Kenwood TM-V708A Service Manual

TM-V708A
6
CIRCUIT DESCRIPTION
Item Rating
Center Frequency 45.05MHz
Pass band width ±7.5kHz or more at 3dB
Attenuation band width ±22kHz or less at 25dB
Guaranteed attenuation 80dB or more within fo -910kHz
(Spurious:40dB or more within ±1MHz)
Ripple 1dB or less
Insertion loss 4dB or less
Termination impedance 800Ω ±10%, 2pF±10%
Item Rating
Nominal center frequency 455kHz
6dB band width ±7.5kHz or more (from 455kHz)
50dB band width ±15.0kHz or less (from 455kHz)
Ripple 2dB or less (within 455±5kHz)
Insertion loss 6dB or less (at maximum output point)
Guaranteed attenuation 35dB or more (within 455±100kHz)
I/O matching
1.5kΩ
terminating impedance
Item Rating
Center Frequency 38.85MHz
Pass band width ±7.5kHz or more at 3dB
Attenuation band width ±25kHz or less at 40dB
Guaranteed attenuation 80dB or more within fo -910kHz
(Spurious:20dB or more within ±1MHZ)
Ripple 1dB or less
Insertion loss 3dB or less
Termination impedance 500Ω ±5%, 6pF±0.5pF
Item Rating
Nominal center frequency 450kHz
6dB band width ±7.5kHz or more (from 450kHz)
50dB band width ±15.0kHz or less (from 450kHz)
Ripple 2dB or less (within 450±5kHz)
Insertion loss 6dB or less (at minimum lost point)
Guaranteed attenuation 35dB or more (within 450±100kHz)
I/O matching
1.5kΩ
terminating impedance
Table1 MCF (L71-0491-15) (TX-RX Unit XF100)
Table2 Ceramic filter (L72-0979-05)
(TX-RX Unit CF101)
Table3 MCF (L71-0409-15) (TX-RX Unit XF400)
Table4 Ceramic filter (L72-0981-05)
(TX-RX Unit CF401)
2-5. Audio Circuit
The detected VHF audio signal is amplified by Q108 and
de-emphasized by Q110. The UHF audio signal is amplified
by Q402 and de-emphasized by Q405. One of these audio
signals is selected with a cross point switch (IC702). The
signal passes through the electronic variable resistor (IC804),
is amplified by the AF amplifier (IC806), and fed to the
speaker or the external speaker jack.
The VHF or UHF audio signal selected by the cross point
switch, passes through the filter circuit (IC701) and goes to
the CPU (IC604) for CTCSS and DCS decoding. The signal
buffered by Q701 is output to the PR1 terminal of the DATA
connector, and the signal buffered by Q700 is output to the
PR9 terminal.
Fig. 6 Audio Circuit
IF IC
IC100
IF IC
IC400
AF AMP
Q108
2SC5108
(Y)
DE-EMPHASIS
CROSS POINT SW
VR
AF AMP
IC806
IC804
IC702
Q110
2SC4617
(R)
Q402
2SC4617
(R)
Q405
2SC4617
(R)
BUFFER
PR1
PR9
Q701
2SC4617
(R)
BUFFER
Q700
2SC4617
(R)
SP

Kenwood TM-V708A Specifications

General

Brand	Kenwood
Model	TM-V708A
Category	Two-Way Radio
Language	English