Samlex 1223 (& 21/25) Power Supplies

• Yaesu FP-1023
• Kenwood KPS-15

The most common failure you will come across is these three capacitors. They will bulge from the top when they have (or will) fail. When you buy a used Samlex, open it up and check for these three capacitors. If any are bulged, replace all of them to be safe. Be sure to use a quality part, preferably Japanese or something other than Chinese.

What tends to cause these failures is two fold - They were probably pushed to their limit quite a bit, and also, the part is apparently “just enough”. Repair notes I've seen state to take the 2200uF/25V capacitor, and replace it with anything higher than 2000uF and use one rated for 50v to avoid this issue.

• https://www.repeater-builder.com/samlex/pdfs/sec1223-rf-filter-mod.pdf
• http://www.w0qe.com/RF_Interference/Samlex_SEC1235(M)_DC_power_supply.html
• http://boringhamradiopart.blogspot.com/2013/02/samlex-sec-1223.html
• https://ka7oei.blogspot.com/2013/09/quieting-high-current-switching-power.html

• http://w4kaz.com/yaesufp1023.html
• https://www.youtube.com/watch?v=SWOv57OE538 - Quick overview of failures
• https://www.youtube.com/watch?v=D5ZREWM3g60 - Long form repair
• https://www.qsl.net/gm3woj/sec1223mod.htm - Binding Post Terminal mod
• https://www.repeater-builder.com/samlex/samlex-index.html - Repeater Builder's Complete Repository
• https://forums.qrz.com/index.php?threads/samlex-power-supply-repair.547756/ - Extra tidbits of info