Kenwood TS 770 Service Manual

Page 2

CONTENTS/ FEATURES

FEATURES .................................................................. 2
CIRCUIT DESCRIPTION ............................................... 3
SEMICONDUCTOR/FILTER DATA .............................. 15
OPTIONIBUJ) ..................................... 7 ...................... 16
OUTSIDE VIEWS ....................................................... 17
PACKING .................................................................. 19
PARTS LIST .............................................................. 20
BLOCK DIAGRAM ..................................................... 34
PC BOARD VIEWS .................................................... 35
FEATURES

1. 144/430 MHz. all mode (FM. 558 (U88. LSB). CW)
transceiver,

o Microprocessor controlled VFO and full variety of aux-
iliary functions.

0 FM circuitry based on KENWOOD's advanced technology

and outstanding SSS quality.

Built~in VOX.

Built-in side tone and CW circuitry capable of semi-

break-in operation.

0 Easy-to-operate 1 band. 1 MHzVFO stops at 999.98 kHz
or is continuously adjustable (endless system).

2. Built-in digital display that indicates operating frequency
in all modes.

0 Digital display equipped with easy-to-read green
cheephor tubes.

0 7-digit digital display that directly reads down to 100 Hz.

0 Frequency indicator that reads out carrier positions when
mode of operation is changed.

0 Indicates fixed channel (stores any given frequency) and
call channel frequencies, besides VFO A and B frequenv
cies.

0 Digital display indicates which VFO (A or B) is in use. fix-
ed channel numbers I1 through 8).

o The use of display select circuit turns off the 100 Hz
digits in FM mode.

3. Dependable electrical and mechanical functions.

0 VFO frequencies are switchable in 2 speeds. SLOW (in

20 Hz steps) and FAST {in 200 Hz steps).

VFO knob equipped with variable torque mechanism.

Pushbutton band select switches (UP and DOWN) that

shift up and shift down frequency between 144 MHz and

440 MHz in 12 bands at 1 MHz intervals.

0 Wide band design for both transmitter and receiver that
eliminates the need for tuning the RF circuits.

DISASSEMBLY .......................................................... 49
TROUBLE SHOOTING ................................................ 54
ADJUSTMENTS ......................................................... 56
LEVEL DIAGRAM ...................................................... 76
CIRCUIT DIAGRAM ................................................... 80
REFERENCE DATA .................................................... 84
MEMO ...................................................................... 86
SPECIFICATIONS ....................................................... 89

0 Panel layout based on human engineering.

0 Full variety of indicating functions to check operating
conditions (Pilot lamps: ON AIR. Hi/LOW (FM transmit),
F-LOCK. RIT. SLOW/FAST. Back-up power ON/OFF).

o Amplified type AGC and ALC circuits that maintain
receive and transmit outputs at constant level without
distortion.

4. A multitude of auxiliary functions for more enjoyable
operation.

0 The use of RAM memory system microprocessm enables
any given frequencies to be stored in or cleared from fix-
ed channels I8 CH).

0 Built-in back-up power circuit to keep data stored at all

times.

Built-in scan and search circuits.

0 RIT circuit functions on VFO. fixed channels and call
channel

0 Adoption of frequency lock circuit.

KENWOOD's unique noise blanker (NB) circuit to

eliminate pulse type noise.

0 Equipped with two meters. one is an "8" meter (with
RF/ALC selector) and the other is a center meter for use
on FM.

0 RF power HIGH/ LOW selecting function provides con-

venience in transmission with local stations.

Auxiliary IAUX) socket.

Designed for fixed and mobile station services.

AC/ DC 2-way power operation.

Equipped with a grip for carrying convenience.
Sufficient AF output power [2.5W/4m.

Built-in large sized speaker (7.5 cm). External speaker
connecting iack.

0.0091