RCA BR200DV, Service Manual

Page: 42 / 79

BR200DV/BR300DV
Service Manual
38
Table 2
High/ Intermediate/ Low Frequency Point of All Models
Low Frequency Point Intermediate
Frequency Point
High Frequency Point
DR6000-1
DR7000-1
136.000 MHz 155.100 MHz
173.975 MHz
7.3.2 PLL frequency calibration
Double-click to enter “Frequency Stability” in “Interphone Performance Tuning” to achieve the rated
transmitting frequency by adjusting the number from 0 to 255 (Error<200Hz).
7.3.3 Transmitting frequency adjustment
Double-click to enter “Transmitting High Power” in “Interphone Performance Tuning” to adjust the five
frequency points including ”Lowest”, “Low”, “Mid”, “High” and “Highest” respectively and set transmitting
power to over 5W by adjusting the number from 0 to 255 and observe the operating current (
≤ 1.6A) at
the same time.
Double-click to enter “Transmitting Low Power” in “Interphone Performance Tuning” to adjust the five
frequency points including ”Lowest”, “Low”, “Mid”, “High” and “Highest” respectively and set transmitting
power to over 1W by adjusting the number from 0 to 255.
7.3.4 Transmitting low-voltage alarm
Adjust power voltage to 5.8V and double-click to enter “Transmitting Low Voltage” in “Interphone
Performance Tuning” Mode for automatic detection of the software, and then click “Save” for exit after no
or little variation in numbers.
7.3.5 Frequency offset adjustment
Input audio signal (12mV, 1000Hz) at MIC jack of interphone. Adjust the potentiometer VR501 and set
frequency offset to ±4.2kHz.
7.3.6 DCS transmitting signal waveform and frequency offset adjustment
Double-click to enter “DCS frequency offset” in “Interphone Performance Tuning” Mode, adjust
potentiometer VR1 to observe demodulated signal (the waveform shall be smooth and similar to square
wave), and then click “Broadband” to adjust all points including ”Lowest”, “Low”, “Mid”, “High” and
“Highest” respectively for frequency offset of
0.8kHz. After that, click “Narrowband” to adjust the
frequency offset to 0.4kHz.
7.3.7 CTCSS frequency offset adjustment
Double-click to enter “QT(67) frequency offset” in “Interphone Performance Tuning” Mode and click
“Broadband” to adjust the five frequency points including ”Lowest”, “Low”, “Mid”, “High” and “Highest”
respectively to 0.75kHz and then click “Narrowband” to adjust the frequency offset to 0.35kHz.
Select “QT(254) frequency offset” in “Interphone Performance Tuning” Mode, and the debugging method