Shure UC1L Service Manual page 16

Shure UC1 Body-Pack UHF Transmitter
Deviation Reference Voltage: Using a UC4 or U4S Receiver
UC4 RECEIVER (BACK)
AUDIO ANALYZER
UC4 Receiver
Output: Unbalanced
Gain: Maximum
Squelch: Mid
Tone Key (S501): OFF
Operating freq: See Table 2
Figure 7. Deviation Reference Voltage Test Set-Up, Using a UC4 or U4S Receiver
Service Procedures
Deviation must be set to make sure the companding systems be-
tween the transmitter and receiver correctly track each other. The level
coming out of the transmitter's audio compressor must match the level
going into the receiver's audio expander. A fixed gain structure does not
ensure an exact match, primarily because of variations in voltage-
controlled oscillators (VCOs).
This test requires a UC4 or U4S receiver and is designed to tune the
transmitter regardless of the accuracy of the receiver's tuning. However,
it is recommended that a properly-tuned receiver be used to perform the
transmitter deviation adjustment.
Be sure to use a KK model receiver when tuning a KK model transmitter.
SQUELCH
DC BLOCK
RF SIGNAL GENERATOR
Audio Analyzer
Measurement: AC level
Filters:
Low-Pass (30 kHz): ON
High-Pass (400 Hz): ON
1. See Figure 7 for equipment test set-up and equipment settings.
2. Connect the rf signal generator output to the UC4 receiver
antenna input (A or B).
3. Turn the UC4 receiver on and set switch S501 inside the UC4
receiver to the OFF position to disable the tone key function.
4. Connect the audio voltmeter to the receiver's unbalanced output.
5. Measure the output voltage.
Record this voltage. This is the deviation reference voltage .
16
UC4 RECEIVER (FRONT)
A B
NOTE: DC VOLTAGES ARE PRESENT AT MOST
RF TEST POINTS. USE A DC BLOCK ON THE
RF SIGNAL GENERATOR TO PROTECT
TEST EQUIPMENT.
Rf Signal Generator
Output Amplitude: –60 dBm
Frequency: See Table 2
Modulation:
S501
(TONE KEY SWITCH)
TK ON TK OFF
INT: FM
INT: 1 kHz
See Table 2
25A1043 (RI)