Getting involved in an insurance
claim scam, whether intentionally or unintentionally, can profoundly affect the
future of a business. Mac McGregor, of course, would never consider bilking any
customer be it a person or insurance company. Diligent bookkeeping, annotation,
and on-the-record statements from claimants seeking his repair services were in
1956 (when this story appeared in Radio & Television News) and are
today the keys to covering your posterior. Also mentioned is a scheme to electromechanically
make dynamic adjustments to a tape recorder's read/write head in order to compensate
for minute skew angles of the magnetic tape media as it feeds through the machine.
Many of the topics covered in the Mac's Service Shop episodes concern real-life
products, research, or processes, so my guess is that Mac's reference to a friend
applying for a patent on this tape head scheme was an actual invention. Reading
about the dynamic head positioning idea reminds me of how all new giant telescopes
are composed of multiple, independently mounted and
servomechanically deformed hexagonal sections that move in response
to perturbation measurements of the atmosphere whose scintillation effects (aka
"twinkling") on images can be almost entirely cancelled so images are nearly as
good as space-based instruments.
Mac's Radio Service Shop: Insurance Jobs
By John T. Frye
Barney glanced down the workbench to where Mac, his boss, had the clock out of
a clock radio and was apparently dismantling it.
"It's not enough that we radio-TV technicians must be electricians, roof-monkeys,
salesmen, and furniture refinishers," Barney said with a sigh; "now we apparently
must be jewelers, too. Do you really think you can repair a clock?"
"I know I can repair this one," Mac answered as he removed the motor field winding.
"The only trouble with the clock is that lightning burned open this winding. I managed
to get a new winding which I am now installing."
"How do you know lightning did it?" "That's a good question and the same one
asked by the customer's household fire insurance agent. In this case, fortunately,
it was easy to answer."
As he said this Mac reached over and turned the small radio chassis upside down.
The capacitor that went from the line switch to the opposite side of the line was
blown apart, and a large scorched area on the chassis directly below showed clearly
the effect of the flash of fire that must have accompanied the "blowing" of the
"This visual evidence, backed up by the customer's story that a flash of fire
and a puff of smoke came out the back of the set at the same instant lightning struck
nearby might all be called circumstantial evidence; but, as Thoreau remarked, 'Some
circumstantial evidence is very strong, as when you find a trout in the milk.' ''
"Did the clock stop at the same instant ?"
"That's right. Incidentally, a new clock listed at about seventeen dollars, and
that is what the distributor wanted to sell me. He said he could not furnish individual
clock parts. Most clock-radio manufacturers buy the clocks as units from a clock
manufacturer, and the only way the radio distributor could furnish a new coil would
be to take it out of a clock he had in stock. This would leave him stuck with the
rest of the clock. However, I wrote to the company that made the clock and asked
them to send me a coil C.O.D., which they did for about one-tenth the price of a
new clock. That's worth keeping in mind, for we are likely to get more of these
burned-out-clock cases now that the thunderstorm season is starting."
"The insurance company will have to pay for this job without question, but what
would you have done if the clock had been out but you did not have the other visual
evidence of lightning? The coil could have opened by itself, you know. There must
be many similar cases in which you are the one to decide whether the repair job
is on the customer or on his insurance company. How do you handle such decisions?"
"To answer that and other questions that are bound to bubble out of you, let's
just take a typical case right from the beginning. Suppose a customer brings in
a set he says has not played since the last lightning storm. I make a note' on the
tag to check for possible lightning damage. If any is found, I call the customer
and ask if he has insurance. If he has, I suggest that he call his insurance company
and see if they want to inspect the set. Usually they do not. They simply call me
on the 'phone and ask if I think lightning did the dirty work. If I say "Yes," they
take my word for it. Even when I candidly admit I cannot be sure, they often say
to go ahead and repair the set and send the bill to them. Occasionally a company
that does not know me will send a man around to look at the set. In this case I
explain what I have found and point out any evidence of lightning's having been
in the set. The decision is entirely up to him. In all of these cases, I feel that
I have done my best to see that my customer receives all that is coming to him.
It always surprises me to discover how many people do not realize that their insurance
covers damage to their radio and TV sets from lightning."
"Yeah, but what do you do with the wise guy who deliberately sets out to rook
the insurance company? You know the kind I mean. They tell you that the set was
damaged by lightning, slyly mention that you can pad your bill because an insurance
company will pay it, etc., etc."
"Fortunately we do not "run across many of those, but when one does rear his
ugly head I simply reply that unless I find some evidence of lightning damage I
cannot say it is an insurance loss. If the fellow wants to take his set elsewhere,
he is perfectly free to do so.
"And about that business of padding the bill when an insurance company is paying
it: that is strictly for the birds. You can't be 'almost honest.' It is just as
crooked to pad a bill for an insurance company as it is to pad the bill for a poor
widow, even though you may be able to build up a better sentimental defense of one
than the other. Take the case of this clock radio. We could have increased our take
by several dollars if we had sold the customer a whole new clock; but by treating
the insurance companies just as fairly as we do our oldest customers, we have won
their confidence. Very often when the insurance agent is called in first he sends
the business to us because he knows his company will get a square shake here. So,
if you just want to look at the thing purely from Ben Franklin's practical point
of view, honesty is still the best policy."
"Is there any difference in billing and getting your money for these insurance
"I usually make out the bills in triplicate on those Dave Rice Order Book Forms.
One copy goes to the customer; one goes to the insurance company; and the third
stays in our files. The charges are carefully itemized, and mention is made of the
fact that 'Repair of lightning damage' was performed. The insurance company ordinarily
sends the check to their insured; and it often takes two or three weeks for the
check to come through. That means that you must exercise a little caution in securing
your pay. The best idea is to have your customer pay you when he picks up the set
and to give him both his own bill and that for his insurance company marked 'Paid.'
From then on the matter is strictly between him and his company. However, when the
bill is pretty good size and when the customer is an old and reliable one, I do
not mind waiting until he gets his check."
"That's about all. The most important thing is to get an OK from the insurance
company before you start any repairs. The insurance people may decide to replace
the radio or TV set instead of having it repaired. In this case they will still
be willing to pay you a fair amount for your appraisal of the damage."
"Not to change the subject, but Sunday right after I got home from church I tried
to get you on the phone two or three times, but the line was busy all the time.
Was your wife on the line?"
"No, I'm afraid I was the guilty one this time. A friend of mine who is in the
tape-duplicating business over East called me, and we had a lengthy and most illuminating
chat about some of the things he had discovered about tape recording in general
while working with his particular line."
"For one thing, he said that the fidelity of tape recordings made and played
at comparatively slow speeds, such as 3 3/4, and 7 1/2 inches-per-second, depended
chiefly on three important factors: (1) the quality of the tape, (2) the gap-size
of the heads, especially the reproducing head, and (3) head alignment. He paid the
tape manufacturers quite a compliment when he said he felt they had achieved about
all the major improvement we could reasonably expect in that direction. Modern tape
is good enough to 'take' all the fidelity required if we can just devise means of
putting the signal on the tape and picking it off. He went on to say that he doubted
that the gap size could be mechanically reduced much below that found in modern
"Hold it!" Barney interrupted. "How else could you reduce the gap size except
"I asked about that, too, and he seems to think that possibly something could
be done along the line of producing an 'electronic gap.' Candidly, I am not too
clear on what he has in mind. Perhaps he means to produce the gap by some electronic
lens shaping action. At any rate, substantial improvement in that direction would
seem to be very much in the 'iffy' category."
"That leaves only head alignment." "And that is where he thinks a lot can still
be done. He tells me head alignment rapidly increases in importance as the tape
speed is reduced. When he speaks of head alignment, he is not talking about just
making sure the slit in the reproducing head is exactly parallel to that of the
recording head. He says this is not enough. Experiments in his laboratories with
first-class recorders reveal that when the heads are perfectly aligned in this respect,
you can record a seven-inch reel of tape with a high-frequency tone and play it
back immediately and lose several db of this signal between one end of the tape
and the other. At any point, though, the loss can be recovered by changing the azimuth
of the pickup head."
Instead of answering, Mac marched out into the office and stripped a couple of
yards of paper from the roll on the adding machine. He fed this into the typewriter
and lined up the edges so the strip of paper was being fed straight through the
rollers. As he continued to turn the feed roll, however, the narrow ribbon of paper
began to skew, and as it finally left the typewriter it was describing an acute
angle with the paper bail.
"That," Mac explained, "is what happens in the tape transport system of a recorder.
It is virtually impossible to insure perfectly even tension clear across the width
of the tape; yet the slightest difference results in skewing as happened to the
adding machine paper. Remember one edge of the tape has to lead the other by only
a small fraction of an inch to seriously impair the high-frequency response."
"Are better tape guides the answer?"
"No. We might be able to improve this condition by using enough rollers, special
tape guides, etc., but then we should end up with a complicated tape-threading mechanism
that would be a great nuisance."
"What is the answer then?"
"My friend thinks it's a self-aligning reproducing head. He argues the thing
to do is to make the head align itself to the tape. That way the tape can skew if
it likes without impairing the high-frequency response in the least. In fact, he
has actually patented a head that works in this fashion."
"How does it work?"
"I am not sure how his works, but I have been thinking about possible ways of
doing this. One would be to use a special recording head that put three tracks on
the tape. Very narrow tracks along each edge would be recorded simultaneously with
the same high-frequency note. The center track would be left for the music or other
information that you wished to record. The pickup head, too, would be a three-part
affair in which separate heads would pick up the edge-tracks and feed them to a
special phase-comparing circuit. As long as the pickup head was perfectly aligned
with the signal on the tape, the signals from the two edge-track heads would be
exactly in step; but if the tape skewed, the signal from one head would lead that
from the other by a definite amount, and this could produce a correcting voltage
that could be used to exert a mechanical correcting influence on the head. The mechanical
device might be a servomechanism when a slow-acting correction would be adequate,
while for a more nearly instantaneous correction the electrostrictive characteristics
of a crystal might be used. Since the three gaps in the recording head would be
in a perfectly straight line and so would the three gaps in the reproducing head,
keeping the reproducing head perfectly aligned with the edge recordings would automatically
insure that the center head would be aligned with the information on the center
"Sounds a little fantastic, but I can't see anything wrong with it," Barney said
slowly. "I'd imagine something like that would be pretty expensive, though."
"Quite likely it would, but in certain industrial applications where good high-frequency
response is essential, this would not be too important. Well, we had better pull
our heads down out of the clouds and get to work."
"I should have known better than to mention 'expense,' '' Barney said with a
grin as he picked up his soldering gun.
Posted January 25, 2019
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
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.