Service manual

Shure LX2 Hand-Held Transmitter
Preliminary Tests9
25D1006 (CG)
Rf Tests
SPECTRUM ANALYZER
BAT
MUTE
LX2 Transmitter Spectrum Analyzer
Power switch: PWR Center frequency: transmitter frequency
Mute switch: MUTE Span: 30 MHz
Reference level: + 20 dBm
Scale: 10 dB/div
Figure 3. Rf Functional Test Set-Up
1. Install a new 9 Vdc battery and turn on the LX2.
2. Measure the current drain: it should not exceed 35 mA.
3. Maximize the signal received on the spectrum analyzer by
attaching a telescoping whip antenna. Then measure the near-
field output power. It should measure 3 dBm .
4. Verify that the carrier frequency of the transmitter varies from its
nominal value by no more than "6 kHz.
5. Check for an intermittent problem by shaking the transmitter and
tapping on it, keeping the transmitter a constant distance from
the spectrum analyzer. Verify that the output power on the spec-
trum analyzer shows no large and sudden drops in power level.
It will, however, vary a few dB according to hand position.
6. Turn the LX2 OFF.