Maxon SD-171E User manual

- 1 -
SD-171E / SD-174E
Data Radio
Service Manual

Service Manual SD170E Series
Page 2 of 44
Amendment Record Sheet
All amendments to this manual should be incorporated as soon as they are received and
recorded below:
Issue No.
Effective
Date
Reason for Change
Date
Signature
All Engineering Bulletins relevant to this product should be placed at the rear of this binder.
Please ensure that this manual is updated with any replacement pages, which may accompany
these Engineering Bulletins.
Always read all Engineering Bulletins before carrying out work on a radio.
Please read the WARNINGS on the next page before referring to subsequent sections.
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Service Manual SD170E Series
Page 3 of 44
Warnings
1. NEVER connect the transceiver to a power source of more than 13.8V.
2. NEVER dispose of the battery in fire –it can explode causing personal injury.
3. NEVER attempt to disassemble the battery or remove its case material or charging
contacts. Do not short the battery terminals.
4. NEVER expose the transceiver to rain, snow or any liquids.
5. NEVER modify a radio or accessory except as instructed in the service manual,
engineering bulletins or formal communication as this may invalidate any warranty,
guarantee or type approval.
6. DO NOT use or place the transceiver in areas with temperatures below -30°C or above
+60°C, In areas subject to direct sunlight, such as the dashboard.
7. DO NOT hold the radio in such a manner that the antenna is next to, or touching,
exposed parts of the body, especially the face or eyes, while transmitting.
8. DO NOT allow children to operate transmitter-equipped radio equipment.
9. DO NOT operate the radio near unshielded electrical blasting caps or in an explosive
atmosphere, unless it is a type especially designed and qualified for such use.
10. NEVER modify this device or its accessories, except as instructed in the Service Manual,
Engineering Bulletins or formal communication as this may invalidate any warranty,
guarantee or type approval.
11. AVOID placing the transceiver in excessively dusty environments.
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Service Manual SD170E Series
Page 4 of 44
Contents
Amendment Record Sheet............................................................................................................2
Warnings .....................................................................................................................................3
Contents ......................................................................................................................................4
Introduction.................................................................................................................................5
Pre-Install check, Accessories & Options ......................................................................................6
Pre-Installation...........................................................................Error! Bookmark not defined.
Accessories ...............................................................................Error! Bookmark not defined.
Options....................................................................................................................................6
Product Introduction ....................................................................................................................7
Installation...................................................................................................................................8
Installation ...............................................................................................................................8
External Connections...............................................................................................................8
General Specification....................................................................................................................9
Transmitter Specification............................................................................................................10
Receiver Specification ................................................................................................................11
Reference Crystal.......................................................................................................................12
Enviromental..............................................................................................................................12
Dimensions ................................................................................................................................12
Features ....................................................................................................................................13
Access to digital and RF boards..................................................................................................16
Alignment ..................................................................................................................................19
Alignment points........................................................................................................................23
Flow Diagrams ...........................................................................................................................24
CTCSS .......................................................................................................................................27
Modem Options..........................................................................................................................28
Interfacing.................................................................................................................................29
External connections..............................................................................................................29
DB-15 PIN descriptions with input/output level........................................................................29
Channel Selection ......................................................................................................................31
SD174E Layouts Control Board...................................................................................................34
SD174E Layouts RF Board..........................................................................................................39

Service Manual SD170E Series
Page 5 of 44
Introduction
This Maxon Product Manual is a comprehensive guide to the maintenance and field repair of this
equipment. It covers all versions of the SD170E Series data radio(s). Before using this manual
please read the whole of this introductory chapter, this will help you to make the best use of it. If
you have not done so already, please also read the warnings immediately in front of this chapter
before proceeding any further.
Using this Manual
The organization of this manual has been arranged to enable the location and referencing of
information, as quickly as possible.
Section 3 - Installation, Commissioning & Alignment. Describes connections to the radio, how to
commission it and how to align the radio should this becomes necessary.
Section 4 - Detailed functional description.
Section 5 - Troubleshooting.

Service Manual SD170E Series
Page 6 of 44
Pre-Install check, Accessories & Options
Programmer
ACC-916E SD-170E Series Programming software allows frequencies and
features to be changed.
ACC-2016E USB programming cable
Service
ACC-516 Extender PCB Allows RF PCB to be spaced off of the Digital
PCB to facilitate Alignment procedures.
Options
The option boards that can be fitted are:
ACC-513E GMSK modem (up to 9600 baud rate on 25 kHz channel spacing)
ACC-514E FFSK modem (up to 4800 baud rate on 25 kHz channel spacing)
The frequency versions of radio that are available are:
V2 142-174 MHz
U2 450-490 MHz.
12.5 kHz or 25 kHz versions of all bands.

Service Manual SD170E Series
Page 7 of 44
Product Introduction
The SD-170E Series (here in after called “the radios”) of RF wireless modems from MAXONCIC
utilize the latest technology in its design and manufacturing. Both the UHF and VHF models are
Phase Lock Loop Synthesizer (PLL) / microprocessor controlled and offer five watts of power with
16-channel capability. Multiple functions including 1200 to 9600 baud rates, AC and/or DC audio
coupling, GMSK, FFSK and FSK modulation are standard in these fully programmable wide
bandwidth RF wireless modem units. Programmable sub-audio squelch system (CTCSS & DCS)
and two-tone squelch system are newly added to the signal level detect squelch system (RSSI)
through PC Program. GPS Data handling is provided to interface and control internal GPS
receiver.
The radios are programmed using ACC-916E programming software, an Intel Pentium2 or higher
Personal Computer. Operating system is Microsoft windows 98, ME, 2000, and XP and Vista
based software. This allows the radio to be tailored to meet the requirements of the individual user
and of the System(s) it is operating within.
Antenna / RF connector
GPS antenna (where fitted)
BNC type nominal 50impedance
SMA
Programmer ACC-916E
XP, Vista, ME, 2000 and Windows based
programmer allowing personalization of the SD-170E
Series Modems via the RS232 port.

Service Manual SD170E Series
Page 8 of 44
Installation
Installation
The SD-170E Series Radio Modems usually requires mounting in a suitable location.
Attention should be given to the heat sinking of the radio if prolonged transmission is
required, see Section 2, which also includes details of the mounting hole dimensions.
Note: Continuous transmission is not possible at high power (5W) without a suitable heat
sink.
The SD-170E Series Radio Modems can be used with helical or whip aerials or may be
connected to an external antenna, via a suitable connecting cable.
External Connections
Connection is made to the SD-170E Series Radio Modems via an external 50 ohm BNC
socket (RF signal) and a high density 15-way “D”-type socket (DB-15 connector; control
and data signals) with 4-40 UNC threaded jack posts for more permanent connection.
Besides, SCN-12 type circular connector is added to separate power line from data and
analogue signals of DB-15 connector.
DATA MOD IN 1
2
3
4
5
6
7
8
9
10
Data OUT (AF)
PTT IN
VIN(12V)
SERIAL OUT (PROG.)
BUSY
MIC IN (AF)
SERIAL IN/OUT PROG
SPK OUT
SERIAL DATA IN (OPT)
11
12
13
14
15
SERIAL DATA OUT (OPT)
SERIAL BUSY OUT (OPT)
GPS DATA IN (OPT)
DGPS DATA IN (OPT)
GPS DATA OUT (OPT)
DB-15 CONNECTOR
BODY GROUND
************IMPORTANT –PIN 14 is GROUND*************
Fig. 1 Pin-outs of DB-15 connector
Fig. 2 Front panel

Service Manual SD170E Series
Page 9 of 44
General Specification
VHF
UHF
Equipment Type
Data radio (Wireless Modem)
Data radio (Wireless Modem)
Model Series
SD-171E
SD-174E
Performance
Specifications
TIA/EIA-603 /ETS 300-113
TIA/EIA-603 /ETS 300-113
Frequency Range
142-174MHz
450-490MHz
RF Output
1-5W
1-5W
Channel Spacing
12.5KHz, 25KHz Programmable
Modulation Type
F3D, F3E
Intermediate
Frequency
45.1MHz & 455KHz
Number of Channels
16
Frequency Source
Synthesizer
Operation Rating
Intermittent
90 : 5 : 5 (Standby : RX : TX)
Power Supply
Ext. Power Supply (12 VDC Nominal)
Temperature Range
Storage
Operating
From -40°C to +80°C
From -30°C to +60°C
Current Consumption
Standby(Muted)
Transmit 5Watts RF
Power
Transmit 2Watts RF
Power
< 65mA
< 2.0 A
< 1.0 A
Lock Time
< 10ms
TX to RX attack time
< 20ms (No Power Saving)
RX to TX attack time
< 20ms
Dimensions
(118mm)W X (63mm)H X (35mm)D
Weight
266.5grams
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Service Manual SD170E Series
Page 10 of 44
Transmitter Specification
VHF
UHF
Model Series
SD-171E
SD-174E
Carrier Power (Nom. Max.
Min.)
Hi Power
Low Power
5W < 6W > 4.5W
1W<1.5W>0.8W
5W < 6W > 4.5W
1W<1.5W>0.8W
Sustained Transmission
Time : 5 10 30 Sec
(Nominal Conditions)
Power : >90% >85% >80%
Power : >90% >85% >80%
Frequency Error
Nominal condition
Extreme condition
< 0.5 KHz ±2.5 ppm
< 0.75 KHz ±2.5 ppm
Frequency Deviation
25 KHz Channel Spacing
12.5 KHz Channel Spacing
Peak ±5.0, Min. ±3.8KHz
Peak ±2.5, Min. ±1.9KHz
Audio Frequency
Response
Within +1/-3dB of 6dB octave
@ 300 Hz to 2.55 kHz for 12.5 kHz C.S.
@ 300 Hz to 3.0 kHz for 25 kHz C.S.
Adjacent Channel Power
25 KHz Channel Spacing
12.5 KHz Channel Spacing
< 70 dBc @ Nominal Condition , < 65 dBc @ Extreme Condition
< 60 dBc @ Nominal Condition , < 55 dBc @ Extreme Condition
Conducted Spurious
Emission
< -36 dBm
< -36 dBm
Modulation Sensitivity
100mV RMS @ 60% Peak Dev.
Hum & Noise
25 KHz Channel Spacing
12.5 KHz Channel Spacing
> 40 dB (without PSOPH)
> 40 dB (with PSOPH)
Modulation Symmetry
< 10% Peak Dev @ 1KHz input for nominal dev. + 20dB
Load Stability
No osc at ≥ 10:1 VSWR all phase angles and suitable antenna
No destroy at ≥ 20:1 all phase angle
Peak Deviation Range
Adjustment
@ 1 KHz, Nom Dev + 20dB
:
25 KHz Channel Spacing
12.5 KHz Channel Spacing
Min. 3.5, Max. 6.0
Min. 1.5, Max. 4.0
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Service Manual SD170E Series
Page 11 of 44
Receiver Specification
VHF
UHF
Model Series
SD-171E
SD-174E
Sensitivity (@ 12dB SINAD)
25 KHz Channel Spacing
12.5 KHz Channel Spacing
< 0.28uV
< 0.30uV
< 0.28uV
< 0.30uV
Sensitivity (1/100 Error Rate)
With ACC-513
With ACC-514
< -113dBm
< -110dBm
< -113dBm
< -110dBm
Amplitude Characteristic
> -3dB , < +3dB
> -3dB , < +3dB
Adjacent Channel Selectivity
25 KHz Channel Spacing(Nom.)
(Extreme Condition)
12.5 KHz Channel Spacing(Nom.)
(Extreme Condition)
> 70 dB
> 60 dB
> 65 dB
> 50 dB
> 70 dB
> 60 dB
> 65 dB
> 50 dB
Spurious Rejection(100KHz ~ 4GHz)
> 70 dB
> 70 dB
Image / Half IF Rejection
> 70 dB
> 70 dB
Intermodulation Response Rejection
±25 kHz/ 50 kHz
±50 kHz/ 100 kHz
> 70 dB
> 70 dB
> 70 dB
> 70 dB
Conducted Spurious Emission
9 KHz - 1 GHz
1 GHz –4 GHz
< - 57 dBm
< - 47 dBm
< - 57 dBm
< - 47 dBm
RX Spurious Emissions (Radiated)
9 KHz - 1 GHz
1 GHz –4 GHz
< - 57 dBm
< - 47 dBm
< - 57 dBm
< - 47 dBm
AF Distortion :
Nominal condition
Extreme condition
< 3%
< 10%
< 3%
< 10%
RX Hum & Noise (only audio)
25 KHz Channel Spacing
12.5 KHz Channel Spacing
< 40 dB without PSOPH
< 40 dB with PSOPH
Receiver Response Time
< 16 ms
< 16 ms
Squelch (factory pre-set)
Open
Close
-113dBm
-116dBm
Squelch Attack Time :
RF Level at Threshold
RF Level at Threshold + 20dB
< 20 ms (RSSI), < 40 ms (Analog)
< 10 ms (RSSI), < 30 ms (Analog)
Squelch Decay Time
5 ms Min., 20ms Max.
Antenna Socket Input Match
> 10 dB Return Loss
Temperature Stability for
L.O. Frequency
1st < 5 ppm, 2nd < 15 ppm from -30° to + 60° C
L.O. Frequency Aging Rate
±2 ppm/ year
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Service Manual SD170E Series
Page 12 of 44
Reference Crystal
VHF
UHF
Model Series
SD-171E
SD-174E
Frequency
12.8 MHz
Type
DV-5-2.5H1
Temperature
Characteristic
±2.5 ppm from -30° C to +60° C
Aging Rate
< 2 ppm/ year in 1st year
< 1 ppm/ year thereafter
Enviromental
VHF
UHF
Model Series :
SD-171E
SD-174E
Temperature (deg C)
Operating
Storage
-30° to +60° C Degradation Specified @ Extreme condition
-40° to +80° C
ESD
20 KV
Due to continuing research and development the company reserves the right to alter
these specifications without prior notice.
Dimensions
Dimensions: 122mm (L) x 62mm (W) x 35mm (D)
Fig 3. Dimensions
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Service Manual SD170E Series
Page 13 of 44
Features
16 Channels
The SD-170E Series radio can store up to 16 channels within the same band. These channels
can be selected by inner DIP-S/W or serial command inputted from external control system.
Channel Spacing
The SD-170E Series is capable of programmable channel spacing, in both UHF and VHF bands.
Each channel can be programmed via the PC programmer, ACC-916E, having 12.5 kHz or 25
kHz channel spacing.
Output Power
Each channel can be programmed via the PC programmer to a high-power output, 5 Watts, and a
low-power output, 1 Watt.
Channel Scan
For audio application, SD-170E Series supports channel scan enabled via serial commands.
During programming of the radio, any channel can be selected as a scanned channel. When a
scanned channel is selected, it becomes a part of the scan list. Once the scan list has been
established, initiates scan by serial commands. If a conversation is detected on any of the
channels in the scan list, the radio will stop on that channel and audio signal will be released
through pin 9 of the DB-15 connector. At that moment, busy channel data is sent to external
equipment or device through serial command. So, busy channel data can be identified as
decoding received serial command from radio in the external equipment or device. Normally, if
user tries to transmit during scanning, the transmission will be made on the channel that the call is
received during the programmable scan delay time. (The scan delay time is the amount of time
the radio will stay on that channel once working has ceased. Dealer programming of 4 ~ 7
seconds is typical). The radio will resume scanning once the scan delay time has passed, and will
continue to scan until the serial command for scan stop is inputted by external equipment. After
the scan has resumed, if a transmission is made, the radio will transmit on the selected priority
channel. This feature is similar to priority scan TX except for selection of priority channel. You can
assign a priority channel by inner dip switch only.
Scan Delete
To temporarily delete a channel from the scan list, simply input the serial command for scan
deletion to the radio while scanning and stopped on the channel to be deleted. This will
temporarily remove that channel from the scan list until the scan is closed or the radio‟s power is
reset.
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Service Manual SD170E Series
Page 14 of 44
CTCSS / DCS Scanning
To help to block out unwanted calls to your radio, the SD170E series can be programmed by your
dealer to scan for tones.
Busy Channel Lockout
This feature, when enabled, disables the transmitter when the user would attempt to transmit
during the receiving channel is busy. It will be dealer-programmable on/off and applicable to all
channels.
Marked Idle
When used in conjunction with Busy Channel, lockouted transmitter is allowed to operate as long
as valid RX tone is received. Dealers program this feature as ON or OFF. This feature will be
dealer-programmable on/off and applicable to all channels.
TX Time-out
This feature, when enabled, limits the amount of time that the user can continuously transmit. This
time can be set in increments by 10 seconds from 10 seconds to 990 seconds. If the user
attempts to transmit longer than the TX Time-out period, five seconds prior to expiration, the radio
will release Time-out alert signal through pin 9 of the DB-15 connector and will cease
transmission.
Power Save
The function of Power Save is used when an external battery is used as the power source. When
Power Save is enabled, the receiver ON and OFF time can be programmed and allows the
operator to set the length of time the receiver gets asleep.
TX Delay
The TX will remain active for 150 ms at the end of TX when using CTCSS tones. This eliminates
squelch tail. Dealer programs this feature as ON or OFF.
Squelch Options
Compared to existing Maxon data radios, programmable sub-audio squelch system (CTCSS &
DCS) and two-tone squelch system are newly added. Each channel will have these squelch
option sets during dealer programming. More detail descriptions for all available squelch systems
of SD170E are the following:
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Service Manual SD170E Series
Page 15 of 44
Sub-audio squelch system
The SD-170E Series can operate singly or with optional modem boards. Even if user wants to use
sub-audio SQ system, the radio will permit this SQ option according to some cases to avoid
confliction between sub-audio and data.
Contrary to general-purpose two-way radio, the input of the radio is data or audio. In case of
audio, its frequency spectra are limited to 300 ㎐∼3 ㎑by internal BPF. So, the division of this
and sub-audio is possible on the frequency spectra because sub-audio has under 300 ㎐
frequency. But, Data has wide frequency spectra compared with audio. Normally, that has 30 ㎐∼
4.8㎑frequency (except harmonic freq.) at 9600 baud rate. Accordingly, the conflict of sub-audio
and data are inevitable and so broken data or SQ error is unavoidable. To solve this problem, the
radios can use the FFSK modulation which converts data into two different continuous audio tone
according to their logic levels. Therefore, available cases of sub-audio SQ system are Audio and
FFSK signal. But, it‟s not permitted to FSK (FM direct modulation of data) and GMSK signal.
Note: SD-170E Series provides the connection of external modems to receive and
transmit external modulated data which can be inputted and outputted through
pin 1 and 2 of DB-15 connector, respectively. In this case, the external signals
are referenced to ground and may be A.C. or D.C. coupled depending on the
user requirement. Especially, if the type of external modem is AFSK or FFSK,
Sub-audio Squelch (SQ) System can be applied by dealer programming. For
reference, its related parameter is “TX Tone Generation for Data Input” of “TX
option” group on the “System Option / GPS” tap window of ACC-916E.
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Service Manual SD170E Series
Page 16 of 44
Access to digital and RF boards
Removing top cover
Disassembly and Re-assembly of the Radio
In order to carry out the following Test and
Alignment procedures it will be necessary to gain
access to the inside of the radio.
Care should be exercised when opening up the
radio for maintenance or repair.
In order to
Disassemble the radio, the following procedure
should be used:
1. Unfasten and remove the four mounting screws
located on the top cover of the radio.
Removing the Digital board
2. Remove the four mounting screws located
on the top of the Digital board.
3. Gently lift Digital board away from the
connector on the RF board from the opposite
end to the D-type.
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Service Manual SD170E Series
Page 17 of 44
Removing Screen
4. Remove the screen by carefully
desoldering the screen from the RF board
near to the BNC connector.
Figure -4 Removing Screen
5. Then lift screen out.

Service Manual SD170E Series
Page 18 of 44
REMOVING & REPLACING THE RF BOARD
6. Unscrew the four holding screws from the
RF board.
7. De-solder the RF lead at the BNC
connection
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Service Manual SD170E Series
Page 19 of 44
Alignment
Transmitter Alignment
Connect the unit to a Service Monitor with the power meter set to the 10 W scale (or auto range).
Refer to figure 4.4 under commissioning section
TCXO
Set the channel selector to the mid-range frequency 460MHz (U2) and 155MHz (V2), adjust
TCXO1 for a reading accurate to within ±200Hz.
TX VCO
TX VCO is pre-tuned at the factory and no further adjustment is required
To verify the alignment of the TX VCO, check the VCO Control voltage.
Set the unit to the highest transmit frequency, 490MHz (U2), 174MHz (V2). Key the
transmitter and verify that the VCO control voltage is under 10.0 Volts. If necessary adjust
C208 of TX VCO to 10.0 Volts.
Set the unit to the lowest transmit frequency 440 MHz (U2), 146(V2) key the transmitter and
verify that the VCO voltage is above 1.8 Volts. If necessary adjust C208 to 1.8 Volts.
Note: use TP1 to measure the voltage.
Deviation
CTCSS and DCS Deviation and Balance Adjustment
Set the unit to a mid-frequency range and a CTCSS of 67Hz. Activate PTT and adjust RV402
(deviation adjustment) for desired CTCSS tone deviation.
Switch to a channel with the same frequency and CTCSS of 250.3Hz. Activate PTT and adjust
RV1 (balance adjustment) to desired CTCSS tone deviation, same as above step.
Switch between the 67Hz channel and the 250.3Hz channel and adjust RV1 until the deviation
is the same on both channels. It may be necessary to readjust RV402 to get the desired
deviation.
Audio balance and deviation adjustment
Set the unit to a mid-frequency and input the TX data with 400 Hz standard audio level
(100mV for data or 10mV for audio in). Increase the signal level to 20 dB from standard
level.
Monitor the demodulated signal from service monitor. Adjust RV1 to make the monitored
signal to be a balanced square wave.
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Service Manual SD170E Series
Page 20 of 44
Sweep the audio frequency from 300 Hz to 4 kHz and ensure that the peak deviation does
not exceed the limits shown below. If necessary adjust RV2 to vary audio deviation.
12.5 kHz channel spacing <= 2.5 kHz dev.
20 kHz channel spacing <= 4 kHz dev.
25 kHz channel spacing <= 5 kHz dev.
Note: When using one of the internal modems (ACC-513E or ACC-514E) a test signal needs to
be applied to the radio (e.g. data from the computer). The deviation levels should not exceed the
limits as shown above.
APC (output power)
When using the extender board (ACC-516) there is a voltage drop in transmission mode
and so output power drops. As a result the radio outputs higher power than assigned
after assembly. To prevent over-power output, follow below procedure
Adjust RV4 to set high power at the point of 4.6W.
Adjust RV3 to set low power at 0.6W
Assemble the radio and again check if RF transmission power is near 5.0W for high
power and 1W for low power.
RECEIVER
Refer to figure 4.5 in the Commissioning section for details on test equipment connection
RX VCO
RX VCO is pre-tuned at the factory and adjustment should not be required
To verify adjustment of the RX VCO, check the VCO Control voltage.
Set the unit to the highest receive frequency, 490 MHz (U2), 174 MHz (V2) and verify the
VCO control voltage is under 10.0 Volts. If necessary adjust C308 of RX VCO to 10.0 Volts
Set the unit to the lowest receive frequency 440 MHz (U2), 146 MHz (V2) and verify that the
VCO voltage is above 2.0 Volts. If necessary adjust C308 to 2.0 Volts.
Note: Use TP1 to measure the voltage.
AUDIO OUTPUT LEVEL Adjustment
Set the RF signal generator to the receiver frequency of the radio and set the AF modulation
signal to 1 kHz with the following deviations depending on channel spacing:
1.5 kHz deviation for 12.5 kHz channel spacing
2.4 kHz deviation for 20 kHz channel spacing
3 kHz deviation for 25 kHz channel spacing
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