Lexicon MC-1, Service Manual

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Lexicon
5-15
Power Control Trigger Outputs
There are two trigger outputs available on the MC-1. One is a Power on Trigger labeled (PWR). This
indicates the trigger is active when the unit is powered on. The other is a programmable trigger labeled
(PGM). This trigger can be assigned to be active for a specific input. They are both available on two
different styles of connectors on the back of the unit. A 5-pin DIN connector and a 4-pin removable screw
terminal are the two converters provided. See the pinout diagram below. Each trigger output can be
independently configured for +12 Volts or +5 Volts.
The following information shows what jumpers are used in the MC-1 in order to change the unit from a 12
volt to a 5-volt trigger depending on application.
Trigger Output Voltages +5V +12V
Jumpers to be used for Power On (PWR) W1-2 W1-2
Pins 1+2 2+3
Jumpers to be used for Programmable W3-4 W3-4
Pins 1+2 2+3
The voltage and amp specifications for both voltages are as follows below
Configuration Voltage Spec Max Iout
+5 V Reg/- 5 % 500mA
+12V Reg/- 5 % 500mA
Video Subcarrier Calibration
Calibration Procedure
1. Enter the MC-1 into Extended Diagnostics mode.
2. Press TV on the remote to enter the Video Test
3. Pressing the Menu
∇ will set the MC-1 into this test. The output frequency at TP2 on the Video board is
now at the NTSC standard calibration frequency.
4. Set the counter to measure at the gate rate of 0.1 seconds and adjust the variable capacitor (C78) to
set the frequency at TP2 to 3.57168MHz.
5. Press Select. At this time the frequency reading on the counter should red between 4.43737 and
4.43781 MHz.
TRIGGERS
TRIGGERS
IR IN
PGM
PGM
PWR
PWR
GND
GND
1
2
3
4 5