Congratulations on your purchase of your new IBM 026 keypunch ;-)) Our IBM 1401 restoration operation has 4 IBM 026 keypunches restored to full operation Several notes: a) None of ours have a ferroresonant regulator. They are all as wired in http://www.ed-thelen.org/1401Project/026-KeypunchSchematic.pdf general area http://www.ed-thelen.org/1401Project/1401RestorationPage.html#Unit-Record-E… b) One or more of the electrolytic capacitors may need re-forming A symptom of the need is the immediate blowing of fuses when powering up. My favorite method is to place a 4 watt 115 volt tungsten bulb in series with the charging circuit to the capacitor. This reduces current and local heating in the capacitor to acceptable values while the electro-chemistry is taking place. http://ed-thelen.org/1401Project/Sched2005Jan.html see Wednesday January 19th c) Fortunately, 25L6 tubes are available on e-bay ;-)) d) Two of the keypunches had an open hold coil in one of the relays. We couldn't find: - a replacement - a volunteer to rewind to solenoid so did a work-around including a 7 watt lamp as a current limiter. http://ed-thelen.org/1401Project/Sched2006December.html#13 e) Strong suggestion: Unless you absolutely have to, don't mess with the print section. Getting it lined up again will drive you nutz. One of ours had run out of lubrication and the print wires would not move correctly - Bob Erickson, who fixes analog watches for fun, had a long "interesting" battle !! f) We "re-ink" our own ribbons - by re-oiling them, as there still seems to be enough "black" in 'em. g) We have two people who have done most of the restoration on the four keypunches - Bob Erickson http://ed-thelen.org/1401Project/TeamBios.html#Erickson Joe Preston http://ed-thelen.org/1401Project/TeamBios.html#Preston They fixed 'em when they were working for IBM, Oh so many years ago :-)) Please regard us a resourse of knowledge if you need help. ... The ferroresonant question has been correctly answered in another e-mail, Our IBM 1401s are "full of 'em" ;-)) I did some experiments on one, they are surprisingly "stiff", ie good. Ours are rated at 133 volts nominal output Into a light load, the output stayed within 5% with inputs ranging from 85 volts to 220 volts :-)) According to "Solar" documentation - the output voltage will vary 1% for each 1% deviation of input frequency. Good Fortune Ed Thelen