Final Stage Power Amplifier - Kenwood TS-820 Operating Manual

VOX-VR B O A R D 1x54-1190-001
Three variable resistors. VOX GAIN. ANTI VOX and DELAY.
are directly mounted on a printed circult board.
5V AVR B O A R D (OPTION1 1x43-1220-001
Thts is a 5V power s t a b ~ l ~ z e r used for the counter unlt It
uses IC to provlde rated voltage wlthout maklng any adjust-
ments
M A R K E R 8 0 A R D 1x52-0005-011
The MARKER board holds the 1 0 0 kHz crystal oscillator
101) and a 2 5 kHz multivibrator 102 and 0 3 ) to produce
marker signals at 2 5 kHz intervals to calibrate the TS-820.
0 4 amplif~es the calibrator signal^
RECTIFIER B O A R D 1x43-1090-021
This board holds all of the diode rectillers for the power
sup^
ply section of the transceiver. D l through D 4 rectlly the
hlgh voltage. D 5 rectifies the 3 0 0 volt supply.
D6
rectifies
the 2 1 0 volt supply. D 7 rectifies the 9 0 volt supply. and D 8
through D l 1 rectify the 13.8 VDC supply.
H V ( H I G H VOLTAGE) 8 0 A R D
1x43-1110-001
Thls voltage divider crrcuit s~lpplles a high voltage metering
s~gnal for the HV meter reading and also a low voltage
screen source used in the TUN mode of 'operation.
INDICATOR B O A R D 1x54-1180-00)
Thls clrcult controls the light emitting diodes which indicate
1
when the RIT circuit is on, when the fixed frequency oscilla-
-
tor
IS
operating. or when the VFO is oscjllat~ng
RELAY B O A R D 1x43-1190-001
F I N A L B O A R D 1x56-12'00-00)
T h ~ s unit ~ncludes all the circuits of the power amplifier of
the flnal stage wrth the exception of the p i ~ n e t w o r k clrcuit at
the output side.
Fig. 2 2 F I N A L Board
5.3 F I N A L STAGE P O W E R AMPLIFIER
Thjs a m p l ~ f ~ e r deltvers 2 0 0 W PEP tnput by 2 transmli power
tubes (S2001A) I t is equlpped w ~ t h a cool~ng fan to
avoid
temperature rlse during operatton
T h ~ s unit holds the stand-by relay. a 5V power
stabilizer
to
feed power to the PLL circuit. and
smoothing
capacitors to
obtain low voltage DC power.
The relay of thls unit 1 s used to select OC signal for con-
trolling block b ~ a s , cross channel operation. etc