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Modifications for the Kenwood PS-430

No protection on Power supply

Hallo Guys.
I had have some problems with original Kenwood Power supply (PS-430) The final-solid-states has broken on it, so absolutely no protections on this Equipment, and the full 24V DC came to my rig. And I seen it only when the ventilator begins to run, (faster as usual) so some minutes I had 24V on my TS-690S , because the display on this Rig has no usual scale-lamps.
But it seem to be, no damage on the Rig detectable for the moment.
When I repaired than the supply I made a little change on it. So take a look on your Power supply if they has an over voltage protection, if not you can use following very simple, but sure circuit.
 


                                                          +13.8 V <- from 
                                        _________________________ Regulation
   -> +24 V     Fuse                    ¦
       ________¦----¦_________          ¦
               ¦----¦        ¦         /   Zd 14 or 15V 1W
                             ¦        /---
                             ¦          ¦
                             ¦         _¦_
                         Th  ¦         ¦ ¦  R1 100 1/2w
                           __¦__       ¦_¦
                              /        ¦
                             /         ¦
                             ¦\_________¦
                             ¦          ¦
                             ¦         _¦_
                             ¦         ¦ ¦  R2 1K 1/2w
                             ¦         ¦_¦
   -> -24 V                  ¦          ¦
      _______________________¦__________¦______________________
Explication :
If the Output voltage (13.8V) came over the Zener diode + the ignition-voltage from the Thyristor, this will be Short-circuit the +24V and the - So the fuse will be smelting, and no damage on your Equipment.
Important the fuse and the Thyristor must been adapt to your Power, not that the Thyristor are broking and the fuse not
All mods found on this database are offered to me by other amateur radio hams or captured by Packet system. 
KB2LJJ  take no responsibility or liability for any damage done resulting from any modification.  
 I have been trying to help our ham radio with the radio modifications and have asked for any type of new radio mods.
 However, I haven't received too many.  If all of you contributed a little more,  I believe I would be able to help 
all the other ham's that are looking for these mods. I know it is possible to get more mods from all the Ham's because of
 the wide range that exist throughout the world.  By doing this we can  flourish and enjoy more of this hobby that 
we've taken part in for so many years. Furthermore, I ask you not to forget to send me any modifications that you might
 have through email.  I would really appreciate it.

      Email                webmaster@kb2ljj.com

 73's
   John Ribeiro
             KB2LJJ