Ah yes, the Kenwood KPS-21. An acquisition from the same source I got my Astron RS-50A. I was told it was broken and I could have it for the commodity price of $0.00 which was music to my ears.

This is the power supply that exists but for which there is very little information online for. I didn’t see this post at the time I was going through this, but KK4REY noted this looks like the Astron RS-20A or RS-35A for which he was right – internally, this is basically the Astron RS-20A. I did try to contact Kenwood (USA and Japan) and both said that the KPS-21 model does not belong to any device present or past that they have a record for… even though their own brochures for the Kenwood TS-430S and QST advertisements from the 80’s proudly displayed it. In my process I also reached out to Astron, who never replied after a couple of attempts. I had found a black and white version of the brouchure and from the specs listed there I was able to match it close enough to the Astron RS-20A.

When I opened up this power supply I expected petrified capacitor juice all over the place, but did not find that. I actually found that the control board for the power supply had some burnt components and even though the board powered and the capacitor charged up, the output was in the mV range. Having approximated it to the Astron RS-20A, I took a leap of faith and ordered a control board for the Astron RS-20A and this ressurected the unit. I have since used it for the club’s Minnesota QSO Party in 2022 and 2023, Field Day 2022 and 2023, and has been in storage with light use since.