Modification - Kenwood TKR-751 Service Manual Supplement

TKR-751
3. Single Antenna
The TKR-751 can be used as a base station by sharing an
external antenna connector for both transmitting and receiv-
ing data.

3-1. Modification

1. Change the installation position of C92 and C160 of the
final unit using a soldering iron.
Final unit (A/2)
Component side
ANT SW
CN3
2. Short-circuit the printed pattern of ANT SW near the CN3
connector by soldering.
3. Disconnect the pin connector from CN18 of the TX-RX
unit.
Remove the two screws used for securing the BNC con-
nector on the back panel of the unit. Detach the antenna
cable assy. (E30-3418-05)
4. Cut off the coaxial cable of the removed antenna cable
assy on the BNC connector side.
Strip off the insulation of the cut-off coaxial cable to pre-
pare it to be soldered.
About 20mm
About
8~10mm
Strip off the insulation so that
the cable can be soldered.
2
MODIFICATION
C160
FWD
C92
E
REV
Fig. 3
Cut off the coaxial cable
at this point.
Fig. 4
3-2. Connection
1. Solder the prepared coaxial cable to the final unit.
2. Connect the pin connector of the coaxial cable to CN18 of
the TX-RX unit.
CN18
RX
CN53
TX-RX unit (A/2)
Component side
3-3. Setting the FPU
Set the channel to be used as "Simplex" using the FPU.
Final unit (A/2)
Component side
Route the coaxial
Solder the coaxial
cable under the lead
cable.
wire extending from
CN3
CN3 and CN16.
Style the coaxial cable as
illustrated in the figure.
Fig. 5
RX
E
CN16