6:25 sometimes the heater shorts with itself, what i mean is that the heater is made of a wire twisted and its insulation sometimes fails making it short in the middle of itself etc... that makes the heater pull a lot more current and be a lot brighter because it has less resistance beacuse of the short.....it also boosts the crt emissions because at 6.3v you will be pulling like 600ma or 800ma instead of 300 for example thus making the temparture be higher and increasing emissions... the tv will work fine like this but the heater may fail open or may develop a H-K short due to overheating... by the look of that bright orange glow i would say it is the case so I suggest you measure the current tha the heater is pulling at 6.3v and compare it with the tube datasheet. remeber that the tv may work fine like this but you might consider running it on a transformer with reduced voltage so it doesnt glow that bright
I’m familiar with heater-cathode shorts but have never - at least not that I’m aware of- encountered a partially shorted heater. But your suggestion is a good one. I’m out of town at this moment but when I get back I’ll run the heater at 6.3v and watch the current. Hopefully, 0.6A ±10% as it should be. I’ll let you know what I find. If it is partially shorted then I suppose I could partially shunt it with a resistor to reduce the current through it though that would reduce the brightness too. A CRT issue like this would be a real bummer considering all the work done so far (see part 2, part 3, part 4 and part 5). If I had known it was going to be such a time & money pit I would probably have taken a pass on this set.
@@Mr.BrownsBasement its very common overehere (Europe)... i always encounter that fault on the aw 43-80 or aw 53-80 picture tubes (european) so i guess american/canadian tubes are built similarly. They usually work just fine if you power them with a separate transformer with a voltage of your choice while eyeballing the brightness of the glow. a 5v powerbrick should do the trick...of course the emission will be affected, its a matter of playing with the voltage until you get a satisfactory result.....i would choose a transformer and not a SMPS, because SMPS may introduce interference on the tv, it could leak to the cathode and mess up the picture.. resistor would also work but beware, if that tv is a series string set and the heater is shorted to itself , the tube will not glow at all during operation of the set because of the high current draw, in that case you MUST use a transformer or youll grow white hairs trying to play with resistors... if the set has a transformer for the filaments then its easy, because it always gets 6.3v regardless of the current draw, thats why they glow so bright when theyre shorted... (sorry for my poor English).. in this hobby money is not very important i think, its about the satisfaction we get when we complete a step so dont give up on the tv, it looks really cool, would love to have it on my collection and BW crts are very easy to adapt, i have a british tv with a broken 70º crt with magnetic focus, unobtainable and i retrofitted a 90º tube with electrostatic focus, you cant even tell...mechanical part was easy and wiring was easy too. But i wouldnt worry, i have some tvs with that problem and they work fine, of course i only plug them once in a while to watch a movie and thats it, theyre mostly display pieces
I just put the CRT on the bench power supply set to 6.3 V. After settling, the filament is pulling 0.51A. That’s a little bit low (15%) but not indicative of a partially shorted filament. At least I ducked that bullet!
I'm no glutton for punishment. Personally I avoid vintage TV's of any sort. Their repair usually involves lots of time and many parts to be replaced. With a good pix tube it would be a repairable candidate but not as a daily watching TV.
I don’t even know how many vintage televisions I own at this point. I’m going to venture a guess close to 20. I don’t recall the last time I watched more than 15 consecutive minutes of a program on any of them! However, I really enjoy the challenge of getting my hands into tube TVs and (hopefully) the thrill of success. Maybe this TV (#21?) will give me a reason to watch a whole 30-minute program with its huge 17”, expansive, panoramic screen.
Mr. Brown: thank you very much!
My pleasure. 😊
6:25 sometimes the heater shorts with itself, what i mean is that the heater is made of a wire twisted and its insulation sometimes fails making it short in the middle of itself etc... that makes the heater pull a lot more current and be a lot brighter because it has less resistance beacuse of the short.....it also boosts the crt emissions because at 6.3v you will be pulling like 600ma or 800ma instead of 300 for example thus making the temparture be higher and increasing emissions... the tv will work fine like this but the heater may fail open or may develop a H-K short due to overheating... by the look of that bright orange glow i would say it is the case so I suggest you measure the current tha the heater is pulling at 6.3v and compare it with the tube datasheet. remeber that the tv may work fine like this but you might consider running it on a transformer with reduced voltage so it doesnt glow that bright
I’m familiar with heater-cathode shorts but have never - at least not that I’m aware of- encountered a partially shorted heater. But your suggestion is a good one. I’m out of town at this moment but when I get back I’ll run the heater at 6.3v and watch the current. Hopefully, 0.6A ±10% as it should be. I’ll let you know what I find. If it is partially shorted then I suppose I could partially shunt it with a resistor to reduce the current through it though that would reduce the brightness too. A CRT issue like this would be a real bummer considering all the work done so far (see part 2, part 3, part 4 and part 5). If I had known it was going to be such a time & money pit I would probably have taken a pass on this set.
@@Mr.BrownsBasement its very common overehere (Europe)... i always encounter that fault on the aw 43-80 or aw 53-80 picture tubes (european) so i guess american/canadian tubes are built similarly. They usually work just fine if you power them with a separate transformer with a voltage of your choice while eyeballing the brightness of the glow. a 5v powerbrick should do the trick...of course the emission will be affected, its a matter of playing with the voltage until you get a satisfactory result.....i would choose a transformer and not a SMPS, because SMPS may introduce interference on the tv, it could leak to the cathode and mess up the picture.. resistor would also work but beware, if that tv is a series string set and the heater is shorted to itself , the tube will not glow at all during operation of the set because of the high current draw, in that case you MUST use a transformer or youll grow white hairs trying to play with resistors... if the set has a transformer for the filaments then its easy, because it always gets 6.3v regardless of the current draw, thats why they glow so bright when theyre shorted... (sorry for my poor English).. in this hobby money is not very important i think, its about the satisfaction we get when we complete a step so dont give up on the tv, it looks really cool, would love to have it on my collection and BW crts are very easy to adapt, i have a british tv with a broken 70º crt with magnetic focus, unobtainable and i retrofitted a 90º tube with electrostatic focus, you cant even tell...mechanical part was easy and wiring was easy too. But i wouldnt worry, i have some tvs with that problem and they work fine, of course i only plug them once in a while to watch a movie and thats it, theyre mostly display pieces
I just put the CRT on the bench power supply set to 6.3 V. After settling, the filament is pulling 0.51A. That’s a little bit low (15%) but not indicative of a partially shorted filament. At least I ducked that bullet!
I'm no glutton for punishment. Personally I avoid vintage TV's of any sort. Their repair usually involves lots of time and
many parts to be replaced. With a good pix tube it would be a repairable candidate but not as a daily watching TV.
I don’t even know how many vintage televisions I own at this point. I’m going to venture a guess close to 20. I don’t recall the last time I watched more than 15 consecutive minutes of a program on any of them! However, I really enjoy the challenge of getting my hands into tube TVs and (hopefully) the thrill of success. Maybe this TV (#21?) will give me a reason to watch a whole 30-minute program with its huge 17”, expansive, panoramic screen.