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Mac's Radio Service Shop: The Worm Turns - and Squirms |
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This episode of "Mac's Radio Service Shop" goes down a drastically different path than most, at least until the very end where a completely unrelated anecdote about interference with a remote garage door opener is told by Mac. Although the exact issues chanted by electronics technician cum repairman Barney Gallagher regarding many manufacturers' penchant for designing and selling unserviceable equipment is dated, the principle remains the same. We have all wished a designer had to service the product he/she has designed and sold to us. Mac's Radio Service Shop: The Worm Turns - and Squirms By John T. Frye
Mac had to stop at the bank during his noon hour, so he was a little late getting back to his service shop. When he finally did step in out of the raw January wind, the outer office was empty; but he could hear Matilda Perkins, the office girl, giggling like a high school freshman back in the service department. Walking softly across to the door, he opened it upon a strange sight. Barney, his assistant, was sitting cross-legged on the service bench, his red thatch of hair concealed beneath an improvised turban of paper towels. In his left hand he clutched a small, misshapen doll, and with his right hand he was repeatedly thrusting a sharp scribing tool into its soft body. All the while he kept muttering to himself in a low monotone. Matilda was perched on a service bench stool in front of him trying to stop her almost hysterical laughter by cramming a handkerchief into her mouth. "What's with Balmy Barney now?" Mac asked her. "He's getting rid of his inhibitions," she managed to gasp. "I never thought he had any," Mac said; "but how does all that help?" "He read in a magazine that children often can be freed from their secret hates and angers by allowing them to deface and destroy pictures of people they dislike," Matilda explained, wiping her eyes. "He says if that's good for kids it ought to be good for him, too; so at noon he bought that kit of modeling clay and made that little man-figure that stands for all the manufacturers, engineers, and production men who dream up radio and TV sets that are hard to service. Now he's punishing this effigy and so ridding himself of a suppressed desire to commit mayhem on the persons of these men." "Sounds like witchcraft to me," Mac commented as he sat down on the other service stool and picked up a lump of the colored clay. Like most good Irishmen, Barney Gallagher had a little of the ham (sock-and-buskin as well as key-and-mike variety) in him, and he was playing this scene to the hilt and way beyond - say about half-way to the elbow. He had sat silent with his chin on his chest like a brooding Buddha during this exchange between his boss and Matilda, but now he took up his sing-song chant again: "So you will run leads from a set down through a hole in the cabinet shelf and then solder them to the speaker so a man has to use a soldering iron just to get the chassis out, will you? And how about that business of stapling loop antennas into console cabinets? Too cheap to use a couple of wood screws, aren't you? But when it comes to putting backs on console and TV cabinets you don't mind using screws. Oh no! Then you throw in one about every two inches so a poor guy has to take out a whole hatful of them just to change a tube. Speaking of antennas, my bucko, this jab is for cementing a loop inside a plastic cabinet and then using short leads soldered to chassis connections so a party can't even pull out the chassis and turn it over without breaking those solid-wire leads. Why couldn't you fasten the loop to the chassis where it belongs? You knew that putting the chassis back into the case, into the field of the loop, would upset any alignment done outside; yet you made no provision for reaching the alignment screws with the set in the cabinet. Another prize crock you have pulled is in mounting a loop with its turns wound in a horizontal plane. You certainly should know that the only way a customer can pick up any but the stronger vertically-polarized signals on that loop is to turn the set on its side. "This gouge is for the crimes you have committed in the name of dials and dial-drives. Take the case of those transparent dial covers that are riveted to metal or celluloid backing plates with only room for the pointer to move in between. How do you think the technician is going to clean those dial covers? Do you think he is going to remove and put back all those eyelet rivets each time, or did you intend for him to replace the whole works every time the cover got dirty? "Another thing: are you trying to see how much you can overload a poor little dial cord? You rig up contraptions requiring the dial cord to turn the tuning condenser, work a slug-tuning assembly, move a pointer back and forth, and revolve forty-eleven pulleys besides - and sometimes you are too tight even to use wooden pulleys! You know that cord will start slipping on the shaft before the set is out of the store a month. If you can't make the thing work longer than that, how do you expect the technician to do so? "Take that and that for the things you have done with record changers! Only a bird with malice in his heart would ever design a changer that must maintain tolerances and clearances to a few thousandths of an inch and then make the thing out of warping, wearing pot metal. . All you want to do is get the thing out of the factory. A lot you care if it is impossible to keep in adjustment in the field. You prove that again by cooking up a changer design that taxes every last ounce of power of the phono motor. When everything is clean and brand-new, the motor barely has enough power to complete the change cycle; but as soon as a little gum forms in it and the drive wheel loses a tiny bit of its traction, the motor no longer can do the job. You never thought of designing in a little reserve of power, I presume." Barney stopped for breath, and Mac reached over and took the sharp-pointed scriber out of his hand. "Let me try a little of this voodoo stuff," he drawled as he held up a little figure he had molded from various colored bits of clay while Barney was talking. "Now this little figurine stands for a few technicians I have known in my time and who have gotten into my hair more than somewhat in that period." "The first sharp prick we give you, my friend," Mac said to the little clay doll, "is to deflate your ego. I often hear you heaping fine scorn on radio and television manufacturers for the mistakes they have made. You never give these men any credit for having to meet competitive prices and for not having limitless time at their disposal for working out every last bug from a new model. You do not seem to realize that you are second-guessing all of these errors. They might prove to be a lot harder to see if you were depending upon foresight instead of hindsight. "And this prod is for your doing all your yelling where it will do no good. If you see a mistake has been made in the design of a chassis or a record-changer, why don't you sit down and write a courteous letter - not one of the smart aleck, how-can-you-be-so-dumb type - to the manufacturer telling him what you have found and making suggestions for correcting the trouble? You may be surprised at the appreciation he will show, and you can be certain he will not repeat the mistake in future models. "I might suggest, too, O Bumptious One, that sometimes you are guilty of trying to blame your own lack of service skill and enterprise on to the set-maker. Time after time I have seen your kind try to persuade yourself that a poorly-operating set never did work any better, that it was made that way; consequently, nothing could be done about it. How you can make yourself believe anyone would pay his good money for a new receiver in that condition I'll never know. If you would concentrate more on improving your own knowledge and technique instead of always being so alert to catch the manufacturer off base, you'd be a better technician for it." "Hey, lemme see that technician-doll of yours," Barney demanded as he grabbed it from Mac's hand. "Uh huh, it's just as I thought. Did you have to make him with red hair?" he asked plaintively. "You know," he went on reflectively, "I'm beginning to think there is something in this voodoo stuff after all. I could have sworn that I actually felt some of those jabs you gave this little feller." "Imagination - and a guilty conscience - can play strange tricks," Mac commented; "but let's get away from all this hocus-pocus and talk a little sense. I ran across something yesterday I think may interest you. A fellow came in with the complaint that his radio-controlled garage door had suddenly become very erratic in its behavior. It opened and ·closed of its own accord while the car that had the controlling transmitter was miles away and the transmitter was shut off. "I went over and checked the thing over carefully, but I couldn't find a thing wrong with it: a good healthy signal from the transmitter was required to trip the pilot relay; there were no gassy tubes to cause trouble; running the line voltage up and down made no difference. First thought of mine was that possibly a harmonic of a ham transmitter was getting into the receiver and making the relay trip, for I have read of that; but since Ten went dead none of the local gang are working the high-frequency bands; so I decided to look for something else. I asked the man if any new electronic equipment had been installed in the neighborhood lately, and after I explained what 'electronic equipment' was, he said all he could think of was a new TV set in the house across the street that had been in for a couple of weeks. "Playing a hunch, I went over and asked the folks if they would mind turning on their TV receiver for a few minutes. As I stood in front of the receiver I could see the closed garage doors; and when I turned the channel selector to Channel 10; the doors opened up. I tried it two or three times, and every time the set was tuned to Channel 10, the doors worked. With the i.f. used in that set, the oscillator was on about 219 megacycles when the receiver was tuned to Channel 10, and that is squarely inside the 210-250 megacycle band in which the door-opener works. Fortunately, provision had been made for using any one of six different frequencies in the garage-door setup; so I just moved the transmitter to a different frequency and peaked up the receiver on that. When this was done the TV set could be switched to any channel without affecting the doors." "That is one for the book," Barney said; "and it just goes to show you what a hefty signal is radiated from the oscillator of some of the TV receivers. No wonder we hams get the blame for a lot of blanking out and herringbone patterns that are caused by a neighbor's TV set tuned to a lower channel!"
Posted January 20, 2016 Mac's Radio Service Shop Episodes on RF Cafe This series of instructive 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 Radio & Television News magazine (which itself started as simply Radio News), and then changed its name to Mac's Service Shop after the magazine became Electronics World. 'Mac' is electronics repair shop owner Mac McGregor, and Barney is his eager, if not somewhat naive, technician assistant. 'Lessons' are taught in story format with dialogs between Mac and Barney.
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RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ... All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged. My Hobby Website: AirplanesAndRockets.com
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