| Home |
|
Although a technician's eyes are fabulous "tools" in diagnosing troubles, with miniature electronics equipment they need help. By John Frye USUALLY Barney stormed right through the office into the service department when he came to work, but this morning he circled slowly around Matilda, the office girl sitting at her desk, staring down at her critically. She ignored him as long as she could but then hit a wrong key and gave up on her typing. "You got a problem?" she asked, furtively checking the buttons on her blouse. "No, I was just frying to decide what kind of nose you have," he explained, cradling his chin thoughtfully in his hand. "Is it a round nose, a long nose, a needle nose, a flat or duckbill nose, or perhaps a chain nose ?" Matilda reached for a paperweight and Barney beat a hasty retreat to the door of the service department. "I'll 'nose' you," she threatened. "Since when did you become a connoisseur of noses ?" "Since very recently. You see the noses I'm talking about all belong on service pliers. Most of the names are self-explanatory, but chain nose pliers aren't--at least as far as I am concerned. I began to wonder what made these pliers different from, say, long nose pliers and why they were called 'chain nose.' The Merriam Webster Third New International Dictionary does not list the term. Neither did the newer American Heritage Dictionary nor the Encyclopedia Britannica. My distributor didn't know, nor did the salesman who sold him pliers. I looked in a huge hardware catalogue but there was no explanation there. Finally, I talked to the engineers at the local electronics factory. They admitted using dozens of the pliers in the plant, but they never really thought about the matter! " Let me make one thing clear: these people did not know what made chain nose pliers different, but they had lots of diverse ideas. I was told chain nose pliers were short-jawed long-handled pliers; they were pliers with smooth jaws; the jaws had beveled edges; etc. etc. But when I looked in a few tool catalogues, I found pliers labeled chain nose that didn't match any of these descriptions. There were chain nose pliers with long jaws and short handles and vice versa; some had serrations in the jaws while others were smooth; some jaws had beveled edges, but there was no mention of this in others. And to make things still more confusing, I found hyphenated 'needle-chain nose pliers,' 'bent chain nose pliers,' and 'offset chain nose pliers.' " "So what did you find out ?" Mac's voice asked behind Barney. The latter gave a start because he had not realized his employer had been in the service department all the while. "I wish you'd quit sneaking up behind a guy," Barney complained. "Do you know what these pliers are ?" "I hate to admit I don't." "Good; then I'll tell you. On a hunch I wrote Sheldon Gates, president of Jensen Tools & Alloys out in Phoenix, and asked my question. He wrote back promptly and gave me his considered opinion, although he modestly denied it was authoritative. He said in the old days chain nose pliers were used in the jewelry business to make chains by hand from gold and silver wire. A strong, fairly short plier was needed to bend the wires into individual loops. The jaw had a curved bottom to make half-round of the loops. There were no serrations to nick the soft gold or silver. A radius edge to the jaw would be an advantage but probably not essential. Length of the handles would not be important. "The thing you have to remember, Mr. Gates warns, is that the name gets passed along from item to item and eventually loses it original meaning. For example, suppose an electronics technician is using a pure chain nose plier but decides it would be more helpful for his job if the jaws were serrated. So he orders a 'chain nose plier with serrated jaws.' Even though the result would not be useful for making chains, it still carries the name of chain nose plier. "That's why I was getting all those ideas about what the plier was like. Remember the blind men who wanted to know what an elephant was like and were permitted to feel a live elephant? One felt the animal's leg and said, 'An elephant is like a tree.' Another felt his side and said, 'No, an elephant is like a wall.' The third felt the tail and remarked, 'You are both wrong; an elephant is like a rope.' Each, of course, was partially right; but he made the mistake of trying to expand a single observed item into a complete description. Not until you know the original purpose of chain nose pliers can you say what features necessarily distinguish them from other pliers." "Very interesting," Mac remarked; "but now come on back here and tell me what you think of a new addition to the service bench. I have a hunch it, too, came originally from the jewelers." Dutifully Barney followed Mac back to the service bench and examined a large magnifying lens with a built-in lamp mounted by a counterbalanced adjustable arm to the end of the bench so it could be moved over a wide arc and adjusted to any desired height above the bench. "As you know," Mac explained, "our work is becoming more like jewelers' work all the time. Electronic equipment is becoming smaller; components are shrinking; and they are being crowded closer together. The human eye, still one of the best service instruments we have, needs help. We already have jewelers' loupes of different magnification, and they are fine for a quick examination of a suspicious connection or component, but holding one of these in the eye becomes tiring very quickly if you are not used to it. I think this magnifier will be fine for actually working on a tiny printed circuit. You can stand in a normal comfortable position and watch what you are doing through this large lens. The circular lamp, as you will note, does not permit the casting of dark shadows on the work with tools or hands." "Looks like a winner to me," Barney approved; "but let's not sell those jewelers' loupes short. I see some jewelers using a loupe fastened to a headband so you don't need to hold it in your eye like a monocle. When not in use, the loupe can be swung out of the way. I like even better the binocular headband-type with flip-up interchangeable lenses. This new large lens will be excellent for working here at the bench, but the loupes have the advantage of portability. Lots of times in the home I want to make a very close examination of a receptacle for a plug-in unit or of a suspicious printed-circuit lead in a vertically mounted board. That's where the magnifiers I mentioned really come in handy. On top of that, I just know I look very professional and competent when I screw that loupe into my eye and peer knowingly into the innards of a customer's set." "I can just see you making a production of the examination," Mac said with a grin; "but while we're talking about magnifiers, let's not forget a couple of others we've found very useful. I'm talking about the stylus microscope and the color-picture-tube magnifier. That stylus magnifier is the only reliable way to tell if there is anything wrong with a stylus. I know some fellows who say they can tell by the 'feel' of a stylus point if it is chipped, broken, or badly worn; but I don't believe it." "That dot magnifier certainly does tell you what is happening when you can't seem to get proper purity on the picture tube or do anything with the static convergence," Barney offered. "When you blow up those dots until they look like poker chips-well tiddlywinks, anyway-you can tell where the picture-tube guns are really shooting. You don't need that magnifier often, but it certainly can save time when you do." "While we're talking about visual aids," Mac suggested, "let's not forget the mirrors we use. Think what a great improvement that adjustable metal mirror on a stand we use for converging picture tubes is over the cobbled up glass-mirror arrangements we used to use--and break--with great regularity. And that nifty idea of yours for hanging a magnifying shaving mirror on the stand for close-ups of particular portions of the screen is, in the tired vernacular of the day, right on." "Thank you. It is always nice to have one's true worth recognized," Barney replied with an impish grin. "But I think I get almost as much good out of those tiny dental mirrors we use as I do out of the big reflectors. They are really a life-saver when you simply have to see the back side of a bolted-down circuit board and don't want to loosen all the screws holding it in place. I'm especially glad that we have several with different lengths of handles and different sized mirrors. At one time or another, I've had a use for every ones. And it's amazing how often I find myself using the adjustable little mirror mounted on the end of a pen-type flashlight. By properly adjusting that little jigger, you can send the light right into the place you need to see and make the mirror do double duty by reflecting the illuminated spot back up to your eye." "We mustn't forget our 7 X 50 binoculars," Mac warned. "When I think of all the foot-pounds of energy those things have saved us by eliminating unnecessary trips up and down antenna towers or across rooftops, I feel like kissing them. Being able to stand on the ground and tell if a feed-line is broken loose, if a coupler line is open on one side, or if a phasing bar is shorting out is no small advantage." "I'm grateful for all these aids that permit us to make little things look big, to make far away things look close, and to enable us to see around corners," Barney testified. "As you said in the beginning, the human eye is an invaluable service instrument and diagnostic device, but it needs help in electronics servicing just as it does in the practice of medicine. The modern physician would be severely handicapped if he did not have the microscope to reveal and identify the pathogens responsible for disease in his patients. While our technicians' eyes do not need that much help yet, I would hesitate to say we will never have to use the microscope for service-at least if the present trend towards micro-miniaturization continues, and there is no reason to doubt that it will. What are you grinning about ?" he demanded of his employer. "I was just wondering if we will be using chain nose miniature tweezers," Mac replied. ====== Integrated Circuit Audio Generator ====== (adapted from: Electronics World magazine; Jul. 1975) ================ |
| PREV. | | NEXT | EW Article Index | HOME |