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4.1
PRECHECKS
If you are a newcomer
to this type of equipment, or if you
have replaced a power tube, you should first assure yourself
of the following before connection of power and turn on:
a
Power tubes are installed correctly.
Verify tube installation checkout with Section 2.2.
b.
The upper case cover and inside shield plate are cor-
rectly installed per Section 2.2.
The
upper
case
cover
controls
the
high
voltage
primary protection
circuit. This circuit also controls
the fan motor
power. The inside shield plate controls
the high voltage protection circuit, grounding the HV
supply, which will immediately blow the power fuses
if incorrectly installed. Particular care should be ex-
ercised when installing the inside shield plate. In addi-
tion, the upper case cover and inside shield plate are
needed
for heat-sinking
the
interior
of your
TL-
922A.
For installation of these plates, please refer to
Section 2.2, "How To Install Power Tubes."
e
Line voltage change terminals are properly bridged for
your local Line voltage.
Refer to Section 2.5 ''Line Voltage Change."
d.
Make certain that the exciter, antenna and ground
wires are connected properly. Verify that the POWER
switch on your TL-922A is in the OFF
position BE-
FORE CONNECTING the AC power cable.
e
Set the front panel controls of your TL-922A as fol-
lows:
TABLE 4-1 — Front Panel Controls Initial Set-Up
Control
Position To:
LINEAR
STBY
METER
HV
MODE
cw
PLATE
Center of band used
LOAD
Fully counter-clockwise ''O"
BAND
Exciter frequency
CAUTION: Be sure to set the BAND switch to the same
band as that of the exciter before operation is
attempted.
Now you may turn the POWER switch "ON". Make certain
that the fan motor
is revolving. The Multimeter will read
approximately
2 kV
on
the HV
scale.
If you
turn
the
MODE
switch to the SSB position the meter will read ap-
proximately 3 kV.
Turn the LINEAR
switch to the OPERATE position. The
exciter now controls the TL-922A for automatic transmit/
receive operation. In the CW transmit mode, Ip (plate cur-
rent) in the no signal state should be approximately
100
mA; in the SSB transmit mode, no signal state should be ap-
proximately 200 mA.
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SECTION 4. OPERATION
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4.2
CW OPERATION
CAUTION: Tune-up should be accomplished quickly or
power tube life will be shortened. Maximum
key-down: 10 minutes.
Adjust the exciter for maximum
output.
2:
Set the amplifier Mode
switch to the CW
position,
multimeter to RF.
3.
Adjust the carrier control on the exciter for a 50 W
level.
4.
Set the LINEAR
switch on your TL-922A
to the
OPERATE
position.
5.
Increase the carrier control on the exciter for suf-
ficient drive to adjust the tuning.
6.
Quickly switch the amplifier to Ip and dip the plate.
7.
Switch the amplifier to RF and adjust loading for max-
imum output.
8.
Increase exciter output to maximum
power (about
100W).
Repeat steps 6 and 7 several times for the
highest RF output.
If the Ip exceeds 650 mA, reduce
the RF input from the exciter by turning the ALC ADJ
control on the rear panel.
Refer to Section 4.5 "'Set-
ting the SLC".
9.
Make certain that the Ig (grid current) is below 200
mA. If not, adjust the ALC ADJ control to reduce
the RF input level.
CAUTION: Never change the BAND switch while trans-
mitting.
TABLE
4-2 —Tune and load initial setting
100W
input 502 output loading.
Band
Freq.
Initial load setting
(MHz)
cw
SSB
160
1.8
4
2
( 2.0
(5
(35
3.5
3
25
&
4.0
G
(3
7.0
3
2
40
C 7.3
Gs
G
14.0
45
4
20
14.35
G
( 3.5
21.0
5
45
a
Ors
(e
45
a}
4.3, SSB OPERATION
Tune up as in CW operation.
Reduce the exciter carrier con-
trol to minimum and change the linear mode to SSB.
In-
crease the exciter carrier control and tune for maximum out-
put.
When
tune
up is complete,
reduce
carrier level to
minimum
a]
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