Red and Fuzzball on Convergence
January 1958 Radio-Electronics Article
not sure when storytelling as a style of technical writing went
the way of vacuum tubes (probably about the same time, come to think
of it), but this article from the January 1958 edition of Radio-Electronics
is a prime example of how such prose was utilized. Two characters,
Red and Fuzzball, meet at a coffee counter and discuss the intricacies
of color convergence in color television sets. Such issues are not
a concern with today's electron-beam-less displays, but back in
the day, it made the difference between an acceptable picture and
frustrating images with color fringing. Maybe you remember those
days. After having read many articles on troubleshooting, repairing,
and aligning TV sets prior to LCD and LED displays, I have a real
appreciation for the knowledge of really good repairmen. In some
ways the vacuum tube sets were easier to troubleshoot because the
tech could easily pull tubes from sockets to make voltage and resistance
readings rather than needing to unsolder transistors or ICs.
January 1958 Radio-Electronics
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. All copyrights hereby acknowledged.
Red and Fuzzball on Convergence
By Robert G. Middleton
Fuzz is still learning about color TV - the hard way
Fig.1 - (left) Blue lateral corrector separates blue and
lines for easier checking.
Fig.2 - (center) Make the
red and blue lines parallel.
Fig.3 - (right) Red, green
and blue vertical center lines must all be parallel.
I still got a job?" asked Fuzzball anxiously, as he sat down beside
Red at the counter. "Take it easy," Red replied. "Old Fatpants is
late himself this morning - he don't even know that you didn't show."
Fuzz' hand shook visibly as he reached for the cup of coffee.
"So where you been, anyhow?" Be asked curiously.
out to be sort of a lost weekend for me," Fuzzball explained. "I
took one too many and ..."
"There are times," Red chuckled,
"when Fuzz lives in a world of his own."
"There ain't no
such world," Bess snorted, and flounced off.
a good reason for me falling off the wagon though," Fuzz said in
"Always is," Red agreed. "What's yours?"
"It's that installation out on the South Side," said Fuzz.
"Line voltage drifts up and down so much that I can't converge the
picture tube for sour apples."
"That's easy," replied Red.
"All you got to do is put in an automatic line-voltage regulating
"That's easy?" Fuzzball asked. "This guy won't
even buy an outdoor antenna. I can't get him off my back."
"Lord have mercy," Red breathed. "The penny-pinching public
"What can I do?" Fuzzball asked helplessly.
"Ignore him," Red advised.
"Suppose he calls up Old
Fatpants and complains?"
"Let him. I'll talk to Fatpants.
I been on these hey-rube runs before."
"Can you cash me a check?"
"The answer is
no. Here's a fin I'll give you. That way nobody ain't kidding nobody."
"Thanks, Red. I dunno what I'd do without a buddy like you."
"I know what you'd do - and so do you."
Not to change the subject but I got a new way to converge
a picture tube that I like better."
"When I start making the vertical dynamic, I kill the red gun
and line up the green dots with the blue dots."
wrong with doing it that way, if you want to."
you started me out," explained Fuzzball, "I left the red gun on.
It's less complicated to adjust the green by itself."
the beginning, yes," Red agreed. "But it's a sure bet that after
you get some more experience, you'll be leaving the red gun on."
"I suppose you're right," Fuzzball remarked. "Right now,
it seems easier to work with two colors at a time."
you get experience," Red explained, "you'll learn to pay no attention
to the colors you're not working with. It will just be a bother
to you, then, to be turning guns off and on."
"I see what
you mean," Fuzz replied. "Tell me this," said Red, "do you keep
the green and blue dots converged in the center?"
took your hint before, Red. I use crosshatch to start the job and
I found it's easier that way."
"Thought you would."
"But I don't keep the green and blue lines converged at the
center unless I'm working in a real dark room."
"Hope so," Fuzz replied. "I found that when
there's light shining on the screen, it's easier to judge if the
green and blue lines are straight with each other if I keep them
separated a little bit." (See Fig. 1.)
"Most techs would
agree with you on that one," Red assured him.
the set manufacturers have done that really helps on this convergence,
"They are either mounting the
dynamic controls on the front of the set or on a box that you can
bring around to the front."
"You can say that again. It's
cut convergence time just about in half."
"OK. I will say
it again," Fuzzball grinned.
"You're a real character,"
Red replied disgustedly. "But what are you doing after you line
up the green and blue vertically?"
"Well, then I kill the
green gun and turn the red gun back on."
"I adjust the red beam magnet or the blue lateral corrector
to separate the red and blue lines a little bit."
"Just like the green. I adjust the red vertical amplitude
and tilt controls to make the red and blue lines straight with each
other up and down the screen." (See Fig. 2.)
"I hope you
mean you are watching just the vertical center column on these vertical
adjustments," Red interjected.
"What do you think I am.
Stupid?" Fuzzball asked.
"I'd rather not answer that question
yet," Red observed. "Then what next?"
"That's when I turn
the green gun back on and check to see whether the green light is
still straight." (See Fig. 3.)
"A little green touchup might
be in order," Red agreed.
I adjust the beam magnets and the lateral corrector to bring the
three color lines together and make a white line."
your luck running?" "Sometimes there's a little tattle-tale color
showing at the top or bottom," Fuzzball admitted.
never get it 100% perfect," Red reassured him. "We discussed that
"But you can't see it very far back from the set,"
"Better hadn't, at viewing distance anyhow."
"It's a funny thing," Fuzzball mused, "when there's a little
color showing at the top of the white line, the dynamic adjustments
will shift the color fringing to the bottom of the line, or to the
middle. But you got to leave a little fringing somewhere."
"You're getting hep," Red remarked, "and just where do you leave
"Does it make a difference?" Fuzz asked innocently.
"Sure does. You'll have lots less complaints if you leave
the final fringing at the bottom."
"But why should that
be?" asked Fuzz.
"Simply because programming usually carries
the action above center screen - that's where John Q. Public looks
"I got to admit it makes sense," Fuzzball
"Now what next?"
"That's when I switch over
to white dots and work on the blue amplitude and tilt controls."
"You can keep on with the crosshatch if you want to," Red
"How would you do that?"
"Well, the crossovers
on the hatch give you the same use as dots."
"I guess they
would, at that."
"So you can look up and down the vertical
center line, and see how the crossovers are doing."
always looks OK at the center of the screen," Fuzzball reminded
"That's right. The static adjustments make it easy
to bring the center in."
"But the crossovers are pretty
cruddy at the top and bottom of the screen."
Now the blue
"Right again. So you should open up the blue vertical amplitude
control wide and adjust the blue vertical tilt to get the same blue
separation at both the top and bottom of the screen."
get away from the dot routine on this deal," Fuzz remarked.
"Naturally, because you're working with a different type of
"Well, after I get equal blue line spacing at
the top and bottom, where do I go from there?"
you do is turn down the blue amplitude to get equal blue line spacing
all the way up and down the vertical center column."
I might have to touch up the blue tilt adjustment," Fuzzball suggested.
"Only a miracle could save you," Red agreed. "There's quite
a bit of interaction."
"And, then, when the blue lines are
spaced exactly the same amount from the yellow lines all the way
up and down the center column, the static adjustments would give
final vertical convergence."
"Fuzzball, there are times
when you are so bright you dazzle me," Red said effusively. "Permit
me to buy you another cup of coffee."
"That's coffee?" Fuzzball
exclaimed, ducking agilely as Bess heaved a creamer at him.
"We can use crosshatch all the way on the horizontal dynamic
convergence too, if we want to," Red added.
"How about giving
me a rundown?" Fuzzball suggested.
"Well, you started off
by telling me how you kill the red gun when you start the vertical.
So you can start the horizontal the same way, killing the red gun."
"Makes it easier to remember that way," Fuzz observed.
"Then," continued Red, "turn the green horizontal amplitude
and the green horizontal phase at the same time and get the green
crossovers on the same side of the blue crossovers. Get the crossovers
the same, all the way along the horizontal center line."
"Guess I might need to hit the beam magnets or lateral corrector
a little to separate the green and blue," Fuzzball suggested.
"But definitely," Red agreed, "and positively if there is
much light in the room."
"So after I get the green crossing
all on the same side of the blue crossings, where do I go from there?"
"Then you get down to fine points," Red explained.
"Look at the spacings between the green and blue crossings. You'll
find it's dollars to doughnuts that the spacings aren't all exactly
"So I suppose I got to touch up the green
amplitude and phase to make all the crossover spacings the same."
"Posilutely. Then, you do exactly the same thing for the
red crossovers. Kill the green gun and turn on the red gun. Adjust
the red amplitude and phase to get equal crossover spacings, with
all the red crossings on the same side of the blue crossings."
"That makes a pretty good routine for remembering," Fuzzball
remarked. "What do I do next?"
"Turn the green gun back
on. Both the red and green crossovers will be pretty near even from
the blue crossovers. A little touchup on the red and green controls
should do it about right."
"What about the blue horizontal
dynamics?" Fuzz asked.
"I'm getting to that," Red replied.
"But, first, you want to make sure you are satisfied with
the job so far. Get on the static adjustments and make the pattern
white in the center of the screen. Then, you might want to do just
a little more touching up to get real good crossovers at the same
points all along the horizontal center line."
"Then I go
to the blue horizontal controls?" asked Fuzz.
Now we straighten up the blue line and bring it in with the yellow
"So far, I've always been resonating the blue phasing
coil," Fuzz ventured.
"Saves time," Red agreed. "You should
do it on this all-crosshatch routine also. Open up the blue horizontal
amplitude and adjust the blue horizontal phasing coil for a peak,
smack in the center of the screen."
"That's just like we
were using dots." "Right. Then, back off on the amplitude until
the blue line is as near parallel with the yellow as possible."
"But I'll probably need to touch up the blue phasing here."
"You're reading my mind," Red stated. "The touchup will
give the parallel spacing you're looking for between the blue and
"And the static controls will give me final
overall convergence," Fuzz suggested.
"Just about," Red
agreed. "But there are a couple of little points to keep in mind."
"Look carefully at the vertical convergence.
You might have knocked it out a trifle, and need to touch it up
a wee bit."
"Anything else?" asked Fuzz.
the corners of the screen. There's no adjustment here, but sometimes
if you see a little fringing in the corners, you can compromise
a little to improve it, without hurting other parts of the screen
"Whoof!" exclaimed Fuzzball, blowing hard.
"And I took up television for a living. I could of had a job in
a putty-knife factory and nothing to worry about."
you could get a job as a pilot on a rocket to the moon," Bess suggested.
Fuzzball rose to his feet. "Give the gal her money, Red,
and let's get out of this booby trap."
Bess banged another
creamer on the door behind the fast-moving Fuzzball's back.
Posted February 4, 2014
Copyright: 1996 - 2024
BSEE - KB3UON
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