Step 1 Connect the base station’s transmit port to the communication test set.
Step 2 Using the X=1400,19 command, generate data messages.
Step 3 Slowly increase the base station output power by turning the power control potentiometer
Do not exceed 40 watts output power, as this will reduce the life of the amplifier module. If the base
Step 4 Perform a close visual inspection of the base station paying close attention to
while the base station is transmitting real data messages to and from a mobile radio. This is most easily
done using the ping command to ping the IPNC from a mobile radio. This will cause the base station to
repeatedly send data messages and will facilitate the REFMOD adjustment.
consistent data quality readings of 248 (as observed on the mobile radio’s attached PC
IPMessage window). Access the MSDOS prompt and ping using the following command:
>;ping 192.168.3.3 –t –l 500 –w 2000
stop the ping.
clockwise until the power noted in Step 2.
station uses a power amplifier, output power must be set to achieve power output specified for the
specific base station installation.
manufacturing related problems such as loose screws, solder practices, etc.
298994.DOC Page 16
MUSTBESUITABLEFORTYPING.
IP4B Base Station FCC Label Placement
IP4B Base Station FCC Label
Serial No.
Model: IP4B
400-512MHz BASE STATION
U.S. PATENT Nos. 5.640.695, 6,018,647,
6,243,393
Made in U.S.A.
Serial No.
Model: IP4B
SCALE : 2X
SECTION 3: FCC LABEL
400-512MHz BASE STATION
U.S. PATENT Nos. 5.640.695, 6,018,647,
Made in U.S.A.
6,243,393
298994.DOC Page 17
System Controller
Receiver - Top
REWORK INSTRUCTION
ADD JUMPER (30 AWG INSULATED WIRE)
from U19 Pin2 to VIA (RVCC)
APPENDIX A: CIRCUIT BOARD DIAGRAMS
32
U2
109
108
C8
R33
U19
U20
C58
C59
R88
R39
12
U18
U17
R81
R82
R83
D7
+
C90
R41
R43
R42
R44
R40
1
J7
U6
U21
8
J8
1
7
C89
C88
9
10
VR3
J5
1
2
C7
R31
73
72
U7
Y2
26100
C84
16
R62
C83
50
C56
U14
U15
U16
Y1
U13
1
25
R50
R66
R65
76
51
75
U10
TP5
J2
C76
R80
C74
J3
R79
T1
C75
R51
C77
S3
S2
J1
C28
U8
S1
U4
TP8
TP4
F1
+
IP4B Rx S/NIP MobileNet
298994.DOC Page 18
Receiver – Bottom
Receiver Injection
APPENDIX A: CIRCUIT BOARD DIAGRAMS
TB1
C46
U7
C28
U8
U5U6
P3 P2
C51
VR1
C50
+
C49
VCO1
AT1
C31
C34
L1
R17
JMP1
1
R8
C1
C36
C35
P1
C52
R26
VR2
C54
+
C53
C32
C33
C26
U3
R5
C10
R25
+
C20
R21
C29
C30
R16C2
C19
R3
L2
C37
C21
C16
R4
+
CR3
C4
C5
U2
C3
+
+
C6
C14
+
C8
C12
C13
C7
R24
R23
R22
Y1
+
CR2
C27
R11
298994.DOC Page 19
Exciter – Top
Exciter – Bottom
APPENDIX A: CIRCUIT BOARD DIAGRAMS
298994.DOC Page 20
Power Amplifier
APPENDIX A: CIRCUIT BOARD DIAGRAMS
+
298994.DOC Page 21
Program and Configure the Base Station
Date
Serial Number
Firmware Revision
End User
Tester
Adjustment / Alignment Procedures
Receiver Injection
APPENDIX B: IP4B TEST DATA SHEET
Parameter
Injection Frequency Error at RXINJ1(within +/- 10
Hz of exact injection frequency)
P1 & C39
Receiver Diversity Reception Controller 1, 2 & 3
Parameter
U6 Pin 4
RSSI Test Point TB1-4
Distortion
(1 kHz Test Tone @ 5.0 kHz)
SINAD 12 dB
(1 kHz Test Tone @ 5 kHz)
SINAD 12 dB TP1
Spec Measured
Spec
+10 to +5 dBm
2.8 to 3.0 VDC
3%<
-119dBm >
0.75 VDC
+/- 1 mV
Receiver 1
+/- 100 Hz
5 +/- 1 dBm
Measured
Receiver 2
Measured
Receiver 3
Measured
SINAD +50 dB TP1
Audio AC Amplitude
(1 kHz Test Tone @ 5 kHz
Deviation)
Audio DC Amplitude
(1 kHz Test Tone @ 5 kHz
Deviation)
Carrier Detect Light Set
298994.DOC Page 22
2.75 +/- 1 mV
350 mVRMS
+/- 1mV
2.5 VDC
+/1 1mV
-116 dBm
Data Quality
APPENDIX B: IP4B TEST DATA SHEET
Parameter
Receiver 1 Data Quality
(x=1400, 19 Command IPMessage Utility)
Receiver 2 Data Quality
(x=1400, 19 Command IPMessage Utility)
Receiver 3 Data Quality
(x=1400, 19 Command IPMessage Utility)
Exciter
Parameter
Transmit Frequency Error
(Transmitting 1400 character test message)
Transmit Modulation Deviation
(5.3 kHz while transmitting 1400 character test
message)
Transmit Data Quality
(While transmitting 1400 character test message
to the base station)
Transmit Power Control
Warning: Do Not exceed 40 Watts RF output power during this test
Spec Measured
240>
240>
240>
Spec Measured
+/- 500 Hz
5.1 kHz to 5.3 kHz
240>
Parameter
Output Power
(Use x=1400,19 command)
Test Check List
Test Task
Attached copy of Base Station’s Firmware Settings
Visual Inspection
Copy Base Station Settings Below:
298994.DOC Page 23
Spec RF Out RF Out Max Level set to
40 +/- 1 Watt
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