Fig. 16. Calibration on Station Selector Drums
To calibrate make a short dash on
each dial drum immediately opposite
the center indicator and mark the
station call letters opposite each dash.
MAINTENANCE
Radiotrons.
It is good practice to keep one or more spare
Radiotrons of each type on hand for emergency use. This affords
some insurance against interruptions in service on account of possible
failure of a Radiotron, and permits ready detection of any Radiotron
not operating properly. When not mistreated, the Radiotrons should
operate satisfactorily for many months. They may, however, be
seriously damaged, or their normally long useful life lessened by:
(1) Mechanical injury resulting from dropping or severely
jarring them, causing displacement of the internal elements or
breakage of the filaments.
(2) Electrical injury caused either by advancing the "
BATTERY
SETTING
"
control further in a clockwise direction
20
