Page 245
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CAUTIONS:
CARRIER SUPPRESSlON
(
)
Connect the 50
.Q
dummy load to the ANT socket
1.
Do not exceed
30
seconds in HI power and TUNE.
( )
Connect the microphone.
2.
Whenever the Transceiver
is
o~erated in both HI
power
and
TUNE,
the
duty
cycle
requires
an
OFF
(
)
Depress the PWR, USB. HI and ON buttons. Other
period (receive mode) of five times the TUNE time
buttons may be released.
(for example, 10 seconds TUNE followed by 50
seconds
w/th TUNE button released). This must be
carefully observed in the following steps. Complete
duty cycle information
is
shown in the Operations
section of this Manual on Page 261.
(
)
Depress the following buttons; all other buttons
should be released: PWR, HI and ON.
( )
Depress the TUNE button..
( )
Advance the LEVEL control. The meter should read
approximately 10 on the upper scale.
(
)
Depress the ALC button. The meter should
read
approximately full scale.
(
1
Release the TUNE button.
(
)
Perform the preceding four steps at each position of
the BAND switch, being careful to observe the duty
cycle. There should be no output at the
WWV
position.
-
(
)
Release
all
buttons,
POSSIBLE CAUSE CHART
1.
No output or low output.
A. P.A. transistors. Measure voltages
as
shown
under P.A. on Page 269.
0.
Transformers incorrectly wired or shorted. Use
an ohmmeter to check for a short circuit from
connector pins 5 and 6 to chassis.
C.
Leads of L813 on
ALCIFilter board incorrectly
wired.
D.
Gray wire through LB13 shorted.
E. Chassis wiring (particularly
RG-58AIU).
2. No input from driver.
A. Check at connector pin
3
with RF probe.
(
)
Turn the BAND switch to
7.0.
NOTES:
1.
Key the transmitter (use the microphone PTT switch)
for several short periods while making the following
adjustment. Prolonged keying of the Transceiver while
attempting to achieve an optimum setting creates an
undesirable heat rise which could damage the output
transistors.
.
2.
Look down into compartment
E
along the right side
of the circuit board and identify control
R666 and
trimmer capacitor
C648. (See Carrier Suppression
controls in Figure
1-3. fold-out from Page 237).
It
may be necessary to bend the two disc capacitors
apart to gain access
to the screwdriver slot of C648.
(
.
Turn the MICICW LEVEL fully counterclockwise.
( )
Key the transmitter for short periods and alternately
adjust
R666 and C648 for the best possible null
(minimum meter deflection). The meter indication
should be at, or near, zero.
(
)
Depress the LSB button. If the meter indication
is
any
higher, make the best possible compromise adjustment
between USB and LSB.
NOTE: If you have a general coverage receiver, tune
it
to the
carrier frequency and use its S-meter as a sensitive indication
of maximum carrier suppression.
3.395
TRAP ADJUSTMENT
( )
Remove circuit board D.
( )
Preset these controls:
BAND: 3.5
LEVEL: Fully counterclockwise
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