Does this description make sense?
 

I'm writing a novel about a teevee repairman circa 1961. You guys have been so helpful so far and I've stored away info you've already given me. Anyway, I wanted to include a routine color teevee repair job and stole some stuff I found on the web and tried to match it with some stuff I found in the vintage teevee repair books I bought. Does the following sound realistic? My main character is repairing Mrs. Amato's teevee in his shop.
:scratch2:
The color set was a '58 RCA Anderson with a CTC-7C chassis, a heavy beast. It drew 380 watts of power and had over 22 kilovolts of zapping power. He had to be careful and couldn't tinker with it while Mrs. Amato tried to shove cookies and tea down his throat, so he brought it to the shop.

A few years earlier, she blew almost eight hundred bucks of her late husband's insurance on the new set and complained when all her shows weren't in color. He explained most shows weren't broadcast in color and she should save her money and return it for a nice black and white set. Nope. She wanted to be ready for the color revolution. She'd read in Life it was coming.

The problem was the image, though centered, was very small. As usual, he wore his sneakers and kept one hand in his pocket as he worked. He started by testing the tubes--twenty-eight of them!--and found a short in a filter capacitor. That blew one of the 5U4 rectifiers. After replacing the bad parts, the set worked good as new and he lived to talk about it.
:sigh:
Thanks for any advice.

He was looking for a power supply problem and tested the 5U4s last...?

This is why I depend on you guys. For a run of the mill issue with this set, what should the problem be and what should his testing order be? Thanks!!!

You could write that he was so annoyed by the owner or the children, that he elected to take it to the shop and do the repair there (for a higher fee), in spite of already knowing the simple fix needed for the set.

Mrs. Amato could also possibly degauss the picture tube with the vacuum cleaner running nearby, creating a swirling rainbow mess on the screen as she moved the sweeper back and forth.

Just a couple of ideas, hopefully helpful.

He tested all the tubes first, and found a shorted cap? I would not have spent time testing tubes that could not cause the problem. That would have been a waste of time as far as trouble shooting a power supply issue such as a small raster. He also would not have found a shorted cap by testing the tubes. The cap probably would not have been shorted, but leaky. This would load down the power supply and cause low B+ voltage. This would cause a small picture. A dead 5U4 would cause a dead set.

Thanks, but Mrs. Amato doesn't have children and I wanted it to be a real repair. I do like the swirling rainbow mess, but he would be able to see the interference on the spot if that were the case and he wouldn't bring the set in to the shop.

Damn, I wish I knew how to translate what you're telling me into prose.

So if Mrs. Amato had a dead set, does that mean the power wouldn't come on? Or does it mean it clicks on but there's a black screen?

If there was no power (or is it low power?), would he take it into the shop? If so, what would he test/look at first? The 5U4? Thanks.

When the picture is very small on the screen does that mean there's a power supply problem?

Actually, with the vacuum cleaner scenario, the picture could remain discolored after she ran the vacuum cleaner. I don't think the CTC-7 had a degausser circuit, so the image would be stained with poor purity until it was properly degaussed by a tv repairman.

A dead set would act the same as an unpluged set. A shrunken raster can be caused by a power supply issue, and in some sets by horizontal issues (the horizontal output in addition to horizontally sweeping the CRT it also generates the 20KV HV, and a boosted B+ supply that is often used for part of the supply of the vertical, and sometimes other circuits).
So partial failure of either could drop the raster size down to the point of being objectionable to the owner.

Once one knows what to look, listen and smell for one becomes able to isolate the problem to 1 to 6 tubes and the parts arround them (in most cases) without takeing the back off. From experience I can say that this skill is a double edged sword allowing me to find and fix fault fast (when I'm thinking clearly), but it also makes it hard to watch TV as I end up constantly scrutinizing the most piciune details of the image constantly gauging the preformance of the circuits (unless I'm super lost in a good program).

I wish I could hand you a scenario that would require benching a set, but I've never worked on other people's sets before so I don't have a good idea of what jobs could be done in home easily.

No way a Tech would test all the tubes first thing, he'd have a pretty good idea what section the problem was in and start there.
As David mentioned the 5U4's would be the first on the list to test in this case, also a shorted filter would most likely take out the Heater in a 5U4 making it very obvious at a glance that it was bad.

Ah, I see now. That's pretty cool. But he wouldn't bring it back to the shop, would he? Could he degauss it there? Of course, he might want to bring it back to the shop to see what's inside because he's not all that familiar with color sets. I've been flipping through my old teevee repair manuals and can't find this problem (or it's staring me in the face and I can't recognize it). How does he fix the poor purity problem? Thanks!

Unfortunately, I'm a moron when it comes to this and I need specifics for my character so that he'll sound like a repairman. (The story is from his POV.) Let's see if I understand what you're saying.

Problem: Tiny picture aka shrunken raster.
Cause 1: Power supply issue
or
Cause 2: Horizontal output "sweeps the CRT?" and generates the 20KV HV (high voltage?) and B+ supply used for vertical (and other circuits)
Task 1: Identify where the power problem is occurring.
or
Task 2: Identify the tube/s making the horizontal output sweep the CRT

I told you I was a moron at this. Thanks.

Thanks, Eric. Heater is a new term for me.

Actually, I found something on the web and took pieces from that.
http://www.vintagetvsets.com/ctc7.htm
It said:
My first attempts to check the chassis led to the destruction of one of the 5U4 rectifiers due to a short in one of the filter capacitiors, fortunately nothing else (like the power transformer) was damaged.

So in one of my repair books, it connected a too small picture with the 5U4. That's why I wrote the scenario as I did. But I'd already mentioned he'd brought the set to the shop, so I figured he'd need to test the tubes in the shop (you guys are always testing tubes and I thought that was the first step).

Sorry that this is such a foreign language to me. I appreciate your help.

:DTThat sounds like a few of the old biddies i ran into during my years as a road techie (as well as an in-shop techie).
Well, first off i never knew a road techie who 'wore sneakers' specifically for electrical safety or kept one hand in pocket while working on a set in-home. I never knew one to routinely carry a tube tester into the home either. The test for a given symptom is to substitute the suspected tube(s).
But to address your specific scenario of a shrunken raster on the CTC-7, the very first thing the techie would know to do is substitute the 5U4s. But since there's no improvement, this indicates the 5U4s are not the problem. However the shrunken raster exhibits a hum bar, that is, a dark band that slowly scrolls vertically through the picture, accompanied by an S-bend in the sides of the raster that scrolls with it. This is the classic symptom of the main filter capacitor gone bad. The set would have to be shopped for this repair.
But note that the raster could not be "very small" and still display a picture. It would be pulled in maybe an inch or two from the sides along with the telltale hum bar.

I think I found the manual for the RCA CTC7C. May be 7AC. May be both.

http://www.earlytelevision.org/image...ice-manual.pdf

Thanks! My main character is actually a teevee repairman circa 1961 fixing a 1957 RCA CTC-7C. So the teevee owner's complaint would be, "The picture's messed up. It's got a black bar that keeps rolling up and the sides are wiggly." So the repairman would right away know the main filter capacitor was bad? Why wouldn't he fix it at the home? Thanks!

As for the sneakers and hand in the pocket, the repair manuals I have say to do that. If no one ever did that, I won't have him doing it!!!!

If you go down to fig.# 46, you can see the main filter cap, actually two of them, designated C104-A and C105-A. If these dry out and lose capacitance it'll cause the shrunken raster and hum bar described earlier.

To do a correct repair is a pretty involved process. It involves unsoldering multiple connections, untwisting the 'Twist-Lock' lugs that hold the capacitor can(s) in place, (sometimes) drilling out rivets, re-installing the new can(s) and re-soldering the leads back onto the correct section of the can (a single can can have up to four sections, designated A, B, C etc.). Although it `could` be done in the home, it would not be practical. Anything much beyond tube or fuse replacement was generally a shop job. Sometimes with a big heavy set or combo, the chassis was pulled to the shop, leaving the cabinet and pic tube in the home.
That's an obligatory precaution given to neophyte newbies and well worth the warning. But a seasoned techie such as depicted in your novel would not likely be seen working with one hand in pocket.:smoke: He might be wearing sneakers, but not specifically to avoid electrocution in the customer's home.

Cool. So why would he need to bring it to the shop? I just need a reason why he doesn't fix it at the house.

Does this sound okay?
=================
A few years earlier, Mrs. Amato blew almost eight hundred bucks of her late husband's insurance on the '58 RCA Anderson with the CTC-7C chassis and complained when all her shows weren't in color. He explained most shows weren't broadcast in color and she should save her money and return it for a nice black and white set. Nope. She wanted to be ready for the color revolution. She'd read in Life it was coming.

Her problem was, "The picture's messed up. It looks smaller and it's got a black bar that keeps rolling up and the sides are wiggly." A shrunken raster, hum bar, and S-bend. At her house, he tried replacing the 5U4s, but that didn't fix the problem, so he brought it back to the shop.

While Yoyo was out of his hair, he sat down with the heavy monster. It had 28 tubes, drew 380 watts of power, and had over 22 kilovolts of zapping power. Once he was familiar with its layout, he found the problem--a dry C104-A and C015-A. He replaced the main filter capacitors, and the set ran good as new.
=====================

Also, I'd like to use the vacuuming/degaussing problem noted earlier. I can use it later in the story. Would this work? (I'll rewrite it for the scene. I just want the facts straight.)
=========================
Mrs. Amato was vacuuming and degaussed the picture tube, creating a swirling rainbow mess on the screen as she moved the sweeper back and forth. With no degausser circuit on the CTC-7, the image was stained. To restore purity, he used a demagnetizing coil.
========================
Would he do this at her home or would he have to bring the set to the shop?

Thanks. Merci beaucoup. Mucho gratias.

OK, the vacuum cleaner motor puts out a strong magnetic field which can magnetize the shadow mask in the pic tube. This causes the three electron beams passing through the shadow mask to incorrectly 'register' when they land. That is, they don't land perfectly on the correct phosphor dots, and partially illuminate the adjacent dots. This screws up the color purity. (For example, an all-red screen will have blotches of the wrong colors in it.)
The shadow mask can thus be said to be "gaussed" by the vacuum cleaner (or any other source of a magnetic field).
DEgaussing is done to restore the purity. It's done with a tool called a degaussing coil. It's a hoop about a foot in diameter with a momentary contact push-on button and a long cord that plugs into AC. There's a special technique (NOT the one shown in the UTube video !!!!!!). The coil is switched on while at least 6 feet away from the TV set. The coil is slowly brought in to the CRT face and moved around, and around the sides and top of the TV, then slowly moved back at least 6 feet away from the set before switching the coil off. If the coil is switched off while close in, it will "gauss" the CRT instead of degaussing it. (Also in the UTube vid, the guy switches the coil on directly in front of the CRT. Wrong!)

In the days before auto-degaussing (which didn't come until the CTC-16), the sets had to be degaussed every time they were moved, or even rotated 90 degrees, because even the Earth's magnetic field would disturb the purity.

Dang, dunno why "the vacyoom cleaner" got formatted in blue.:sadwave: T'warnt me did that. :no:

Wow, fabulous detail! All I knew about degaussing was when I pressed my computer monitor button and the screen boinged. You've explained the procedures I need to follow for the degaussing of the gaussed set.

One question: Does the shadow mask only apply to color sets? I figure that's the case, since we're talking about color.

I ask, because I was going to have another customer ask my main character Hunny (Gil 'Hunny' Hunnicutt) move her teevee set. This would be after he put in a wave-trap for an interference problem. She has rabbit ears, so I'd have him suggest an antenna, which he'd wire up through closets to her attic. (She finds outdoor antennae to be 'tacky'.) The mayhem of the story will happen with this customer who'll be kidnapped by an Albanian hit man in drag and the husband won't pay ransom. (Uh, it's not based on a true story.)

As for the links, something is automatically doing that. I didn't link compooter monitor either!

BTW, I didn't realize there were examples of this on the yoohootoob. Way cool. I found this first. http://www.youtube.com/watch?v=6MMsYrfLHXs

Others fixed it with a hand drill that had a magnet attached!

Well, being an old geezer who authentically did this stuff for a living 'back in the day', i might take the liberty of amending your text slightly to read thus..

BTW, Black & white CRTs don't have a shadow mask.

Thank you so much! I'll take your edits. BTW, your nickname isn't Hunny, is it? Ha!

You probably have some interesting stories to tell about your house calls. I was thinking of having someone's pet snake or hamster get stuck in the chassis. I figured the customer would say the teevee doesn't work and it smells funny. Do you know if the pet inside would fry and die?

Great rewrite old_coot88! It's as good or better than Stewart Woods describing an ILS landing.

Pete

For the vacuum cleaner "scene" in your novel, you could say that she had the TV set on while she was doing some vacuuming right in fromt of the set. She sees that the TV set's CRT is having crazy colors running thru the picture on the CRT, and thinking that she is slowly destroying the TV set, turns off the vacuum cleaner right in front of the set. And the CRT now has purity issues and dammit I have to have the TV repairman back in. And a note saying had she just slowly kept vacuuming and eventually turned the vacuum off only when she was about ten feet away from the set the funny colors would have gone away (that she would have degaussed the set herself). If it fits your plot line, the TV repairman could show her this trick with her vacuum (maybe to make his customer feel better, good for future business).

Ha! She degaussed it herself! Cool. Thanks.

I'll jump in on this one...
 

I've never found a fried pet in a TV, but I have seen some really big bugs get toasted, and once found a dead 6" lizard stuck against a damper diode in a 90s (solid state, of course) TV. I almost trapped someones cat in a Magnavox entertainment center once....got a few screws in the back cover and started hearing funny noises. Found the cat had jumped in just before I set the cover in place.

Ack! Stupid cat! Well, since my story is set in 1961 and teevees were mainly tubular, I think a fried snake wouldn't be too bad. I'm not sure how it would play out, though. What would fry it? Would it unseat something and get zapped?

Some thing like a snake is long enough to touch the chassis and at the same time easily hit an above chassis B+ post and get electrocuted to death.

Most companies had circuit boards then which may have buged the snake enough to keep the critter safe (pokey test points and lots of small above chassis components), but someting like a Zenith or a Packerd Bell which had no circuit boards....Many of these 100% hand wired sets by that time used chassis mount terminal strips that could be accessed above chassis (Zenith REALLY liked useing these) often placing several B+ terminals easily touchable above chassis where that snake could comfortably get to them.

...nothin' quite like letting other people write your books for ya:rolleyes:

Over in Audiokarma's tube audio forum, someone had an audio amp that had a dead mouse inside it. Said mouse had crawled under the chassis inside the amp, and found some internally exposed powerline voltage, and thus was electrocuted. This was at some terminal strips (metal posts attached to a phenolic plastic strip) with bare wire connections feeding the powerline to the amp's power transformer. Before the mouse bought the farm it had chewed some wax off nearby wax paper capacitors. This audio amp could easily have been that color TV set in your novel.

Electricians occasionally find fried mice and snakes inside circuit breaker panels. Tends to be stinky and yucky...

Would this be one I could use for the snake? I don't think it has circuit boards but I can't really tell.
http://www.vintagetvsets.com/fm1.htm

So the snake would touch the chassis and an above chassis B+ post. I see B+ a lot. I wish I knew what a B+ post was. Does it have another name?

Thanks for the info!

Nice that you're writing a novel that is of interest to us VK'ers. However, way to much technical detail for the average reader to comprehend or even care about. I know your main character is a TV repairman circa 1961, but keep it simple and moving. Ie: Damn, It was an older model RCA color set. He'd worked on his share of these hulking beasts. "I just know this is gonna be a bench job" he muttered, as he started to remove the giant set's back to check the tubes. Sure enough, the acrid scent of burnt electronics invaded his nose. "No simple tube swap here." Guess I'll give her the bad news that I have to pull the chassis and take it to the shop." Then you can get into the woman's reply, how much she paid for the set and there's no damn color shows most of the time. Ect. I'll leave the dialogue to you. If you get into all the details of deguassing the set or changing specific tubes your reader's eyes will glaze over. Have the woman complain and discribe the symptons and your experienced hero TV repair guy do a quick diagnosis, explain the problem, what ever you come up with, and pull the chassis. Hell, it could be the "fringe area localizer switch" for all the woman knows. She just wants it fixed and he wants out of that house.

-Steve D.

You're absolutely right! I really don't want to get bogged down in the details. And the main story will be a suspense romance (yes, a chick book). I'm writing it from the repairman's POV, and since I'm waaaaay out of my element with vintage teevee repair (but I think it's way cool anyway), I want a sentence or phrase here or there for color. I just want it to be correct, that's all. The repairman would look at a set and identify the exact model in his head, I think. Then again, you'd know that best!

Right now you taught me the phrase "bench job" which I take to mean he's gotta spend time testing to diagnose the problem. You taught me there's an acrid scent to burnt tubes. I didn't know that.

I'm not above making things up. Heck, the location I'm using is made up. But I don't really want to make up television repair details. I think it's cooler when real details are provided.

I swear, this is like learning a foreign language and trying to translate correctly! Thank you.:yes:

BTW, nice site! I love the Merrill.

Do you mean his life insurance? She could only have blown eight hundred bucks of that after he died. If he is dead then how could he explain the lack of color broadcasts? Is he a ghost?

It's 1961, right? A 1958 RCA color set would be still very new.

Did any 3-year-old RCA TV sets ever blow their filter capacitors? Isn't a dried-out or leaky capacitor an age-related failure? Like after 15 or 20 years, minimum?

That seems true. I would make the symptom a simple rolling vertical hold, the repairman knows it's a sync tube, but he doesn't have a spare in his caddy. Rather than appear incompetent, he takes the chassis into the shop. Then he sends his least-favorite co-worker out later to put the chassis back in, to distribute the tea-n-cookie torture evenly.

No. Burned wiring or burned resistors. A "burnt tube" isn't likely. a "burned out" tube is, but that would be odorless. Like a burned out light bulb.

Exactly. I never said burnt tube produces an acrid scent. As Accumulator said the acrid scent or smell is from an electrical short or rubber insulation or a resistor or any number of other toxic components in a television chassis. A "bench job" means that the chassis is taken back to the shop and put on the work bench to be repaired.

-Steve D.

You are right of course. In my little rewrite of the author's text, i was trying to accomodate his expressed interest in the technical stuff and having it correct. He then has the option to dial the dialog back to suit the average reader's interest level.