Hi welcome to everyone's favorite segment Mailbag. Let's get to it. I've got a ton of stuff. I think there's about 30 odd packages just can't get through them.

I don't want to say stop sending them, but yeah, maybe for a little while. Anyway, this one comes from I am I, we w Feeler Whitfielder. I'm not quite sure and I think it's from Maine in the United States of America. All my viewers from Maine.

I've never been to Maine. Um, let's well, bubble wrapped, let's have a look. It's a little Matrix Auto Chromatic Tuner. two minute tear down.

So this is the Matrix Sr 4000 Auto Chromatic Tuner. I have no idea what one is. I'm not a musician, but yeah, you either in tune or you aren't and you can calibrate the thing. There's the microphone, which, uh, can determine like if you're in an orchestra or something.

if you're in or out of tune. I guess something like that. I'm sure the more musically inclined will leave it in the comments. And here we are.

Inside the puppy. Old school looks like single-sided layout. I doubt there's going to be anything on the top, so let's oh, there's our battery snap. Oh yeah, yeah.

Double-sided construction. Fancy. pantsy. Woo-hoo What do we have? Look at this Intel 80c 51 Classic.

We got a uh, date code on that 8901 1989. I thought it would be a bit earlier than that and um, yeah, there's not much at all. It's all just a processor controlled. It wouldn't have a analog to digital converter, so it's likely just doing.

um, that would probably be a microphone. Uh, preamp. So Gl 358. Is that an Lm? A? You know, a knockoff Lmr358? perhaps? If so, that's probably being used as the mic.

Uh, preamp there. and they're probably just like squaring that up and feeding it into the micro. And then the micro is just doing, uh, timing? That's basically all it's going to be doing. It's not going to be doing any sort of signal process or anything like that.

Um, classic? those? Um, I'm not sure I I can't remember what style of Leds. they're actually what they actually call them. But yeah. Your classic, um, bent leaded resistor formed leaded resistors here with a little kink in them.

Absolutely totally old-school from the Uh, 70s and 80s. But yeah, these are tapered bar graph Leds. They made them larger at the bottom and then taped them up. fairly common.

and uh, got a uh, oddball square one and the triangle ones in there as well. And that puppy is screaming along at 10 megahertz. Woohoo! and uh, not exactly sure how it works, but obviously you select your, um, your key or whatever it is on here and then you can determine whether or not you're in tune. So let's see if I'm in tune.

Shall we? still have no idea what I'm doing, but here we go and check out the array of transistors that they got here, all driving the Leds there. Hilarious. Didn't have enough grunt on the 805 one, so that's quite a crude little uh thing. I mean, it looks like they just got a transistor voltage regulator up here because it's just a 9 volt battery snap.

And yeah, it's probably what those transistors up there are doing it, making a crude 5 volt regulator. As I said, it's probably just like squaring up the microphone signal, doing some timing stuff, And you know it's got a few modes and calibration things and stuff like that. So yeah, you know, there's probably actually quite a bit of, uh, smarts inside that puppy. But yeah, totally old-school construction.

Thanks Tom. Next up, one from Romania. Just came in this morning. actually.

well, it was on top of the pile there. Yeah, sorry. I should probably open ones that have been sitting here for months shouldn't I? That's very bad. I won't say who it's from because it kind of might give away.

if you know the name. It might give away what's actually in here. So hi to all my Romanian viewers. we have ta-da the parrot clip.

Which is, um, I I've never actually used one. I've heard a lot about them. They're like a a new, well, not new. I think they've done it.

Probably maybe a decade old now. I've been hearing about them forever. and uh, they're parrot clips. They're um, designed to be like a modern, um, a dual sort of clip that's better.

hooky type thing. hence parrot. You know, parrots have hooked beaks or something, don't they? um and whoa. Look at a whole box full of them.

Let's check them out. So thank you very much Philip Pesco for sending in all these parrot clips. Take a look at the collection here and well, let's take a look at what parrot clips are. There's three different art types Pcx, Pcm, and Pcs and they're basically look, it looks like a parrot.

It's got a little hook on it and yeah, it's just another way to hook on to. um, in this case, like they can come in different, uh, sizes, down to one 1.5 millimeters there for uh, just small terminals and things like that. But I think they do show like ic, um, pins and stuff like that so we'll try that out. So I think we've got various sizes here so let's take a closer look at them.

They're just an alternative to your easy hook that you're used to or a crocodile or alligator clip. Check it out. Made in Romania? I know all my Romanian viewers. Awesome how much stuff is made in Romania these days.

Anyway, Look, you can get them in all different types of configurations. This is the smallest one, so we've got the tiny one millimeter tip here. They can come in different rated voltages, different cat ratings, and uh, current ratings as well and temperature ratings. and also, um, well, what's in connection to the leads solder? I guess it's either solder or crimped.

Is that like a thermal Emf? Uh thing? I'm not not entirely sure. but look, they come in all different uh configurations. This one's got like extendable banana jacks so you can actually, um, plug that in and they tap off. You can plug another banana plug in the end.

Then we've got standard right angle, uh, four millimeter shrouded ones for your banana plug. We've got ones with just the um, open, uh, clip like that so you can clip those around, uh, test posts and things like that. and uh, yeah, more multimeter type probes. It looks like these are just, uh, uh, free floating and like to adjust the connectors uh, themselves so that you can hook on your own wire.

So here's the clip itself. and they do feel rather plasticky and a bit cheapish. I must say, I'm not, uh, hugely impressed by the quality. They're certainly adequate, and look, if I put a bit of force on that, I can get that to actually, um, like not close properly like that depending on how I, uh, how I actually get my what angle I get that on.

So in terms of quality, I'm not hugely impressed by them. But I do like the concept how that, uh, closes and close that around wires. I think that is going to work really well and I can't see it. You know, breaking loose or anything like that.

It's um, it's a rather a good concept. It's all patented and all that. sort of, uh, jazz, but yeah, like just folded metal in there for the, uh, test clip. They they almost not homemade.

But they're They're not manufactured to a massively high standard. But I do like the concept. and this individual clip here actually has a banana socket in there. and you can just plug your banana plug in that fits quite well.

So yeah, I thought you could fit a bare wire into there. But no, not really. it doesn't. uh, do that.

It's designed for a four millimeter banana plug. And here's the difference between the biggest one, the W4 one here, and the W: One little one millimeter thing. It's tiny. The one millimeter one's actually square on the end.

It's not almost square. it's not, really. uh, sort of hooked like that one. But yeah, it's still gonna work.

A treat. I think. So if I get this breadboard, the wire here and just whack that in there like that, that's having a hard time getting out of that, even without a decent hook on there. So yeah, I think these even these tiny ones work really well.

I don't mind that at all. But if you compare the parrot clip to one of these tiny little easy hooks here, which sort of get in there and can grab the wire like that, I think yeah, the oh no. They're probably on par in terms of strength, I suspect, but that totally depends on the type of easy hook. Here we go, I've got another one.

This is just a cheap one that comes with logic probes. typically comes with logic probes and I I think these ones the easy hooks are ultimately got a much smaller area. so if you're going to grab Ic pins and things like that, there's just less metal to short out. There we go.

I think they're just physically smaller these easy hooks. So if I was doing Ic pins, I think I'd rather have the easy hook. But the problem with uh, easy hooks is that they don't come with like nice attachments that you can then uh, you know, go and plug into your multimeter. Whereas this comes with all sorts of, you know, we got the piggyback style banana plugs, We've got the shrouded ones here and uh, we've got these um uh, binding post, uh, clips and you know I yeah, I mean these are just a bigger, sort, of like more robust and if you have a look at these ones, check out the finger guards on these.

So if you're probing like you know decent voltage stuff, then you know you don't want to be around with like an alligator clip or or something like that. These are much safer. And they come with really nice silicone leads as well. Ah, these are just beautifully flexible, just like proper multimeter leads.

Awesome! And there we go for those playing along at home. 600 volt. So these that look to be um, oh, there you go, they've got uh yeah, they're suitably rated. No problems at all.

Underwriters Laboratory. So yeah, that's 10 amp cat, 3 600 volts. So yeah, I really like these. and I think these para clips are a good solution for you know, just get your fingers in there like that and just bam and it's got a decent hook on the end of it.

I think they're really like actually that one that's different to what we saw before. Look, that one's got more of a hook on it than this one. like the smaller one there, it's uh, it's not quite as hooked as much. Anyway, they do grip fairly well, quite innovative, and I'd rather use these than alligator clips any day of the week.

Very nice. Well, I'll tell you what, I really wouldn't want to use these to probe Ic pins. it just it just doesn't work. Completely wrong tool for the job.

Look, it can easily short out to the one next to it. whereas with your easy hook, look at that. No problems whatsoever. So yeah, I think it's a bit rich to show that like you know, through whole Ics on here.

Granted, it does not show you it actually hooking into an Ic uh pin on here. This is what they're for for hooking onto wires and other, you know, maybe through hole resistors and you know other large components things like that. But I do rather like these. These will be a nice addition to the lab here, and probably everyone should have a set, I suspect.

Just you know, just really, quite nice. Uh hook probes? You know, better than the big ass alligator clips. Anyway, for high voltage stuff and you know, any sort of reasonable size, that's for sure. And there is a lot of spring tension force on here.

I can't Obviously, this is not filo vision, but there is a lot of force actually holding these backs. I expect to get really good contact on wires and be fairly low resistance and fairly reliable contact. And of course you got metal on metal contact as well. And I think ultimately, what they are trying to, uh, show here with this Pcb is that this metal, this pointed metal tip on here can actually be used as a probe to get in there.

and probe pins? Well, yeah, okay, but then so can you use your multimeter probe. So thank you very much Filipescu for sending in all these parrot clips. These will, uh, come in handy no doubt. But yep, for big stuff, not for tiny little Pcb stuff.

Next up, one from Australia. How can I tell? Well, it's an Australia Post padded bag and it's got an Australia Post stamp on it. It's from Timothy B. Thank you very much Timothy.

He's from Roseville here in Sydney. not that far away. Although Sydney's a reasonably big place, you know what? Are there? Four million people in Sydney or something and it's about. You know it's it's a half radius.

Sydney's like a half uh, radius from the coast going all extends all the way to the base of the Blue Mountains. Pretty much so. Um, yeah, We've got lots of little bagged parts. We've got lots of individual capacitors, funnel capacitors in bags, and a genuine.

Is it genuine or is it dodgy Apple? Oh, it's not just a charger, it's got an ethernet uh port thingo and a Usb. and like an audio microphone thing. I'm giving you some capacitors I was going to use to replace the one hung low capacitors that were in the Tv he was trying to repair, but he drilled too large of a hole and I was trying to move there and therefore stuffed up the Pcb. Oops.

So thank you very much. I'm good to have. um, assorted capacitors and stuff go in. The um, go in the component trays over there.

Awesome. No more use for the caps. Yes, I've included an old Apple Airport Express. Aha see, I don't know my Apple products.

You may want to show in a Tear Down Tuesday episode. Maybe a two minute tear down here now because this requires a very messy dremel to get apart. I suspect. Um, then I think I will leave this for a Tear down Tuesday.

Thank you very much Timothy! And of course we got one from Deutschland! Hi to all my German viewers again. Um, this one comes from Roland Christophic. He's from Dusseldorf. Um, I've never been to Dusseldorf.

As I said, the only places I've been in Germany are um, Hamburg and Lubeck. So they're the only cities I've been to apart from a brief stopover in an airport somewhere that was about it. So let's see what. we have a note and oh, this is a vintage electronic device.

We love vintage stuff here. It's in several parts. or maybe it's several vintage electronic devices. Geez, that weighs a bit and uh, is this a, um, could be a t-shirt It could be a t-shirt Let's have a look.

I don't know what it says. What does it say? I can't read, I can't read the camera from here. Do salts. Nick Logan, I can't pronounce that.

I won't even try. Um, I hope it doesn't say something rude. Should I just immediately go wear it down to the shops or something? perhaps? Thank you very much. I don't know what it stands for, but um, I'm sure someone will inform me or it's on the note.

And there's Roland and his son. He's a tall fella with their um awesome looking bikes. Are those uh, beamers fantastic? Anyway, um he has sent in. let's have a look here.

There's a ton. Oh look at this Sony Video walkman. Wow. Vindy, This is absolutely hilarious.

A Video Eight Walkman. Oh, that's great. This is definitely not a two minute tear down. this is.

Oh look at that. look at that. That would have been the ducks guts back in the day, right? What? Um, vintage are we talking about here? And he says the Gv8. Although this is the Gv9 model, about 1980? Um, Nine Vintage or thereabouts.

Ah, Fantastic. And this is, um, interesting Because I was actually gonna do a video on this. I had planned it. It's just a matter of getting one.

Let's have a look. Oh, the Sony Dat Walkman. Fantastic. The Digital audio tape.

Um, system. is that still going officially supported? Or did it just? I think it just died in the ass. Um, no, it didn't. Sorry, no I lie.

I think that you know the Dat format was very popular for a while. the digital audio tapes and one of the original Sony Walkmans, the Tps L2. I don't know. I don't think that's like the original one because after I did that, um, Sony memory card video, I got all nostalgic about uh, uh.

old Sony products and I was going to try and get hold of like the original 1979 Sony Walkman for a vintage, uh, teardown. So I'm not quite sure of this date. Early 80s? probably? Yeah, about early 80s. Ah, I just checked.

and yes, this is the very first original 1979 Sony Walkman. The Tps L2 it is. I thought I recognized like the blue and the gray, but I thought it made. it might have been the second model.

Um, Roland says he bought this in the spring of 1980. So whether or not it was, well, they probably were sitting on the shelves for a year because these were the hot product back in the day and fantastic. I was looking for one of these on ebay. Awesome! Thank you very much Roland.

That's fantastic. I will definitely do a Sony Vintage Teardown. Could I include them all in the one video? Maybe three separate video? Geez. I can have a film them all in the same day and release them as three separate videos.

But thank you very much. I definitely wanted to do this video, so I will endeavor to do that. Oh, I'm super excited. Awesome! Thanks Roland! And by the way, the t-shirt says you shall not lie and well, I never lie, I just spin a bit of a yarn.

Well, Roland and Max have certainly sent in some classics here and these will make for a fantastic separate tear down. As I said, I was really trying to get one of these uh, puppies. and uh, at one stage I thought, yeah, it'd be interesting to do a dat tear down as well comparison. And we've got both of them plus the video one we'll take a quick look at.

Yes, the Tps L2. This is what started everything 1979 and it's for those who weren't around. In the 1980s, it was dominated by the Sony Walkman. This is what started the personal music revolution and it was like it was phenomenal.

It was just everyone had a Sony walkman and then other companies jumped on board and everything else. But Sony absolutely dominated this thing. And it all started with this Tps L2 weird model number for sort of it. See, at the time there is no walkman, um, branding on this thing.

It's just, uh, it's just Sony and we've got, uh, stop eject and it's stereo of course. Fantastic. And it's got a microphone I didn't know that. Um, it actually.

uh, did recording. Fast forward rewind and it's got dual headphones so that two people could listen at once. Fantastic. And now this full graphic equalizer.

Rubbish. No siree tone, high or low, thank you very much. And this hotline button supposedly let you talk between the two, um, the people, well in between yourself and the other person listening here. but then like you've got the mic here and you're like right next to them, like you hold it up and you can like we talk into it and you the person who's tethered to you by the um, headphone socket a meter away is gonna hear you.

What the I don't know for use on motorbikes or something else. I got serial number 61 954. that's pretty low. Um, I wonder if it is the original? Uh.

1979 wasn't released in the Us until 1980 though. But once it did, oh boy, it changed people's lives. The Sony Walkman and then in 1987, Sony went. well.

bugger this analog rubbish. We want to go to digital. So they released the Dat. The digital audio tape walkman that is a format physically uses a smaller uh cassette than the there we go smaller cassette tape than you than your regular um audio analog cassette.

And of course it recorded digitally. It was like helically uh, scanned head and all that sort of jazz. And if we open her up there, we go look at that. Aha fantastic.

That's it all. Looking to see the head down in there? Fantastic. Can't wait to do a tear down of this puppy. And there we go.

Digital audio tape could sample terribly advanced for the day. It could, uh, sample 16-bit 48 kilohertz? Um, so you know, as good as or better than Uh Cd basically. And this was, well, pretty revolutionary. and the music industry was so uptight that people could actually copy things digitally and and record and rip things in super high quality that they tried to have this, uh, sucker band I believe in the uh, late 80s, but I don't think I'm not sure if that was that successful or not.

Anyway, uh yeah. record, it's got. you know, some fairly sort of, you know, high-end features. We've got.

uh Record. level. You can got auto music or speech, uh, record level modes or you can set it manually and it can take line in or an external mic with a selectable sensitivity. So these were great for field recording and things like that.

And there were professional versions of these uh dat recorders, but you know, even this one would be fairly useful to uh, people like you know, reporters and things out in the field. and it's still work. A treat. This is actually the Tcdo7 model and battery compart.

I really like the flippy retained metal. Is that A? Is that a metal bar? No, it's not a metal bar, but it's a plastic retained that actually works really well. And the what I do actually like the battery battery carrier. Look at that.

Beautiful. Just slides right into those contacts down there. Very nice. Aha.

Check out this Maxwell tape would you look at this? Digital capacity? Massive. two gigabytes for a 90 minute tape. 2 gig? Unbelievable. But hey, back then that was absolutely absolutely phenomenal.

And it's loading, loading, loading. and the Lcd is not great. You tilt it like that, almost horizontal and it's just yeah. it's pretty darn ordinary.

I don't think there's anything. there wasn't anything on the well. the other tape didn't seem to work, it didn't seem to do anything, so I'm not sure like it's not, it's not playing, Maybe it doesn't detect the data. I don't know.

I've never used a dat. Very interesting shape there. How it just, uh, protrudes out and is rounded like that. I'm not sure if that was like a physical design.

uh thing. They tried to make it, uh, all square and then they went, oh no. We're gonna squeeze in the headphones connector here and well, let's just make it sort of a funky shape and make it look like oh, it's you know, designed to fit in your hand or something like that. And actually it's a really quite a good looking unit.

It's really quite heavy though. Once you put the batteries in there and it's like all metal case. it's yeah. hmm.

And I had completely forgotten about the Sony Video walkman. Look at this. plays video Eight, uh, cassette tapes. Fantastic.

Got a beautiful tilt screen. Look at this. Uhf and Vhf. haha.

You can watch the video from Uhf on this puppy. Well, only if they were broadcasting it. Analog Tv is dead. but oh wow, this thing is built like a brick.

Dunny, it really is. looking. Plugger a camera into the thing for uh, you know, a field field recording on this thing. Fantastic.

So you could, uh, use composite um input and uh, you could get composite output to drive an external monitor as well. but to hook a camera up to it? I wonder if anyone used this for any, uh, professional fill recording or anything like that, but modulation in? what does that do? anyway? Uhf, Vhf? Fantastic. And look at the ventilation grills on this thing. I mean, it just goes all the way around like that.

This puppy must have got really hot. Look at that metal grill on the back, you can see the uh, see some I think, no not shielded cans. It's just a plastic matrix in there. But yeah, there's probably like a big shield, bigger shielded can for the whole thing or something.

But yeah, uh, don't have the battery. Unfortunately, that would have plugged in here gave about 45 minutes to an hour's use. look. Serial number that's reasonably low 18 426.

I wonder how many of these things they actually sold, but geez, yeah. 1989 vintage look at that. The Sony Video walkman. can we power on? Oh, it helps if I turn my bloody power supply on.

doesn't it? okay? Here we go. No, no, not a sausage. Ah, I haven't got one of those stupid coated batteries, have they? I tell you what, I found a use for my parrot clips already. I don't think I was getting good contact on these, uh, terminals with my little crappy alligator clips.

So um, I've used my parrot clips here. Unfortunately, there's not a huge reach on there. I might just spin it around, but let's try it again. Oh yeah, I'm drawing my power supply showing showing Six Milliamps now and when it's turned off.

so hello, hello look. we got crap static battery down. Oh that's yeah, that's dropping the test leads. Yeah, oops.

and yeah, I was trying to use these little wimpy thin things. Now I put in some beefier cable in there and no problems whatsoever not getting as much drop along. The cable wasn't the parrot clip, it was the was the copper in there and this puppy just on idle draws about five watts. Ah, we're in Like Flynn.

Look at this. I'm just go. There is a tape in here. I have no idea what's on it.

I hope it's not someone's porno play. Let's see what we got. What is it? I can't It's oh no. There's something wrong with the screen that that all that stuff is on the screen.

Ah, bummer. What do we got? We got some dude with a rocking mustache and all right, he was operating something. Got no idea. Yeah, that screen is in bad shape.

I'm not sure what the hell's it almost looks like it's some sort of physical thing behind the screen. maybe? Oh god, we've got some sort of corporate presentation. Ah yeah, it's not something behind the screen because we can turn the screen off and on. here.

We can, uh, data screen on off. There we go. No, there's uh, no. there's there's something wrong with.

like the video decoder. or you know, something like that. I mean, all the digital, um overlay stuff looks just fine. We've got an Splp switch on the side long play mode really, uh, yet 1980s problems here with the Uh, Sp and Lp mode.

So there's some dude talking about something, but I can't hear anything. I assume it had a built-in speaker. Surely I got the volume up. Oh, we've got a nice sunset now.

Fantastic. And I can adjust the color as well as a tweaker on top to saturate the color there. Ha ha. Beautiful black and white color.

Thank you very much so. Thank you very much Roland and Max! This was fantastic. Exactly what I wanted. The Sony Walk, original, Sony Walkman, and two other Absolute classics.

These are going to make some great teardown videos coming up. I think I'll shoot one tomorrow. Next up, we've got one from Vietnam. Hi To all my Vietnamese viewers, this one is actually a third sucker.

The Savage comes from uh, Tech Box who? You've been watching the blog for a while. You know they've sent in a couple of things before, namely the Uh Listen device, the um, you know, Emi, um, common mode, uh sniffer box, and and sorry and the Um, and the Emc sniffer probes as well. They're sending something new hi, Dave, another open hardware um thing from Hein thank you very much Hine And oh, is it going to come out? Come on, come on. it's got a nice big heatsink on the top.

Anyway, Tech Box makes some nice stuff and this Is another open source hardware thing. Oh, I think you actually saw it. Did I give it away on the front door? I think I did. Oops, sorry for.

oh I don't want to pull it. if I pull it out by the heat sink, it feels a bit. I don't want to break the mounts on the heatsink. Ah, there we go.

It's a real tight fit. Ta-da look at that. It is a self-powered active load 2 volts to 70 volts. Beautiful.

Let's take a closer look at it and here it is. It's a self-powered active load I.e a dummy load and it's got both constant current and constant resistance mode as well. I'll tell you why it's important in a minute, but here we go. We've got where you plug your load into here.

It's got a current made up by the looks of it. you can actually measure your current going through if you want to, and it's got external voltage control as well. So if you want to like do a pulse load for example. Um, this will just do constant current or constant resistance.

But if you wanted to like feed in a pulse into here you could go boop and then load and then boom. So you could actually or step different loads or ramp up a load or whatever you want with the voltage control here. Very nice. Yes it is open source hardware and it's got a nice little um 10 turn pot here to precisely set that.

We'll measure that in a second see how precise it just is. But the interesting thing about this one, as opposed to all other or most other dummy loads out there, is it's self-powered And that's why it only works down to two volts. It's got to have from at least two volts in there to power the circuitry inside. Now, the reason this self-powered is important is because this model is completely analog.

There is no digital stuff in there at all, even to do the constant resistance mode. There is no digital switching circuitry in here at all. There's no processor, no nothing. The reason this is important is because when you're using a dummy load on a power supply, for example, to test the output of a power supply, and you're getting noise measurements on the output of your power supply.

really low level measurement stuff. you don't want your measurement devices, I.e your load. Here, you don't want your load actually contributing either, radiating out from through the wires, radiated emissions, any noise, and you certainly don't want to emit in any Rf stuff as well. Or even you know you don't want it, you don't want anything.

So there being a purely analog, non-digital non-processor no clock in there, or whatever active load. Fantastic for low noise power supply measurements. Here's a little manual that comes with it says it's not their original design. it's based on Joel Setton's design.

He's from France. Hey, Joel, if you're watching. I was publishing a 2005 Edn article. Precision Active Load operates as low as 2 volts, so it's based on that circuit.

But um, Hein and the people at Tech Box have just turned this into a nice little project. There's a schematic. I'm having a hard time reading the stuff on here. It's a very, incredibly small print.

It's A4 shrunk down to like a one-fifth of the size or something. Anyway, um, there's an instrumentation amp here. Here's our constant resistance mode selectable over here, or constant current mode over here. We've got various Uh output transistors.

They're a, uh, they're a darling. No, they're not exactly a dot. Well, they're like a darlington uh type configuration and um, various, uh, sense resistors down the bottom here. But yeah, there's not much to it.

It's all analog and specs. As I said, two volts minimum input. which is okay. You know, if you're testing a 1.2 volt power supply, Yeah, you're out of luck.

Unfortunately, only works down to 2 volts. but uh, yeah. Maximum dissipation now. 25 watts with just the passively cooled heatsink on top.

Although if you whack a fan on top, which wouldn't be hard at all, you can get up to 100 watts a continuous four different ranges zero to one amp with the ten turn pot, zero to ten amps, one ohm to ten items, and ten ohms to a hundred ohms of very usable ranges there. I like it. And the reference drift. Ah, half a bees dick.

All right, I've got it on a hundred milliamps. Uh, per turn here. So it's per turn of this 10 turn pot. it's down at zero and um, this is quite an accurate power supply the road or dp832 like 0.05 percent so we don't need anything better.

So let me turn this up to single turn here and we should get bam on 100 milliamps And we do. Fantastic. Super duper accurate. Awesome.

So let's go. uh, let's get close to full scale here. Well, let's go right up to an amp. Shall we? Here we go.

Oh, actually turn the bag, tweak it back? Oh look at that. It's bang on beautiful and stupid me. Tried to test the uh, constant resistance mode so I set it down to one volt so the math would be nice and easy. and of course duh it doesn't work at all because it's minimum voltage is 2 volts.

Now the thing with constant resistance mode here. it's actually backwards so like it might be 100 ohms per turn, but I've got it on zero. which you'd expect. Well, okay, it should be like zero ohms but it's not.

It's actually the lowest possible. So I turn it up so I'm increasing the resistance and the current is increasing. so there you go. it's just back to front.

just be aware of that. so it actually makes sense if you read it properly. It's a hundred ohms not per turn. but it's a hundred ohms divided by the number of turns.

So in this case, I've set it to exactly five. So it's a hundred ohms divided by five. So that's 20 ohms and I've got an output voltage of 10 volts. So 10 volts on 20 ohms? give me gives me my half an amp and it's going to be slightly out there because you're going to get some increased contact resistancy.

If I wiggle that around, it's going to change a bit. You're going to get some increased resistance, which is going to be a, you know, a small percentage of your value. And just be aware that during general use you have to actually put a shorting plug on here. You can't just leave this amper thing, um, open.

I realized that when I first plugged it in and it didn't work and I was scratching my head and yeah, there should be like a shorting switch on there or something like that. Now I don't mind the uh case design there, but it's a little bit how you do and this is like one of these. It's not even a genuine pack tech case. The tilting bail is a bit wonky and the front panel check it out doesn't quite fit properly.

So yeah, it's a bit how you're doing, but it's still it looks okay. Don't mind the concept of having the heatsink on top. That's pretty good. And here's a two minute tear down.

This is actually upside down because they've got the board mounted on the top. because the transistors are. You probably just see them under there. They're actually bolted to the bottom of the heatsink down there.

and well, are they actually screwed it? Yes, they are actually uh, screwed into there. And then they've drilled the holes in the plastic case on top, so that's rather neat. Anyway, there's our 10 turn pot. It's all nice and neat and tidy.

They've crimped those and put heat shrink over those and it's all fine and dandy. It's just a shame that that front panel is a little bit loose. But yeah, that's nice. So there you go.

That's the tech box. Self-powered active load. Really quite nice. I rather like it.

This will actually come in handy for the testing. The new micro supply. Shame. It only goes down to two volts.

But yeah, you can understand because it's self powered active load. The Op amps inside have to. You know, the active. The Op amps have to.

You know, work so you're not going to. You're going to have a hard time getting much lower than that. The only issue might be is I'm not sure about the protection on the input. If you get reverse polarity, they warn you on the back.

You know, don't hook it up reverse polarity. They do have a uh, there we go. a reverse biased diode in the Im imported in series with a 10 amp, um fuse there. So yeah, assuming that the diode can, um, handle that and yeah, you don't blow up anything else.

it's not too bad. Or if you plug it in backwards yet, just don't plug it in backwards because you can screw up the power supply under test two. That would really ruin your day. So yeah, but it's not like that.

they can you know, put like a series diode in here or something because then you're you know, blowing out an extra half a volt? 0.6 of a volt. So yeah, so I can understand the limitation there. But anyway, um, self-powered active vote? Very nice. 139 us dollars.

Quite a reasonable price, so I think well worth having if you're in the market for an active load. especially if you're testing low noise. Well, any power supply and you intend to test power supply noise and things like that you don't want your active load contributing to your noise because you can get conducted emissions out of here as well as radiated emissions from other products. So really, very nice.

I think pretty good value at 139 bucks. So links down below. Thank you very much Hein! And it's not a mailbag without one of these. Let's take a look.

This one comes from Ron Berry. Thank you very much Ron. He's from uh, Monterey in Uh oh, Is it yeah, California? Yes it is. I'm wondering if there's more than one Monterey in the Us.

I've been to Monterey Awesome. When I drove up from Um, right down from San Diego all the way up to uh, San Fran by way of uh, Silicon Valley and everything else. So let's have a look. It's going to be vintage.

It's going to be vintage Late 70s. Whoa. Let's it's that looks Russian that looks Russian to me. Rushing Calculator Awesome.

Late. That's got to be. It's a Mark 52 Rushing calculator. Ah, two minute tear down Beauty.

And here's the electronica. Mark 52. I'm sure that says electronica. It's got an A on the end.

Um, and this is a Soviet calculator. As in the Soviet Union. Before they, yeah, the Soviet Union dissolved. Awesome.

And um. Ron says that, uh, it's supposed to work. but I've put some oh oh. actually.

kind of. can you see it? Can you see it? Oh, barely. it's supposed to work something. Oh, there's a zero.

There's a zero. I can just see it. Yes, it it does kind of work. There we go.

Wow, look at that. It's maybe it takes time to warm up. Oh geez, that vacuum fluorescent display has really seen better days. Looks like it's a two for enzyme Two, Four Six eight, ten, 11 digits.

Is it with 2, 4, 6, 8 working digits? So it'll have our exponent as well. So probably a Two, digit exponent on there. And plus the negative sign. But yeah, it does work.

And yeah, there we go. There's the negative exponent down in there. Wow. that's really super duper dim.

This has quite possibly the worst calculator keypad I've ever used. These keys are just so wonky. Look at that oh man, dodgy brothers look. I can just force them to go in one direction.

Ah, that is terrible. That's terrible. Muriel, Look at that. Unbelievable wow.

And the feel is. And of course, being the fluent Russian speaker that I am, I know that that's the exponent key now. Ron says this was manufactured in the Soviet Union during the 80s and the early 90s. I was still going into the early 90s.

Oh my goodness with this sort of quality. But it's I guess typical. uh, typical Russian. Have we got a serial number on there for those playing along at home? There we go.

And for you fanboys out there, yes, it's Rpn. Reverse Polish notation. Fantastic. And Ron says, is.

far as he's aware, it's the only calculator. There's an internal E Squared prime memory, external rom modules connector under the upper right panel oh, is that it and which allowed them to play, change apps and play games and stuff. Yes, it is programmable. It's not just a scientific calculator, it's certainly not a four banger, that's for sure.

And Ron says that these these were used as a backup for onboard uh computers on the Soyuz spacecraft. Um, I don't know. I wouldn't rely on that keyboard. and it's all really flimsy.

It's not exactly. uh, go ahead and see the screen, go on. Oh goodness yeah. Well, you know, rough and ready.

Hmm. And I think we've got some genuine 1980s Soviet Uh. warranty void if removed gunk. Wow.

Check out inside this puppy. look at this resistor network. single inline package resistor network. Just bend them over.

She'll be right mate, No worries. and check out that wonderful uh flipped like? is that? no, that's like a Donden bonded, uh, die like chip on board kind of arrangement. Wow, it's got some gunk over it and uh, got some through-hole diets? Yeah, it does look like, you know, 1980s vintage. We've got ourselves a custom custom Asic there.

Oh, let's let's trim the frequency, shall we? I think that's what it's for. And uh, there's our um inverter for our vacuum fluorescent display. Oh fantastic. But there's another chip on board device under there, and another one there as well.

But yeah, wow. look at that old school. Got some flat flex going down there to the keyboard, no doubt. And there's the expansion rom connectors.

Uh, on there. the expansion packs under these dicky little uh clips here. I already sort of broke one off. Only two of them are work.

These two don't have anything. You can tell by the tell by the connectors there. This is an external uh Dc jack here and there's a close-up shot of our uh, chip on board. It's not actually chip on board.

It goes to like what looks like a flat. so it's chip on. uh, flat flex. It looks like it is flip chip so it could be like it wouldn't be Bga back in the 80s.

Um, so I don't know what or it. Well yeah, it doesn't look high enough to be die bonded. like it doesn't look like gunked high enough to be die bonded. Don't see any bond wires coming out of the thing.

but yeah, it's on a separate. I've seen this construction in another Uh calculator. It might have been a Soviet one actually. But yeah.

so they've put it onto this, uh, flat flex on the back. I you know I can't get under there. but yeah, it's like a printed flat flex. And then that is.

um, surface mount. You know acts as basically a surface mount chip to, uh, go onto the board there. It's not, uh, reflow soldered. Somebody's done that with a good old-fashioned soldering iron.

And for those who want to translate the keypad, there you go. Ron's very thoughtfully done that for us, so thank you very much Ron. That was certainly one very interesting 1980s bit of calculator kit. And just like awful construction.

like the board inside is okay, you know, no problems whatsoever. It's actually quite advanced there with its surface mount. uh, construction and stuff like that. but just the just the quality of the case.

It's got like a couple of clips here. It's only got two screws on the back here and they use this as the backup for the Soviet Soyuz um capsule computer. It's like I wouldn't trust this thing to survive at all. It's just it's just all flimsy and um, yeah, no thanks.

Next up, I got one from La Post Hi to all my French viewers, we don't get too many from France, do we? So uh, let's looks like it's got a pool tab thingy and I have no idea what it says because I think it's French. um in the description. So Ta-da let's have a look at this. La Posta.

Oh oh thank you very much. I'm gonna like this. I'm gonna like this. I haven't got one, I have not got one.

but I do now. Ta-da Back to the future. That's the um. Sun Star 1 180, 1 18 scale.

I was just looking at. Uh, awesome. Thank you very much. I was just looking at the Matchbox 118 one.

I um, yeah, because there's I think there's three companies that are making one. I invent Sunstar somebody else and there's a there's a matchbox one as well. So I was probably going to get the Matchbox one so I can do an awesome comparison with the Sun Star one. Oh well, it's just foam at the moment.

Looks like he's added the foam for my own protection. Thank you very much. Uh, Fred Frederick Dutrey? Um, he's from Saint Laurent in France. I'm going to be pronouncing that wrong.

It's got to have some feminine or masculine form or something. Sorry, I don't speak French. I did like two lessons and then gave up because I used to work for a French company and they offered, uh, free French lessons. And so I thought, yeah, it'd be cool to learn, uh, French.

So I went along to the classes thinking, oh, we'll learn how to say hello. You know, just general stuff first And no, let's jump straight into the masculine form and the feminine form and learning all the base structure. God, I'm sure that's important, but it's kind of like learning electronics by being taught. You know, fundamental physics First, Well, here's the electron.

Here's the atom, the electron and blood. And before it takes two years before you get to bloody, you know, flashing a lead. Unbelievable. So yeah, I didn't last too long.

wasn't too impressed by that awesome 1 18th. This is the original. Um, the original movie one. It's got the hover uh, conversion.

I think there's a lever on the bottom to move the wheels up. I was literally just what, uh, looking at the these last night. Well, the Matchbox one in particular. but I sort of wanted to like.

get the complete set. And yeah, this is the Sun Star one. Fantastic! It's got Mr. Fusion on the back and the Um and the hover conversion wheels.

The Matchbox one does not have the hover uh, conversion wheels, but um yeah. I was watching some youtube review uh last night and I think uh compared the Sunstar one had better um state brush, stainless, more accurate brushed stainless steel finish than the Matchbox one. And if this one also rode lower to the ground than the Matchbox one, it rode higher and um, but that is oh too generous. Thank you very much Fred, That's awesome.

Oh, it's gonna have to like sit on the desk along with my Lego back to the future. Brilliant. And there is apparently a, uh, what is it a one, not one one-fourth like one-sixth scale or something like some huge thing coming out. I don't think it's actually a release yet.

Forget the actual scale, but yeah, I think this is about the biggest. I think there's a 1 15 somebody might do, but this is a a 1 18 scale isn't it? But ah yeah. Terrific. Oh love it.

Oh and there's the money shot. Look at that. Yes, the goal wing doors don't stay up. kind of oh beautiful.

Oh wow look at that. It's a thing of beauty. Fantastic. A bit of a wonky how you doing out of time number plate there.

Wow. And Mr. Fusion doesn't tilt or come off but uh yeah it's not. I think the Matchbox one is, uh, superior in all its detail up the back here.

I'm going to get one and have a look. So yeah, I don't think it's as screen accurate as the Matchbox one, but still very very nice model time circuits on. there you go. You can see the time display.

You can see the big lever and the big rotating switch there for the to switch the time circuits on in. Where's the flux capacitor? It's in there somewhere. You can just see the flux capacitor in there. The bloody flippy door doesn't stay up.

Oh unbelievable. Can't say I'm a big fan of the uh seat belt here, which is sort of just all moulded into the seat there. I'd rather just not have any seat belt at all. That's a bit lame.

and yes, it converts to hover mode. I'm going to admit I do like the stainless steel, the brushed stainless steel look of the paneling on this thing. It works, uh, works really well for me. And yes, the bottom opens.

But no, there's no engine in there because it's in the back. So thank you very much Fred. That is way too awesome. And if you want to see a comparison of this and the Matchbox model, I will no doubt have that on my Ev blog 2 channel which is linked in down below.

That's how where I put all my sort of miscellaneous videos. They don't really belong on the main channel. they're not sort of important enough to put there. I've already got like 10 000 subscribers or something on my secondary channel, so hop on over there.

So that's it for mailbag for another week or two. No, probably I'll try and do one next week. So much stuff to clear out. Thank you everyone for sending in stuff.

It keeps the mailbag segment alive. Very awesome. Very generous of everyone because I know it does actually cost a lot of money to send. um, big and heavy stuff.

um even light stuff overseas so everyone really appreciates it. Certainly me. So I feel like Mailbag Monday. Ooh, thumb off screen, poor framing error there.

amateur video blogger? I am. Yeah, give it a big thumbs up. I think it's that way on Youtube. Catch you next time you.