/
rz****=*r-*d
Page 265
To check the VFO circuit board, remove the mounting nut
from
L1201, slide the 4-pin connector up out of its slot, and
remove the VFO bracket so the entire VFO assembly can be
removed from the VFO chassis. Then reconnect the 4-pin
connector to its mating connector
so
the VFO can receive
power and the LSB shift voltage.
Make the RF voltage checks in the following steps. In the
Test Point column,
B
=
base, C
=
collector, D
=
drain,
G
=
gate, and
S
=
source. The
DC
voltages and resistances to be
expected at the transistor leads are given in the table at the
end of the steps.
TEST RF
(
)
Check for
+
11 VDC at the appropriate leads of
R1226 on the buffer circuit board, and I31206 onthe
VFO circuit board.
NOTE: In the following table, if your voltage reading agrees
with that in the RF Volts column. follow the instructions in
the Action column. If the RF voltage reading varies in excess
of 20% from the column
figurs, disregard the Action column
and proceed to Ehe following step.
(
)
Turn oentrol RlZ32 on the buffer circuit
board
fully
clockwise.
POINT
-
VOLTS
-
Am
( )
VFO output
0
~roceadto f~llawlng step.
(
)
CofQl205 126 Check continuity to Output connection.
Check C1234 for a short circuit.
(
I
B
of Q1205
0.1
If
all
?::%
OC
Voltage and resistance
_
/--
----
readings are correct, replace '21205.
(
I
eat Q1204 0.35 Check continuity to 01205.
(
\
6 of Q1204 0.8
It
all 01204 DC voltage and resistance
readings are correct. replace
Q1204.
(
S of Q1203 0.82 Check continuin/ to 01204.
(
I
GofQ1203 1.7 If all 01203 DC voltage and resistance
readings are correct, replace 01 203.
(
)
D of 01202 2.9 Check continuity to Q1203.
(
I
Sof 01202 1.7 If all 01202 DC voltages and resistance
readings are correct. replace
Q1202.
(
Repeat the "VFO Output Adjustment" on Page 237.
OHMS
RESISTANCE*
Q1205 Collector
Base
Emitter
Q1204 Collector
Base
Emitter
Q1 203 Gate
Source
Drain
Q1202 Gate
Source
Drain
'Negative or common lead to chassis.
DC RF
VOLTS VOLTS
--
0 1.25
9.2
.1
9.8 .3
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