Shure UC1L Service Manual page 14

Shure UC1 Body-Pack UHF Transmitter
Frequency
FREQUENCY COUNTER
UC1 Transmitter
Power: ON
Operating freq: See Table 2
Service Procedures
Use this service procedure to correctly align the transmitter's
operating (output) frequency. C510 tunes the voltage-controlled
oscillator (VCO) to the operating frequency selected, with a 1 – 4 Vdc
tuning range.
C123 adjusts the reference oscillator on the synthesizer.
SIDE 1
CH 2
CH 1
*R144 and J103 are for JA, JB frequencies only.
Frequency Counter
Operating freq: See Table 2
Connect CH 2: W101 and GND
Figure 5. UC1 Frequency Alignment Test Set-Up
1. Remove the antenna and connect the 50 Ω cable, center
conductor to W101, and shield to GND, as shown in Figure 5.
(For JA, JB frequencies, use J103 and GND.)
2. Connect the BNC cable end to the frequency counter, CH 2.
3. Measure the dc voltage at TP130 (tuning voltage line) and
ground (GND).
4. Use the pink torey to adjust the VCO trimmer, C510, until the
voltmeter reading equals that shown in Table 2,
5. Use the blue torey to adjust the variable capacitor, C123, until
the frequency counter measurement matches the desired
frequency, within
6. Disconnect the test cable from the frequency counter.
7. Use the test set-up and equipment settings in Figure 6 for
the next test, the power output measurement.
14
C123
TP130
*R144
VCO
C510
U501
*J103
GND
W101
Connect + : TP130
Connect – : J202 (ground)
For JA, JB use
J103 and GND
1 kHz.
DC VOLTMETER
+
–
S102
(GREEN)
S101
(RED)
J202
J201
DC Voltmeter
0.125V..
25A1043 (RI)