TB 9-6625-128-24
(9) Set the frequency counter as required to measure frequency.
(10) Verify the frequency counter indicates within 950 to 1050 Hz; if not perform b
below.
b. Adjustments. No adjustments can be made.
a. Deenergize and disconnect all equipment.
b. Annotate and affix DA label/form in accordance with TB 750-25.