Roy, I have had to change some in several of the ST-6000's I have had over the years. The 40 mfd at 500v in the power supply is getting a little hard to find. The thing I am wondering about in the Hal units are all the tantalum caps in there. Wonder what the life of those should be?? There are DOZENS of them, when they decide to age, hi. 73, Don, WB5HAK