home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
World of Ham Radio 1997
/
WOHR97_AmSoft_(1997-02-01).iso
/
mods
/
kenwood
/
asb_text
/
asb1061.txt
< prev
next >
Wrap
Text File
|
1997-02-01
|
3KB
|
60 lines
==============================================================================
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 # 1061
MODEL: TM-733A
SUBJECT: PL Tone Bleed Through
Symptom: When transmitting a PL tone a "humming noise" might be heard
coming from the internal speaker of the TM-733A. This is caused by a
difference of potential between the tone generating circuit and the AF
amplifier circuit.
Countermeasure: This symptom is corrected by tying the ground connections
in the AF amplifier and Tone generating circuits together.
Parts Required:
Qty Description Old Kenwood Part No. New Kenwood Part No.
2 Screw N87-2606-46 N87-2608-46
2 Star washers N/A N16-0026-46
1 Small gauge hookup wire
Procedure:
1. Disconnect the power cable, microphone and antenna's, etc.
2. Detach the front panel and set it aside.
3. Remove the top and bottom covers.
4. Remove the speaker and speaker mounting bracket
5. Disengage the plastic front panel from the main chassis.
6. Remove the two Phillips head screws that secure the TX/RX unit to the
chassis.
7. Install the new screws and star washers.
8. Solder a jumper wire from the ground side of C424 (the one nearest IC405)
on the Control Unit to pin number 8 of IC7 (next to battery) on the 144
Mhz TX-RX Unit.
9. Reverse steps 1 - 5 for reassembly.
Caution: This modification requires advanced surface mount soldering
equipment that is rated for CMOS circuits. It also requires familiarity
with advanced surface mount soldering techniques. If you do not have the
proper equipment or knowledge do not attempt this modification yourself.
Seek qualified assistance from your closest Kenwood Service Center
(Long Beach, CA, or Virginia Beach, VA).
Time required for this modification is 30 minutes or less.
Service code A:09 B:X57-4360 C:ADDW D:91