From: Cliff Stoll
Email: Friden132@kleinbottle.com
Hi Gang, Just a quick note to say that over this past summer, I have completely rebuilt a pair of Friden 132 calculators (the square root one). Each needed extensive repairs: for example, I had to track down open-circuits on the printed circuit boards and cold solder joints in the power supply and crt drivers. Indeed, several carbon resistors had increased in value by over 30 percent! In the end, I repaired several logic boards, and extensively repaired the power supplies (both high and low voltage). The video driver sections also needed work. I replaced the CRT in each of the Friden 132's. The original 5DEP1 is occasionally available surplus. The 5UP1 tube seems to be more commonly available. The 5UP1 substitutes for the 5DEP1 quite well, although the digits are about 10 percent smaller due to the need for slightly higher deflection voltage. One important warning: The original (1963 to 1966) copper printed circuit boards have severe problems with plated-through holes. Avoid handling these boards, as even a minor bending can cause the plated-through connections to open. After 1966, Friden used a better method for printed circuit boards, and those boards are slightly more robust. If you are working on one of these, feel free to drop a line, as I've picked up a great deal of experience; if there's enough interest, I may post my findings and photos. Best wishes, -Cliff Stoll in Oakland, California September 14, 2006
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