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                             K E N W O O D
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                        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

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BULLETIN # 946
MODEL: TH-215A/TH-415A
SUBJECT: TX SIGNAL-TO-NOISE RATIO IMPROVEMENTS

The TH-215/415 transmit signal-to-noise ratio is typically 30 dB. This 
ratio is more than sufficient for routine operations. For those users 
who would like to obtain additional performance, the following modification 
will provide an improvement of 5 to 8 dB.

REQUIRED PARTS:

47 OHM 1/10 WATT CHIP RESISTOR         RK73FB2A470J
220 OHM 1/10 WATT CARBON RESISTOR      RD14BB2B221J
22uF 6.3V ELECTROLYTIC CAPACITOR       CE04CW0J220M
1uF 50V ELECTROLYTIC CAPACITOR         C90-1248-05


1. Disconnect the battery and antenna.
2. Remove the 7 screws from the back panel of the transceiver 
3. Lift the front panel from the transceiver and lay it to the right side.
4. Disconnect the 2 flex cables and remove the 3 screws from the IF unit
5. Pull the top panel off and then remove the IF unit.
6. Remove the 8 screws from the RF unit and unplug connector CN2 
   Remove the RF unit from the back cover.
7. Locate R50 (TH-215) or R60 (TH-415) on the foil side of the RF unit 
   Replace the resistor with a 47 ohm chip resistor.
8. On the component side of the IF unit, add a 1uF capacitor as shown in 
   figure 5.
9. Also on the component side, cut one foil, add a 220 ohm resistor, and 
   add a 22uF capacitor as shown in figure 6.
10.Assemble the transceiver by reversing steps 1 - 6.

Time required for this modification is 1.0 hrs or less.