The other one being a similar Perma-Power unit and then there's one that I crudely built using a transformer from AES and an LM317 for the filament voltage regulator. That should cut down on the amount of heat produced. The only other thing that I might end up doing is replace the 5Y3 with a 1N4007 and a suitable dropping resistor. This power supply originally had an in-line power switch and I will place such a switch in the hot side of the line. I did replace the power cord with a polarized type, with the neutral side going to ground. I had to bypass the resistor completely in order to achieve 1.5 VDC on an ordinary 4 tube RCA radio. The screw terminals are for a jumper which can be connected to bypass part, or all, of the resistor in order to obtain proper filament voltage for various tube counts. There is a tapped wirewound resistor in the filament line, which is connected to the three screw terminals on the front. I replaced the 2.5Kohm resistor with a 2.2Kohm, 2W and I made a bridge rectifier from standard 1N4007 silicon diodes. Also, the B+ filter resistor had risen from 2.5 Kohms to nearly 4Kohms and the bridge rectifier for the filament supply was dead. 05 uf "across the line" cap, a electrolytic can, and a dual 1000uf,6.3V cardboard tubular cap). The plates of the 5Y3 are tied together, making it a half wave rectifier and, the tube gets it's plate voltage directly from the AC line. The circuit design is such that it uses a power transformer with one 5V winding for the B+ rectifier (5Y3) and a 3.5V winding for the filament supply. However, I just got around to repairing this particular battery eliminator. This radio has long been fixed (just needed the usual bad caps, some resistors, and some rotten wiring replaced) and it works well. I thought I'd give an update on the battery eliminator. It's a basic 4 tube battery radio that runs on a 1.5V-90V pack. There is a model number inside the radio but, I can't see it without removing the chassis. I was more interested in the power supply than the radio as these power supplies are getting scarce and usually not very cheap on greedbay. The radio case has some veneer damage but, it can be fixed by someone who knows what they are doing. I offered $15 and she asked if I would go $20, which I did. I asked about the radio and figured I'd get the usual "that's not for sale, the kids want it" reply. The homeowner's husband recently passed away after 63 years of marriage and the lady was moving into a retirement home. I turned it around and saw a battery eliminator inside! This sale was actually a living estate. While I was looking around, I saw this Silvertone battery radio on a shelf. It turns out that the record players were BPC and a late '60's cheap Symphonic console stereo. Me and a friend went to a "pre-estate" sale by some people that someone that he knows knew (yeah, one of those deals) to see about buying an "old record player".
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