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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 # 902
MODEL: TS-430S
SUBJECT: LOW/INTERMITTANT RX

Low or intermittent receive on the TS-430S may be caused by a poor contact
on one or more of the LPF relays. In most cases the following procedure will
correct the problem without having to replace the relays. The procedure has 
two steps, first initial cleaning of the contacts by passing a relatively
high cirrent through them (about 500 ma.) and then installing a contact 
maintenance circuit that will apply a relatively low current (about 8 ma.)
whenever a new band is selected. 

PROCEDURE

Initial contact cleaning procedure-

Parts List:

56 ohm 5 watt ceramic resistors (R92-0622-05) 2 pieces

1. Press and hold the "UP" bandswitch of the TS-430S (Assure the 1 Mhz switch
   is on)
 
2. Apply 13.8 volts to the Antenna Connector center terminal though a 28
   ohm resistor for approx. 1 minute. This will cycle through all the relays
   and burn any oxidation/contamination from the contacts.


   +13.8v power supply <----28 ohms 10 watts ----> TS-430S SO-239 Center

   Power Supply Ground -------------------------- TS-430S Ground


II. Contact maintenance circuit installation

Terminal Strip (E22-0371-05.....................1 each
C1,CS (CK45D2B473M)     .047uf..500v  ..........2 each
C3 (C91-0117-053)       .01uf  50v  ............1 each
L1 (L33-0259-05)        470uh    ...............1 each
R1 (RD14CB2E102J).......1k 1/4w ................1 each
Small length of hookup wire

1. Disconnect the center lead of the coaxial cable from the antenna terminal.
2. Install the contact maintenance circuit as shown in the accompanying
   diagrams. Attach thr terminal lug strip with one of the filter unit cover 
   screws.
3. Solder the 8 v lead to the JP terminal of the Filter Unit.


  Filter             -- C1---
   Unit    <--------|       |---------> ANT CONNECTOR
               |     ---C2---
               |
               |
              L 1
               |
               |
  8v <----R1---|    
               |
              C 3
               |
               |
              GND