TB 11-6625-821-35
NOTE
In the following step, do not allow the spur gears to become
disengaged. Disengagement will cause loss of spring loading
(5) Loosen the two setscrews on the hub of the tuning synchro gear of Direction
Finder Control C-6899/ARN-83 (see fig 10 for location), and use a narrow-bladed
screwdriver to rotate the shaft on the tuning synchro of Direction Finder Control C-
6899/ARN-83 until the VTVM indicates null. (R)
Figure 10. Direction Finder Control C-6899/ARN-83, parts location.
(6) Apply blue varnish to the threads of the two setscrews and tighten.
(7) Set DC POWER switch on the unit under test to OFF, and replace Direction
Finder Control C-6899/ARN-83.
12. Final Procedure. In accordance with TM 38-750, annotate and affix DA Label 80
(US Army Calibrated Instrument). When the unit under test receives limited or special
calibration, annotate and affix DA Label 163 (US Army Limited or Special Calibration).
When the unit under test cannot be adjusted within tolerance, annotate and affix DA Form
15