TM 11-5820-921-40-1
noted during operation which would damage the equipment if operating were continued. After-operation-
services shall be performed by the operator after every operating period. After-operation-services will be
performed at intervals based on the normal operations of the equipment. Reduce interval to compensate
for abnormal conditions. Defects or unsatisfactory operating characteristics beyond the scope of the
operator to correct must be reported at the earliest opportunity to organizational maintenance (see Main-
tenance Records and Report Forms, paragraph 3-8).
3-13. Safety precautions for protection of personnel and equipment are included throughout this manual
whenever a procedure or condition is described that requires special care. In most instances, the power
amplifier has either been de-energized or removed from the system in which it has been operating before
maintenance is performed. However, the following WARNINGS and CAUTIONS apply in the event that
circumstances warrant them.
DANGER HIGH VOLTAGE
Dangerously high voltages (+1600 Vdc) are present on the plates of power
tubes 1A14V1 and 1A14V2 (Y-621B), Tank Circuit Module 1A8, Plate
Assembly 1A9, and High Voltage Module 1A13. Do not touch any part of
these components when the equipment is energized.
Make sure the power is off before performing any cleaning or inspection
procedures.
Power Amplifier Tubes 1A14V1 and 1A14V2 (Y-621B) contain BERYLLIUM
OXIDE (BeO) CERAMICS. The dust or fumes from BERYLLIUM OXIDE
CERAMICS are HIGHLY TOXIC and breathing them can result in serious
personal injury or DEATH.
Power tubes 1A14V1 and 1A14V2 (Y-621B) contain Beryllium Oxide
Ceramics which are used to conduct heat from the tubes (directly from
the exposed anodes). Normal use of electron tubes having Beryllium Oxide
Ceramics is safe. However, never alter, disassemble, grind, lap, fire, chemically
clean, or perform any other operation on any ceramic parts of the power
tubes which could possibly generate dust or fumes. Provisions for disposal
of the power tubes will be made separately.
Be sure that power amplifier air inlets (front of unit) and exhaust ports
(rear of unit) are not obstructed before operating equipment.
