Yaesu FT-101EE - Main Chassis Components Overview; Power Supply System Details

E .
7 PROCESS
— out
fre? EF SO
LIER
| Fix OuT
TC. cu. CH, Te
CRYSTAL CONTROL
In
addition
to
normal
VFO
operation,
aCe
crystals
May
be
selected
for
crystal
controlled
operation
by
a
selector
switch
located
on
the
front
panel
ot
the
transceiver,
RE PROCESSOR {PB-1534)
The
SSB
signal
generated
through
the
crystal
filter
is
amplified
by
Q1,
2SK19GR
and
fed
co
either
of
Q2,
TA-7060,
or
O4,
2SKIIGR.
When
the
RF
processor
switch
is
OFF,
the
source
of
Q4,
25K19GR
is
grounded
and
then
the
signal
is
amplified
by
O4
and
Q6,
25K19GR
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
VR1
is
used
to
preset
the
signal
level
equal
for
the
both
of
processor
ON
and
OFF.
With
the
RF
processor
switch
ON,
the
pin
3
af
Q2,
TA?70609
is
grounded
and
it
works
as
dipper
tor
the
signals
that
exceed
the
predetermined
level,
The
clipped
signal
is
fed
through
the
source
fol-
lower,
Q3,
28K19GR
to
a
crystal
filter
XF30A
to
eliminate
the
harmonies
generated
by
the
clipper.
Then
the
signal
amplitude
is
conerolled
by
Q5,
PSC3727.
Q3
varies
its
resistance
between
collector
and
ground
by
the
voltage
applied
to
the
gate
fram
a
potentiometer
VR3b
located
on
the
front
panel,
(10)
RECTIFIER
UNIT
(PB-1076B)
The rectifier unit PB-1076B is located under the
main chassis in the power supply compartment,
and delivers four different DC voltages. The
power amplifier plate voltage (600 Voles Dt) is
supplied from the bridge connected silicon recti-
fiers D1-D4 and D9-D12. 300 Volts DC is also
obtained from this circuit for the driver plate
supply.
160 Volts DE and—100 Volts DC are obtained
through D5 and D6. D5 supplies. the final tubes
screen grid voltage, and D6 is used for the bias
supply.
10,5 Volt AC is rectified by D7 and D8 for the
transister supply voltage.
(11) MAIN CHASSIS
The main chassis contains the power supply, transmitter
driver, final amplifier and other associated circuits, All
sockets for plugan modules are mounted on the main
chassis,
(A) POWER SUPPLY
The power supply is designed to operate from either
TOON ITT ZOO 220/234 volts AC or 12 volts DC
(negative ground} Inserting the appropriate power plug
into the rear panel receptacle makes the necessary
connections to operate the supply in either mode, AC
or DCU,
When the transcerver 1s operated from a 12 volt DC
power source, transistors QI and Q2, 2SB206 fune-
tion as a low frequency oscillator to provide AC to
the power transformer. Starting bias for the oscillator
is obtained from divider resistors RG, R4 and RS. All
of the tubes heaters and input voltage to the DC con.
verter are supplied through the HEATER switch,
With the HEATER switch in the “OFF” positian,
voltage is still supplied to the receiver section,
which
allows
continuous
reception
at
reduced
power consumption levels,
The fugh-voltage winding of the power transformer
Tl ts connected to a bridge-type selid state rectifier
to supply appreximately +600 volts and +300 volts
to the transmitter tubes. Output from the 120 volt tap is
rectified
to
deliver
+160
volts
to
the
screen
grids
and
—100
volts
for
the
bias
supph,
During
AC
operation,
TT]
is
energized
by
two
primary
windings.
These
windings
can
be
connected
in
series
for
200/220/234
volts
and
in parallel for 1OO/110/117 volts operation.
The output from a high current winding of 10.5 volts
is
rectified
and
is
used
to
supply
the
transistorized
stages.
(By PRESELECT
The preselect contro! adjusts three gang-tuned coils
THA, T102 and T1035. TLOTA tunes the receiver
front
end,
T1LO2
provides
interstage
tuning
on
receive
as well as driver grid tuning on transmit. [103
tunes
the
driver
plate
circuit.
T1H4,
T1105
and
TLO6
are placed in the circuit when the band switch is
in 160 thru 40 meter band to abtain aproper impe-
dance match for minimum distortion,
TI as connected to the heterodyne crystal Al— All
through the band switch and delivers the Signal from
the secandary to the mixer stages
Diode switches are used in several locations for isola
bon of the circuits.
—)