RCA BR200DV, Service Manual

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BR200DV/BR300DV
Service Manual
37
Figure 1 External Speaker/microphone Interface Definition
7.2 Adjustment Items
Some detection and adjustment shall be made to the station technical data after changing the
components during the maintenance. The debugging introduction of some related circuits goes as
follows:
Some parameters of the product can be adjusted (“Interphone Performance Tuning”) by use of ARD001
Programming Software of our company. The adjustable parameters are as follows
：
1) Frequency stability”
2) Transmitting power
3) Alarm threshold for battery low-voltage
4) Squelch level
5) QT frequency offset
6) DCS frequency offset
7) Receiving sensitivity
Steps for adjustment
：
a 、 Enter Computer Test Mode by selecting “Test Mode” in main menu of ARD001 Programming
Software.
b
、
Select the items to be adjusted in choice menus, and then adjust the parameters by function keys on
the computer keyboard.
c
、
Exit Computer Test Mode after adjustment.
7.3 Adjustment
7.3.1 VCO Adjustment
Close “Power-saving Mode”. Set receiving frequency to low frequency point (see Table 2) and in the
receiving state, test voltage of PD by DMM and adjust fine-tuning capacitor TC1/TC2 to get CV voltage
of 1.0V±0.2V
Set transmitting frequency to high frequency point (refer to Table 2), press PTT and test voltage of
PD by DMM, which shall less than 4.0V