 there YouTube. Right I'm gonna show you what's inside these Avermeters. As you can see that one there has a metal, metal enclosure around this type of casing, this plastic type of casing. That's because this one is from the RAF or at least it was made not so much for domestic. I'm not quite sure exactly whether it's like a NATO thing or I've just cut back some leads that I had and cut some of the shroud off to give me leads for this one. These leads came with this and this came after this. So I'd already made up a set of leads and then I was going to have two and I just used some. They're not too bad actually. These are say cat 3,000 volts. Let me just check underneath the light. I'm just getting used to using this phone and I'm starting to really really like it. It's the Samsung S7 and look now I'm gonna tap because look it's all out of focus. I'm just gonna tap on that on the image on the screen. That's the first camera I've had I've noticed does it. I'm not gonna say maybe the first phone I've had that it does it on because I've just never noticed it before. I didn't need to start on here by accident. Now these are gonna come in handy. I'll show you another video. I'm gonna just shift these out the way. I'm gonna bring these down and just take the screws out and then we'll have a little look in the back. I'm just gonna leave the screw in so hopefully you can see inside there that's not looked up at all. There's a little tiny bit of stain there but there's no corrosion. Just smells of, oh I've got to smell a leather then really. That's the battery compartment. That's where the 15 volt cell goes and that's where the D cell would go. Positive, positive. Too inter-negative. There's a spare battery, spare fuse there and a fuse that's in use. I think it could be resistances. Even there look underneath each of these screws. There's a little mark and that represents the bigger space so you know that it goes on like this. I've not put batteries in this one. I've got a D cell in the other one and the only reason it's there is just for the novelty of using the resistance on the low end and it's pretty good. It's pretty good. I do like it. I like it a lot. So that's the battery on there. I'm gonna just put these screws out. I'll speed it up. This is where the calibration stick will be. At least on this one. It's a bit dinked in there now because I paled it back so I couldn't do the screw when I first went into it but I can see what it says on that. Hopefully the camera can pick it up. I can't do that. I'll zoom the focus thing. Force pushing down on the screw to undo it because there isn't any thread. That's such a trick to come out of. I hope that you can just catch part of the case and just gently, gently, gently, gently help it comes. That's not going back in. I'll put it in the back side. Okay. Now, it's just inside the back here. That's what the batteries would have been. That's like an oily grease type thing in the bottom. Now I wonder if that's there too because the moisture goes on there. I don't know. I don't know why that would be there. I see the way these connections, they're quite tough then. It's a spring. That's probably why it's put quite a bit of force to push the front out when you do these two screws. Then you've got the camera here to show you. It's big old resistors. It's surprisingly clean. But then I suppose not really. Look, there's a seal. It goes around the outside and it's going to lean it forward first. It'll sit on its own. It does. It'll sit on its own. Okay, I just moved the light round. Look inside of this. It is really clean. It doesn't look like there's been any moisture in there at all. See if I can just zoom in a little bit. There are diodes down there. What that is. What's going on in there? Could these be resistors? Which are tailor-made resistors? Because that's what this thing's all about, isn't it? There's no microprocessor. There's not even a plastic circuit board. Look, no PCBs. It's got this plastic, this bake light maybe. That's what it is. There's no damage on this. I don't have to worry about breathing in any of the potential problems that come from bake light. I'm not going to be boiling it either or smashing it up. Let's see what I should get. It's going to be dust problems. It's really, really clean. I'm really impressed about how clean it is. It's got some sort of grease or something on here. I'm not going to let it fall. You know, in its day, this is like one of the best meters. Oh, my lamp's decided it's going to play. I'll wait and I'll mention one of the best meters you could buy in the sort of for-far, the video. Modern multimeters. How clean the joints are. There's no moisture in there. Very nice. I want to cross the movement. These magnet each side. I'm going to assume that's the bit that gives this needle on this scale its accuracy. Well, there's someone to deal with this. This is the zero in bobbin all that there. I've been reading the manual. There's a couple of manuals out there for these. One of them's a service manual. Not that I intend on getting in here and particularly doing anything. But that's the zero in the needle, the zero. Amazing. Absolutely amazing. All of it's so clean. I suppose you'd expect that for a posh, because this would have been a posh one. Voltage measuring and resistance measuring instrument. It's just a modern electronics. Just all resistors. I'll assume. I've seen some other people taking these apart and having a look inside. But I'm hoping just give you a little bit clearer. I can't, you know, I can't tell you all the things I know. That's a transformer and there's a whole bunch of resistors. I'm not sure why that's in a spiral the way it is, but I'm sure they're supposed to be. That resistor looks pretty funky there on the back of that, doesn't it? Those look pretty nice. And of course this one's got its mirror or the lower part of this particular scale. And after all that moving it about is that on zero pretty much. I just got that needle behind, the reflection of it behind the needle. Pretty much still there. Because that's one of the things that's a complaint about analog meters, isn't it? Some people say that you've got to keep zeroing them. But you know, for the, I don't know what the word would be, but for the retro enough of playing around with one of these, I think it's worth it. I think it's worth getting old school a little bit. And just having these two sat up there for the price that I got on both four, it was pretty dumb cheap. And it's got the case. I've got leads, A1 pair of leads, any A1 case. The case came with this one. And the leads came with this one. And they're both the same price. But it's great. I took the mirror off before when I first went in the back of them. And I cleaned it up just to make sure it was nice and dust and everything free. And as you can see, it's very easy to see the needle, the reflection of the needle. So you can read accurately. And this is like 20 minutes already. There will be some sped up stuff. I'm sure you don't want to have an hour long video. But I'm going to do a few measurements with it. But first of all, we're going to just take that one apart. So I'm going to speed up again and get that one apart and look inside and compare the two. Okay, well, this one's much heavier. That's metal as well. But this is much heavier. And this one is built in weightlifting gymnasium as well. It's got a diesel battery there. I don't have another battery for here. I might do the five of the three volt cells, you know, the round lithiums and the nut. And you can get it in there for the measurements there for the higher resistances. I have tested it all. I just hooked up to different power supplies, 15 volts and a 1.5 volt for one stage. And everything works on both of them. This is like heavier because it's completely encased in metal. So let's whip that off. Okay, let's lift this puppy out. I should have probably put that to set the point before I started moving it up too much. Inside of here again, really clean. A little bit of grease coming in now. Big old resistors, wire wound, very big mechanically. You know, it's not just like a little tiny, not like a little tiny bit of metal there. That's a big chunk of metal. It's still a bit of dust, a bit of dust, but embedded in the sort of greasy part. I suppose that'd be a good thing if dust did get in it, went on the grease, at least it would stay there. And hopefully won't get into the movement. Same setup as before. A bit of nice sponge in there. This one's absolutely clean as a whistle inside. Even more so than the other one. Show you look. But I think they could be replacement sponges. Good possibilities. Look how clean that is. Really clean. Of course with this you get this, I'll zoom in. You get this, so you can earth it. And clamp an earth to it. Brilliant stuff, eh? There we go. Hold on. Okay, well this is inside the, this is what they call, it's an over weight, but it's called test set number one. Let me show you. Zoom in a bit. Test set number one. High sensitivity. That's the full name for this one. There we've got some, there's a couple of straight away differences on this one. One, this thing here. Two, these, I've got cases around them. These pots. And this is a plastic coated, some sort of casing on the transformer as well. And even though that looks grubby, it's dry. It is dry and I think it's just some sort of maybe grease or something over them. But it's like a dry, dry sort of grease. I don't really want to try now. Because it looks like it's like dirty oily, doesn't it? But look, it doesn't come off. Try to actually get something to come off and look. It's obviously nothing on my finger. Apart from paste and stuff that I've been putting around with chips. But that's not like a, I think that must be part of the protective coating for it. Because these, these from what I've read would go to different, you know, harsher environments, dampness places, the jungle, being in the military. And so they were coated. They're just more protection on them, you know. And apparently they're a bit more accurate than the other ones. So that's a good thing. That's a bit different underneath than the other one. I wonder if you can see the switches. And you've also got this, see the button button here. So it's all this mechanics, this bit here. I think that, not that, but this, because there's a button here and it pops out if you overload it. So an overload trip device. It's on both of them. In actual fact, I mean, they has got some protection built in. I can't give you all off the top of my head at the minute, but there is a few elements of protection. I'm going to go on the limit and say that these are like the custom made resistance. Because there's no way to adjust these. So everything was made custom. Even down to the sets themselves, if they had to have slightly different, you know, like if there was another one of these, but it was just slightly out. And they were just one of the resistance. So from what I understand, I'm going to be talking absolutely dribble. This is just because I've been sat reading about them and have a drink at the same time. Sometimes, you know, one thing can mix into another, maybe not as good as trying to repeat it all back. Some interesting, as I can say about the switches. Now I'm going to try and turn these in my hand. Try to get it to stay still. Right, see if you can get it so we can see. So you see that moving down and then you can see down the bottom there. Look as it goes from one position to another. I want to get a better view of that. If I can get a better view, because I've got to hold this camera at the same time. Let's see what we can see from here. You can see that moving down. So that must push those plates together. And what's that going from? That's going from the 3 volt range onto resistance. Then you get to see it push all that away. As it goes onto the resistance, completely different mode. But they are definitely built to last that way. Nice and precise. I mean, they clunk right into place. Beautiful. Absolutely beautiful. So there we go. Look at that. Moving in this one. Not really that much different. Slightly different setup. What's inside that yellow thing? I don't need to do that. What's inside here? I don't know why that's there as well. Let me just put the other one next to it. So I'm going to do another few minutes and we'll call it a video done. Okay, so that's the underneath of them both. Now there are some clear differences there, aren't there? But again, let me see the mechanical trip. I'm not really sure how you set it off. They've both got them there. And they seem to go throughout the AVO multimeters. I can see even the AVO 9 multimeters. So of these mechanical trips. So obviously they must work. They must work. There are some differences in the setup here. And this test set them all was based on a Mark 1 or Mark 2 AVO 8. And of course, this is the Mark 3 AVO 8. Here. And so this one hasn't been prepped for different climates, like the RAF one has, where it's more sort of greased up. You can see it's got this enclosure around the transformer. This one hasn't. It's just paper. It's nice though. Put this on. So I'm just going to sit on its terminals. We like doing balance on acts like this, but you get to a little look at the difference between those inside like that. Now there's a lot of these type of encapsulated whatever they are in there. I'm not sure, but of course they're not here. They've just got all these resistors now. They're adjustable resistors. There's a lot of the rest of the layout I've seen so you're pretty much the same. Look more at why is there happening here. Even though they're both 10 amps, those parts look either the side for the calibration, zeroing on there. They've got big old enclosures. Again, of course this thing here. There isn't one in there. And on this one here is where you've got a diode. This is the over eight mark three. On this one you don't have, but then there could be a diode in here. Oh sorry, in here tucked away. I don't know. It's surprising to see an orange and a blue wire. Do anybody else notice that in these? It seems to be grays and blacks. Oh, there's a bit blue down there. And of course I said orange and that's purple. No idea why I said orange. Maybe I was looking at the yellow. Why would I say orange still? Let's not get into it. I've got no idea. So there you go. And of course there's a difference between that one's got the lower mirror on the front of it and this one's higher, the reflector. So that's why that's like that. I think 50 quid they cost. And I think for the money and for the history, for the nostalgia and just to have them there looking beautiful on the bench, I think that was a great buy. And I'm going to be doing lots of measurements for these. I don't have to put batteries in them to get them to work. That's another good thing. And I got one there as well, look, because I wanted an analog meter. I got one of them first, you know, a year or so ago. But that doesn't feel, look, and just isn't one of these. These are benchmark multimeters for their time. And, you know, they're pretty cock on now with my Breimer. That's not bad at all. I hope you like the little look inside of their history here. Old time, old school instruments. I absolutely love them. Absolutely love them. And I don't mind having to recalibrate quite a lot. Even though you don't have to actually do it, once you've done it for the different resistances anyway, you've got three different parts for them. That's pretty much it. It is okay. And you get, you know, even with them set up there upright, you get good, good readings, pretty dumb bang on. And they're actually engineered to be used face upwards for their absolute maximum accuracy. The old prongs look to connect to those fluffy bits of the lacquer there. It's lovely the way they're built. Absolutely lovely. Nowhere, I was whipping them through on a printed circuit board in the, you know, flow, flow soldered. This is all done by hand. Catch you in the next one, guys. I think it would be terrible of me if I didn't just throw this on at the end of this video on the everywhere. Well, maybe not. Maybe I should just do a, I don't know, I can't call it a tear down, because I'm not going to take anything apart from taking the case off. But it'd just be interesting to have a look at the inside of this, wouldn't it? Let me just take the case off for two minutes at the end of this AVO video. You know, as you can see on the back here, it's got a battery compartment. 1.5 volt, 1 volt battery is doing. It's not a great deal to, but it's functional. There's a, this bail is movable. Fuse compartment, probably not the greatest fuse. And then it's just in case you're trying to split it open. Now, I wouldn't have done the screws, at least it felt like they wouldn't have closed more. And then it's open. Oh, okay. And there we go. Enclosed. Nice. Let's see if we can just cut this. Okay. Well, I hope I can put it back together again. Doesn't look much to it, does it? And they say this thing can do 10 amps, 250 volts. Oh, sorry, 2,500 volts. It's got a, I wouldn't want to stick anything through that. I put it on my mains before. I don't think I'll be doing that again. That's a big difference, isn't it? To what's inside the AVO. At least this one is quite easy just to take apart and then put that together again. Even though, yeah, the AVO wasn't particularly difficult to do with the screws. Brilliant. So there you go. Very quick look at the inside of this. Just as a Monday comparison of something which is nowhere like the AVO. I'll add that onto the end. See you guys watching, guys.