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Mac's Service Shop: Recognizing the Profession
August 1960 Electronics World

August 1960 Electronics World

August 1960 Electronics World Cover - RF Cafe  Table of Contents

Wax nostalgic about and learn from the history of early electronics. See articles from Electronics World, published May 1959 - December 1971. All copyrights hereby acknowledged.

As is usually the case, in this "Recognizing the Profession" installment of Mac's Service Shop, valuable lessons on business practices and/or technical know-how are presented along with an interesting storyline. In the early 1960's when appearing in Electronics World magazine, vacuum tube radios with point-to-point interconnections were standard fare. Components like capacitors, potentiometers, tuning coils, wire insulation, and even dial cord were vulnerable to moisture under normal operating environments, but were particularly prone to significant damage when immersed in salt water. Mac brought a relative's radio home with him from a Florida vacation in hopes of resurrecting it after a dunking. Carbon tetrachloride (aka "carbon tet") was used as a cleaner and to displace as much of the water as possible - a widely recognized method of treatment under the circumstances. Even in the 1960's, carbon tet was known to be a potentially grave threat to health, so Mac makes a point here to describe proper use of it. Today, you might rather use WD40 for the job, given that the "WD" part of the name stands for "water displacement" ("40" is from it being the 40th formulation tested by the company chemists). Incidentally, WD40 hit store shelves nationwide just about the time this story hit the printing press. If you read the "About" page, you'll see that WD40 was chosen for clean-up and restoration after the 1961 Hurricane Carla disaster.

Mac's Service Shop: Recognizing the Profession

Mac's Service Shop: Recognizing the Profession, August 1960 Electronics World - RF CafeMac was just back from his Florida vacation, and he had the sun-burned, peeling skin to prove it. He was already whistling cheerily at the service bench when Barney, his red-headed assistant who had kept the store in his absence, came down to open up the shop.

"Hi, boss," the youth greeted him.

"I'm glad to see you back, but I didn't expect you to be so eager to hit the ball. It's only a quarter of eight."

"Hi, Flame-head," Mac returned affectionately. "I just couldn't wait another minute to find out if you had run me completely out of business in two weeks. How did everything go?"

"Just like downtown," Barney said cheerfully. "I'll not lie and say we didn't miss you, especially when the dogs were giving me a hard time; but Matilda and I kept the doors open anyway, and the shop still has a few dollars in the bank. But where did you get that transistor set you're working on? It wasn't here when I closed up last night."

"I brought it back with me, and there's kind of a story goes with it if you have time to listen."

"I got all the time in the world," Barney said promptly as he hopped up on the bench; "but you know something? When I was in charge, I couldn't enjoy loafing at all. I felt guilty. But now you're back, gold-bricking is just as much fun as ever. Tell me about the radio, and take your time."

Mac favored him with a fierce scowl before he continued: "A few days before I got there my cousin's husband was fishing over at Sebastian Inlet and had this receiver playing on the front of the boat. In the excitement of landing a large fish, the set toppled over and fell into two or three inches of salt water accumulated in the bottom of the boat from waves and spray. It soaked there unnoticed for at least thirty minutes before it was rescued. The owner, not knowing what else to do, took it home and dried it out for an hour or so, but the transistor set still didn't play.

"When I arrived, he placed it trustingly in my hands and asked me to 'fix' it. After all, I was a radio man, wasn't I? When I took off the back, I saw a very sorry sight. That sea water is about the most corrosive stuff you ever saw, and it had really gone to work on the inside of this receiver. Batteries, printed circuit conductors, shield cans - in fact, every metallic surface - was covered with a thick and growing furry green coat of corrosion. I explained this was something technicians in our area never encountered and suggested I talk with a local technician to see what the treatment and prognosis was on a receiver dunked in salt water.

"I picked a radio and TV shop at random from the Orlando phone book and asked for the service manager. He was out to coffee. So were the service managers of the next four shops I called! Apparently the mid-morning coffee break is a flourishing institution in Southern service shop circles. The manager of the next service store was in. I started to explain to him that I was a service technician down there on vacation and would appreciate a little advice on a problem peculiar to the area. He interrupted me to say that I was not fooling him one bit! He knew I was just leading up to an attempt to sell him something and that if I wanted to talk business with him I could call at his shop; and he slammed down the receiver. Apparently my 'dam-yankee' accent made him suspect me.

"By this time I was growing a little discouraged, but I made one more call to Dodson's Radio & TV Service on E. South Street. I was connected to Mr. Royal Dodson himself, and he listened patiently to my story. Then he told me that salt water soaked radios were a very common service problem in the area. He went on to say that if the radios were thoroughly cleaned with carbon tetrachloride within a very short time after the immersion, they usually could be restored to playing condition; but if they were allowed to lie around for several days with that hygroscopic, corrosive salt in them, the possibility of their ever playing again was small. He was most pleasant and cordial and invited me out to see his establishment. I explained my Orlando relatives had almost every minute of the vacation planned and that it was doubtful if I could break away; but we did have a nice chat about mutual problems and those peculiar to our respective localities. His warm friendliness made me truly sorry I did not get to meet him and see his shop.

"The experience carried me back to when I was a small boy in Weiner, Arkansas, and my dad operated a pioneer movie house. By modern standards, it was certainly crude. The customers sat on long benches instead of individual seats; we had only one projector and had to stop at the end of each reel and put in a new one; and, of course, there was no sound except the enthusiastic advice or criticism given the actors by the small boys occupying the front rows. Mom sold tickets; I took them in; my brother operated the projector; and dad kept the 32-volt d.c. Delco generator going to provide power for the theater. (As you can see, the Gem Theater was a family operated affair.) But it was the only public entertainment for miles around, and it was regarded with far more affectionate awe than even the scientific marvel of color television can inspire in the blase audiences of today.

"One day a small travelling circus with a mangy lion and a moth-eaten camel pitched its tent in our little town. That night mother suddenly saw a pair of small grubby hands appear at the edge of the ticket window, and a very small and dirty boy pulled himself up to where she could see him. 'Can I see the manager?' he asked gravely.

"Mom summoned dad with a buzzer, and the little boy looked him straight in the eye and asked, 'Do you recognize the profession, mister?'

"'We certainly do!' my father instantly replied. 'Go right on in-no, wait a minute. Take this box of Crackerjack with the compliments of the house. We hope you enjoy the show.'

"'Thank you kindly, mister; and we'd be mighty proud to have all of you as our guests at the circus tomorrow,' the little fellow said as he walked into the show. We went, too, and were treated as though we were the salt of the earth.

"That incident made a deep impression on me, and it always pops into my mind when I see a demonstration of professional courtesy between service technicians. I do not hold with the idea we are supposed to regard our competitors with jealousy, suspicion, and contempt. I am very proud of the fact that we are on good terms with all our competitors. As you know we often get calls from them asking to borrow a component temporarily out of stock; and we do not hesitate to call them under the same circumstances. On several occasions I have had service technicians from another area drop into the shop and explain they were visiting relatives in town and had been forced into 'just looking' at a radio or TV set. They usually wanted to look at a diagram or to buy a resistor, capacitor, or tube. Invariably, I sold them the wanted item at cost, for I felt deep sympathy for them. The technician who has never been put in this spot while visiting has either not been a technician very long or has some peculiarly considerate relatives and friends. In this shop, we 'recognize the profession,' and we'll keep right on doing so as long as we're in business."

"How did you come out with the salty little radio?"

"Since it had already been out of commission several days, I suggested to the owner I bring it home with me to where I would have something to work with; but I was careful not to hold out much hope. Last night at home I gave it a good going over with carbon tetrachloride out on the cook-out table in the back yard where the breeze would carry off the poisonous fumes of the chemical - and I was darned careful not to get the stuff on my skin or in my eyes. With a toothbrush dipped in carbon tet, I scrubbed all the corrosion off the printed circuit wiring and the other metal parts. Then I squirted the chemical very liberally into the i.f. and oscillator cans with an eye-dropper. Contact cleaner was used on the volume control, the battery contacts, the earphone jack contacts, and the wiping contacts of the tuning capacitor. New batteries were installed, but the thing still wouldn't play. The oscillator in that little monster just would not take off.

"I suspected that the salt was shorting out the tuning capacitor; so this morning I removed the capacitor from the printed circuit board and measured the resistance between the stator sections and ground. In both instances, the resistance was only a few dozen ohms. I washed the tuning capacitor very thoroughly in warm, soapy water, squirted some more carbon tet between the plates, and then dried the capacitor under the heat lamp. I've just finished putting it back; so let's see what gives. The resistance between either set of stator plates and the frame of the capacitor is now infinite at any position of the rotor plates - which is as it should be."

As he said this, Mac turned on the receiver, and it instantly began to play with good volume and surprisingly good clarity.

"Well now! The patient is responding to treatment!" he said with a pleased grin as he tuned in several different stations. "Naturally I'll re-align all the tuned circuits and spray a new protective coating over the printed circuit. We'll keep the radio playing for a week or so and see if anything else shows up. If not, I'll send it back with a warning to the owner not to be surprised if trouble does pop up later. I hate to be so pessimistic, but I'm afraid it's next to impossible to get all the salt out of the thing; and a minute amount of that stuff will draw dampness and form a corrosive, short-circuiting solution that can put the set out of commission several weeks from now."

"What's' the idea back of using carbon tet?"

"Did you ever see a mechanic start a drowned-out car by squirting carbon tet from a fire extinguisher onto the plugs and inside the wet distributor? Carbon tetrachloride is very volatile and evaporates quickly. Apparently it has the ability to combine with water and take the water along with it as it evaporates. That gets rid of the moisture, but the only joker is that it still leaves the traces of salt. I'm hoping that spraying the whole circuit with Krylon will seal up these little particles of salt so that they can't attract moisture and renew their corrosive action at a later date."

"You know something?" Barney asked. "I'm darned glad I'm a fresh-water service technician instead of a salt-water type. I'd never be able to sleep at night thinking about that slimy salt gnawing away quietly at my service jobs; and trying to decide when to try and repair a set that had been dropped into the drink and when to advise throwing it away. On the one hand, I wouldn't want to encourage the customer to waste his money on a set that probably never could be restored to its original condition; but on the other hand, it would gripe my soul to have some other technician do a successful repair on a receiver I said should be junked!"

"Yeah," Mac said sympathetically; "the horns of that dilemma could be called Ethics and Pride, and they could really gore you."

"Anyhow, it is a consoling thought that we aren't entirely alone in this predicament - I imagine most people in business get in that bind every once in a while."

 

 

Posted February 14, 2023

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