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INITIAL OPERATING AND TUNE UP PROCEDURE
Before attempting to tune up the transmitter, make sure it is
connected to the transmission line and antenna that will pre-
sent a load of a nominal 50 ohms,
or a non- reactive dummy load
with the proper power handling capability.
At this time, re-
ference should be made to the Factory Test Data Sheets and all
controls and adjustments set to the readings given.
Before
actual tune-up begins,
the tube data sheets included in this
instruction book should be carefully studied and compared with
the factory test sheet.
In general these ratings are maximums
and should not be exceeded under normal operating conditions.
Inserting 4CX10,000D into sockets:
1.
Pick up tubes by handles.
2.
Carefully align the tube so that it is directly over the
plate line contact ring.
3.
Carefully contact the anode radiator with the plate
contact ring.
4.
Continue lowering the tube into the socket.
5.
When the tube has made contact with the filment con-
tact rings,
a gently downward thrust will set the tube
in place.
6.
When the tubes have seated,
the tube should be rocked
slightly to insure that all contact surfaces have mated.
DO NOT AT ANY TIME twist the tube into the socket.
Before applying any high voltage it is recommended that an
ohmmeter check be made of all power supplies to see that they
have not become grounded by accident.
The supplies will read
about 100,000 ohms once the filter capacitors have chargecL
After the installation is complete,
all input and output cables
have been connected and the crystal operating for a couple of
hours or more, primary power may now be applied.
Before apply-
ing primary power,
the switches on the driver control panel
should be in the following position.
S518, which is a local-
remote switch,
should be in the local position.
The tune- oper-
ate switch,
S519,
which is used in conjunction with the auto-
matic recycle unit should be in the tune position.
Next,
press the low voltage " on" button on the driver control panel.
This applies all primary power to the complete transmitter.
At
this time it is well to check the rotation of the main blower
in the Y2 cabinet to make sure the blower is running in the
right direction.
As previously mentioned,
if the blower is running backwards
change any two of the three phase wires on TB803 to change
rotation of the blower to the right direction.
Check P.A.
filament voltage and adjust filament voltage with
powerstat,
T803,
to read
7.5
volts as read on the filament
6/22/61
- 9-
FM-20B
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