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August 1960 Electronics World
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.
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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 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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