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This month we are going to discuss two quite unrelated products, both of which are, however, very useful. Micro Design recently sent us a port able microfiche reader. With more and more service data available on micro fiche-often less costly than standard printed copy, and an obvious choice for outside service-the Micro Forty-Four is very logical for field service or when a compact unit is needed on the bench. The Micro Forty-Fours screen is about 4 inches square, which seems a small area on which to project a standard 8 1/2 x 11 inch page. I had no trouble reading any of the text or schematics viewed, however. Focus and brightness are good. The Micro Forty-Four measures about 3 x 5 x 12 inches, and is obviously very portable; it has as accessories a soft carrying case, an ac adapter, a cigarette lighter adapter, And a battery holder. A hard carrying, case also is available. Lenses are available for various magnifications. We also received, some time ago, a circuit board prototype kit from Electronic Trend Products. This kit, ETP-II, contains all the equipment and supplies necessary to produce circuit boards and panel labels of up to 6 x 9 inches. Major components of the kit are an ultraviolet exposure unit, a high speed drill, trays, developer, etc., and a timer. A variety of glass laminate board and label material also is included. I have worked with various circuit board processes off and on for a long time, but certainly am not expert in any way. The kit processes required a little learning; our first try didn't look very good. With a little practice, very acceptable boards resulted. To produce a board, the pattern is laid out with drafting aids on transparent drafting film using a 0.1 inch grid behind it for accuracy. The pattern is placed on the resist coated board and exposed, developed and etched-a straightforward process. We used--copied--a circuit board layout from Weekend Projects For the Radio Amateur. The circuit selected was a power supply regulator board measuring about 2 x 4 inches. Our first at tempt did not etch properly; streaks of copper were left on the board. We looked things over and carefully tried again. This time we produced an acceptable board. A little experience and experimentation is very useful. Schematics and circuit boards (source: Electronic Technician/Dealer) Also see:
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