Service Notes - GE BC-375-E Preliminary Instructions

melt out at high temperatures or oxidize rapidly and
become gummy when packed in the bearings.
(4). Cleaning Solvents: Naphtha or petroleum
spirits are strongly recommended. Carbon tetrachloride
is used for dynamotor unit bearings and commutators.
b. Periodic Lubrication Routine
Dynamotor Unit PE-73-C:
Under normal operat-
ing conditions, the dynamotor bearings should be
lubricated in accordance with the following schedule :
(1). After every 1000 hours of operation or at
intervals of six months, add 3 drops of SAE 20 oil
into the small oil hole which is provided in the top of
each bearing housing and is closed by a screw plug.
(2). After every 5000 hours of operation or at in-
tervals of one year, add approximately 0.05 cu. in.
(/-in. cube) of ball bearing grease to each bearing
through the oil hole mentioned above.
NOTE: Do not add more oil or grease then speci-
fied above, since the excess lubricant will tend to
work out of the bearing housing onto the commu-
tators and brushes where it will cause trouble if not
wiped off. Too much grease in the bearing will have a
tendency to churn and may cause the bearing to
overheat. Always make certain that the lubricants
used are clean and that no dirt, moisture or foreign
matter enters the oil hole when adding the lubricant.
Tighten screw plugs securely into the oil holes as
soon as lubricant is added.
(3) After every 10,000 hours of operation or at
least every two years, remove the armature from
the dynamotor, thoroughly clean the bearings and
bearing housings with carbon tetrachloride and
repack each ball bearing level full of approved ball
bearing grease. See procedure for disassembly and
cleaning of bearings (paragraph 22d. (4).)
c. Reel RL-30-B: The construction of this unit is
such that it will require very little attention. The
following lubrication routine is recommended to
obtain the best operating results:
(1). After every 20 hours of flying service apply
six drops of SAE 10 oil at the oil hole indicated on the
hub nameplate.
(2). After every 1000 hours of flying time or every
six months, whichever comes first, do as follows:
(a) Remove the three fillister head screws which
hold the crank handle lever to the hub and remove
the crank.
(b)
Remove the small cotter pin and castle nut
on the end of the reel shaft.
(c)
Remove reel spool and hub from the shaft.
(d) Clean the accumulated dirt from reel
shaft and the parts in the mounting base. Examine
the exterior parts of the reel hub and clean off all dirt.
(e) Lubricate these points using SAE 10 oil:
Counter gear shaft bearing-1 drop.
Main shaft-several drops along the bearing
surfaces.
Rear ball bearing on hub adjacent to ratchet
teeth-5 drops.
Front thrust bearing around the edge of the
retaining nut at the front end of the hub-5 drops.
Front ball bearing around the gap between the
outside of the hub and the edge of the piece into
which the three screws from the crank handle
lever are threaded-5 drops.
(f) Reassemble the reel as follows: Place the
reel spool and hub on the shaft. Give the spool a
slight spin clockwise until the ratchet engages the
pawls.
Replace the castle nut with the fingers, run it
down until snug and then back it off until the
hub runs free (at least IA of a turn). Replace the
cotter pin. Assemble the crank handle and tighten
the three fillister head screws.
This completes the operation of servicing the
reel.
d. Miscellaneous Lubrication
The following miscellaneous lubrication instruc-
tions should be followed in connection with the
maintenance of Radio Transmitter BC-375-E. Places
to oil and grease are listed. Do this after every 500
hours of service or at least after every 1000 hours.
Do it oftener if dirt accumulation is excessive. Clean
parts as required.
Oil SAE 20—Switch shafts in radio transmitter,
transmitter tuning units, and antenna tuning unit:
Vernier mechanisms in radio transmitter, transmitter
tuning unit, and antenna tuning unit. Variable capac-
itor shafts in radio transmitter and transmitter tuning
units.
Grease—Contacts of switches, and switch position-
ing devices in radio transmitter, transmitter tuning
unit and antenna tuning unit.
NEVER lubricate the contact roller or the contact
roller shaft of the rotating antenna inductor. These
parts should run DRY and should always be kept
spotlessly clean. Naphtha or petroleum spirits should
be used to clean these parts.
22. SERVICE NOTES
In the servicing and locating of faults in the radio
transmitter and associated equipment, it is necessary
to remove various shields and covers to make the
circuits accessible. Great care must be taken in
testing with shields removed, because a great many
points of high voltage are thus exposed. Whenever
such testing is necessary, the proper procedure is to
remove all power from the equipment, make the
necessary circuit changes or meter connections and
then apply power, keeping clear of all meters which
are connected in the "high" sides of circuits where
there may exist an appreciable voltage to ground.
Always remember _that when the dynamotor is
running and the transmitting key is open, high
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