Shure SLX2 User manual

SLX2 Wireless Transmitter Service Manual
©2006, Shure Incorporated
25A1090 (Rev.3)
25A1090
SLX2 WIRELESS HANDHELD TRANSMITTER
PRODUCT DESCRIPTION
The Shure Model SLX2 is a µP (microprocessor) controlled frequency agile UHF
handheld transmitter operating over the frequency range of 518 to 865 MHz (in eight
different 24 MHz-wide frequency bands). The transmitter will operate for a minimum of 8
hours using two "AA" alkaline batteries. The User Interface includes "mode" and "set"
buttons, and an LCD that displays battery status, group/channel, and transmitter/
receiver frequency synchronization. The SLX2 has a plastic enclosure, and utilizes an
internal antenna for optimum range and reliability. This product is intended for use in
entry-level presentation, installed, and performance markets.
FEATURES
1. Frequency agile; microprocessor controlled. Model number extension determines frequency band
of operation.
2. Minimum of 12 compatible systems per SKU in the U.S. Additionally, a minimum of 12 compatible
systems in the top 50 U.S. markets across all three domestic SKU's (H5, J3, and L4).
3. Operating frequency programmable locally or from the receiver using a built-in IR link.
4. Designed for use with "AA" alkaline batteries (2 required). May also be used with rechargeable "AA"
batteries. Note: battery condition indicator is calibrated for alkaline batteries and may not be accu-
rate with rechargeable types. Electrical reverse battery protection is included.
5. Minimum battery life of 8 hours with new "AA" alkaline batteries.
6. Designed for use with SM58, BETA 58, SM86, and BETA 87A&C microphone heads. Compatible
with "active load" or standard heads (active load circuitry to be incorporated in heads).
7. Tone key squelch.
8. Power/Mute and Select buttons with LCD display for frequency group/channel selection and con-
trol. LED backlight for easy reading of LCD display.
9. Bicolor, green/red LED for power "on" and low battery, mute and infrared link indications.
10. Rugged plastic construction.
11. Utilizes Shure Patented ARC (Audio Reference Companding) audio processing.
SLX
mute select

2
25A1090 (Rev.3)
DETAILED DESCRIPTION
Features
1 Interchangeable microphone head (SM58 pictured)
2 Power / Infrared (IR) / Mute indicator
Green: ready
Amber: mute on
Flashing red: IR transmission in process
Glowing red: battery power low
Pulsing red: battery dead (transmitter cannot be turned off until batteries are changed)
3 LCD screen
4 On-off / mute switch
Press and hold to turn on or off. Press and release to mute or unmute.
5 Select switch
6IRport
Receives infrared beam to synchronize frequencies. When using multiple systems, only one
transmitter IR port should be exposed at a time.
Adjusting Gain
Access the gain adjustment switch aby unscrewing the head of the microphone.
Two gain settings are available on the SLX2. Choose a setting appropriate for vocal volume
and for the performing environment. Use the tip of a pen or a small screwdriver to move the
switch.
• 0dB: For quiet to normal vocal performance.
•
–10dB : For loud vocal performance.
SLX
mute select
1
2
3
45
SLX
mute select
6
SLX
mute select
BIAS
AUDIO
0dB -10dB
a
b

3
25A1090 (Rev.3)
SLX2 Transmitter Programming
Manually Select a Group and/or Channel
1. Press and hold the select button until the GROUP and CHANNEL displays begin to alternate.
2. To change the group setting, release the select button while GROUP is displayed
a . While GROUP
is flashing, pressing select increases the group setting by one.
3. To change the channel setting, release the select button while CHANNEL is displayed
b . While
CHANNEL is flashing, pressing select increases the channel setting by one.
Lock or Unlock Transmitter Settings
Press the mute/ and select buttons simultaneously to lock or unlock the transmitter settings. When
locked, the current settings cannot be changed manually. Locking the transmitter does not disable in-
frared synchronization.
Battery Status
Indicates charge remaining in transmitter batteries.
Master List Indicator
Indicates that a master list frequency is currently in use. No group or channel information is
displayed.
Note: the transmitter cannot be used to change master list settings.
INCOMPATIBLE Frequency Warning
The INCOMPATIBLE warning indicates that the receiver and transmitter are transmitting on different
frequency bands. Contact your Shure retailer for assistance.
select 5
i8 i8
MASTER LIST
Incompatible
GROUP
CHANNEL
i8 i8
MASTER LIST
Incompatible
GROUP CHANNEL
a
b
select
select
select +
i8 i8
MASTER LIST
Incompatible
GROUP CHANNEL
i8 i8
MASTER LIST
Incompatible
GROUP CHANNEL
i8 i8
MASTER LIST
Incompatible
GROUP CHANNEL
i8 i8
MASTER LIST
Incompatible
GROUP CHANNEL

4
25A1090 (Rev.3)
AUDIO/RF BLOCK DIAGRAM
CIRCUIT DESCRIPTION
AUDIO CIRCUIT DESCRIPTION
AUDIO SECTION
Audio enters the transmitter board through pin 4 of the mic-jack board connector (CON100).
Pin 2 of the connector provides 5 Vdc bias for the mic head. Pin 6 supplies the ground connec-
tion. The audio preamp (IC150-2) provides either 0 or 10 dB of gain (user switchable via
SW100). Capacitor C140couples the signal into apre-emphasisnetwork formedbyR140,R141,
and C141.
Next, the audio signal enters the patented Shure ARC™ processor. The main elements in this
section are the VCA (IC100-5) and the RMS Detector (IC100-4). The VCA, or Voltage Controlled
Amplifier, is a DC controlled amplifier. Following the VCA, the signal enters a 3-pole 17kHz low-
pass filter stage (IC100-2) that protects the RMS detector from energy above the audio band.
Next, the signal is coupled to the RMS detector (IC100-1), which converts it to a DC voltage. A
+1 dB increase at the input to the detector produces a +6 mV increase at its output. The detector
output is fed to the compression threshold stage (IC150-2). This stage provides the transition
from uncompressed to compressed signal. At low levels, the audio is uncompressed because
diode D169 is turned off. As the AC level increases, the output of IC150-2 decreases enough to
turn the diode on. As D190 conducts, the compression ratio changes from 1:1 to 5:1. Once D190
is turned fully on, the audio compression ratio remains fixed at 5:1. An additional diode in the bias
Audio Input
(mic head)
User Gain
Control Switch Pre-
emphasis
RMS
Detector
Limiter
Compressor
VCA
2-pole,
17kHz,
LPF
Deviation Trim
and Tone Key
Sum Amp
Frequency
Synthesizer
16
MHz
RF
A
mp
LPF
Microcontroller
Frequency
Synthesizer
control
Channel
Select,
Power Mute
32.768
kHz
Tone Key
DC-DC
Co
nv
e
r
te
r
A
A Battery
Supply
+5V DC
Source
VCO (Carrier
Range)
Loop
Filter
RF
A
mp Pad
RF Muting
0-4 dB (Band
dependent)
A
udio Muting
IR
Photodetector
LCD
Driver
EPROM
LCD
Pad
0-4 dB (Band
dependent)

5
25A1090 (Rev.3)
network (D162) provides temperature compensation for changes in the VY, or "cut-in" voltage of
D190. After the compression threshold stage, the DC control signal is amplified by a 40 dB fixed-
gain stage (IC100-5). It is then sent to the VCA control voltage input (EC+).
Following the ARC™ processor section, the audio signal must pass through a muting network
consisting of R199, R200, C205, and Q205. A trim pot (TR200) allows the audio deviation level
to be set. Next, audio enters the tone key summing amp (IC150-4). Here, tone-key is added to
the audio before passing to the RF section for transmission. The tone key signal is used in the
receiver to provide audio output only when the tonekey signal is present with the transmitted sig-
nal; therefore, if the tone key or the transmitter is turned off, the receiver will be muted. The tone
key squelch will eliminate receiver noise associated with loss of the carrier, which usually sounds
like a "pop". The tone key signal is generated by a square wave from the mP (IC300). It is then
filtered by active filter stage Q185 and attenuated by R188/R189 (under µP control) before being
fed to the summing amplifier. The combined audio/tone-key signal is then sent to the VCO
through R504.
POWER SECTION
Two "AA" batteries supply power to the transmitter through FET Q410, which provides electri-
cal reverse battery protection. Next, power enters switching boost converter IC400, which sup-
plies regulated 5V power. To turn on the transmitter, SW325 shorts the base of Q480 to ground,
enabling the converter and powering up the unit. The microprocessor keeps Q480 disabled until
shutdown.
Power is turned off by a "shutdown" signal from the microprocessor, which can be initiated
manually by the user (by holding down SW325 for 2.2 seconds) or automatically by the system
(e.g.,whenthe batteryis tooweakfor properoperation).At this time, themicroprocessorenables
Q480 and shuts down the converter. When the unit is off, Q480 and its bias circuitry draw less
than 30 µA, so the effect on battery life is negligible. The converter and microprocessor are dis-
abled.
LOW BATTERY SHUT DOWN:
A software battery shutdown routine allows the battery supply to run down to 2.05 V before
shutdown, and will not turn the system back on until a voltage greater than 2.25 V is present. The
hysteresis keeps the system in a controlled state when the batteries are low, and also helps pre-
vent weak batteries from being used from the start.
RF CIRCUIT DESCRIPTION
RF SECTION
The system block diagram is shown above. The SLX2 uses a PLL system with direct carrier
frequency modulation. Processed audio enters the VCO through a passive "reflection" network
before being applied to the varactor diode (D500) through choke L503. The VCO is shielded to
prevent external RF fields from affecting its operation, and to help control radiated emissions of
its harmonics. Power for the VCO and PLL circuitry is supplied by the main 5 V regulator. Power
and signal lines in the VCO area are heavily decoupled and bypassed to remove noise.
The VCO has a tuning bandwidth of more than 30 MHz on all bands, with a tuning voltage
range of approximately 1 to 4 volts. The VCO employs separate stages for the oscillator (Q502)
and buffer (Q501) to minimize phase noise and load pulling. The VCO output is isolated by ca-
pacitive and resistive dividers, before being applied to the frequency control pin of the PLL syn-
thesizer (IC501) through C538. The synthesizer's internal circuitry divides the RF signal down as
necessary to achieve a tuning precision of 25 kHz. The synthesizer circuit contains a quartz-con-
trolled reference oscillator operating from a 16 MHz reference crystal (Y801) that is adjusted by
means of trimmer CV501. The transmitter output frequency is user selectable in groups of com-
patible channels within each of the eight available bands. Frequency selection is made via mi-
croprocessor controller IC300, which interfaces with the user by means of the Group and
Channel switches, SW324 and SW325. The output of the synthesizer is a series of pulses that
are integrated by a passive loop filter consisting of C532, R514, C533, R513, and C531 to pro-
duce the control voltage signal.
The VCO output is coupled to the RF buffer stage (Q600) by a matching network consisting
of R602, C614, and L610. R600 and R603 provide base bias for the transistor, while R605 sets
its operating current. RF choke L600 provides power and decoupling for the stage, in conjunction

6
25A1090 (Rev.3)
with C600 - C604. The collector of Q600 feeds the power amplifier stage via an impedance
matching network consisting of L602, C611, and C618.
The bias voltage for the RF power amplifier (Q601) is supplied by R601 and R604. Its operat-
ingcurrentis controlled viaemitter resistorR606. RF choke L601 provides power anddecoupling
for the stage, in conjunction with C605-C609. For Japanese systems only, the output power is
trimmed via TR640. L603, C612, and L604 provide the output impedance matching into the low
pass filter, which consists of L604, L605, L606, C615, C616, and C617. The low pass filter output
couples to the battery antenna via C641 and L607. Connector CON640 and C613 are only used
for Japanese (JB) units. Coupling capacitor C610 is used to ensure that both batteries are driven
equally.
The transmitter is capable of delivering up to +15.0 dBm to the antenna (depending
on band and country). During transmitter power-up and frequency selection, the RF
output is muted by bringing the base of Q631 low, which removes bias from Q630
and shuts down power to the RF stages. The RF output is also muted during the
transmitter power-down sequence. This is done so that the carrier signal will not
interfere with other transmissions when the loop becomes unlocked.
DIGITAL CIRCUIT DIAGRAM
RF Band
DC Level
Battery DC
Level
Power Mute
Button
Select
Button
Softstart
Shutdown
Infrared
Photodetector
(Sharp GP1U10X)
EEPROM
(MicroChip
93AA46 )
Microprocessor
(Motorola
MC68HC908GR16)
Backlight
LED
Power LED
LCD
VCO
RF Power
Tonekey
Squarewave
Tonekey
Level
LCD Driver
(Rohm
BU9729k)
Sythesizer
(National
Semiconducter
LMX2335)
Audio Mute

7
25A1090 (Rev.3)
DIGITAL SECTION
ACCESSING DIFFERENT MODES
ATE MODE
If TP_PB0 is held to TP_EGND, or logic level 0, at startup, the microcontroller will enter ATE
Mode. To ensure proper operation, TP_PA0 and TP_PA1 should be held to TP_EGND at startup.
In ATE Mode, each band has a three test frequencies that are controlled by the logic levels at
test points TP_PA0 and TP_PA1.
RF BAND RESISTORS
Two resistors (RAand RB) are responsible to start the microcontroller in a RF band. They de-
termine the voltage at test point TP_RFBAND.
This table shows RA's and RB's reference designators and how the voltages at the test points
reflect the operating RF band.
This figure depicts the voltage divider feeding the microprocessor analog to digital converter.
.
Frequency TP_PA0 TP_PA1
Low 00
Center 01
High 11
Test Frequencies (MHz) H5 J3 JB L4 P4 Q4 R5 S6
SLX2 Low 518.400 572.400 806.125 638.400 702.100 740.125 800.525 838.100
Center 529.500 583.500 807.500 649.500 714.000 746.325 810.275 851.300
High 541.800 595.800 809.750 661.800 725.900 751.875 819.800 864.800
SLX Reference Designators
SLX2
RARB
R319 R320

8
25A1090 (Rev.3)
This table shows the variant resistor values and resulting voltages at TP_RFBAND for each
band.
Note: Voltages are calculated with a 3.30V (+/- 0.10V) reference from the power
supplies. If power section supports less than 3.30V, thresholds need to be adjusted.
µC DECISIONS BASED ON ANALOG VOLTAGES
Note: There is a dead battery lock voltage set at 2.30 Volts. If the transmitter is powered
on with a voltage of less than 2.30 Volts, the system will lock, forcing the user to either
recharge or replace the batteries. During the dead battery lock out, the battery gauge is
empty and the red led flashes.
RF BAND Rb TP_RFBAND(+/- 0.10V)
H5 1.00k 0.30V
J3 2.99k 0.76V
L4 4.99k 1.10V
R5 7.50k 1.41V
S6 12.10k 1.81V
P4 18.2k 2.13V
Q4 30.1k 2.48V
JB 49.9k 2.75V
Continuous Operation Battery Thresholds
BATTERY_A2D RF Level Display Logic Voltage (V)
Measured @ 3V
block battery clips - dBC >= 2.25
- dBC < 2.25
- dBC < 2.14
-8 dBC < 2.05

9
25A1090 (Rev.3)
NOTES

10
25A1090 (Rev.3)
FUNCTIONAL TEST
REQUIRED TEST EQUIPMENT (OR APPROVED EQUIVALENT OR SUPERIOR MODELS):
LISTENING TEST
Before completely disassembling the transmitter, operate it to determine wether it is functioning normal-
ly and try to duplicate the reported malfunction. Refer to pages 2 and 3 for operating instructions, trouble-
shooting, and specifications.
Review any customer complaint or request, and focus the listening test on any reported problem. The
following, more extensive, functional tests require partial disassembly.
FUNCTIONAL TEST
Refer to the Disassembly section to partially disassemble the transmitter for the following functional
tests.
TEST SETUP
1. Remove the PCB from the handle.
2. Set gain switch to “0” dB.
3. Connect the (+) terminal of the power supply through a milliammeter to the (+) battery terminal and
the (-) power supply terminal to the (-) battery terminal.
4. Connect a DC Voltmeter across the power supply and set the power supply for 3Vdc.
5. Connect the audio analyzer to the microphone via the microphone test head (PT1840) as needed.
DISPLAY TEST
1. Power unit ON.
2. Verify that all display segments are displayed for approximately 2 seconds. This includes a full bat-
tery indication and "1818" displayed for group and channel.
REVERSE BATTERY PROTECTION TEST
1. Adjust power supply to -3.0 ± 0.1 V dc.
2. The current should be less than 0.5 mA.
VOLTAGE REGULATION TEST
With power applied properly, and the unit switched on, measure the DC voltages at the following test
points. All test points are located on the top side of the PCB. Refere to the component diagram.
• TPBATT+ (Battery input) = 3 ± 0.2 Volts
• TP5V (Power Converter) = 5 ± 0.2 Volts
• TP3.3V (Power Converter) = 3.3 ± 0.2 Volts
• TPA1 (Audio Preamp) = 2.5 ± 0.2 Volts
• TPA3 (Tone Key Summing Amp (IC150 Pin 14)) = 2.5 ± 0.2 Volts
• TPVREF (IC100 Pin 5) = 2.5 ± 0.1 Volts
CURRENT CONSUMPTION TEST
1. With +3V applied to the battery terminals and the unit powered on.
2. Verify the current drain is 130 ± 15mA.
Spectrum analyzer or power meter HP8590L/Agilent E4403B/Agilent E4407B
Digital multimeter Fluke 87
Audio Analyzer HP 8903B
Frequency Counter HP 53181/HP 5385A
Power Supply Power Supply must be able to supply 3Vdc
with an internal ammeter.
Shielded test lead Shure PT1838F
BNC (Male) to BNC (Male) cable (1) Shure PT1838A
UA820 Antenna Frequency Dependent
Audio Test Head PT1840
Brass Ring PT1838Y

11
25A1090 (Rev.3)
FREQUENCY RESPONSE TEST
1. Set the audio generator as follows:
• Frequency = 1 kHz
• Amplitude = -20 dBu
• Filters = 30 kHz LPF
2. With the audio analyzer, probe TPA2 (top side), it should read -3.4dBu ± 0.5dB. Record this level
using the Ratio button. This level will be used as your reference level for the following test.
3. Change the generator's frequency to 100Hz and measure the level at TPA2 to be -2.2dB ± 0.2dB
relative to the 1kHz reference level.
4. Change the generator's frequency to 10kHz and measure the level at TPA2 to be +2.3dB ± 0.2dB
relative to the 1kHz reference level.
5. Disengage the Ratio button.
DISTORTION TEST
1. Set the audio generator frequency to 1kHz with an amplitude of -20.0dBu.
2. Activate the 30kHz LPF on the audio generator.
3. Measure the total harmonic distortion and noise (THD+N) at TPA2 to be less than 0.7%.
RADIATED RF OUTPUT POWER AND FREQUENCY STABILITY TEST
1. Choose any group and channel free of interference. Using a spectrum analyzer with the appropri-
ate-band UA820 antenna, measure the approximate near field radiated power as follows:
• SPAN=100 MHz
• REF LVL=10dBm
• FREQUENCY=(Look at tables on pages 18 thru 23)
2. Extend the UA820 away from the analyzer into the horizontal plane (straight out). Align the SLX2
antenna parallel to the UA820 as close as possible. Move the unit along the UA820 antenna until
you find a maximum peak.
3. Do a peak search and measure the power to be at least 2 dBm for H5, J3, L4, and P4 bands and at
least 0 dBm for Q4, R5, JB, and S6 bands.
4. Set SPAN to 200 KHz. Measure the frequency to be within +/- 3 kHz of the nominal frequency you
are testing. (See frequency tables on pages 19 to 24).
TONE KEY LEVEL TEST
1. Set Power Supply to 3.0VDC
2. Find transmitting carrier on the spectrum analyzer with a span of 200 kHz. Use the "Peak Search,
Marker Delta, Next Peak" soft-keys on the analyzer.
3. Measure the 32.768 kHz tone key level to be -21 dBc ± 1.5 dB.
4. Set Power Supply to 2.1 V (1 segment on LCD battery icon).
5. Measure the 32.768 kHz tone key level to be -14 dBc ± 1.5 dB.
OCCUPIED BANDWIDTH TEST (JB model only)
1. Set transmitter gain to maximum.
2. Set up the HP-8591E spectrum analyzer to measure Occupied Bandwidth with the following set-
tings:
• Percentage Power = 99.5%
• Channel Spacing = 250 kHz
• Bandwidth = 110 kHz
3. Connect the audio generator to TQG connector CON90. Use a 1 kHz tone with a level that gives -
23.47 dBu (52mV) at TPA3.
4. Increase the audio level by 36dB.
5. Measure Occupied Bandwidth to be less than 110 kHz.
ADJACENT CHANNEL POWER TEST (JB model only)
1. Set the spectrum analyzer, and audio input level to the same settings as stated in “Radiated RF
Output Power and Frequency Stability” and “Distortion Test”.
2. Measure Extended Adjacent Channel Power to be less than -60 dB.
IF ALL TEST PASSED, THIS MEANS THE UNIT IS PROPERLY FUNCTIONING, AND
NO ALIGNMENT IS REQUIRED.

12
25A1090 (Rev.3)
ASSEMBLY AND DISASSEMBLY
EXPLODED VIEW
!CAUTION!
Observe precautions when handling this static-sensitive device.
I.D. # Description Part Number
0001 Cartridge
0002 Tuned PCB assembly 200--082
0003 PCB assembly, IR 190A098-01
0004 PCB, head board 190-057-03-34
0005 Contact 53F2039A
0006 Frame, internal 65B8467
0007 Retaining ring 30A1314
0008 bezel, painted/printed 65A8475B
0009 Pushbutton actuator, silicone 66A8070
0010 Battery cup, painted 65BA8451
0012 Shield cover, steel, plated 53A8590A
0014 3 pin interconnect 170A74
0015 PCB Screw, hi-lo #4 30J1245
0016 Handle assembly 95A9047B
0017 Battery holder assembly 95B9048
0018 Battery holder, Machine screw, #2–56 30D443E
0019 Nameplate, frequency 39--8466
0022 Battery cover assembly 95A9068

13
25A1090 (Rev.3)
SERVICE PROCEDURES
MEASUREMENT REFERENCE
NOTE: Audio levels in dBu are marked as dBm on the HP8903.
REQUIRED TEST EQUIPMENT (OR APPROVED EQUIVALENT OR SUPERIOR MODELS):
dB Conversion Chart
0dBV = 2.2 dBu
0dBu = 0dBm assuming the load = 600 ohms
Be aware that dBu is a measure of voltage and dBm
is a measure of power. The HP8903, for example,
should be labeled dBu instead of dBm since it is a
voltage measurement. These two terms are often
used interchangeably even though they have
different meanings.
Spectrum analyzer or power meter HP8591E/Agilent E4403B/Agilent E4407B
Digital multimeter Fluke 87
Audio Analyzer HP 8903B
RF Signal Generator HP 8656B or HP E4400B
Frequency Counter HP 53181/HP 5385A
Receiver Matching SLX4 Receiver
50 ohm, RG-174 BNC to open (stripped)
coaxial cable or "rocket launcher" tip (P/N
95A8278). For JB, Murata cable #
MXGS83RK3000 may be used.
Shure PT 1824
Audio Test Head Shure PT1840
Brass Ring Shure PT1838Y
BNC (Male) to BNC (Male) Cable (2) Shure PT1838A
DC Blocker Shure PT1838W
XLR (Female) to Banana Plug Adapter Shure PT1841
20 dB Attenuator Shure PT1838T
Toray non-inductive tuning tool - BLUE Shure PT1838K
Toray non-inductive tuning tool - PINK Shure PT1838L

14
25A1090 (Rev.3)
ALIGNMENT PROCEDURE
Alignment and Measurement Procedure
The alignment procedure is sequential and does not change unless specified. Use RG58 or
other low loss 50 ohm cables for all RF connections. Type RG174 (thin) 50 ohm cables can be
used for short (e.g. 6 inch) runs. Keep RF test cables as short as possible. Include the insertion
loss of the cables and the connectors for all RF measurements. DC voltages are present at most
RF test points. Use DC blocks to protect the test equipment, if necessary. All audio analyzer fil-
ters should be OFF unless otherwise specified.
VOLTAGE REGULATION CHECK
With power applied properly, and the unit switched on, measure the DC voltages at the fol-
lowing test points. All test points are located on the top side of the PCB. Refere to the component
diagram.
INITIAL SETUP
1. Proper adapters should be used to connect the test equipment.
2. Apply +3 V to the battery terminals with the proper polarity.
3. Set audio gain switch SW100 to "-10 dB".
4. Remove L641 to disengage the antenna (ALL EXCEPT JB).
5. Solder the center of a 50Ω unshielded test cable (PT1824) to the node between L606 and
L641, and the shield to ground.
6. Connect the audio generator output to the Mic Test Head input of the transmitter as
required.
7. Turn on the SLX2 by pressing and holding the POWER button, SW325.
RF TUNING
The removal of L641 (prevents antenna loading of output).
VCO Tuning:
1. Set transmitter to its LOW frequency as indicated in the table above.
2. WIth a DC meter probe TP_PLL_TV (top).
3. Tune CV500 to obtain 1.10-1.40 Vdc at TP_PLL_TV. For Q4 units, this voltage should
read between 1.45-2.25 Vdc. For JB units, this voltage should read between 1.75-2.05
Vdc.
4. Set the transmitter to HIGH frequency.
5. Verify voltage at TP_PLL_TV is less than or equal to 4.3 V DC.
Test Points Voltages
TPBATT+ (Battery input) 3 ± 0.2 Volts
TP5V (Power Converter) 5 ± 0.2 Volts
TP3.3V (Power Converter) 3.3 ± 0.2 Volts
TPA1 (Audio Preamp) 2.5 ± 0.2 Volts
TPA3 (Tone Key Summing Amp,
(IC150 Pin 14)) 2.5 ± 0.2 Volts
TPVREF (IC100 Pin 5) 2.5 ± 0.1 Volts
Frequency
Level H5 J3 JB L4 P4 Q4 R5 S6
LOW GRP. 1 /
CH. 1 GRP. 1 / CH. 1 GRP. 1 / CH. 5 GRP. 1 / CH. 1 GRP. 14 / CH. 1 GRP. 1 / CH. 1 GRP. 4 / CH. 1 GRP. 13 / CH. 1
MID GRP. 4 /
CH. 7 GRP. 4 / CH. 7 GRP. 1 / CH. 2 GRP. 4 / CH. 7 GRP. 14 / CH. 5 GRP. 1 / CH. 5 GRP. 4 / CH. 7 GRP. 14 / CH. 7
HIGH GRP. 6 /
CH. 12 GRP. 6 / CH. 12 GRP. 5 / CH. 4 GRP. 6 / CH. 12 GRP. 15 / CH. 10 GRP. 1 / CH. 8 GRP. 2 / CH. 11 GRP. 3 / CH. 13

15
25A1090 (Rev.3)
FREQUENCY ALIGNMENT:
1. Set the transmitter to MID frequency (see table on page 14).
2. Connect the 50 Ωcable to a frequency counter.
3. Adjust variable capacitor CV501 until the frequency counter measurement matches the
appropriate frequency on the table below, ± 1 kHz. .
RF OUTPUT POWER
The output power measurement ensures that the output signal is strong enough for
sufficient range when the system is in use. The output power measurement also verifies
tha the output power is not above the specified maximum level, to ensure compliance
with regulatory angencies’ standards.
1. RF output power is only adjustable on and JB units. Use RG58 (PT 1824) or any other low
loss 50 Ωcables for all RF connections.
2. Include the insertion loss of the cables and connectors in rf conductive power measure-
ments.
3. Connect the RF output of the transmitter to a spectrum analyzer.
4. Set the spectrum analyzer center frequency to match the transmitter frequency.
5. Using a power meter or spectrum analyzer, verify the output power matches the range
indicated in the table below. JB models can be adjusted at TR640.
6. Remove the BNC to unterminated test cable (PT1824) and replace L641 to reconnect the
antenna.
DEVIATION ADJUSTMENT
Deviation must be set to make sure the companding systems between the transmitter and re-
ceiver correctly track each other. The level coming out of the transmitter’s audio compressor
must match the level going into the receiver’s audio expander. A fixed gain structure does not
ensure exact match, primarily because of variations in voltage-controlled oscillators (VCO’s).
USING A SLX4 RECEIVER
The following procedure requires a SLX4 receiver. It is recommended that a properly tuned
receiver be used to perform the transmitter deviation adjustment.
GROUP CODE FREQUENCY RANGE
H5 529.500 Mhz ± 1 kHz
J3 583.500 Mhz ± 1 kHz
JB 807.500 Mhz ± 1 kHz
L4 649.500 Mhz ± 1 kHz
P4 714.000 Mhz ± 1 kHz
Q4 746.325 Mhz ± 1 khz
R5 810.275 Mhz ± 1 kHz
S6 851.300 Mhz ± 1 kHz
GROUP Pout RANGE
H5 14 dBm ± 2 dB
J3 14 dBm ± 2 dB
JB 7.0 - 10.8 dBm
L4 14 dBm ± 2 dB
P4 14 dBm ± 2 dB
Q4 10 dBm ± 2 dB
R5 13 dBm ± 2 dB
S6 10 dBm ± 2 dB

16
25A1090 (Rev.3)
RECEIVER SETUP
1. The SLX2 transmitter should be powered OFF for this procedure.
2. Connect the rf signal generator to any of the antenna inputs on the receiver. Make sure the
dc block is on the rf signal generator.
3. Set rf signal generator to the same frequency as the SLX2 transmitter.
4. Set rf signal generator modulation to 1 kHz and deviation to 33 kHz.
5. Set the amplitude of the rf signal generator to -50 dBm.
6. Disable tonekey by shorting the pads of R280 on the receiver.
DEVIATION REFERENCE LEVEL
1. Power ON the receiver.
2. Connect the unbalanced output of the SLX4 receiver to the audio analyzer input.
3. Note the voltage obtained. This is the deviation reference voltage.
4. Disconnect the rf signal generator from the SLX4.
5. Power OFF the receiver and remove the short on the R280 pads to enable tonekey.
RADIATED DEVIATION REFERENCE VOLTAGE
1. Connect the audio analyzer output to the Mic Test Head input of the transmitter.
2. Power ON the receiver.
3. Apply +3V to the battery terminals on the SLX2 and power up the unit.
4. Set the audio analyzer frequency to 1kHz.
5. Adjust the audio analyzer amplitude level (typically = -6.5 dBu) to obtain -13 dBu
± 0.1dB
at TPA1. (This corresponds to -9 dBu ± 2dB at the audio input (TPA0)) .
6. Adjust TR160 to obtain -3 dBu
± 0.15dB at TPA2.
7. Place the transmitter closer than 12 inches (36 cm) to the receiver.
8. Connect both antennas on the receiver.
9. Connect the un
balanced output of the receiver to the audio analyzer.
10. Adjust TR200 until the ac voltmeter connected to the receiver unbalanced output reads the
same deviation reference voltage ± 0.1dB, as measured above.
(TR200 adjusts the deviation for 33 kHz, 100% modulation.)
If successful in the alignment of the unit, assemble it back together as indicated on
page 12. If not successful refere to our Bench Checks section on page28.
SLX4 RECEIVER AUDIO ANALYZER RF SIGNAL GENERATOR
Output: Unbalanced Measurement: AC level INT: FM
Gain: Maximum Filters: FM RATE: 1kHz
Toke Key: Disabled (R280) Low-Pass (30 kHz): ON Amplitude: -50 dBm
High-Pass (400 Hz): ON Deviation: 33 kHz
SLX2 TRANSMITTER AUDIO ANALYZER
Power: +3 Vdc Measurement: AC level
Atennuation: -10 dB Output: 1 kHz
Channel: See Table Filters:
Group: See Table Low-Pass (30 kHz): ON
High-Pass (400 Hz): ON

17
25A1090 (Rev.3)
NOTES:

18
25A1090 (Rev.3)
FREQUENCY TABLES
H5: 518.000 - 542.000 MHz
J3: 572.000 - 596.000 MHZ
Preprogrammed frequencies in total: > 120
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6
1518.400 519.250 518.200 519.775 519.100 518.425
2521.500 520.500 519.675 522.500 521.225 520.400
3523.575 522.225 520.800 524.200 522.550 523.425
4525.050 524.725 522.450 525.600 524.575 525.475
5527.425 526.350 523.750 526.700 526.900 527.775
6529.200 527.550 526.200 528.250 530.500 531.675
7532.450 530.800 528.325 529.500 531.750 533.800
8533.650 532.575 532.225 533.100 533.300 536.250
9535.275 534.950 534.525 535.425 534.400 537.550
10 537.775 536.425 536.575 537.450 535.800 539.200
11 539.500 538.500 539.600 538.775 537.500 540.325
12 540.750 541.600 541.575 540.900 540.225 541.800
Explanation of group
content Full Range even distribution for each
TV-CH (option 1)
Full Range even
distribution for each
TV-CH (option 2)
Full Rangemax.# of
frequencies for CH-
22 (option 1)
Full Range max. # of
frequencies for CH-
23 (option 1)
Full Range max. # of
frequencies for CH-
24 (option 1)
Full Range max. # of
frequencies for CH-
25 (option 1)
Preprogrammed frequencies in total: > 120
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6
1572.400 573.250 572.200 573.775 573.100 572.425
2575.500 574.500 573.675 576.500 575.225 574.400
3577.575 576.225 574.800 578.200 576.550 577.425
4579.050 578.725 576.450 579.600 578.575 579.475
5581.425 580.350 577.750 580.700 580.900 581.775
6583.200 581.550 580.200 582.250 584.500 585.675
7586.450 584.800 582.325 583.500 585.750 587.800
8587.650 586.575 586.225 587.100 587.300 590.250
9589.275 588.950 588.525 589.425 588.400 591.550
10 591.775 590.425 590.575 591.450 589.800 593.200
11 593.500 592.500 593.600 592.775 591.500 594.325
12 594.750 595.600 595.575 594.900 594.225 595.800
Explanation of group
content Full Range even distrobution for each
TV-CH (option 1)
Full Range even
distrobution for each
TV-CH (option 2)
Full Rangemax.# of
frequencies for CH-
31 (option 1)
Full Range max. # of
frequencies for CH-
32 (option 1)
Full Range max. # of
frequencies for CH-
33 (option 1)
Full Range max. # of
frequencies for CH-
34 (option 1)

19
25A1090 (Rev.3)
JB: 806.000 - 810.000 MHZ
L4: 638.000 - 662.000 MHZ
Preprogrammed frequencies in total: 21
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6
1806.250 806.375 806.125 806.500 806.125 806.250
2807.500 808.625 807.375 807.375 807.375 807.250
3809.625 809.750 809.500 808.625 808.375 808.500
4809.625 809.750 809.375
Explanation of group
content Full Range max. # of compatible
frequencies (option
1)
Full Range max. # of
compatible
frequencies (option
2)
Full Range max. # of
compatible
frequencies (option
3)
Full Range max. # of
compatible
frequencies (option
4)
Full Range max. # of
compatible
frequencies (option
5)
Full Range max. # of
compatible
frequencies (option
6)
Preprogrammed frequencies in total: > 120
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6
1638.400 639.250 638.200 639.775 639.100 638.425
2641.500 640.500 639.675 642.500 641.225 640.400
3643.575 642.225 640.800 644.200 642.550 643.425
4645.050 644.725 642.450 645.600 644.575 645.475
5647.425 646.350 643.750 646.700 646.900 647.775
6649.200 647.550 646.200 648.250 650.500 651.675
7652.450 650.800 648.325 649.500 651.750 653.800
8653.650 652.575 652.225 653.100 653.300 656.250
9655.275 654.950 654.525 655.425 654.400 657.550
10 657.775 656.425 656.575 657.450 655.800 659.200
11 659.500 658.500 659.600 658.775 657.500 660.325
12 660.750 661.600 661.575 660.900 660.225 661.800
Explanation of group
content Full Range even distribution for each
TV-CH (option 1)
Full Range even
distribution for each
TV-CH (option 2)
Full Rangemax.# of
frequencies for CH-
42 (option 1)
Full Range max. # of
frequencies for CH-
43 (option 1)
Full Range max. # of
frequencies for CH-
44 (option 1)
Full Range max. # of
frequencies for CH-
45 (option 1)

20
25A1090 (Rev.3)
P4: 702.000 - 726.000 MHZ
P4: 702.000 - 726.000 MHZ CONTINUED
Preprogrammed frequencies in total:
148
12 12 12 10 10 9 9 10 11
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 8 Group 9
1702.200 703.750 703.650 702.750 703.750 702.100 704.775 702.300 703.000
2704.200 705.975 705.650 704.500 705.750 704.025 706.225 704.975 706.025
3707.200 707.200 708.650 705.750 708.250 705.500 710.500 706.775 708.000
4709.425 708.850 710.875 708.250 711.750 708.500 712.025 709.100 710.300
5711.000 710.950 712.450 711.250 714.500 710.100 714.225 710.300 712.225
6713.675 712.425 715.125 712.500 715.750 712.025 716.900 712.225 716.000
7715.575 714.325 717.025 715.250 718.750 713.500 718.500 714.775 717.100
8717.050 717.000 718.500 718.750 721.250 717.300 720.775 716.700 719.000
9719.150 718.575 720.600 721.250 722.500 725.300 725.300 724.000 720.225
10 720.800 720.800 722.250 723.250 724.250 725.900 722.775
11 722.025 723.800 723.475 724.700
12 724.250 725.800 725.700
Explanation
of group
content
Full Range
max. # of
compatible
frequencies
(option 1)
Full Range
max. # of
compatible
freque-cies
(option 2)
Full Range
max. # of
compatible
frequencies
(option 3)
France
preferred:
UserGroupA
(option 1)
France
preferred:
UserGroupA
(option 2)
France
preferred:
UserGroupB
(option 1)
France
preferred:
UserGroupB
(option 2)
France
preferred:
UserGroupC
(option 1)
France
preferred:
UserGroupC
(option 2)
665108108
Group 10 Group 11 Group 12 Group 13 Group 14 Group 15 Group 16
1702.200 710.200 718.200 702.550 702.100 702.700 702.500
2703.300 711.300 719.300 705.600 704.700 704.700 705.500
3704.700 712.700 720.700 707.500 710.300 709.450 707.000
4705.800 713.800 721.800 709.000 712.400 711.500 712.200
5707.675 715.675 723.675 711.500 714.000 714.500 714.100
6708.775 716.775 715.100 716.500 716.550 716.400
7717.000 719.400 719.900 719.500
8720.000 721.300 722.000 722.200
9723.500 724.700
10 725.900 725.900
11
12
Explanation of
group content Optimized TV channels: TV ch.
50 702-710 MHz
Optimized TV
channels: TV ch.
51 710-718 MHz
Optimized TV
channels: TV ch.
52 718-724 MHz
Compatible setup
for use with
PSM400-P3 (P4 >
P3)
Compatible setup
for use with
PSM400-P3 (P4 =
P3)
Compatible setup
for use with
PSM400-HF (P4 >
HF)
Compatible setup
for use with
PSM400-HF (P4 =
HF)