Service manual

Shure LX2 Hand-Held Transmitter

Service Procedures

25D1006 (CG)

Rf Alignment: Euro (ETSI)

Do not apply modulation during the following rf alignment

procedures. If you cannot achieve any of the settings described

in this procedure, consult the Bench Checks section.

SPECTRUM ANALYZER

–

RF BOARD (TOP)

ETSI

L201

Y201

R217

C214

C216

C222

C226

J201

J202

TP7

TP6

TP5

LX2 Transmitter Spectrum Analyzer

Power source: 9 Vdc Center frequency: 1/3 of the transmitter freq

Power switch: PWR Span: 30 MHz

Mute switch: MUTE Reference level: + 20 dBm

Scale: 10 dB/div

Figure 13. Rf Alignment (Euro)

Note: See the Service Equipment Manual for conversion of a 50 Ω

BNC cable–to–RGU174 cable to a high impedance probe.

1. Tack-solder the high-impedance probe to the rf circuit board bottom:

S Connect the center conductor to TP5 (base of Q202).

S Connect the shield to circuit ground.

2. Carefully remove C242 from the rf board. This disconnects

the battery (antenna) to allow accurate conductive-power

measurements.

3. Connect the high-impedance probe to the spectrum analyzer.

4. Verify that the mic switch is in the MUTE position.

5. On the spectrum analyzer, set the center frequency to one-third

the frequency of the transmitter. Set the span to 30 MHz, the

reference level to +20 dBm, and the scale to 10 dB/div.