Alignment And Measurement Procedure; Voltage Regulation Check; Initial Setup; Rf Tuning - Shure SLX2 Service Manual

ALIGNMENT PROCEDURE
Frequency
Level
LOW GRP. 1 /
MID GRP. 4 /
HIGH GRP. 6 /
25A1090 (Rev.3)

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
H5 J3
GRP. 1 / GRP. 1 /
CH. 1 CH. 1 CH. 5
GRP. 4 / GRP. 1 /
CH. 7 CH. 7 CH. 2
GRP. 6 / GRP. 5 /
CH. 12 CH. 12 CH. 4

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
TPBATT+ (Battery input)
TP5V (Power Converter)
TP3.3V (Power Converter)
TPA1 (Audio Preamp)
TPA3 (Tone Key Summing Amp,
(IC150 Pin 14))
TPVREF (IC100 Pin 5)
JB L4 P4
GRP. 1 / GRP. 14 /
CH. 1 CH. 1
GRP. 4 / GRP. 14 /
CH. 7 CH. 5
GRP. 6 / GRP. 15 /
CH. 12 CH. 10
14
Voltages
3 ± 0.2 Volts
5 ± 0.2 Volts
3.3 ± 0.2 Volts
2.5 ± 0.2 Volts
2.5 ± 0.2 Volts
2.5 ± 0.1 Volts
.
Q4 R5
GRP. 1 / GRP. 4 / GRP. 13 /
CH. 1 CH. 1
GRP. 1 / GRP. 4 / GRP. 14 /
CH. 5 CH. 7
GRP. 1 / GRP. 2 / GRP. 3 /
CH. 8 CH. 11 CH. 13
S6
CH. 1
CH. 7