Service manual

KB2LJJ Radio Mods Database and Manuals
DTMF Paging and Squelch
The DTMF Paging & DTMF Squelch protocol (AAA*BBB) is compatible with the Yaesu 530 and all Kenwood radios supporting this.
Wireless Cloning
The advertised but undocumented Wireless Clone function is described in App Note AAN-0008 which they will mail out on request. (Maybe if
enough people ask for it, they will include all the functions in future instruction manuals.) In summary:
● Prepare the two radios for simplex operation on the same frequency.
● Turn both radios off
● Press [CALL]+[SHIFT] + [Pwr On].
● This should place the radios is clone mode with "CLonE" on the display.
● Press PTT on the "Master" radio momentarily. This will start sending the programming DTMF tones.
● After all data has been transferred, the display of all radios will read "End", indicating success.
● If the signal is interrupted or corrupted, the "Slave" displays will read "Err". Turn them off and try again.
Notes:
● Both the Master and Slave radios must have the same number of memory channels available for each band. Example: You can not
clone a stock Master to a Slave with ME-1 memory expansion.
● You can not clone between different Kenwood radio models, even if they seem identical.
Be careful when using the clone feature. It has been known to wipe out or scramble memories on the master radio during or right after clone.
TM-733A PL Tone Distortion
Symptom
Transmitted PL tones at the receiving station have a relatively high level of distortion. This is easily seen when the incoming signal is viewed
on an oscilloscope.
Countermeasure
Change the value of the "Pull-up" resistors in the PL tone encoder circuit as shown in the accompanying chart and illustration. This reduces the
distortion from around 9% to approximately 4%.
Part OLD value NEW value
---- --------- ---------
R542 1.8k 2.7k
R543 1.8k 3.3k
R544 1.8k 4.7k
R545 1.8k 6.8k
R546 1.8k 10k
R547 1.8k 10k
R548 1.8k 10k
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. Carefully disconnect the two ribbon cables from the Tx/Rx unit C/4.
7. Remove the two Phillips head screws that secure the Tx/Rx unit to the chassis.
8. Turn the circuit board over and replace the resistors using the parts list and illustration as a guide.
9. Reverse steps 1-7 for reassembly.
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