story with 'remote control' in its title piques my interest, so
of course this installment of "Mac's Radio Service Shop" met the
criterion. Unlike in this story where the remote turned out to be
wired, it it the wireless type - like those used to guide radio
controlled model airplanes, boats, cars, and helicopter - that really
grab my attention. Along with discussing the newfangled (in 1954)
Regency television remote control for changing channels, fine tuning
and adjusting volume, shop owner Mac McGregor discusses how atmospheric
conditions affect radio signal strength. In discussing the advent
of color TVs, the question arises re what color the 'snow' (picture
noise, for those who have never watched an OTA broadcast) would
be. An authoritative answer was received from RCA, but you'll need
to read the story to find out. For some reason the concept of colored
snow make me think of that old
Zappa song, "Don't
Eat the Yellow Snow."
As is often the case with these decades old stories, you learn
a little about the conditions of the era along with the main storyline.
In this case Mac mentions installing the Regency remote control
for the benefit of a friend's child who has contracted rheumatic
fever and will be in bed for a few months. That was before better
treatment, including superior antibiotics, were available. We've
come a long way, baby, in all areas of science. Not everything about
'the good old days' was very wonderful.
Regency RT-700 Remote Tuner photos are from the
RadiolaGuy.com website. I reproduced them here because they
are for sale and could disappear from the RadiolaGuy.com website
Mac's Radio Service Shop: Remote Control and Colored Snow
By John T. Frye
sudden warm-up during the night had left the entire city wrapped
in a thick blanket of fog. As Barney entered the service shop that
February morning, he thought to himself that this would probably
be a "hot" television reception day in the ultra-fringe area. The
moisture-saturated air on the ground with drier air above it usually
produced a condition in the troposphere favorable for bending TV
signals back to earth.
When he opened the door of the service department, he saw his
hunch had been right. A chassis on the trial-run bench was displaying
a steady, crystal-clear picture. As Barney watched, another channel
was switched on and then another and another until five different
pictures were revealed. When the program carried by each channel
came into view, the fine tuning was adjusted and the volume was
cut down to zero and then brought back up. Yet the only other person
in the room was Mac, and he was sitting on a stool clear across
the room from the set.
"Hey!" Barney exclaimed, "what's going on here? How are you doing
"Now calm down, Buster, or you'll flip your lid," Mac admonished.
"It's being done with this new Regency remote TV tuner," he explained
as he tapped a small mahogany cabinet resting in his lap. Watching
closely, Barney saw the picture and sound were being manipulated
by two large dual-dials on the face of this cabinet; and he also
noticed the unit was connected to the set by a cable about the size
of a pencil.
"How does it work?" Barney asked.
"Inside the cabinet is a complete cascode tuner with its own
power supply. These concentric dials on the right select the channel
and adjust the fine tuning in the usual manner. The output of the
tuner feeds through that small coaxial line to the input of the
set's i.f. system. Another connection is made to the receiver's
audio system so that this outside dial on the left can adjust the
volume. Finally, the remote control unit generates a d.c. voltage,
either positive- or negative-going, the amplitude of which is controlled
by the inside dial on the left; and this voltage is fed to the set
for varying the contrast of the picture. A 'local-distance' switch
on the back of the unit permits placing proper bias on the tuner
for extremes of signal strength."
"Now let me get this straight," Barney interrupted. "If I understand
you correctly, that same little concentric cable is carrying an
i.f. signal from the remote control unit to the set, an audio signal
from the set to the unit, and a d.c. voltage from the unit back
to the set. Why that little old chunk of coax must be busier than
a party line the night the banker's wife left town with the traveling
salesman! How do all those signals keep from getting into each other's
"A good question," Mac said with a chuckle. "It is all done with
an arrangement of chokes, blocking condensers, and filters inside
a small potted unit mounted inside the set chassis. The coax line
goes to this potted unit, and then leads go from it to the various
sections of the receiver controlled. Here," he said as he tossed
a yellow-covered instruction book across to the boy. "Take that
home with you tonight and see if you can figure how it is done by
looking at the diagram."
"Can you hook that outfit on to any receiver?" Barney wanted
"Just about any. It comes in two models: one for sets with an
i.f. around 21 megacycles and another for sets with an i.f. near
41 megacycles. A set with an odd i.f. too far removed from these
standard frequencies could not use the remote tuner. Neither could
the remote control be applied to an old set using manual gain control
without a.g.c. But outside of such rare cases, the device will work
on any set. It functions equally well with split i.f. and intercarrier
systems. When you want to use it for u.h.f. reception, you simply
install u.h.f. strips in the remote control tuner. If you want to
employ a booster in conjunction with the remote control tuner, there
is an a.c. outlet on the rear of the cabinet into which the booster
can be plugged."
"How about using the unit in a weak-signal area? Can you get as
good reception with the remote unit as you do with the set's own
"If you hook it on to a set employing a less-efficient type of
tuner, you will actually get better reception when the modern cascode
circuit of the remote unit is in use. In general, you should be
able to use this remote control unit in any area in which the set
alone will receive a watchable picture."
"Whose set is this you are using?"
"The wife and I were visiting friends at Big City over the weekend:
They have a little boy with rheumatic fever who must spend the
next few months in bed. Television is the best thing they have found
to keep him entertained; but, like most kids, he likes to do a lot
of channel hopping. That means his mother has to dash in from the
kitchen, laundry, or upstairs dozens of times a day to adjust the
set. I was telling them about this remote control gadget, and they
insisted I bring their set home and install the unit. We are going
to take it back to them tonight."
"That will certainly be a fine thing for him and his mother,
and I can see where it could be used to great advantage in a public
place where the set must be up high so everyone can see it but yet
you want to control it from a convenient location. Also, I can understand
how elderly people will like not having to jump up and down every
time they want to change programs, touch up the tuning, or adjust
the volume; but I wonder if many other people - young and able-bodied
people, I mean-will buy them."
"I am sure they will," Mac said emphatically. "I remember that
when automatic gear shifts were first introduced a lot of people
thought that they would only be used by women and 'other' inept
drivers. As soon as drivers in general found out how convenient
they were, though, everybody wanted them.
"Remote control of TV sets is not a brand-new idea, for we have
had some novel electrical-mechanical systems in the past that worked
pretty well. This unit here, however, is representative of several
new all-electronic remote controls that are being placed on the
market by various manufacturers at this time; and these new units
have several things to recommend them. In the first place, they
can be installed easily and quickly and do not interfere with the
normal operation of the receiver. It is a well-known fact that you
can do a better job of adjusting a picture from the viewing position.
That is proved by the wide use of that earliest form of remote control:
a wife in her easy chair instructing her husband at the set exactly
how to set the volume and contrast controls. Unless you are a contortionist,
it is practically impossible to set the controls on the set without
blocking the view of some of the watchers. Finally, a remote control
unit fits in beautifully with the radio-phonograph-TV custom installations
that are becoming so popular these days.
"I have been thinking these control units would be a good item
for small shops such as ours to stock and sell," Mac said musingly.
"They are small and take up very little room. Every owner of a set
we repair is a potential customer. We have the jump on an ordinary
store because only a service technician is in a position to install
"A technician friend of mine reports a kind of sneaky but effective
way he has of selling them. When he has to remove a tuner and send
it in for repair, he temporarily installs one of these units so
the set can be used while the tuner is away. He says not a single
set owner so far has let him remove the remote control when the
repaired tuner is returned."
"Say, I think I know another use for that remote control unit,"
Barney exclaimed. "Suppose I run the output of that coax line through
a blocking condenser into the antenna connections on my communications
receiver tuned to twenty-one megacycles. Then a short piece of twin-lead,
run through a high-pass filter to the tuner's antenna terminals
ought to make dandy probe for detecting TVI-causing harmonics leaking
out of any transmitter. The receiver's S-meter would show instantly
any change in strength of those harmonics."
"It would probably work," Mac said with a grin; "but you remind
me of a guy who can't watch a steam shovel at work without thinking
about how he could use it to dig his garden potatoes."
Barney wandered across to the bench and picked up a large red-backed
book lying by Mac's elbow. "What's this?" he asked.
"Handle that with care," Mac warned. "I had a heck of a time
borrowing that copy. It contains the information RCA presented to
the FCC when they were seeking approval of their color television
"What kind of information?"
"Just about any sort you can think of, from detailed engineering
description of the apparatus used in transmitters and receivers
to purely personal opinions of the observers."
"I've read a lot about color television," Barney remarked, "but
I have never seen anything about how color receivers are going to
compare with black and white sets in fringe areas. How will color
reception be affected by things like adjacent channel interference
Mac took the book from Barney and flipped the pages to a section
near the center. "Ah, here we are," he said. "Color and monochrome
sets are about equally susceptible to co-channel interference and
to lower adjacent channel interference. Color sets, though, are
a little more disturbed by upper adjacent channel interference.
Color reception, too, is a little more susceptible than monochrome
to random noise. However when the noise is of the impulse type,
such as is produced by an electric razor, one type of reception
is not bothered any more than the other. And for good measure, I
might add that observers decided multi-path reception - 'ghosts'
to you - interfered a trifle more with the enjoyment of color reception.
The important thing is, however, that in every comparison of the
effect of interference on color and black and white receivers, the
difference was slight."
"That must be a pretty complete report," Barney conceded, "but
let's give it one more acid test. See if it can answer the same
disturbing question everyone pops at me when I try to talk about
color television: What color is the snow?"
A slow grin spread across Mac's wrinkled face. "I know the answer,"
he said, "but I must confess I did not find it in the book. I thought
I knew what color it would be, but I was not sure; so when everyone
out here in the fringe area kept asking the same question, I wrote
to RCA and asked them. They came right back with a telegram, which
made me feel that I was getting serious consideration of a rather
silly question; but now we have an authoritative answer right from
the horse's mouth.
"As we might have suspected, snow on color television can be,
and is, any color through the whole spectrum. Since it is a manifestation
of random noise, it affects the color circuits as well as the others;
and this results in the snow's appearing as multi-hued sparkles
Barney heaved a big sigh of relief.
"It may be a silly question, but I'm surely glad they answered
it. You can't imagine the awful thing it was doing to my ego to
have to say, 'I don't know,' every time someone asked about the
color of the snow. Now I'll just snap, 'It's technicolored, of course!'
Posted March 11, 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
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.