Section III-IV
RESTRICTED
AN 08-40SCR274-2
(1) FOR TONE OR CW OPERATION.
(
a
)
Set the "TRANSMITTER SELECTION"
switch to the desired preset transmitting frequency in
dicated on the write-in plate.
(b)
Set the "TONE-CW VOICE" switch to
either "TONE" on "CW".
(
c
) Turn the "TRANS. POWER" switch to
"ON" position.
(d)
Wait 15 seconds for the transmitter to
warm up. Leave switch on throughout the flight to
avoid repetition of the 1 5 second warm-up.
(e
)
Press either the built-in key or the external
key to transmit. A tone of approximately 1000 cycles
per second should be heard while transmitting in either
the "TONE" or
"cw"
position.
(2) For "VOICE" operation.
CAUTION
Do not key the transmitter with the built-in
key, an external key, or the microphone switch
when the controls are the "VOICE" position.
(
a
)
Set the "TRANSMITTER SELECTION"
switch to the desired pre-set transmitting frequency in
dicated on the write-in plate.
(b)
Set the "TONE-CW-VOICE" switch to
"VOICE" position.
(
c
) Turn the "TRANS. POWER SWITCH" to
"ON" position and let it warm ur for 15 seconds.
(d)
Press the Hpress-to-talk" button on the mi
crophone and talk clearly and distinctly into the micro
phone. The transmitting dynamotor will not start until
the press-,to-talk button has been.closed. Sidetone should
be heard distinctly when transmitting.
(3)
Leave the HTONE-CW-VOICE" switch on
"VOICE" unless controlled use on "TONE" or HCW"
is expected.
SECTION IV
EMERGENCY OPERATION AND REPAIR
I. FUSE REPLACEMENT.
a.
FUSE IN RECEIVER RACK.
WARNING
Dynamotor DM-32-A, on each of the receiv
ers, generates 250 volts direct current. The
danger of exposure to the voltage must not
be ignored. Make certain that all control
switches are "OFF" before performing any
adjustment to the equipment.
(1) Make sure the "CW-OFF MCW" switch is on
"0
FF" position.
(2) Remove the fuse cover located on the top end
of the receiver rack. It is held in place by a snapslide
and stud.
(3 Replace the bad fuse by a good 10 ampere fuse.
( 4) Replace the fuse cover.
(5) Place the HCW-OFF-MCW" switch to either
CW or MCW" position, if further operation is de
sired.
b.
FUSE IN MODULATOR UNIT.
WARNING
Dynamotor DM-33-A, on the modulator unit
generates 600 volts direct current. This is
sufficient to cause severe shock or even death.
Make certain that the dynamotor is not run
ning before making any adjustment.
(1) Remove Plug PL-148 from Modulator Unit
BC-456- (
)
*,
or if this -is difficult because of the loca
tion of the equipment, exercise extreme caution to
prevent the metal fuse end from coming in contact with
the fuse cover central locking stud.
(2) Remove the fuse cover from the spare fuses
located to the right of the dynamotor.
(3) Remove the fuse cover from the fuses in serv
ice, located to the left of the dynamotor. Fuse covers
are held in place by a snapslide and stud.
( 4) Replace the bad fuse with one of the spare
fuse 20 ampere fuses.
( 5) Replace the fuse covers.
(6) PI�ce the "TRANS. POWER" switch to "ON"
position, if further operation is desired.
*
Any issue may be used.
3-2-4-0
RESTRICTED