TC1 CHi CH1 TCi
RF Speech Processor/Crystal
Control Module ( PB- 1 534 )
CRY STA L CON T RO L
}
PROCESS
OUT
I n addition to normal
V FO
o
p
e
ra
t
i o
n
.
tw o
c
r
ys
ta
l
s
m ay be
selected
for crystal c o ntrolle d
o
p
era
t
i
o
n b
y
; selector switc h l oc ated on
th e
front panel of th e transceive r.
RF
PROC E S SO R
( PB- 1 5 3 4)
The
S S B
signal generated through the crystal filter
is amplified by Ql,
2SK 1 9GR
and fed to either
of Q2,
TA-7060 ,
or Q4 ,
2SK 1 9GR.
When the RF processor switch is
O F F ,
the source
of Q4,
2SK 1 9GR
is grounded and then the signal is
amplified by
Q4
and Q6,
2SK 1 9GR
of which gain
is controlled by the
ALC
voltage declined from
the final amplifier grid circuit to prevent the distor
tion which may be caused by the over drive .
A
potentiometer VRl is used to preset the signal
level equal for the both of processor
ON
and
O F F .
With the
RF
processor switch
ON ,
the pin 3 of Q2,
T A 7060P
is grounded and it works as dipper for
the signals that exceed the predetermined level.
The clipped signal is fed through the source fol
lower, Q3 ,
2SK 1 9GR
to a crystal filter
X F30A
to
eliminate the harmonics generate d by the clipper.
Then the signal amplitude is controlled by Q5 ,
2SC3 72Y.
Q3 varies its resistance between collector and
ground by the voltage applied to the gate from a
potentiometer VR3b located on the front panel.
( 1 0) RECTIFIER UNIT ( PB- 1 076B)
The rectifier
PB
-
I
0 7 6 B
i s located under the
main chassis in the power supply compartment,
and delivers four diffe rent DC voltages. The
power amplifier plate voltage
( 6 0 0
Vol ts DC) is
supplied from the bridge conne cted silicon recti
fiers Dl-D4 and D9-Dl2. 3 0 0 Volts DC is also
obtained from this circuit for the driver plate
screen grid voltage , and D6 is used for the bias
supply.
1 0. 5 Volt AC is rectified by D7 and D8 for the
transistor supply voltage .
( 1 1 ) MAI\' CHASSIS
The main chassis con tains the power su pply. transm itter
driver. final ampl i fier and other assoc iated ci rcu i ts. A l l
sockets for pl ug- i n modu les are moun ted o n the main
chassis.
( A ) POW E R SU PPLY
The power supply is designed to operate from ei ther
1 00/ 1 1 0/ 1 1 7/ 2 0 0/ 2 20/ 2 3 4
rn l ts AC or
1 2
volts DC
( negati\·e ground ). Insert ing the appropriate pow er plug
into the rear panel receptacle makes the necessary
con nections to ope rate the su pply in either mode. AC
or DC.
W hen the tra nsceiver is operated from a
1 2
rnlt DC
pow er sou rce. transistors
QJ
and
Q 2 .
2N4280
fu nc
tion as a low frequency osc i l lator to prO\· ide AC to
the pow er transformer. Start i ng bias for the osc i l l ator
is obtained from d i\· ider resistors R3. R4 and R5 . A l l
o f thl' tu bes heaters a n d i n put voltage t o the
DC
con
verll'r a're suppl il'd through the H E A T E R sw itch.
With the HEATER switch in the
"OF F "
position ,
voltage is still supplied t o the receiver section,
which allows continuous reception at reduced
power consumption levels.
The h igh - voltage w i n d i ng of the power transformer
Tl
l
is con nected to a bridge- ty pe sol id state rect i fier
to supply approx imately
+ 6 00
volts and
+ 3 00
volts
to the
transm itter
tu bes. Output from the
1 20
rnlt tap is
recti fied to deli\' er
+ 1 6 0
rnlts to the screen grids and
- 1 00
rn
l
t
s for the
bias su ppl: . Du ring
.
.\ C
opl'ratiun. Tl
1
is energized by two primary w indings. T hese w indings
can
be
connected in series for
2 00/ 2 2 0/ 2 3 4
volts and
in parallel for
1 00/110/117
volts operation.
The output from
a
high
cu rren t w i n d ing
of
10.5 volts
is recti fied and i s u sed to supply the
t r
an
s
i
s
tor
i
z
ed
st ag<'s.
( B) PRESELECT CONTROL
T h e p r e s e l e c t c o n t r o l ad j u s t s three gang-t u n ed co i l s
T lO l A , T l02 and T l0 3 . T lO l A t u n e s the rece ive r
f r on t e nd. T 10 2 p r ov ide s i n t e r s tagf'! tun i n g on r e c e ive
as we l l as d r i ve r g r id tun i ng o n t ra n s m i t. T l 03
t un e s the d r ive r p l a te c i r c u i t. T l0 4 , T Hl5 a nd T l06
a r e p l aced in the c i rc u i t when the band s w i tc h i s
i n 1 6 0 th r u 4 0 mete r band t o obta i n ap rope r i mpe
d a n c e ma tc h fo r m i n i m u m d i s to r t i on.
Tl
1 1
is connected
to the
heterody n e crystal X
1 -
X
1 1
thro ugh
the
band sw itch and del ivers the signal from
supply.
the secondary to the m i xer stages.
1 6 0 Volts DC and- 1 00 Volts DC are obtained
Diode sw i tches arc u sed in several locations for isola-
through D5 and D6. D5 supplies th e final tubes
tion of the circu its.
-
1 8 -
