Maxon SD170EX Series User manual

Service Manual SD170EX Series
Page 2 of 38
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.
A
A
Am
m
me
e
en
n
nd
d
dm
m
me
e
en
n
nt
t
ts
s
s

Service Manual SD170EX Series
Page 3 of 38
Warnings
1. WARNING! NEVER connect the transceiver to an AC outlet. This may pose a fire hazard
or result in an electric shock.
2. NEVER operate the radio transmitter without a suitable artificial load or antenna
connected.
3. NEVER connect the transceiver to a power source of more than 13.8V.
4. NEVER dispose of the battery in fire – it can explode causing personal injury.
5. NEVER attempt to disassemble the battery or remove its case material or charging
contacts. Do not short the battery terminals.
6. NEVER expose the transceiver to rain, snow or any liquids.
7. 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.
8. USE the supplied microphone only. Other microphones have different pin assignments
and may damage the transceiver.
9. 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.
10. 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.
11. DO NOT allow children to operate transmitter-equipped radio equipment.
12. 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.
13. 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.
14. AVOID placing the transceiver in excessively dusty environments.
W
W
Wa
a
ar
r
rn
n
ni
i
in
n
ng
g
gs
s
s

Service Manual SD170EX Series
Page 4 of 38
Contents
Amendment Record Sheet............................................................................................................ 2
Warnings ..................................................................................................................................... 3
Contents ...................................................................................................................................... 4
Introduction ................................................................................................................................. 5
Pre-Install check, Accessories & Options ...................................................................................... 6
Pre-Installation ......................................................................................................................... 6
Accessories ............................................................................................................................. 6
etc ........................................................................................................................................... 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 ....................................................................................................................................... 26
Interfacing ................................................................................................................................. 27
External connections .............................................................................................................. 27
DB-9 PIN descriptions with input/output level.......................................................................... 27
Channel Selection ...................................................................................................................... 29
SD170EX Layouts Control Board ................................................................................................. 30
SD171EX Layouts RF Board ........................................................................................................ 34
SD174EX Layouts RF Board ........................................................................................................ 34
SD170EX control schematic ...................................................................................................... 34
SD171EX RF schematic ............................................................................................................ 34
SD174EX RX schematic ............................................................................................................ 34
C
C
Co
o
on
n
nt
t
te
e
en
n
nt
t
ts
s
s

Service Manual SD170EX Series
Page 5 of 38
Introduction
This Maxon Product Manual is a comprehensive guide to the maintenance and field repair of this
equipment. It covers all versions of the SD170EX 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.
Amendments to this Manual
From time to time during its lifetime, this product will be updated and improved. To cover such
changes, amendments to this manual will be issued in the form of replacements and/or additional
pages. It is important that anyone working on a product has all the relevant information. Therefore
you should incorporate amendments to this manual on receipt. Please follow the instructions
accompanying the amendment (in the form of an Engineering Bulletin) and be sure to complete
the amendment record at the front of this manual.
On occasion it may be necessary to issue product information more quickly than can be achieved
with an amendment. In this case the information will be distributed as a Maxon Engineering
Bulletin. Engineering Bulletin numbers are prefixed with a category letter – A, B or C.
E.g. CATEGORY C – ENGINEERING BULLETIN 120
Category C describes how Maxon recommends an improvement and/or a modification to make an
improvement to a product
Engineering Bulletin 120 index number allocated to this bulletin.
‘A’ Category A Engineering Bulletins will only be released if, by using the equipment
manufactured by Maxon or its subcontractors, a risk to operator safety or an infringement of Type
Approval is probable.
All units affected should be returned for modification to Maxon CIC Europe Works Department on
receipt of such a Bulletin.
I
I
In
n
nt
t
tr
r
ro
o
od
d
du
u
uc
c
ct
t
ti
i
io
o
on
n
n

Service Manual SD170EX Series
Page 6 of 38
‘B’ Category B Engineering Bulletins are for equipment manufactured by Maxon CIC that may
have component batch problems.
All equipment affected that is in service must be returned to the Distributor or Dealer workshop for
modification. Maxon CIC will supply replacement components free of charge.
‘C’ Category C Engineering Bulletins are for improvement or modification to equipment
manufactured by Maxon.
Dealer / Distributor to modify affected units in the field on the next service call. Maxon will supply
components free of charge.
Please place these at the back of this manual and refer to them before carrying out any work. This
Service Manual should be updated with any accompanying replacement pages. You may wish to
retain the previous issue pages for future reference.
Pre-Install check, Accessories & Options
Pre-Installation
As standard the SD-170EX Series Radio Modem is supplied with fused power Cable and
manual.
Accessories
The following Accessories are available:
Order Code Description
Antennas
CA1506-MB VHF Helical Antenna 148 - 160MHz
CA1506-HB VHF Helical Antenna 160 - 174MHz
CA4502 UHF Quarter-wave Whip Antenna 420 – 470MHz
Programmer
ACC-916 SD-170EX Series Programming kit Allows frequencies and
features to be changed.
Programming lead
Service
ACC-516E Extender PCB Allows RF PCB to be spaced off of the Digital
PCB to facilitate Alignment procedures.
V2 142-174MHz
U2 450-490MHz.
12.5 KHz or 25 KHz versions of all bands.
I
I
In
n
nt
t
tr
r
ro
o
od
d
du
u
uc
c
ct
t
ti
i
io
o
on
n
n

Service Manual SD170EX Series
Page 7 of 38
Product Introduction
The SD-170EX 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. 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. The radios are programmed using ACC 916 programming software, an Intel Pentium2
or higher Personal Computer, Operating system is Microsoft windows 98, ME, 2000, and XP and
Vista based software, an interface module and a programming cable. 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
BNC type nominal 50 impedance
Programmer ACC 916 XP, Vista, ME, 2000 and Windows based programmer
allowing personalization of the SD-170EX Series
Modems via the RS232 port.
P
P
Pr
r
ro
o
od
d
du
u
uc
c
ct
t
t
I
I
In
n
nt
t
tr
r
ro
o
od
d
du
u
uc
c
ct
t
ti
i
io
o
on
n
n

Service Manual SD170EX Series
Page 8 of 38
Installation
Installation
The SD-170EX 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-170EX 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-170EX Series Radio Modems via an external 50 ohm BNC
socket (RF signal) and a high density 9-way “D”-type socket (DB-9 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-9 connector.

Service Manual SD170EX Series
Page 9 of 38
General Specification
VHF
UHF
Equipment Type Data radio (Wireless Modem)
Data radio (Wireless Modem)
Model Series SD-171EX SD-174EX
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
G
G
Ge
e
en
n
ne
e
er
r
ra
a
al
l
l
S
S
Sp
p
pe
e
ec
c
ci
i
if
f
fi
i
ic
c
ca
a
at
t
ti
i
io
o
on
n
n

Service Manual SD170EX Series
Page 10 of 38
Transmitter Specification
VHF
UHF
Model Series SD-171EX SD-174EX
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
T
T
Tr
r
ra
a
an
n
ns
s
sm
m
mi
i
it
t
tt
t
te
e
er
r
r
S
S
Sp
p
pe
e
ec
c
ci
i
if
f
fi
i
ic
c
ca
a
at
t
ti
i
io
o
on
n
n

Service Manual SD170EX Series
Page 11 of 38
Receiver Specification
VHF
UHF
Model Series SD-171EX SD-174EX
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
R
R
Re
e
ec
c
ce
e
ei
i
iv
v
ve
e
er
r
r
S
S
Sp
p
pe
e
ec
c
ci
i
if
f
fi
i
ic
c
ca
a
at
t
ti
i
io
o
on
n
n

Service Manual SD170EX Series
Page 12 of 38
Reference Crystal
VHF UHF
Model Series SD-171EX SD-174EX
Frequency 12.8MHz
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-171EX SD-174EX
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
R
R
Re
e
ef
f
fe
e
er
r
re
e
en
n
nc
c
ce
e
e
X
X
Xt
t
ta
a
al
l
l,
,
,
D
D
Di
i
im
m
me
e
en
n
ns
s
si
i
io
o
on
n
n
S
S
Sp
p
pe
e
ec
c
ci
i
if
f
fi
i
ic
c
ca
a
at
t
ti
i
io
o
on
n
n

Service Manual SD170EX Series
Page 13 of 38
Features
16 Channels
The SD-170EX 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-170EX Series is capable of programmable channel spacing, in both UHF and VHF bands.
Each channel can be programmed via the PC programmer, ACC-916, having 12.5KHz or 25KHz
channel spacing.
Output Power
In case of SD-170EX Series, it’s programmable. 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-170EX 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-9 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.
F
F
Fe
e
ea
a
at
t
tu
u
ur
r
re
e
es
s
s

Service Manual SD170EX Series
Page 14 of 38
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 SD170EX are the following.
F
F
Fe
e
ea
a
at
t
tu
u
ur
r
re
e
es
s
s

Service Manual SD170EX Series
Page 15 of 38
Sub-audio squelch system
The SD-170EX 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.
F
F
Fe
e
ea
a
at
t
tu
u
ur
r
re
e
es
s
s

Service Manual SD170EX Series
Page 16 of 38
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.
A
A
Ac
c
cc
c
ce
e
es
s
ss
s
s
t
t
to
o
o
P
P
PC
C
CB
B
Bs
s
s

Service Manual SD170EX Series
Page 17 of 38
Removing Screen
4. Remove the screen by carefully
desoldering the screen from the RF board
near to the BNC connector.
5. Then lift screen out.
A
A
Ac
c
cc
c
ce
e
es
s
ss
s
s
t
t
to
o
o
P
P
PC
C
CB
B
Bs
s
s

Service Manual SD170EX Series
Page 18 of 38
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
A
A
Ac
c
cc
c
ce
e
es
s
ss
s
s
t
t
to
o
o
P
P
PC
C
CB
B
Bs
s
s

Service Manual SD170EX Series
Page 19 of 38
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, 480MHz (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.
A
A
Al
l
li
i
ig
g
gn
n
nm
m
me
e
en
n
nt
t
ts
s
s

Service Manual SD170EX Series
Page 20 of 38
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-513 or ACC-514) 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 the adjustment of the RX VCO, check the VCO Control voltage.
Set the unit to the highest receiving frequency, 480MHz (U2), 174MHz (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 440MHz (U2), 146(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
A
A
Al
l
li
i
ig
g
gn
n
nm
m
me
e
en
n
nt
t
t