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September 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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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
technodramas™ 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
By John T. Frye
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
