Mac's Service Shop: Time and Temper Savers
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I have quoted previously a saying which my earliest mentor, Westinghouse Oceanic Division über engineer Jim Wilson, liked to utter: "If the tool ain't right, the guy ain't bright." The meaning, of course, is that using the wrong tool for the job can have results ranging from exasperating and time-consuming to downright dangerous. Owner and proprietor Mac McGregor touches on the theme when addressing service shop technician Barney Jameson regarding bad practices that have built up over time and needed to be corrected. He admonished himself as well as Barney for allowing the situation to get so far out of hand. As always, author John Frye's goal in writing these technodrama™s was to both entertain and to teach. Anyone who has put in much time in a workshop can relate to how taking time from the business at hand to keep a neat and orderly environment is a difficult discipline to maintain. Some people jokingly (or not so jokingly) like to say if everything was organized, they'd never be able to find what they. I am not among that crowd. My motto is "Everything has a place, and everything in its place," if for no other reason that my memory is so bad that I can lay down a tool while working on a project and forget 5 minutes later where I put it. Mac's Service Shop: Time and Temper Savers
OK, OK!" Barney was saying as he came through the door of the service department Monday morning; "what were you doing here last night? Marge and I saw a light on at ten o'clock as we drove past, and your car was parked out front." Mac, Barney's employer, heaved an exaggerated sigh of resignation. "A man can't get away with a thing, can he? You won't rest, though, until you know. Actually it all started when I went to Doc Briney for my regular physical checkup Saturday." "Nothing's wrong with you, is there?" Barney asked with quick concern. "Not really. My blood pressure was up a trifle, and he asked if there was anything 'irritating or exasperating' about my work. The more I thought about that the more I grinned; for you'll agree, I'm sure, there are several things about radio and TV servicing that might aptly be termed irritating or exasperating - even excluding the customers." "And how!" Barney soulfully agreed. "Sunday the wife went to a class reunion and left me sort of at loose ends. I got to thinking about some of the petty little goat-getters here at the bench; so I decided to come down and see what I could do about a few of them. The project became so interesting I didn't quit until after eleven last night." "These are new," Barney observed as he pointed to a row of lidless transparent plastic boxes fastened up behind the bench. "Yeah. They are to receive the knobs, back-cover trimounts, and chassis screws and washers you remove and either scatter around over the bench or place carefully in a box on the bench and promptly upset. You know: the same little parts that gradually dribble off the bench during the heat of your tussle with the set and hide on the floor where they can't be found when you're ready to put the chassis back in the cabinet. You can see at a glance what each one of the plastic boxes contains, and notice they are tilted out so that even a tiny lock-washer can be slid up over the side with a forefinger." "A couple of the boxes have stuff in them now." "Those are extra trimounts, dial-cord springs, and knob springs to replace those that still will manage to get away in accordance with Murphy's Law. We're through spending dollars-an-hour time hunting fraction-of-a-cent hardware. Along the same line, I want you to observe and use this little red plastic nut-starter. It is a real time and temper saver. When I think of all the time I've wasted trying to start a nut on an i.f. can spade lug buried down under a nest of wires with fingers that suddenly seem as large and clumsy as bananas, or tried to improvise a nut-starter from a length of solder or a holding-type screwdriver - well, I can really appreciate something like this; but if it is to save time it must be used right in the beginning, not as a last resort. As you can see, the recess in one end can be pressed down over a 3/16" nut and that in the other end over a 1/4" nut. Either size nut will be held firmly in the end of the slender tube while it is easily started in the most cramped quarters." "What's the purpose of the big clip-board mounted behind the bench?" "It's to hold diagrams, step-by-step alignment instructions, or other service literature where it can be easily seen as you work and where it will not be burned with the soldering iron, torn with a sharp chassis corner, soaked and stained in excess contact cleaner, or otherwise mutilated. Not being able to read the value of a component or the number of a trimmer can waste a lot of time. We have a very substantial investment in our service literature, and it behooves us to take care of it." "This doohicky that looks like a small piece of plywood hinged to the back of the bench is new. What's it supposed to be?" "Swing, it out and you'll see that a two-turn loop of wire is fastened to the back side. The signal generator output cable connects to those terminals on the top and permits us to radiate a signal from the two-turn coil into the loop antenna of a set on the bench, as is usually specified in the adjustment of r.f. trimmers. In the past we have tried to get by by simply connecting a piece of wire across the output terminals of the signal generator and draping this near the loop antenna of the set. It was always shorting out, falling off, or sagging away from the loop and giving us misleading output indications. It was hard to be sure if the change in output was produced by a trimmer adjustment or by a change in the position or shape of the radiating loop. This coil can be swung so as to give us any degree of coupling to the loop antenna we wish, and it will stay where we put it. What's more, since we'll always be using the same radiating coil, we'll soon learn what constitutes normal receiver response to a given signal generator output and a controlled amount of coupling between the radiating coil and the loop. "Along that same line," Mac continued, "here's another little item I think will aid in keeping down the blood pressure. It's a simple extension cord for connecting a cabinet-mounted speaker of an a.c-d.c. receiver to the chassis outside the cabinet. The speaker is mounted in the cabinet in a high percentage of the current printed-circuit sets, and connection to the chassis is usually made through a pair of short, comparatively stiff wires permanently connected to the chassis and fitted with plugs that go into simple jacks mounted on the speaker frame. It is virtually impossible to work on the set out of the cabinet with these wires connected. Even if you do manage to turn on the receiver, you are almost certain to break off one or both wires in moving the chassis about. On the other hand, if you use clip leads to extend the wires, these are forever shorting together or. slipping off. As you can see, the 'extension' consists of a couple of lengths of flexible insulated wire soldered to two speaker jacks mounted on a piece of Bakelite. The other ends of the wires terminate in pins to fit the speaker jacks. With this in use, the chassis can be turned every which way, as it often must be in examining, servicing, or aligning, without impairing the connections to the speaker." "That will come in handy," Barney conceded. "If we like, we can connect those pins to the binding posts of our substitute speaker; but I prefer to use the set speaker when I can. Sometimes it has an intermittent defect that may be overlooked if the substitute speaker is used during the servicing." "That's my boy!" Mac applauded; "but speaking of 'overlooking,' you missed this new cheater cord coming out of our variable-voltage isolation transformer. It's connected internally across the 'normal' voltage output socket and will carry the voltage shown in the selector-switch window. It's to be used on any a.c.-d.c. set that employs a safety line-cord connector mounted on the back cover when you want to turn the set on with the back off. In the past, I've seen you use an ordinary cheater cord for this purpose and plug it straight into the light line because you were too lazy to turn on the isolation transformer. Now I'm making it easier for you to use the isolation transformer on these sets, and I better not catch you using anything else!" "Aye, aye, sir!" Barney said with a grin as he tugged at a curly red forelock. "Watch your blood pressure, sir!" "This goes into your house-call tool kit," Mac said, ignoring him, as he handed over a gleaming little chrome-plated tube. "It's a penlight with a completely adjustable dental mirror mounted at the light bulb end. One way to use it is to adjust the mirror so it reflects light from the bulb around corners and into spots you could never illuminate directly. Another use is to shine the light on a spot and adjust the mirror so you can see, by reflection, the illuminated area. This will come in mighty handy when you have to replace a miniature tube in a hidden socket in a TV set. Nothing makes a technician look more stupid or gets his goat quicker than to have to fumble around five or ten minutes replacing a tube he just removed." "I'll buy that," Barney interrupted with deep feeling; "it makes you feel like a real schnook." "Finally," Mac went on, "here are a handful of soft colored crayons to be used to mark the points from which wires are unfastened or unsoldered during testing or replacement of parts. I know paint or fingernail polish would be more durable, but they're also more difficult to apply and to keep ready for instant use. All we need is something to mark the spot from which a wire was removed until we are ready to replace the wire. These will do the job nicely. There are enough colors here to match the colors usually found on wire insulation." "I'll tell you another place where one of those crayons will come in handy," Barney offered. "It's to mark the position of a miniature i.f. transformer can on the chassis, a speaker in the cabinet, or any other part you intend to remove and later replace in exactly the same position. One swipe with a crayon down the side of the part and onto the adjacent area will do it. Then all you have to do is to match up the ends of the broken crayon line and you know the part is just where it was." "Good! That winds up the list of actual devices I dreamed up to save time and temper, but I've been thinking there are a few procedures that will contribute to the same end. Take, for example, the matter of replacing a slipping dial cord. If the cord has been slipping on the drive shaft for some time, that shaft will be polished as smooth as glass; and even the new properly installed, properly tensioned cord will often slip. To prevent this, all you need to do is to make a few swipes around the drive shaft with a bit of sandpaper to knock off the glaze before installing the new cord. Fail to do this and you may have to do the whole job over." "I read you loud and clear!" Barney exclaimed; "and I can think of another example of how a few seconds spent in proper preparation can save minutes. I'm talking about tinning leads before trying to solder them into a circuit. A properly tinned lead requires a mini-mum amount of heat to make it join in a good soldered joint; but I've actually destroyed a tube socket by overheating a lug in trying to solder an untinned lead to it. And if you think the tube socket lug was hot when this happened, you should have seen me!" Mac chuckled sympathetically. "I know. Half the anger we feel about the annoying things in servicing we've been discussing is directed at our own laziness, stupidity, and lack of foresight that permits them to happen. Any time we can remove a source of irritation from our work, we've taken a step toward being a better-balanced, more efficient service technician - and we'll probably live one heck of a lot longer too!" 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.
Posted September 29, 2021 |
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