I have always wanted a Kenwood TS-930S. The shack here has seen a TS-120S, TS-130S, TS-820,TS-820S and TS-830S all are excellent radios. Having read a lot about the TS-930S and its fantastic performance (and problems) the hunt was on. Most of my gear has been acquired in non working condition. Repairing electronic equipment is one of the most enjoyable parts of amateur radio for me. It also served as my profession for 32 years while working for the federal government as an electronic technician. In May of 2009, while at the Dayton Hamvention, I found it. The rig was in mint cosmetic condition and guaranteed not to work. The gentleman told me the finals were bad. The price was right and the struggle to carry it back to the car began. Reviews of the 930S suggested a common problem with the 28V supply which often failed and took out the finals. All other issues mentioned in the reviews were minor. A search of the internet and both the user and service manual were quickly found. There was also plenty of other helpful information from hams who had experienced the power supply problem. Many had repaired the 28V supply only to have it fail again sometime with disastrous results. I read all that I could find on the subject, studied the schematic and concluded as many others had that the power supply design was not that great. One website I found with information on solving the power supply problem was by VK4AMZ, Michael of Australia http://www.vk4amz.com/ . This site provides information on building a new improved power supply. It includes all the information you need including PCB layout and schematic. The new design includes reusing some of the parts from the original supply and provides over voltage and over current protection. Michael does not sell any kits or pre fabricated boards so producing the board is left up to the builder. This is a great design and is in use my many with excellent results.
I found a different approach by PA2VC, Paul from the Netherlands. Paul does not have a website but the information he provided can be found at http://www.eham.net/reviews/review/84948 . Paul's approach is unique and brings the newest of power supply technology to the classic TS-930s. It uses a state of the art switching power supply to replace the transformer and PCB circuit. Goodbye old problems! The supply is a high quality Phoenix Contact, industrial switching power supply, type QUINT, 24 VDC - 28.5 VDC adjustable, delivers output current 10 Amps and 15 Amps boost, code manufacturer 2938604. I contacted Paul by email and have to tell you he is one of the nicest hams I have met. He answered some question I had and sent additional photos of his project and offered additional assistance if needed. The true ham spirit!!!. The Phoenix switcher fits nicely into the space once the old transformer and PCB circuitry are removed. Paul later contacted me to advise that he is experimenting with a new 20 Amp switcher to see if it will fit the available space. Wanting to get this rig on the air I opted to go with the Phoenix switcher. Mouser electronics listed the power supply for $ 409.15. Ouch!! Too much, so I checked Ebay and found a new one in the original box for $ 69.00. Bought it !. This is how this project begins and I will try to show you how it went.