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==============================================================================
K E N W O O D
>>> A M A T E U R R A D I O S E R V I C E B U L L E T I N <<<
==============================================================================
Kenwood Service Centers
Kenwood Service Corporation Kenwood Service Center, East
2201 East Dominguez Street 829 Lynnhaven Parkway, Suite 130
Long Beach, California 90801 Virginia Beach, Virginia 23452
Telephone 1-310-639-5300 Telephone 1-804-340-1702
==============================================================================
BULLETIN # 5
MODEL: TS-700A
SUBJECT: REPEATER OPERATION IN THE 145 MHZ BAND
We have had several inquiries about repeater operation of the TS-700A
in Europe. The 2 Meter band in Europe is 144 MHz to 146 MHz with
repeater operation in the 145 MHz to 146 MHz range. The repeater
offset is generally 600 KHz down from the output frequency. The re-
peater offset in the TS-700A occurs only in the 146 MHz and 147 MHz
bands. By changing these to 144 MHz and 145 MHz, respectively, and
changing the appropriate offset, the TS-700A can be used with European
repeaters.
The TS-700A uses varicap diodes to tune the HET unit, MIX unit and
RX NB unit because of the 4 MHz coverage. These varicap diodes are
used to resonate various stages precluding the need to retune from
band range to band range. The varicap diodes are biased by resistors
that are selected by the BAND and REPEATER switches. These bias re-
sistors must be changed if the band frequency and/or offset crystals
are changed. The table below shows the resistors and crystals that
need to be changed to make the TS-700A useable with European repeaters
All resistors are 1/4 watt.
HET UNIT
Part No. 146-147 144-145
X3 127.100 MHz 125.100 MHz
X4 128.100 MHz 126.100 MHz
X6 128.700 MHz 125.500 MHz
R31 62 K 39 K
R32 82 K 47 K
R34 100 K 39 K
BAND SWITCH UNIT
Part No. 146-147 144-145
R103 12 K 22 K
R104 8.2 K 15 K
R110 12 K 15 K
R112 6.8 K delete
R113 6.8 K 18 K
ADD 138K
It is necessary to remove the front panel to make this modification.
To do this, remove the top and bottom cabinet halves. Next, remove
the FINAL tuning shaft by loosening the shaft coupling and pulling
the knob and shaft out. Then, remove the six screws ( 3 on each
side) holding the front panel. Remove the BAND and DRIVE knobs and
the nuts holding these controls. Gently pull the front panel out
until there is enough room to work on the BAND SWITCH unit. (It is
located on the back of the band switch.) At this point, you will
be able to change the resistors indicated on the BAND SWITCH unit.
The 138K resistor that is to be added consists of a 120 k resistor
and a 18K resistor in series. It is connected from pin 3 of the
band switch to ground.
After installing the new resistors in the BAND SWITCH unit, re-
assemble the front panel, leaving out the FINAL tuning shaft. The
procedure for replacing the resistors in the HET unit is to first
remove the three screws holding the board and tilt it up towards
the VFO. Plugs P-1 and P-2 may be removed if necessary. The re-
sistors that need to be changed are located on the outside edge of
the board. Replace the resistors and reinstall the board and con-
nectors. Install the crystals in the appropriate sockets (X-3, X-4,
and X-6). Replace the FINAL tuning shaft and align as per page 40
of the Service Manual.