Raytheon 138-118 Manual page 36

Adjustment after installation of the magnetic sonde
(see Fig.11)
The Distribution Unit is in operation.
Magnetic sonde is installed and connected to the Distribution Unit.
-- Switch the switches 6,7 and 8 of the DIP switch B20 into the upper position "OPEN").
-- Operate push button B22 until the display shows "MAGS".
-- Operate push button B23 once; the actual heading of the magnetic sonde is
displayed.
-- Measure the voltage at plug B2, there should be a voltage of 1,8V
between pin 2.1 and 2.2 .
-- Connect voltmeter (DC--range) at TP 11 or TP 12 (+) and TP0 (GND) at the I/O PCB.
-- Turn the magnetic sonde (in the holder) until a value between 4.3V and 4.6V is
displayd at the voltmeter.
-- If the voltage is less than 4.3V or higer than 4.6V, than the requeseted voltage has to
be adjusted with potentiometer R155 to a value between 4.3V and 4.6V.
-- If this value cannot be adjusted by potentiometer R155 (display in the Distribution
Unit shows "Err"), the distance between magnetic compass and sonde has to be
reduced. After that the voltage adjustment must be repeatet until the heading value is
displayed (not "Err").
-- After the voltage adjustment, the magnetic sonde has do be adjusted in that way, that
the display in the Distribution Unit shows the same heading value than the magnetic
compass.
If the potentiometer R113 is adjusted inadvertently
-- Divert the compass card into position 45° by an iron tool.
-- Voltage measurement at TP11 (+) and TP0 (GND
Voltage measurement at TP12 (+) and TP0 (GND)
Both values must be the same.
-- If applicable adjust potentiometer R113, so that both values are the same.
3647.DOC010302
Distribution Unit
138- -118
and
28
(400Hz)
eff
Edition: November 21, 2003