Service manual

Shure LX2 Hand-Held Transmitter
Service Procedures29
25D1006 (CG)
Audio Frequency Response (Domestic and Euro)
AUDIO ANALYZER
–
+
R130
R125
U102
U101
S102
S101
C107
LX2 Transmitter Audio Analyzer
Power supply: 9 Vdc Frequency: 100 Hz
Power switch (S101): PWR Amplitude: 230 mV
Mic switch (S102): ON Filters:
400 Hz High-Pass: OFF
30 kHz Low-Pass: ON
Figure 20. Frequency Response Test Set-Up
Note: Press the LOG/LIN button on the audio analyzer to measure in
dB. Then press the RATIO button to perform the relative measurement
in the next section.
1. Remove the 400 Hz high pass filter from the audio analyzer.
2. Change the frequency of the audio analyzer to 100 Hz.
3. Verify that the audio level is equal to –0.5 ± 0.5 dB
relative to the level measured at the anode (+) of C107 at 1 KHz.
4. Activate the 400 Hz high-pass filter on the audio analyzer.
5. Change the frequency of the audio analyzer to 10 kHz. Verify
that the audio level is equal to +3.0 ± 0.5 dB relative to the
level measured at the anode (+) of C107 at 1 KHz.
6. Turn the LX2 power OFF.