9
G-400 A
ZIMUTH
R
OTATOR
C
ALIBRA
TION
Azimuth Offset Null
r
Before calibrating the Rotator, check to see that the
GS-
232A
’s DIP switch (switch 5)
is set to the “
OFF
” posi-
tion.
r
From the Controller panel, set the Rotator fully counter-
clockwise (set to 180°).
r
Press [
O
]
Ž
[
↵
] (the letter “oh”, and “
E
NTER
”) on the
computer keyboard to activate the azimuth calibration
routine. The computer display should show
AZ
aaaa
=
bbbb
returned from the Interface Board, where
aaaa
and
bbbb
are four-digit numbers padded at the left with
zeroes.
r
Adjust the
AZ
trimmer (located on the bottom case of
the
GS-232A
) while watching the computer display, until
the four-digit numbers
aaaa
and
bbbb
are the same
(the precise values are not important).
r
Turn off the
GS-232A
’s
POWER
switch to exit the azi-
muth calibration routine, then turn on the
GS-232A
’s
POWER
switch again.
Azimuth A-D Calibration
r
From the Controller panel, set the Rotator fully clock-
wise (to the right).
r
Press [
F
]
Ž
[
↵
] (“F” and “
E
NTER
”) on the computer key-
board to activate the Control Interface’s azimuth A-D
converter calibration routine. The computer’s display
should show +
aaaa
, where
aaaa
is a four-digit num-
ber which indicates the azimuth heading in degrees.
r
Adjust the
FULL SCALE ADJ
on the
GX-500
so as to
get a reading of “
0180
” on the computer’s display.
This reading (“180 degrees”) corresponds to the actual
beam heading you established when you pointed the
azimuth rotator to the South (the fully clockwise set-
ting).
r
Turn off the
GS-232A
’s
POWER
switch to exit the azi-
muth A-D converter calibration routine, then turn on the
GS-232A
’s
POWER
switch again to turn it back on.
