Mac's Radio Service Shop: TV Without Radio
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By 1952, when this "TV Without Radio" episode of Mac's Radio Service Shop story appeared in Radio & Television News magazine, Mac's technician / protégé Barney had been working there for four years. We know that because the first episode entitled "Mac Hires a Helper" appeared in the April 1948 issue. If after all that time troubleshooting, repairing, and aligning circuits Barney was still using a metal-shafted tool to tweak an IF coupling transformer, either should have been a reason to fire the boy or for Mac to consider whether he had not adequately trained him. During my USAF radar maintenance years in the later 1970's - early 1980's, all techs carried a variety of plastic tuning wands for making adjustments. I did have one tuning wand that had a very small metal tip on the end of the plastic shaft because it was used on a couple tiny (for the day) inductors in the transistorized IFF (Identification Friend or Foe) secondary radar. That is not really the main subject of the "TV Without Radio" story, however. Mr. Frye probably threw it in there as a worthwhile reminder / lesson, as he was wont to do. Mac's Radio Service Shop: TV Without Radio
Mac was regarding his assistant, Barney, with a frown of strong disapproval. That worthy young man, blissfully oblivious of his boss's stern gaze, was attempting to align the miniature i.f. transformers of an AM-FM set by thrusting the metal bit of a tiny screwdriver into the hexagonal openings in the top of the tuning slugs and trying to turn them with this makeshift. Now and then the screwdriver bit would wedge in the opening enough to allow the slug to be turned a little, but most of the time it just slipped around inside the hole. Suddenly Mac reached over with the duck-bill pliers he held in his hand and took a firm grip on the lobe of Barney's ear. "Hey! Lookout! Leggo! What are you trying to do?" the boy exclaimed as he squirmed ineffectively to free his ear from the bite of the pliers. Without saying a word Mac led the struggling youth to a wall cupboard and pulled out a drawer with his free hand. "Now there," he said, "as you well know, is every kind of an alignment screwdriver, wrench, and wand that we have been able to find on the market. This little white job is specifically made to fit the openings in the slugs of those i.f. transformers. Don't ever, EVER let me catch you using anything but it on those transformers again." Barney rubbed the ear that Mac finally released and mumbled; "The i.f.'s just needed a little touching up, and I didn't want to take the time to get the alignment tool. I was doing all right with that screwdriver." "You were not!" Mac denied categorically. "All you were doing was reaming out the holes in those slugs until pretty soon nothing would turn them, and on top of that you were taking a strong chance of breaking the slug and making it necessary for us to install a new transformer at our expense. Worse yet, the presence of the metal screwdriver bit in the fields of the windings made proper adjustment of the transformers impossible. A guy who would do a thing like that is capable of committing the unpardonable sin of mechanics: using a screwdriver as a chisel by hammering on the end of the handle. "I'm serious about this, Barney," Mac went on. "A good mechanic or a good technician is one who has and uses the proper tool for doing every job he ordinarily encounters. Using makeshift tools is a sign of laziness and incompetence and invariably results in slovenly work. Once you start using straight screwdrivers on Phillips screws, corner-rounding monkey wrenches on hex nuts, and so on, these bad habits grow on you and become harder and harder to break. In a way it is too bad that radio men are called upon to use a lot of hand tools with-out ever having had the training of working in a garage or machine shop. If we had served an apprenticeship in one of those places, our bad mechanical practices would have been nipped in the bud right in the beginning in no uncertain or easily forgotten fashion." "I'm sorry, Mac, that I slipped up that time," Barney said as he picked up the tuning wrench and started readjusting the i.f. transformers. "It won't happen again. But now, without seeming to want to change the subject, there's something else I'd like to talk to you about. Yesterday I got a letter from my cousin who lives in Chicago, and he asked me a couple of questions that I think you can answer better than I can. He has been thinking about starting to study television with the idea of going into service work, but he says his friends discourage the idea. They tell him it will take too long to learn television because first he will have to master the theory and practice of radio servicing, even though he does not intend to do radio service. How about that? Do you think it is possible to start right in studying television without having a radio background? How much help do you think a good knowledge of radio really is when it comes to mastering television?" "What do you think," Mac asked. "Well, I don't really know. Working here with you, I have sort of picked up what knowledge I have in both fields in a pretty well-scrambled form, and I have never made any attempt to separate them in my mind. I do know this, though: we don't go at running down TV troubles the way we do radio troubles. Even the instruments we use in each case are different." "That's about the story," Mac said. "It is pretty difficult for us old timers to have to admit that several years of experience in radio repairing is not an absolute essential to becoming a good TV technician, but that is the fact. Some of the crackerjack television technicians of today never worked at repairing radios at all. Their entire schooling and experience has been with video sets." "Wouldn't they have been still better technicians if they had been exposed to a few years of fixing radios?" "I'm not at all sure about that. It depends a lot on how flexible or set in his ways the individual technician is and also on how much of his radio knowledge is held in the form of sound and clearly-understood theory and how much in the form of mere experience. "The bull-headed type of radio technician insists on using exactly the same technique in TV servicing that he uses in radio repairing. He can hardly wait until he gets an ailing TV chassis upside down so that he can start probing with his meters, looking for shorted condensers, incorrect voltages, etc. The fellow with an adaptable mind, On the contrary, will soon realize that you can learn a lot more about what is wrong with a television set by studying the face of the tube than you can by prodding around in the bottom of the chassis. He will start concentrating on test pattern symptoms. The cathode-ray oscilloscope, that was used only on very rare occasions in radio service, will become his right hand in running down TV ailments." "But won't his knowledge of radio help him any?" "Certainly it will, for no knowledge is entirely wasted. His radio background will be particularly helpful if he has thoroughly mastered the theory behind the functioning of the radio receiver. If he is completely familiar with the uses of resistors, condensers, transformers, coils, and tubes in radio circuits, it will be easier for him to grasp both the old and the new uses to which these components are put in television circuits. On the other hand, if his knowledge of radio has been acquired entirely through experience, and if he has only concerned himself with the how of radio repairing and has never been interested in the why, his radio background will be much less useful when he encounters the host of unfamiliar circuits in a television set." "A big difference I notice between working on radios and working on TV sets is the frequencies used," Barney offered. "When I switch from a radio to a TV set, I have to sort of shift gears mentally and remind myself that when I start dealing with megacycles instead of kilocycles a lot of things change. For instance, inductance is no longer a matter of several turns of wire on a coil; it can be just a short length of straight wire. Capacities that could be ignored as trifling in a radio become low-reactance bypasses in the TV set. Lead dress in video sets is a lot more critical, too. I have to keep remembering that I can't go yanking the wires around willy-nilly the way I can in a radio set without seriously changing the alignment of the tuned circuits." "All very true," Mac agreed, "and the situation is going to be doubled in spades now that we are moving into the u.h.f. region. The fact of the matter is that a good grounding in radar techniques will soon be of more value in television servicing than will a radio service background. 'Transit time,' 'cavity resonators,' and 'parabolic reflectors' will soon slip as easily from the technician's tongue as 'delayed a.v.c.' 'pentagrid converter,' and 'double-stacked yagi' do now. But I do not think this is any cause for dismay to the average radio and TV technician. If he were the sort who liked a staid and unchanging sort of work, he would never have gone into servicing in the first place, for radio itself has always been a growing and progressive thing. A fellow who has successfully hurdled from battery to a.c. sets, from t.r.f. to superheterodyne, and from AM to FM receivers is not going to balk at television, even though the TV set of the near future comes to look like a nearer relative of the bathroom plumbing than that of a radio receiver." "Then you think I should tell my cousin to wade right into the study of television without worrying about not having radio training first?" "By all means. If he goes to a good school, he will be given the basic theory that applies to both radio and television as a matter of course; but instead of wasting time on circuits that are peculiar only to radio receivers, he will spend this time learning about the television receivers upon which he will actually work. While his knowledge of electronics will not be as broad as that of a technician who has served an apprenticeship in radio servicing, this will not be handicap to him in the specialized work he will be doing. As a clincher, you might remind him that the first auto mechanics were blacksmiths, but being able to forge a good plowpoint is no longer a prerequisite to working on a hydramatic transmission!"
Posted November 22, 2022 Mac's Radio Service Shop Episodes on RF Cafe This series of instructive technodrama™ stories was the brainchild of none other than John T. Frye, creator of the Carl and Jerry series that ran in Popular Electronics for many years. "Mac's Radio Service Shop" began life in April 1948 in Radio News magazine (which later became Radio & Television News, then Electronics World), and changed its name to simply "Mac's Service Shop" until the final episode was published in a 1977 Popular Electronics magazine. "Mac" is electronics repair shop owner Mac McGregor, and Barney Jameson his his eager, if not somewhat naive, technician assistant. "Lessons" are taught in story format with dialogs between Mac and Barney.
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