Kenwood TK-280 User Manual

VHF FM TRANSCEIVER
TK-280
© 2000-4 PRINTED IN JAPAN
B51-8521-00(S) 553
SERVICE MANUAL
GENERAL ................................................................................. 2
SYSTEM SET-UP ..................................................................... 2
OPERATING FEATURES......................................................... 3
REALIGNMENT ...................................................................... 16
CIRCUIT DESCRIPTION ........................................................ 20
SEMICONDUCTOR DATA ..................................................... 26
DESCRIPTION OF COMPONENTS....................................... 32
PARTS LIST............................................................................ 33
EXPLODED VIEW .................................................................. 40
PACKING ................................................................................ 41
ADJUSTMENT ........................................................................ 42
TERMINAL FUNCTION .......................................................... 52
PC BOARD VIEWS
DISPLAY UNIT (X54-3210-12) ............................................ 53
TX-RX UNIT (X57-6192-70) ................................................ 59
SCHEMATIC DIAGRAM ......................................................... 65
BLOCK DIAGRAM .................................................................. 69
LEVEL DIAGRAM ................................................................... 71
OPTIONS ................................................................................ 72
SPECIFICATIONS ...............................................BACK COVER
CONTENTS
CAUTION
When using an external power connector,
please use with maximum final module
protection of 9V.
Photo is E type with KRA-14
Knob (ENC)
(K29-5232-03)
Knob (VOL)
(K29-5231-03)
Cabinet assy
(A02-2055-53)
(16 keys)
Badge
(B43-1106-14)
Packing
(G53-0896-02)
(16 keys)
Panel assy
(A62-0535-04)
Knob (PTT etc)
(K29-5157-03)
Helical antenna
(T90-0680-05):T
(T90-0695-15):E
E VERSIONS

Kenwood TK-280 Specifications

General

frequency range	146 to 174MHz
channel spacing	25kHz/20kHz/12.5kHz
battery voltage	DC 7.5V ±20%
temperature range	–30˚C to +60˚C

Receiver

rf input impedance	50Ω
sensitivity 12dB SINAD (Wide/Narrow)	0.25µV/0.28µV
selectivity (Wide/Narrow)	70dB/65dB (EIA), 73dB/63dB (ETS)
intermodulation (Wide/Narrow)	70dB/65dB (EIA), 65dB (ETS)

Transmitter

rf power output high	5W
rf power output low	1W
rf output impedance	50Ω
spurious	-70dB

Weight and Dimensions

height with KNB-16A battery	5.33” (135mm)
width with KNB-16A battery	2.29” (58mm)
depth with KNB-16A battery	1.34” (34mm)
weight with KNB-16A battery	1.01lbs (460g)