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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   <<<
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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 # 39
MODEL: TR-7600/TR-7625
SUBJECT: ALTERNATOR WHINE


In some mobile installations, alternator whine may be heard during
transmit.  External B+ filtering does not have sufficient effect.

In some instances, using the cigarette lighter will cause this problem.
Running off the fuse block, and even directly from the battery may still
not eliminate the noise.

First, check power line routing in the engine compartment.  It should be
kept clear of all secondary HV harness wiring, and clear of the alternator,
regulator, and ignition primary circuits.  Careful routing should reduce or
eliminate noise coming in through the power line.

Check for clean ground connections at the antenna and radio.
Check for clean and tight battery connections.

If all of these measures fail, replace L22 on the VCO unit X50-1580-10 from
the original green coil, to either an orange or black coil.  No adjustments
should be necessary.

Old part number L40-1021-03 1mH
New part number L40-1021-43 1mH

Please make these changes in your service manual.