Sandel
Avionics
SN3308 Navigation Display
Installation Manual
90106-IM-G(4) Installation Manual W SIG.doc
Appendix-A Page 16
is identical to reversing the H/C leads on a standard resolver.
See chart below.
COMPOSITE:
Calibrates the composite nav demodulator for the BRG pointers.
When this is selected the received bearing will display.
SN3308 NAV Page Resolver Troubleshooting
Problem Comment
Action
No resolver action at all
Ensure that you have connected
the SN3308 resolver input to the
correct pin on the navigation
receiver. This is NOT always
the ‘Rotor H’ – it might be ‘Rotor
C’. Check the receiver
schematic
No ‘Vref’ signal to SN3308
Check the receiver schematic to
determine whether ‘D’ or ‘E’ is
the appropriate connection.
No Sin/Cos return to receiver
Check the receiver schematic to
ensure the SN3308 outputs are
connected to the appropriate
active pins D/E/F/G of the
receiver, not the grounded pins.
Calibration problems
See steps below
SN3308 Nav Page Resolver Calibration (does not apply to VIR-30 or KNR-634)
STEP COMMENTS
1. Set nav test set to zero degrees and SN3308
course pointer (OBS) to zero degrees.
2. Go to the NAV maintenance page on the
SN3308 and adjust the NAV-1 OBS calibration to
center the deviation needle.
3. Step to the compass rose display on the
SN3308.
4. Turn the test set to 45 degrees. Set the
SN3308 OBS to re-null the deviation pointer. If
this is within a few degrees to a course angle of
45 degrees, proceed. Otherwise if it is –90
degrees out, step to the SN3308 NAV page and
change the OBS ROTATION to “REVERSE” and
go back to step 1.
5. Step the SN3308 to the compass rose display
(after the last maintenance page) and check the
to/from flag and course pointer rotation. If
to/from is reversed (and the wiring is correct)
step back to the NAV maintenance page and re-
null the OBS calibration 180 degrees from the
current calibration setting with the test set and
the OBS set to the same course.
This step is identical to reversing the H/C leads on
a standard resolver. NOTE: If you are using a
NAV401 test set from the rear-panel TONE OUT,
to/from are backwards out of the generator and
should be expected.
6. Check the OBS at 30 degree increments and
verify calibration.
