I'm surprised you can't get a sponsorship from the Crepe Erase people. You spend so much time replaying their commercials. 🤣 At least they have flesh tones!
On PlutoTV, etc., the "Price Is Right" channel is airing 1972-1973 episodes weekdays at 8PM ET. This exact model of TV turned up on the November 20, 1972 episode. According to Johnny Olson, this is the "Salvini" model with a "pecan Mediterranean" cabinet.
The power transformer is one that saturates at about 85 line volts. This causes the transformer output to be mostly a square wave. The cap is across the transformer output and has the effect of restoring the waveform back to mostly a sine wave. The whole point of the circuit is to allow the TV to operate with line voltage ranging from 85 volts to 135 volts with no real change in the displayed pix. Below 85 volts the pix will start to shrink. Above 135 volts the breaker will trip.
This was a nice trip back in time for me. I worked as a gopher in a local TV repair and sales shop in my hometown in 1973. I helped the owner pick up these sets at the Zenith distributor and went along when we delivered them to customer homes. I remember being stunned when we unboxed the first one and realized that the console sides were made of plastic. Nevertheless, these Zeniths made a beautiful color TV picture back in the day. Thanks, shango!
It might be mainly plastic but it's a great looking TV . So much nicer than the soulless flat screen efforts that are sold today . Not a bad picture either . I would enjoy owning and watching that . Shame that I live about 3000 miles from you in the UK . Best wishes for Christmas to you and thanks for entertaining me over the years . You never fail to do so .
Today’s sets could be made with style. Look at how stylish smartphones are. They are essentially flat screens that we carry about. Anodised aluminium bezels could make tv sets very stylish. Also, making them more serviceable and encouraging repair would good for everyone, both customers and independent repair shops. Sets used to be marketed on their reliability and repairability.
This is soooooooo close to my childhood TV. My father picked out a 1974 Chromacolor II 25 inch set... but it was in the modern style enclosure with the BLACK base. I've searched for a photo online of this set for years, and they seem to have all disappeared. I wish my father hadn't gotten rid of it in the late '90s, replacing it with a set that had a noticeable pincushion problem. The '74 Chromacolor II ate a sound module every two years... and every repair guy had a different story as to why it was problematic. Sometime around 1989 we couldn't afford to fix the sound, so dad just set up a second TV for sound... LOL! We ran that TV to death... 18 hours a day, everyday... and it still had a decent picture at the end.
my dad had a similar age Zenith Chromacolor, in the mid-late 80s, picked it up used, though I think it was a smaller 20 inch set ,that sat on a stand, had the same power switch, but also had another similar switch underneath it, that rocked up/down , to activated a motor, that turned the channel turret...
58:10 - we in the UK had a few Philips TVs in the 70s do exactly that when green LOPT (flyback) tuning capacitors went short-circuit. And they *always* go s/c! So if anyone in the UK is reading this with a Philips G8, G9 or G11 chassis on the bench, you must replace those caps, preferably before even switching the set on!
Nostalgia. My parents first color TV was the hybrid version (a few vacuum tubes and chromacolor CRT) that Zenith sold before solid state color sets. The chromacolor black mask was easily evident with the set running. The chromacolor was a real breakthrough and the dealer had boxes of consumer literature explaining it.
Never underestimate the power of a subwoofer, which had essentially been silent through this video until 43:00 , I got up and looked out the window to find out who was running such a noisy car on the street, then realized I was fooled, and the sound was picked up by Shango's camera when he was recording this. "Award winning Equinox, one of the biggest foaming turds on the road." . . . I was choking from laughter.
In a magnetron the magnets cause electrons to whirl around the cavity which is tuned to the desired output frequency. It's actually an RF whistle! ATSC3 will eventually happen, but right now it's only allowed for use, however ATSC1 is not being phased out, both will live side by side for at least 5 years, probably much longer. Also LG has said they will not support it until all the problems (such as some encrypted signals not being decoded) are worked out.
rf whistle....that's the description i have looking for since i first looked at a magnatron cavity, i knew i recognised the relationship, but i couldn't get the mental connection....
Shango don't miss out $69 for magic crape erase but I got it for $49 and now look 18 again. Yes nice TV reminds me of my family set I had watched in 70s I remember those solid state tv and the price back then was expensive we got ours with a payment plan. I still remember our BW 50s set. Worked in my Ham Elmers TV shop as a kid. Nice memories. Sure enjoye weekely Saturday coffee with Shango,,Thanks
not gonna lie, but the thumbnail for video gave me the vibe " I found it in the bushes, and hauled it out, and did a fake restoration on it, by pressure washing it" lol
the problem with this capacitors is common in many sets, the BU208 used in germany had one advance, they get shorted when the voltage peak came too high. I would not use disk capacitors for general use in this circuit, keep in mind, that this "Flyback"-capacitor has to absorbe the energy from the yoke and the flyback-transformer 15k times a second, this ist the highest loaded capacitor in the set. I use WIMA FKP1 for this, they are highly reliable for this and special made for this up to 31 kHz-H-output-stages in monitors. To use 2...3 with lower capacitance make a total loss of capacity most unlikely. I saw CRTs dying, too, in GDR we had a TV producing HV with a PP-output stage (2N3055-like), if the hv-regulation failed, the could shot the CRT to dead, too, saw this one time in my front, too. ...But not in a set with BU208, they are shorting so fast that the CRT would have survived, if the capacitor lost all of the capacity. ... In GDR this transistor costs 100 "bugs" = "eastern Mark", this was so much money... ^^
If memory serves me well, the first Philips K-9 chassis had the same problem with the capacitors in the high voltage and there was a Grundig chassis (CUC something) that blew those BU-208 like crazy
From picking up and learning just the basics passively I can happily say my trash picked 1983 Quasar black and white TV in lesser words is back up and working. Thanks Shangoo👍. Also my grandfather still has one of these 70s zenith solid state TVs same plastic faux wood, it doesn't work and it way too involved for me to try and resurrect it but it ain't doing no harm just staying in the sun room in the family cabin looking pretty.
I wouldn't worry too much about ATSC 3.0 as it just seems like a non starter not only for the consumer but for the manufacturer as well. BTW I use a DTV box hooked to an Agile modulator that also has stereo output so every analog TV in my house can pick up signals from the rabbit ears. I have 3 working simultaneously on Channels 3, 9, and 11. that way also my mechanical tuners get moved from time to time which keeps them from crusting up.
Besides no copyright problems, I find using the live studio news broadcasting to adjust color settings on TVs is the most accurate, as their color systems are correctly tuned to the most natural flesh tones / hues, than most recorded programming.
That chassis is fascinating because it looks like a tube chassis... with no tubes. (especially with the point to point wiring underneath) "hanging on to the tube era" as you said.
The white high voltage feed trough on the magnetron is also a pair of capacitors and works with a pair of ferrite rod chokes inside the plate as a rf filter, Google magnetron through core capacitor if your intersted mate
I remember the pictures on the 1973 thru 1976 Chromacolor and Chromacolor II sets. Knock your eyes out beautiful. I had a 19" Chromacolor II tabletop in 1975, I was amazed at the vibrant colors and contrast. I did have to put a replacement safety cap kit in it, just for preventative measure. Our local Zenith parts distributor offered the kit at no charge, just needed the s/n of the set. We used that set till 1993, the CRT finally went soft.
The huge heavy transformers in Zenith TVs were operated as saturable reactors. This allowed the transformer to provide a degree of regulation. Along with the bathtub style capacitor the line voltage could drop as low as 80 VPP without a drop in the output. Any excess voltage was dissipated as heat in the transformer.
When you were talking about the EHT problem and those caps, I remember a Panasonic chassis ( and I think a high street chain store brand ) here in the UK that used a regulator IC that used to intermittantly fail, and the HT would shoot up, the protection was an avalanche diode across the HT line (R2M ?) that would permanently short out when overvolts occured. The problem was the regulator was intermitant, and so if the the diode was removed by the engineer after it had shorted, thinking that was the problem, the set would work again with no fault symptoms. If the diode was left out and not replaced next time the regulator failed or 'spiked' the EHT went sky high and the voltage punched a pinhole through the neck of the tube to the the scan coils. An expensive repair !
@28:53 - You're switching topics like an old episode of the Muppet Show. I'm the old man heckling in the balcony enjoying the entire show. You cannot pay for a commercial service to deliver this level of entertainment.
@21:02 - This is a teaching moment for me personally. I begin to ask a question in my head and I often plan to ask said question in a comment. Your content had caused me to slow down, match my brain with your measured conversational tone and let the question linger instead of blurting it out like the fat nerd in the back of 8th grade science class. You invariably get around to answering the question I had in my head - often with great alacrity. This only proves that I know very little about the things you're an expert in.
You MUST change all the 22-5001 caps ( 5 ? ) some on FBT & some under. They were up graded to Sprague orange drops. If all open the set can make 40 KV ! Quite a light show !
Looked quite a decent picture once you got it running, The commercials looked much like the same nonsense we get here in the UK! BTW , you still have analogue Over The Air TV transmissions in that part of the States. In the UK they were closed down about 12 years ago, when they all went to digital terrestrial signals.
My parents had that model but with a much nicer cabinet with a black leather-like top surrounded by real wood. I remember watching Saturday morning cartoons with a bowl of cereal in my lap. They had it from 1973 to 1995 and it worked fine, though it needed a tube brightener towards the end.
By the time I was going through school in the 90's this was legend. A bad capacitor in certain Zenith TV's would cause it to run away and saw the neck off the picture tube. Lacking details and eyewitness accounts I thought it was a tube set, guess not.
Time marching on. Bad firmware in multi-million dollar television transmitters would cause them to run away and destroy millions of dollars worth of LDMOS power amplifiers. Strangely a problem limited to 8VSB (ATSC2) not COFDM(ATSC3)
this Zenith model is simular to the one I grew up with but with one channel knob for both VHF/UHF. behind the door you preset the channels for your area and placed the channel number from a black plastic cutout sheet that came with the set.
CRT failures due to the white safety caps started in late 1974. There's a 10Ω/10W wirewound behind the tripler, change that at the same time as the caps.
If I am not mistaken, the orange 4-legged capacitors are the ones that fail frequently. The 2 separate caps are more reliable for HV control since the HV will not sky rocket when only one fails. EDIT: Just verified it. The 4 legged ones were the type that caused a big recall in the 70s because they failed and caused HV runaway. I would replace the 2 separate ones with new ones and call it a day.
I think the orange 4-leggers are ok. There were white 4-leg "critical safety capacitors" Zenith used before the orange ones. Those would change in value or go open across the cap, instead of across the legs on each side like they were supposed to, causing the HV to go unregulated and blow everything up.
Nice Zenith ! I remember those when I was in high school , Zenith was like at the top of their game then. I'd almost move my flat screen out for something like that. Televisions were furniture back then and now just a plastic rectangle we hang on a wall or block a window on a stand. A little crepe erase for the crappy picture and your in biz.
That would be great double EOL video, that magnetron pointed to something you disike powered by 60kV Zenith-TV provided power supply. It would need to be recorded by Slo-mo guys, though ;)
That power transformer circuit is referred to as a ferroresonant design, it is a resonant as 60Hz circuit, it purposely drives the magnetic core into saturation, ensuring a constant output over a large range of input voltages. They used to be fairly common in computer systems before switchmode supplies took over (as in pre-IBM PC), however this is the first time I've seen one used in a TV
$5.00 a gallon gas in Calif.? I wish we had that here. Would help get everyone off of big gas guzzling trucks and SUVs. Here gas is $3.59. Too cheap. Lots of really big vehicles still on the road here.
Great video shango!! First solid state TV I've seen you do. I was wondering why the picture doesn't fill the screen completely at the top and bottom. I suspect it's the converter box that changes digital to analog. Is that it?
Wifey and I bought that set new right after we were married. Great set but the Rauland CRT didn't last as long as it should have. Other than than that it needed a replacement focus rectifier and periodic cleaning of the pins on the plug in circuit boards. Thanks.
Those had that chromacolor luminance switch, that circuit would over contrast the picture, but, those were fun to work on.....is the H.V. a tripler or doubler..? You find all these gems..👍
To test unhook the oil cap & run on variac, starting @85V. 4 lead cap is NOT a sub !!!! It has built in interlocks that open to kill HV. The HOT C & E paths go through the cap.
“Homeless Encampment smell”. “This looks entirely too replacementy.” LOL!! 😂 😂😂😂😂!! Merry Christmas 🎁🎄 and Happy and safe 😊 New Year!! Your friend, Jeff.
Did you go back and adjust the screen pots to improve the picture? EDIT: LOL! Literally as soon as i posted that comment, I got to the part where he put it into service mode. Thanks again for another great video, Shango!
Shango: I guess I'm wondering why you wouldn't expect the capacitor on the power-transformer to get warm, when it is directly connected across 300V of AC. If you calculate the capacitive-reactance for a 3.5uF capacitor at 60Hz, you get 757.88-Ohms. If you take 300V divided by 757.88-Ohms you get 395mA! Wow! if you then calculate the power: 395mA times 300V, you get 118-Watts which is ridiculous! So something is screwy with either the values or the actual voltage seen by this capacitor; if it's just a capacitor??? Does you chassis gurus have any insights regarding this capacitor strapped directly across the full windings of the power transformer?
What's not 118 watts, it-s 118 volt-amps. It's consuming 118 watts for one quarter-cycle but instead of converting it to heat the stored energy gets sent back into the grid the next quarter-cycle.
@4:40 - "Let's just ignore that..." Let's not. That is the kind of fascinating yarn that you can really put your mark on. I'd enjoy that story immensely. Even if you had a Wit and Wisdom separate channel, I'd be on that like white on rice.
35:30 ATSC 3.0 is a new standard. However at the moment, there is no requirement or mandate for television stations to switch. It is just starting to roll out in larger metros with one TV station converting their entire signal to 3.0 and hosting the programming of the major stations. The host station’s channels has been divided up among the other area station signals so that they can continue to service in 1.0.
That oval capacitor I’m guessing is an AC cap. I wonder if that self voltage regulating system is similar to what those old SOLA voltage regulators used.
Those safety caps are a problem,i had a similar set to this one that would trip the breaker when powered on.Took me a few days to find it but it ended up being the safety cap on the underside of the chassis.I replaced them all to be on the safe side.
Similar model of my parents bought in the fall of '73. Full solid state. UHF tuner was however detent. It was totally reliable for 10 years. It had heavy use and the CRT was as good as new after 10 years. Maybe he was and old kid?
Detented UHF tuners were mandated sometime in the early 1970s. I don't know what the FCC was thinking, the only thing that detented tuners did that continuous ones didn't was make a raspy noise when you turned the dial. Otherwise, it was the exact same thing. Varactor tuners soon came along and made those raspy tuners a thing of the past on all but the lowest end sets. In Winnipeg, we never had to deal with the raspy UHF dial. Our 1974 Electrohome table top TV had a continuous, two speed UHF tuner. We got our first UHF channel in 1998 (ch 35). By then our TVs had remote controlled, cable ready, digital direct access tuning with on screen channel display. And since we were on cable by 1972, we never used the UHF function.
Shango, is there a better way to make contact with you than e-mail ? Several times I was in the LA-area and had some vintage radios (including Russian) to donate to you, but couldn't connect. Great intro footage of the So Cal freeways
@@shango066 Thanks, Just some neat radios you might be interested in (like you need more)... like I need more! There is never enough! Will try again this coming spring. I thought maybe you were only making contact through online forums, etc, and maybe your e-mail was obsolete. Let's keep enjoying your awesome videos sharing so much knowledge.
The excitement of realizing it was a Crepe Erase commercial...priceless. Give this man a CZcams Emmy for that performance!
Come for the TV repair, stay for the award winning commentary 😂😂😂
I'm surprised you can't get a sponsorship from the Crepe Erase people. You spend so much time replaying their commercials. 🤣 At least they have flesh tones!
I know! 😂 LMAO, at his excitement, when he realized it's "Crepe Erase" commercial! 😅😂
Blessed by Crepe Erase
w00000w
On PlutoTV, etc., the "Price Is Right" channel is airing 1972-1973 episodes weekdays at 8PM ET. This exact model of TV turned up on the November 20, 1972 episode. According to Johnny Olson, this is the "Salvini" model with a "pecan Mediterranean" cabinet.
That's my birthday lol
Wow
"Pecan Mediterranean", WOW!
Well how much was it??
The power transformer is one that saturates at about 85 line volts. This causes the transformer output to be mostly a square wave. The cap is across the transformer output and has the effect of restoring the waveform back to mostly a sine wave.
The whole point of the circuit is to allow the TV to operate with line voltage ranging from 85 volts to 135 volts with no real change in the displayed pix. Below 85 volts the pix will start to shrink. Above 135 volts the breaker will trip.
Thank you for the explanation
I died inside a little when you passed on that IBM.
@@paulm3079I love my Dell Dimension 2400.
Even did actual work on it!
Looked like a XT clone
With due respect, not rare at all and almost no use today. Boat anchor applications possible.
@@ntsecrets That looked like an IBM 5150 with a 5.25" hard drive, for $50 that's almost a steal.
Definitely not an IBM, it was some sort of clone.
This was a nice trip back in time for me. I worked as a gopher in a local TV repair and sales shop in my hometown in 1973. I helped the owner pick up these sets at the Zenith distributor and went along when we delivered them to customer homes. I remember being stunned when we unboxed the first one and realized that the console sides were made of plastic. Nevertheless, these Zeniths made a beautiful color TV picture back in the day. Thanks, shango!
It might be mainly plastic but it's a great looking TV . So much nicer than the soulless flat screen efforts that are sold today . Not a bad picture either . I would enjoy owning and watching that . Shame that I live about 3000 miles from you in the UK . Best wishes for Christmas to you and thanks for entertaining me over the years . You never fail to do so .
Today’s sets could be made with style. Look at how stylish smartphones are. They are essentially flat screens that we carry about. Anodised aluminium bezels could make tv sets very stylish. Also, making them more serviceable and encouraging repair would good for everyone, both customers and independent repair shops. Sets used to be marketed on their reliability and repairability.
Today's "tv's" are throw away garbage so the manufacturers aren't going to bother with any visual vaule
This is soooooooo close to my childhood TV. My father picked out a 1974 Chromacolor II 25 inch set... but it was in the modern style enclosure with the BLACK base. I've searched for a photo online of this set for years, and they seem to have all disappeared. I wish my father hadn't gotten rid of it in the late '90s, replacing it with a set that had a noticeable pincushion problem.
The '74 Chromacolor II ate a sound module every two years... and every repair guy had a different story as to why it was problematic. Sometime around 1989 we couldn't afford to fix the sound, so dad just set up a second TV for sound... LOL! We ran that TV to death... 18 hours a day, everyday... and it still had a decent picture at the end.
my dad had a similar age Zenith Chromacolor, in the mid-late 80s, picked it up used, though I think it was a smaller 20 inch set ,that sat on a stand, had the same power switch, but also had another similar switch underneath it, that rocked up/down , to activated a motor, that turned the channel turret...
2:20 the guy on the little motorbike is a member of the Heck’s Angels
I like the way drh4683 talks. Especially the video where sets the convergence and purity on an old TV.
Your videos on repairing old TVs are really interesting. I watch your videos from France even if I don't really understand English. It's really great.
Cool.
58:10 - we in the UK had a few Philips TVs in the 70s do exactly that when green LOPT (flyback) tuning capacitors went short-circuit. And they *always* go s/c! So if anyone in the UK is reading this with a Philips G8, G9 or G11 chassis on the bench, you must replace those caps, preferably before even switching the set on!
New Shango video, its a good day.
aye it is indeed!
Nostalgia. My parents first color TV was the hybrid version (a few vacuum tubes and chromacolor CRT) that Zenith sold before solid state color sets. The chromacolor black mask was easily evident with the set running. The chromacolor was a real breakthrough and the dealer had boxes of consumer literature explaining it.
Never underestimate the power of a subwoofer, which had essentially been silent through this video until 43:00 , I got up and looked out the window to find out who was running such a noisy car on the street, then realized I was fooled, and the sound was picked up by Shango's camera when he was recording this.
"Award winning Equinox, one of the biggest foaming turds on the road." . . . I was choking from laughter.
I have concluded the worst drivers on the road are driving a 1 Nissan Rogue, 2 Tesla any model, 3 Equinox.
@@contrapezist I would add Nissan Altima (in Ontario)... I have been cut off by them all the time, and hit by two when driving in the Toronto area.
In a magnetron the magnets cause electrons to whirl around the cavity which is tuned to the desired output frequency. It's actually an RF whistle!
ATSC3 will eventually happen, but right now it's only allowed for use, however ATSC1 is not being phased out, both will live side by side for at least 5 years, probably much longer. Also LG has said they will not support it until all the problems (such as some encrypted signals not being decoded) are worked out.
rf whistle....that's the description i have looking for since i first looked at a magnatron cavity, i knew i recognised the relationship, but i couldn't get the mental connection....
Shango don't miss out $69 for magic crape erase but I got it for $49 and now look 18 again. Yes nice TV reminds me of my family set I had watched in 70s I remember those solid state tv and the price back then was expensive we got ours with a payment plan. I still remember our BW 50s set. Worked in my Ham Elmers TV shop as a kid. Nice memories. Sure enjoye weekely Saturday coffee with Shango,,Thanks
You put on your arse ? :)
not gonna lie, but the thumbnail for video gave me the vibe " I found it in the bushes, and hauled it out, and did a fake restoration on it, by pressure washing it" lol
the problem with this capacitors is common in many sets, the BU208 used in germany had one advance, they get shorted when the voltage peak came too high. I would not use disk capacitors for general use in this circuit, keep in mind, that this "Flyback"-capacitor has to absorbe the energy from the yoke and the flyback-transformer 15k times a second, this ist the highest loaded capacitor in the set. I use WIMA FKP1 for this, they are highly reliable for this and special made for this up to 31 kHz-H-output-stages in monitors. To use 2...3 with lower capacitance make a total loss of capacity most unlikely. I saw CRTs dying, too, in GDR we had a TV producing HV with a PP-output stage (2N3055-like), if the hv-regulation failed, the could shot the CRT to dead, too, saw this one time in my front, too. ...But not in a set with BU208, they are shorting so fast that the CRT would have survived, if the capacitor lost all of the capacity. ... In GDR this transistor costs 100 "bugs" = "eastern Mark", this was so much money... ^^
If memory serves me well, the first Philips K-9 chassis had the same problem with the capacitors in the high voltage and there was a Grundig chassis (CUC something) that blew those BU-208 like crazy
From picking up and learning just the basics passively I can happily say my trash picked 1983 Quasar black and white TV in lesser words is back up and working. Thanks Shangoo👍. Also my grandfather still has one of these 70s zenith solid state TVs same plastic faux wood, it doesn't work and it way too involved for me to try and resurrect it but it ain't doing no harm just staying in the sun room in the family cabin looking pretty.
I wouldn't worry too much about ATSC 3.0 as it just seems like a non starter not only for the consumer but for the manufacturer as well. BTW I use a DTV box hooked to an Agile modulator that also has stereo output so every analog TV in my house can pick up signals from the rabbit ears. I have 3 working simultaneously on Channels 3, 9, and 11. that way also my mechanical tuners get moved from time to time which keeps them from crusting up.
Thank god for shangos Saturdays posts lifts the spirits
Besides no copyright problems, I find using the live studio news broadcasting to adjust color settings on TVs is the most accurate, as their color systems are correctly tuned to the most natural flesh tones / hues, than most recorded programming.
Because the Black Friday deals have sucked for a number of years now, the safety caps must be polypropylene dielectric NOT mylar
That chassis is fascinating because it looks like a tube chassis... with no tubes. (especially with the point to point wiring underneath) "hanging on to the tube era" as you said.
The white high voltage feed trough on the magnetron is also a pair of capacitors and works with a pair of ferrite rod chokes inside the plate as a rf filter, Google magnetron through core capacitor if your intersted mate
all I want for Xmas is a new sango066 video
I love how this guy appreciates old well made electronics
I remember the pictures on the 1973 thru 1976 Chromacolor and Chromacolor II sets. Knock your eyes out beautiful. I had a 19" Chromacolor II tabletop in 1975, I was amazed at the vibrant colors and contrast. I did have to put a replacement safety cap kit in it, just for preventative measure. Our local Zenith parts distributor offered the kit at no charge, just needed the s/n of the set. We used that set till 1993, the CRT finally went soft.
Nice variety of edutainment on this one. Kept me watching all the way to the conclusion. Way to go Shango!
You are always an inspiration of logic and humility. Keep up the great work.
Located in Sweden I'm watching your videos every Saturday! Really great stuff! 👍
I enjoy your channel, but most of all, I enjoy your narrating and comments. Keep up the good work.
Perfect microphone quality on the camera, very good, thanks for the new video
The huge heavy transformers in Zenith TVs were operated as saturable reactors. This allowed the transformer to provide a degree of regulation. Along with the bathtub style capacitor the line voltage could drop as low as 80 VPP without a drop in the output. Any excess voltage was dissipated as heat in the transformer.
It's great to hear that tech helping you, i hope you thanked him for his valuable information.
He sounds like a smashing bloke :-D
When you were talking about the EHT problem and those caps, I remember a Panasonic chassis ( and I think a high street chain store brand ) here in the UK that used a regulator IC that used to intermittantly fail, and the HT would shoot up, the protection was an avalanche diode across the HT line (R2M ?) that would permanently short out when overvolts occured. The problem was the regulator was intermitant, and so if the the diode was removed by the engineer after it had shorted, thinking that was the problem, the set would work again with no fault symptoms. If the diode was left out and not replaced next time the regulator failed or 'spiked' the EHT went sky high and the voltage punched a pinhole through the neck of the tube to the the scan coils. An expensive repair !
I like the new camera with the 60 fps! MUCH clearer video for people with not so good eyes. 😉
@28:53 - You're switching topics like an old episode of the Muppet Show. I'm the old man heckling in the balcony enjoying the entire show. You cannot pay for a commercial service to deliver this level of entertainment.
@21:02 - This is a teaching moment for me personally. I begin to ask a question in my head and I often plan to ask said question in a comment. Your content had caused me to slow down, match my brain with your measured conversational tone and let the question linger instead of blurting it out like the fat nerd in the back of 8th grade science class. You invariably get around to answering the question I had in my head - often with great alacrity. This only proves that I know very little about the things you're an expert in.
You MUST change all the 22-5001 caps ( 5 ? ) some on FBT & some under. They were up graded
to Sprague orange drops. If all open the set can make 40 KV ! Quite a light show !
Will it produce some X-Ray as added bonus, too? 😅 I suppose even if it does, not for a long time before all blows up...
I grew up (late 70s - early 80s) with the same TV except mines was a cheaper version with 4 screw on legs. Brings back memories.
Looked quite a decent picture once you got it running, The commercials looked much like the same nonsense we get here in the UK!
BTW , you still have analogue Over The Air TV transmissions in that part of the States. In the UK they were closed down about 12 years ago, when they all went to digital terrestrial signals.
There might be one low power analog station in that area, but the clear pictures are from a converter box.
That is the 105 Freeway to Norwalk
Transformer is ferro-resonate with the oil cap
Also a form of Saturated core.
Good regulation.
WAAAAAuw... lol nice tv set and also the commercial and also the funny comments..love it :)
@ 49:00 I love your random product reviews! 😄
I remember these set's very well . I wish I had stock in a trippler Company !
My parents had that model but with a much nicer cabinet with a black leather-like top surrounded by real wood. I remember watching Saturday morning cartoons with a bowl of cereal in my lap. They had it from 1973 to 1995 and it worked fine, though it needed a tube brightener towards the end.
By the time I was going through school in the 90's this was legend. A bad capacitor in certain Zenith TV's would cause it to run away and saw the neck off the picture tube. Lacking details and eyewitness accounts I thought it was a tube set, guess not.
Time marching on. Bad firmware in multi-million dollar television transmitters would cause them to run away and destroy millions of dollars worth of LDMOS power amplifiers. Strangely a problem limited to 8VSB (ATSC2) not COFDM(ATSC3)
this Zenith model is simular to the one I grew up with but with one channel knob for both VHF/UHF. behind the door you preset the channels for your area and placed the channel number from a black plastic cutout sheet that came with the set.
CRT failures due to the white safety caps started in late 1974. There's a 10Ω/10W wirewound behind the tripler, change that at the same time as the caps.
New Shango adventure. Let's go!
my goodness that is a great looking set. 😍
Pretty damn sure this was our set thru my boyhood. BugsBunny R-Runner show, ...etc
It still makes a nice color picture, even with a higher hour CRT. Also amazed that being a high hour set, those original safety caps are still ok!
If I am not mistaken, the orange 4-legged capacitors are the ones that fail frequently. The 2 separate caps are more reliable for HV control since the HV will not sky rocket when only one fails.
EDIT: Just verified it. The 4 legged ones were the type that caused a big recall in the 70s because they failed and caused HV runaway. I would replace the 2 separate ones with new ones and call it a day.
I think the orange 4-leggers are ok. There were white 4-leg "critical safety capacitors" Zenith used before the orange ones. Those would change in value or go open across the cap, instead of across the legs on each side like they were supposed to, causing the HV to go unregulated and blow everything up.
@@coyote_den Ok then I might be mistaken, I don´t remember mentioning anything about the color from what I read. Just that they were 4 legged.
That moped is AWESOME!
bro, you had a close brush with that motorcycle gang, glad you were unhurt
It's very clear that the reticulating interocitor became discombobulated ... your welcome 😏
😇❤
Nice Zenith ! I remember those when I was in high school , Zenith was like at the top of their game then. I'd almost move my flat screen out for something like that. Televisions were furniture back then and now just a plastic rectangle we hang on a wall or block a window on a stand. A little crepe erase for the crappy picture and your in biz.
That would be great double EOL video, that magnetron pointed to something you disike powered by 60kV Zenith-TV provided power supply. It would need to be recorded by Slo-mo guys, though ;)
Very interesting. I enjoyed the road trip. And the news. Shame the picture isn't up to snuff. But very entertaining.
$5 a gallon for petrol, that is today €1.23 per liter. We pay here in the Netherlands ~ € 2.07 a liter.
That power transformer circuit is referred to as a ferroresonant design, it is a resonant as 60Hz circuit, it purposely drives the magnetic core into saturation, ensuring a constant output over a large range of input voltages. They used to be fairly common in computer systems before switchmode supplies took over (as in pre-IBM PC), however this is the first time I've seen one used in a TV
$5.00 a gallon gas in Calif.? I wish we had that here. Would help get everyone off of big gas guzzling trucks and SUVs. Here gas is $3.59. Too cheap. Lots of really big vehicles still on the road here.
Biden Nomics
@@danielknepper6884 Best kind of nomics! Bernienomics would be even better though...
Here in Texas the cheapest in my area is $2.25 and the most expensive is 2.89
Strange if Zenith have never released a service bulletin on the issue.
Thanks for the video.
That kind of transformer is called a "ferroresonant" transformer. Pretty neat design.
Use love those chassis plug in boards plug in IC chips plug in transistors. yup loved those TVs made to last
Looked very serviceable.
Instering Seeing Life Old Sets - A history's thats alive-
I use to put in a couple of triplers a week. Quick money . SK 3306 .
Great video shango!! First solid state TV I've seen you do. I was wondering why the picture doesn't fill the screen completely at the top and bottom. I suspect it's the converter box that changes digital to analog. Is that it?
Ferro-resonant. Also some industrial battery chargers for electric forklifts have that kind of transformer.
Wifey and I bought that set new right after we were married. Great set but the Rauland CRT didn't last as long as it should have. Other than than that it needed a replacement focus rectifier and periodic cleaning of the pins on the plug in circuit boards. Thanks.
Those had that chromacolor luminance switch, that circuit would over contrast the picture, but, those were fun to work on.....is the H.V. a tripler or doubler..?
You find all these gems..👍
Keep doing the pickup vids mate i love em, wheres chris though?
Our family got the bare bones model of this set in August of '72, just in time to watch the olymics. I remember it cost my dad $750.
To test unhook the oil cap & run on variac, starting @85V. 4 lead cap is NOT a sub !!!! It has built in
interlocks that open to kill HV. The HOT C & E paths go through the cap.
CONTROL. IS EVERYTHING. TO ME.
“Homeless Encampment smell”. “This looks entirely too replacementy.” LOL!! 😂 😂😂😂😂!! Merry Christmas 🎁🎄 and Happy and safe 😊 New Year!! Your friend, Jeff.
Did you go back and adjust the screen pots to improve the picture?
EDIT: LOL! Literally as soon as i posted that comment, I got to the part where he put it into service mode. Thanks again for another great video, Shango!
Thanks!
Shango: I guess I'm wondering why you wouldn't expect the capacitor on the power-transformer to get warm, when it is directly connected across 300V of AC.
If you calculate the capacitive-reactance for a 3.5uF capacitor at 60Hz, you get 757.88-Ohms.
If you take 300V divided by 757.88-Ohms you get 395mA! Wow!
if you then calculate the power: 395mA times 300V, you get 118-Watts which is ridiculous!
So something is screwy with either the values or the actual voltage seen by this capacitor; if it's just a capacitor???
Does you chassis gurus have any insights regarding this capacitor strapped directly across the full windings of the power transformer?
What's not 118 watts, it-s 118 volt-amps. It's consuming 118 watts for one quarter-cycle but instead of converting it to heat the stored energy gets sent back into the grid the next quarter-cycle.
@4:40 - "Let's just ignore that..." Let's not. That is the kind of fascinating yarn that you can really put your mark on. I'd enjoy that story immensely. Even if you had a Wit and Wisdom separate channel, I'd be on that like white on rice.
Try around £1.50 per litre for petrol in the UK !!! Maybe the luma processing has crushing/DC level problems?
35:30 ATSC 3.0 is a new standard. However at the moment, there is no requirement or mandate for television stations to switch. It is just starting to roll out in larger metros with one TV station converting their entire signal to 3.0 and hosting the programming of the major stations. The host station’s channels has been divided up among the other area station signals so that they can continue to service in 1.0.
I guess no one is allowed to say Christmas Shopping but yet Hallmark has a million Hanukkah cards.
That oval capacitor I’m guessing is an AC cap. I wonder if that self voltage regulating system is similar to what those old SOLA voltage regulators used.
It's exactly the same as those SOLA transformers.
The computer at 3:50 is probably an IBM XT clone, maybe a Solare.
Very interesting. Sounds like the disc capacitor method is the way to go. Funny that they would go to a device that was so problematic.
Those safety caps are a problem,i had a similar set to this one that would trip the breaker when powered on.Took me a few days to find it but it ended up being the safety cap on the underside of the chassis.I replaced them all to be on the safe side.
Similar model of my parents bought in the fall of '73. Full solid state. UHF tuner was however detent.
It was totally reliable for 10 years. It had heavy use and the CRT was as good as new after 10 years.
Maybe he was and old kid?
Detented UHF tuners were mandated sometime in the early 1970s. I don't know what the FCC was thinking, the only thing that detented tuners did that continuous ones didn't was make a raspy noise when you turned the dial. Otherwise, it was the exact same thing. Varactor tuners soon came along and made those raspy tuners a thing of the past on all but the lowest end sets. In Winnipeg, we never had to deal with the raspy UHF dial. Our 1974 Electrohome table top TV had a continuous, two speed UHF tuner. We got our first UHF channel in 1998 (ch 35). By then our TVs had remote controlled, cable ready, digital direct access tuning with on screen channel display. And since we were on cable by 1972, we never used the UHF function.
Do you prefer working on tube sets or solid state, Or just unique issues you haven't encountered before?
amazing how reliable zenith TVs were shame they can never be made like that again
Shango, is there a better way to make contact with you than e-mail ? Several times I was in the LA-area and had some vintage radios (including Russian) to donate to you, but couldn't connect.
Great intro footage of the So Cal freeways
I thought I replied to you? I don't know I'm so busy right now it's all a blur next year will be better
@@shango066 Thanks, Just some neat radios you might be interested in (like you need more)... like I need more! There is never enough!
Will try again this coming spring. I thought maybe you were only making contact through online forums, etc, and maybe your e-mail was obsolete.
Let's keep enjoying your awesome videos sharing so much knowledge.
You make me feel old , I cut my teeth on these old zeniths .
@18:32 - "The only true wisdom consists in knowing that you know nothing." Ted "Theodore" Logan "Bill and Teds Excellent Adventure"
My husband is finding my Zenith very touchable, I do not object to that.
Merry Christmas to your Zenith.
I saw a web page were a guy repurposed a magnetron to do EME moonbounce for ham radio, pretty neat.
Oh, 50$ for IBM XT fitted with ISA cards with original FDD and HDD? Very good price!
Same set I grew up watching. 😮
Great video on a malaise era TV.