This little Panasonic TV uses tubes instead of transistors

hello everyone and welcome back to adrian's digital basement 2. on today's video well it's on my lap this is what we're going to be talking about a little panasonic television and isn't it a beauty with this green color on the side i'd almost call it olive green but it's more of a light green color very 70s looking and i love that about it on the front of the tv there's a smoked plexiglass cover over the crt makes the tv look a little bit more sleek and nice i think one of the issues with these smoked covers is that you have to turn up the brightness and the contrast higher on the set to get a similarly bright picture because of course it's covered with a tinted plaque plastic so that means that it might be driven harder over time which may mean that this thing is just totally worn out this was saved from e-waste and given to me recently by a viewer here in town and i have no idea of course if it works that viewer did not try to test it or anything like that so we're gonna do that today well as you can see a little closer up it is a little bit dirty we got a uhf tuner here and it's a variable knob meaning it doesn't have indentations for the various channels of course it does go up to 80 or 83 because that is uhf back in the old days here in the us vhf tuner on the bottom it's pretty normal it's got the cheese grater speaker grill very much like the current macintosh pro so maybe apple took some inspiration from this old panasonic tv as is typical with a lot of sets of this time the top knob is the volume and the power switch so you turn it all the way down and click it off to turn the set off contrast and brightness looking at the size of the set there are no headphone jacks or anything like that just a little bit of dirt and scuffs same thing on this side nothing much to report back of the set we have a bar antenna which is broken off a carry handle which works quite well unlike that last tv that i reviewed where when you picked it up due to the angle of the inside of the handle it felt like the tv was going to slip off your fingers not so with this one 300 ohm vhf antenna input and obviously this twin lead here is what comes from this bar antenna and then below we have a uhf i'm noticing a typical japanese fashion there's an arrow pointing to the screw here obviously telling me that i need to remove that screw when i disassemble this set which i'll do shortly this tv is ul listed see if i can get that not to reflect so badly no it's really hard to see does say tv and 828 b like baker here's the badge label panasonic a n-809 120 volt 60 hertz 110 watts that's an extreme amount of power for its tv set this big i think it looks like it's eight or nine inches or so made in japan of course as dave jones says all the best stuff is made in japan looks like a fcc type certification sticker here it's a little hard to read but that might be the serial number but maybe not hard to tell someone's wrapped up the power cord here which i will unwrap it's nice that these plastic things for the holding of the power cord haven't snapped off as they have on so many of these old sets just because the plastic gets so brittle relatively standard issue of fare back here the power cord says interlock over it there's a height control a vertical hold vertical linearity and a horizontal hold and a whole lot of dust inside of all these vents here it's just kind of coming out so that might indicate that this set has had a ton of use and the convection and the heat of the 110 watts this thing takes up or uses has sucked a lot of air through these bottom vents and gone out the top probably bringing all this dust in with it take a look at the plug here it looks like someone has yanked it out of whatever outlet this was plugged into you get this happening when you sort of pull it out by the cord and you get just one prong in there at an angle you yank it really hard you end up with a bent pin like that and this is not a polarized plug whatsoever so this is almost certainly a hot chassis i guess we'll find out if there's a transformer in here in a second um but it does have this little thing on the top of the plug here and that is for wire management so you can push the power cord into it well that would be how it's supposed to work but due to age this is just pretty stiff rubbery plastic here so it doesn't really work so well anymore but that's what that was originally for you wrapped it up on here and then you would clip this onto the wire just to hold it on all right well let's uh take this thing apart let's take a look inside and see how bad the dust really is got a couple screws up in the top and i do see the little arrows in there very nice panasonic it cracked a little bit when i started taking the screw out it's kind of indicate to me that maybe no one has been inside this tv before i think the general consensus whenever i have a panasonic tv on the channel is that they are very reliable generally not being problematic oh look there's a serial number on the bottom ft3453037 now i saw no date code anywhere on this thing although i have to say i did a little bit of searching around on the internet and it seems like the conclusion is 1973 for this tv so it is older than i am these screws on the bottom incidentally do not have the arrows so i'm not quite sure about that if these actually need to come off these look to be screwed into the chassis somehow though because these are metal screws they're not the self-tapping type okay a bit of gunk is coming out of the tv as i flipped it around there hmm all right i've learned from these old tvs that this power cord almost certainly is connecting to the bottom of the chassis so um when i pull this off it's going to be really stiff because the cord's going to be stuck into the two power prongs all right i've released it i ended up using a pc slot cover uh in one of the vent slots here just to hold the pcb while i tried to pull the back cover off because definitely this power cord was really stuck to the two pins the power input pins on it so now this thing is free all right and there it is well so definitely one of the reasons why this thing uses 110 watts should be evident at this point this television runs on vacuum tubes so i'm not so sure about the 1973 date when this thing is back youtubes now personally i have never actually worked on anything that uses vacuum tubes i don't know the first thing about it other than watching youtube channels about them i do know things like dim bulb tester are good things to have when you're powering these things on because short circuits are a possibility especially with old caps and things like that that could result in destruction of various things inside the set the dust in here is definitely a real thing here now like just look at this now i know there are people like shango 66 and others that say clean out sets like this is not a good idea before you work on them but that's not really my style and i don't even know what i'm doing here so i'm probably going to take this outside and at least just hit it with some compressed air i'm not going to shoot the compressed air right close up to things i just want to get a lot of the bulk of this stuff off although there's a bit of a smoker smell to this thing cigarette smoke so i guess it's been smoked around i think there was definitely a time in the u.s in the 70s where sets were sold with both vacuum tubes and transistors at the same time this might be one such set now it's so dusty in here it's really hard for me to see if there are transistors in here but i'm definitely seeing a lot of tubes let's see if i can count the number of tubes we have one two and over here there's uh three four five and six the fifth and sixth are up here on the tuner and then we have seven eight 9 and 10 with this big one right here in this kind of like cage of sorts must have something to do with like the horizontal output going to the flyback which is right here flipping the set onto its side here you can see that of course it does have a pcb so this would be unlike the earlier tube stuff which has point-to-point wiring inside and there's all the caps and whatnot underneath here and i think the general consensus is that vacuum tubes and pcbs don't really mix and match very well because of the heat cycle you have going on from the hot vacuum tubes and the solder joints they frequently crack and break which cause of course issues as we well know about does say right here chassis number n95 for the nine inch and n95a for the 12 inch so i guess there's two different variants of this particular set using the same pcb and the tube in here is a panasonic tube i don't think you can read the number it's blocked by these components here 230 ae b4 and then after at the end here says tyc i'm looking at the pcb looking for any kind of diodes or transistors and i really am not seeing anything and here's the diagram showing the adjustments and the tubes and whatnot you can see right here that this is the mains input connection it's definitely a hot chassis because one side of it goes to ground on the actual chassis and of course it's a non-polarized plug so you could easily plug the live into the hot chassis ground so no no for working on this set without an isolation transformer unless you risk getting a shock that big tube here says horizontal output and damper which is kind of what i thought it is then this tube horizontal oscillator and agc this tube vertical oscillator and output looks like this too over here is for audio output and then this is for video amplification and if stuff so intermediate frequency and then up here the tuner has a couple tubes on it as well and looky looky this is actually a hybrid set there are some diodes here dio2002 sound detector 201 sound detect and win 101 is video detector so there's a little bit of a sound circuit right here and i think this is the other diode right here and that would be the video detector right there noticing up here there's a couple spider balls so this thing has been in the dust all right i'm gonna take this outside and try to blow this out a little bit all right dusting off is complete and it's definitely a lot cleaner inside it's still not perfect of course because um you know there's a ton of dust so looking around here it is all the original vacuum bulbs or tubes matsushita so i don't know it's certainly high hour there's a lot of evidence that this thing has been run a lot inside of the case has a lot of black soot on it from the high voltage so it's well used this set but anyhow this cap here is an electrolytic i wrote the three values it's it is it's 250 210 microfarad the the writing is on the side it's really hard to see there most of the other caps on here are not electrolytics there is one other electrolytic right here it's just a little purple capacitor see it right there by my index finger i gave the underside a little inspection just looking for any broken solder joints and actually i don't see any so i think at this point i guess i'm ready to try this thing out now i have the isolation transformer here on the bench this was sent to my viewer several videos ago so thank you very much for that i i do use this thing when necessary and i actually do intend to mount this thing on the wall here but under the desk and then have a permanent outlet up here that is uh through this thing with a power switch to turn the whole thing off and on now i had mentioned dim bulb tester before and i have never actually used a dim bulb tester but i'm going to try to do that here this little bit of a mess is one such thing so mains power comes in through here kilowatt so we can see the current draw so the whole idea from my understanding of the dim bulb tester is with vacuum tube stuff you want to hook up a light bulb in the series with the set itself and that's because from my understanding unlike silicon transistors you can run this set at a lower voltage than it expects so it wants 120 volts that's what it's designed to do but you can power it up at say 60 volts and it generally may work not everything might work there might be no high voltage or horizontal sweep but you can kind of get the thing starting to work just to see if anything is going to short circuit and cause a fire or whatever in the set now when you hook up the light bulb the thing that's interesting about it is that if there's a short circuit in the set the light bulb will just be full intensity say you put a 60 watt light bulb in there and then the set is only going to be absorbing that 60 watts of power as opposed to the full short circuit now there is a fuse on here somewhere so that would probably blow if there was a short circuit but think of the light bulb as a really high power current limiting resistor which is what it is which just helps protect things now what this was originally is it had a switch on the end of this cord an on off switch and then you plug this into mains plug a light or whatever into here and then you could turn it off and on so essentially the power comes in here goes through this cord all the way down the end comes back goes on this outlet and then the other one is connected straight through so it's a way to interrupt it now what i've done is i have cut this switch off put this little joining block a couple clip leads so i can clip it on to the set here and then obviously whatever i plug into here is going to be in series with the entire thing so i have this which is just a regular light bulb socket thing so this will allow me to screw a light bulb into here and it has an on off switch as well which actually shuts the power off to the whole thing and that should work i think the people are probably yelling at their screens i should replace caps or test the tubes first or a whole litany of other things i don't have any equipment to do that so i really i'm in uncharted territories here remember that this tv was saved from e-waste before it got to me this was literally about to be destroyed forever so at least now this set has a possibility of living and maybe it works so enough babbling let's test this out i'm going to start with this phillips 40 watt light bulb here actually what i'm going to do first i'm going to clip these together so we can see what this looks like under full short circuit condition just testing that it should work as advertised all right so the isolation transformer is on boy this is not readable is it all right well anyways if i turn on the power switch here on this cord there we go we have 39 watts so that is working with these clip leads disconnected when i turn on the power switch now we have nothing of course because the circuit is broken this thing is all in series here i'm going to make sure the set is off on the top here turn this on interesting the set is off and yet the set is consuming 19 watts of power right now even though it's off so does that mean this thing has like um a quick start feature where it kind of warms up all of the tubes even when the thing is off so it turns on quickly i think things in the 70s a lot of them had that so one thing that's interesting is it's now at 18 watts so it's gone down by one and the bulb as you can see it's just on dimly here so yeah that pretty much confirms that this has some kind of standby feature which from my understanding it bakes all the tubes because it runs their filaments at a low current like there's a resistor in in series here with all the filaments it makes everything warm up quicker but it means that it wears out the tubes a lot faster or so i've heard from watching other videos and it's now 16 watts so it's definitely creeping down the bulb is getting a bit dimmer here so it's kind of amazing to think that this is the standby current of this set like it's off and you think that it's actually off and it's drawing this much power and to be honest that's with this light bulb if i plug this set directly into the mains it's going to draw a lot more power than this 16 watts all right well let me try turning on the tv and let's just see what happens here i don't expect it to work not with a 40 watt light bulb in here but yeah who knows here we go so it's drawing 31 watts now the light bulb got brighter obviously see if there's any sound no sound now people talk about electrolytics and reforming them and that would be for like this electrolytic capacitor right here apparently uh when they haven't been used a long time they can kind of be more of a short like they have a lot of leakage and as you apply power to them they will sort of reform or start to work properly and you'll see on a kilowatt here you'd have a higher power draw and it would drop down as everything kind of reforms now personally i've never experienced that happening i've certainly seen people's videos where that seems to be the case but obviously on this set it's just sitting here at 31 watts and nothing has really changed i've gone ahead and i shut off all the lights here i'm going to turn the set back on and i'm going to cover the bulb i just want to see if any of the tubes are warming up i don't see any filaments warming up at all i'm going to power off the switch here so that means that the tv is no longer live with any power at all and i'm going to pull out one of these tubes here i want to see if the filaments on this set are in series and removing one of them means that when i turn this thing back on when i turn the power back onto it the light bulb i don't think should light up at all so let's see and look it didn't nothing at all so that does mean that the filaments in all the tubes are actually working and the filaments inside of these things are little heaters basically that heat up the inside of the tube so that it can function properly let's see if i get this back in here properly all right since i don't know what's off and what's on i'm just going to take this light bulb out entirely there we go that's back in its socket so i'll screw the light bulb back in again okay i did have it off if i turn the switch back on oh okay i just reinserted that in there let's put this light bulb back in i put it back in and there was nothing happening which oh there we go okay it's it's the socket not very reliable all right we're back to where we were again well i think what i'm going to do is swap this out for a higher wattage bulb i think this one here is a 60 watt don't have a big selection of incandescent bulbs anymore let's turn this on so we're getting 23 right now on this standby mode and let's turn this on all right 42 watts now and now with the set turned on i am seeing actual filament glow out of the tube so they are starting to glow which means potentially this thing will make some sound nothing no sound but a dim bulb like this means that i don't think things are quite warmed up enough for anything to start working tubes don't work without the filament heating them up they won't really conduct so i have a light bulb splitter here i'm going to use this to go up in wattage so this is a 60 watt and i'm going to screw this uh y splitter in here and i have this flood light in here i'm not quite sure the wattage of this does say it is 920 lumens though so that is more than a typical 60 watt bulb so we'll screw this in all right and if we turn this on yeah about 21 watts and the set is off right now so let's put the 60 watt bulb in here as well so i think we should be getting the equivalent of 120 watts 32 okay it's all pretty dim right now in fact this light bulb's not even on all right let's turn on the set 54 watts definitely have filament glow out of these tubes here and i feel heat coming off of them as well sound no sound definitely not no high voltage either okay i've upgraded the light bulb to this which is that three-way bulb i think it's running 100 watts right now plus the flood light and the set is running at 76 watts so we're ramping it up it's almost at full power i think it's 110 watts on the back of the label and filament glow is happening on the crt as well definitely no no life to the tv though oh yes there is sound everyone it's not loud but i hear sound so that means it's starting to come to life this is so cool so so cool and 77 watts is not really changing and no smoke and nothing bad is happening it's just sitting here trying to work maybe i'll let it sit like this for a little while just to make sure nothing goes wrong with it and then i think it's time to bypass this this whole arrangement here and just run this thing right off mains power all right the multimeter here is set to ac let's just see what voltage set is currently running at 90 volts 89 volts so of course because we have a big resistor here there's a voltage drop happening so yeah the tv is running at 90 volts obviously not quite enough but almost enough for it to start working don't really hear too much else coming from the set but of course there is warmth coming off these tubes because they are of course running we're still at the same 77 watts so definitely this thing's not going up or down in power draw which is a good thing right incidentally you can buy these three-way light bulbs at dollar tree here in the us still for one dollar with light bulbs you're putting in a lower wattage bulb like this 40 watt bulb this is the equivalent of a higher value resistor and a bigger resistor of course creates a better voltage drop for the set and also would protect it and current limit it if something were to short out when you put in these higher wattage bulbs or two of them in parallel like i'm doing here it's equivalent of a lower value resistor which gives the set the ability to draw more current and more power and have less voltage drop across the light bulbs i've been sitting here for a little while here and it's still drying exactly 77 watts so i think it's time just to run this thing right off the mains see what happens all right isolation transformers unplug from the wall and i have a power cord here mains one cut one of these couplers on here and i made sure to hook the neutral wire up to the left side pin on the tv because according to the diagram under the hood there it showed that the left side one was the chassis ground now that it really matters because that isolation transformer it's that's providing the safety of this is now at mains voltage but it's not referenced to the rest of the house which creates an additional layer of safety if i somehow were to touch things i'm going to turn this around so we can take a look at it when i turn it on just making sure everything is all good on the back and it is i'll plug the kilowatt back in so we can keep an eye on the power draw let's plug this back in here 34 watts that is what this thing draws when it's turned off on standby oh boy all right here we go 112 watts 116 121. all righty and it'll get as soon as the high voltage came up dropped down to 95. look at that everyone we have an image how cool is this but while it's rolling in the camera things look pretty good on here i'm gonna turn this off again look at that no spot either that is cool down to 31 watts on here now theoretically because it's keeping the tubes warm here if i turn this thing back on it should come up pretty quick relatively quickly boy it goes up to 130 watts when it comes up there all right well at this point it seems to be working the pots aren't even that scratchy which is a bit surprising i need to hook up the test pattern generator to this thing so we can see if we can get an image on it i'll just unplug it from this here we have the handy dandy sencor universal video generator the vg91 and i know several people have asked me to do a video specifically on this piece of equipment which i will do at some point in the future but the the gist of it is it's a test signal generator generates test patterns and it can generate them and output rf channels any of the channels that are supported by ntsc tvs here so 2 through 83 and all the cable tv channels as well so it outputs a video composite signal if you need i think actually s video as well or the rf and the rf with the tv like this is essential because it's a hot chassis set so you can't just hook composite up this easily enough but i can hook up rf pretty easily enough to this thing which we're gonna do right now now for the hookup it's really ugly because this thing has a bnc output on the front and this coax cable has f connectors on it so i have an rca to f connector adapter there and on the front of the vg91 there's a bnc to rca and out of this cable is a 75 ohm cable which goes into a balan a lot of people corrected my pronunciation i was calling it a bailin but it's a balanced unbalanced uh converter it's got a little transformer inside there that goes from 75 ohms to 300 ohms and just for ultra jankiness i have this which i just recently found in a box and it's a clip that clips onto the screw leads on the back of this you don't even have to screw it on and that is really crappy and it doesn't offer a good signal but twinley 300 ohm it doesn't offer a good signal anyways especially when you have computers and led lights and everything else that's like full of interference so this is just easier so i just clipped it onto the screw terminals on the back of the set i'm going to set this thing to channel three and let's plug in the tv which will turn it on this is also the true warm-up time of the set when it's not pre-warming up its tubes which of course means it takes longer to wake up but it also prolongs the life of the tubes i would think look at that much much much longer wake up time there comes this is currently on channel three and indeed we're getting pretty much nothing let's just turn up the output power okay wait a second oh no wait a second look we got a signal look at that look at this everyone pretty cool it's very egg-shaped see if the fine-tuning control works it works look at this i can't believe this whole set is functional and you know what it's not even that bad it's pretty bright all things considered color me shocked color me shocked let's see about other channels here so channel four four looks even better five is not great i think the tuner is just a bit dirty there we go that's not so bad but four was the really clear channel look at that look at this i can't even believe it it looks great it looks absolutely great well it'd be nice if i had the camera set to the right frame rate it's at 160 of a second now so at least that bar is just sitting there let me see if i can adjust this a little bit more no there we go that's about as good as it can get there the image is very soft very very very soft like there are vertical lines here and i just basically don't see anything once you pass about here but it's rf which is already weak and then of course this is just an old set let's see if i peak it with the fine tuning a little bit let's send some audio to the tv well audio is definitely working so those diodes in there for the audio detector are good and obviously the video detector diodes are good too it seems like the audio and the video carrier are not quite right because the audio is much louder over here than it is where the image doesn't have any static in it let's go up to the high part of the vhf band channel 13. definitely some sensitivity issues up on the higher part of the vhf band but not really an issue because four was working really well let's try uhf so i said it's a channel 14 on the vg91 turn this knob here to get down to 14. oh um i'm clipped onto the vhf input on the back let me just move that all right there we go cool the uhf definitely functions as well so specifically on uhf there's no fine tuning which is this ring right here on the vhf because you just turn this knob and it's the equivalent of the fine-tuning so it really seems like channel 4 is the best channel so far for this thing let's uh i don't know go to channel 40. let's go up to 40 here there it is and it's looking pretty good as well there's audio working really well wow yeah performance is really good up here so i have the brightness all the way down right now and we turn up a little bit the image appears immediately so this set is actually really good the crt is strong it is amazing i am just surprised and it's sitting here by the way at 91 watts so why don't we see about trying to fix this linearity issue if there was a linearity control on the back of the set so let me try adjusting that all right so this is obviously a size control here all right this control here is supposed to be linearity um oh yeah okay that is oh it lost the sink it's okay let me turn these other pots here okay now it's way egg shape on the wrong side let's fiddle with that again it's nice that these controls are exposed hey that's actually looking quite good now look at this the whole image is shifted down a little bit and to move this we have to adjust the centering rings which are on the um which are on the neck of the crt on the deflection yoke that'll allow us to move the picture up and then this should be a horizontal frequency control or horizontal hold it seems like when i adjust it actually rolls over a little bit but this does adjust some centering here all right so i'm going to try adjusting the centering rings those are just one the other centering ring is sort of behind a bunch of wires here all right with the quick adjustment that's that's definitely better the whole thing is is turned a little bit it could um have the yoke adjusted so it's rotated but at least it's more centered and this is less egg-like it's not perfect but you know you can fill these controls forever it's an old tv it's not going to look perfect right who knows how this set looked when it was new so you know maybe it was never perfect or maybe people have fiddled with those controls over time right who knows as is typical with these types of sets it's got really bad dc restoration meaning like the black of this particular test pattern is kind of a grayish color here and if i turn down the brightness um so that it's not showing up as as gray it's actually worse than the camera that is to my eyes that looks about fine when i switch over to color bars or this ramp here all of this is missing and if i turn up the brightness you see now we can see this if we switch back to here look how washed out that looks and that is because the cathode drive circuit on sets like this a lot of these cheap black and white tvs is just so simplistic that the overall picture brightness is affected by the contents of the picture it doesn't need to be designed that way you could design it a little bit better and computer monitors monochrome computer monitors did a better job with that so that the overall picture brightness is consistent no matter what's displayed on the screen but these cheap tvs just the way they were you can't really fix this without redesigning that whole circuit so i think that's it there's not really much more to say about this set it is absolutely amazing that it's such a survivor all original tubes tons of hours of use and yet it still works good bright picture i mean what else is there to say other than that's simply amazing my first foray into testing out a tube based set instead of regular transistors and look at that it just works this really is one well-made little set fully functional i didn't even have to use deoxide on it and it just works if you have a set like this i think they come in orange and other colors make sure you unplug it when you're not using it because of course you don't want that like 35 40 watts going into those tube filaments all the time unnecessarily especially if it's something you hardly ever use i'd imagine this thing got a lot of use and then was taken out of service unplugged and didn't just sit there on a shelf baking for 30 years because it probably would have killed those tubes if that was the case the way it is here this thing just fully functions and i love it i absolutely love it i'm going to put this back together give it a little clean put it on display somewhere because it's so freaking cool anyhow that's it for my second channel video on this awesome little panasonic nine inch tv if you liked it i'd appreciate a thumbs up if you didn't know what to do all the usual youtube stuff subscribe and comments below huge thanks to my patrons their names are scrolling up the side of the screen well i've actually lazily switched it from this side to this side so maybe their names are scrolling up over here anyways thanks to all those patrons for all the support i really appreciate it if you want to become a patron you can do so there's a link in the description below and of course check out my main channel if you haven't already and hit that subscribe button for my second channel if you haven't as well it really helps me out all right that's going to be it stay healthy stay safe and i'll see you next time bye bye

Channel: Adrian's Digital Basement ][

Views: 96,290

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Id: XmKua8zW-V4

Length: 35min 57sec (2157 seconds)

Published: Wed Nov 24 2021