EEVblog

[@Wtfinc]

Hey Ethan, I hope you find this. You can easily download your scopes service manual, they often include alignment and calibration procedures. Honestly just play with the pots in the high voltage side till it looks right. Should be no need to mess with the vertical amplifier where your probes attach, lots of trim pots, coils, and trim caps, often shielded. If the trim pots in the HV for the CRT display don't get the job done, you will need to check voltages. The wires going to the static deflection plates in the CRT run to the middle of the tube, 2 pair, check them. One more thing, it may be a bad capacitor, just check them for shorts or damage AFTER DISCHARGING THEM. The CRT can also hold a nasty charge. So maybe unplug scope, then turn it on whilst unplugged, and bleed off those giant filter caps. On my scope, I have a handfull of nice fat variable resistors (pots) that are brown and accommodate a phillips. 3 in the back and three on the horizontal side, main board. One of them did focus and one controlled voltage to the machine. Take note of the pots original orientation before you trim it, if when you turn it(powered on mind you) and it does nothing to the display, trim it back how you found it. For God sakes PAY ATTENTION to where your driver tips are, don't electrocute yourself. Oh and on mine there is a trim screw on the front under the display that says ASTIG that I adjusted the other day in order to dial in even better. IDK what ASTIG does. My dot in X, Y mode was a bit out, so ASTIG tightened it up, start there maybe. If you are unfarmiliar with High Voltage electronics and the risks I would avoid this, or steal moms dish washing gloves and a buddy with more experience. Good Luck

[@JesusisJesus]

TL;DR It might not hurt to recap it.

[@Wtfinc]

@@JesusisJesus No, your right, not at all. They should be all right tho. Its highly unlikely its the caps however, which is good news for Ethan.

[@smgvbest]

Looking at a 2213A Schematic, Focus mainly consist of Q885(SPS7950) and a internal trim pot R853(5M), All of course in the high voltage section. there are of course other components, passives mainly but those are two I would check for a quick look it is possible someone tried to adjust the trim pot and messed it up so the front panel adjustment just doesn't have to range to correct it.

[@smgvbest]

Speaking of Discharging things. I took a 40Kv hit fresh out of school that knocked me on my back for that very reason. I swear to this day I got everything but obviously I missed one. So please check, recheck and if your sure, check again.

[@Wtfinc]

@@smgvbest Hell Yeah! Hope you did not loose a foot! What holds a 40KV charge? That's a transmission line rating.

[@ericlawin7333]

The strain gauge in-line is probably used as a resistor in the Wheatstone bridge to “remove” temperature offset from the resistor used in the strain measurement.

[@pnjunction5689]

Yes, I'm pretty sure it is. We used to build pressure gauges in a similar way. Having the temperature compensation resistors flapping around in the breeze is certainly a good thing for mechanical decoupling.

[@malgailany]

Another possibility is they are for bridge completion. in many cases you may need one or two strain gauges and you add a matching bondable resistors to complete the bridge.

[@TrickyNekro]

Yes, yes indeed.... Normally they are perpendicular to measuring gauge but probably added it in "free standing" mode to easily decouple it mechanically.

[@bobweiss8682]

It's a zero adjust network. You adjust it for a null output by cutting various parts of the pattern away like rungs on a ladder. Used to compensate for slight residual stress or variance in the values of the 4 legs of the strain gage bridge. www.micro-measurements.com/press/micro-measurements%C2%AE-bondable-resistors-transducers-now-built-advanced-sensors-technology

[@VerstehenSieMathis]

Also, it's lb*in, not lb/in of course :-)

[@LerrySanders]

Mr. Carlson's Lab is the place to go for repairing anything. Dude makes fantastic videos.

[@Zardox-The-Heretic-Slayer]

definitely for things made 50 odd years ago!

[@padraicmcguire108]

Mr Carlson has an amazing grasp of electronics though I do not believe he is an electrical engineer. He seems equally comfortable working with vacuum tubes and modern digital electronics.

[@notaname8140]

@@Zardox-The-Heretic-Slayer 50 years ago is pretty modern for Mr Carlson's Lab lol

[@PriorUniform721]

Those kinds of torque wrenches are used quite extensively in automotive assembly. In 2002 one of my first jobs was as a grunt replacing terminals on Jeep assembly lines. They were used for data acquisition during final assembly. Sometimes barcode scanning, sometimes manual entry but often from torque wrenches. The Jeep Wrangler line had something like 300 terminals on it and the brand new Jeep Liberty line had 1400 or so. The automotive companies collect the data for QA tracking and for recall notices. In the case of the torque wrenches they collect torque measurements for things like seat and safety belt anchors and various drivetrain and engine components.

[@mrfrog8502]

16:00 SCART does everything. Conposite, S-Video and RGB both in and out.

[@stawmy]

The problem with SCART, apart from being too big & clunky, is that many cables are 'one way' they are not full duplex wired. Plug a SCART the wrong way round and you get no signal. And they are useless after 3 meters. When you buy a SCART cable, make sure it's a thick one, that means (usually) that they are fully wired and well screened! Grr.

[@retrocomputeruser]

Yes please Dave. A full review of that DM-950BT meter including accuracy results. I like to see these cheaper meters reviewed as not everyone can afford a Siglent or Fluke.

[@marcusamancio8302]

About the dso oscilloscope: In Brazil, the minimum wage is 160 US dollars and the unemployment ratio is very high. As a graduate electronic engineer that is the only option I can afford at home and it is actually good if you don't need 2 channels or more.

[@CliveChamberlain946]

Yes, I'd love to see a full review on that CEM meter (at $150 with BT, 40K counts, and all those input protection's it deserves it)

[@joopterwijn]

Dave, small remark,suggestion about multimeter beeping, it is probably for a small group of customers. I have tinnitus, in my case i hear a constant beeping sound. It would help me great if the multimeter beeping would be adjustable in volume and pitch/frequency. I own a couple flukes and others, but they all beep in the sound range I hear constantly. Being adjustable would be great for people like me (and others).

[@EEVblog]

Not sure that's possible. It does have a LED backlight alert though, no need for sound.

[@WCM1945]

My sympathies.

[@joopterwijn]

Dave, the sound is so easy...if you can hear it... i now already have to look at the display, so a led blink on the meter does not make Munch difference. I do not know how the tone is produced, if it is done by the 🧠 “brain” I thought a small adjustment (add) in the programming.

[@LittleRainGames]

@@joopterwijn most of the beeps from multimeters come from a piezo buzzer which only plays 1 tone. Apply a voltage get a tone, nothing else.

[@doug7131]

Some of Keysights multimeters have the ability to change the beep frequency in their menus.

[@bugzigus]

Just wanted to thank you one last time, I am from AIM Academy and those multimeters are really great to play music with! Thank you

[@mr_gerber]

That kink in the curve is very much like something i observed when i tried to run the SAR ADC on an STM32F3 at 3x the max clock frequency. I would notice it on my temperature sensor, when i tested in a thermal chamber, and went past values where the ADC readout was at one below nice round powers of 2 (many caps are switched in for the measurement, i guess). And it was worse with higher numbers - 1023 was coincidentally just about where I wanted to do some room temperature calibration, and it seemingly lost sensitivity around that point. Just when it reached 1023 in a thermal sweep in positive direction, the reading would flatten out, stay there for a while, and "catch up with itself" like is seen in the scope. Sweeping from below, when approaching those values, the measurement would suddenly speed up and stay at 1023 for a while, and then continue with the expected slope, with no hysteresis - again, just as is seen on the scope screenshots.

[@vgamesx1]

Thought I'd mention that DSO138, they also sell a better kit which only costs a few dollars more, the DSO150 it's basically the same scope with some minor improvements and a smaller footprint, but the big reason it's a better kit is that it comes with a case and it's also much nicer to control thanks to having an encoder to work with.

[@peterandersen4676]

Tektronix scope problem: high resistance resistors have increased there value in the focus circuit. Find them and ohm them with a multimeter.

[@ctrlaltdel02]

Those cheap dso scopes can come handy when working with audio gear, as signals dont go far beyond 16khz. Their not great, but just for a quick look on audio signal good enough.

[@JerryEricsson]

Couple of years back, I picked up one of those DSO kits. It came with all the SMD parts installed. It was fun to assemble, it came while we were on our Winter break down in Arizona, so I assembled it with what I had along in our Motor Home, sitting at the booth and soldering with my little USB powered soldering iron. It took great care to keep the tip at a decent temp as those irons are known for just dumping every amp it can get into the tip and overheating unless you allow her to cool a bit between joints. The unit works great really for what it is, I have had a lot of fun with it and learned quite a bit about circuits by testing out boards I buy and such. I did buy the clear lexan case for it to protect her when we are moving about with the rig, plus I found a little leather case that she fits very nicely in for storage. Earlier I built a tiny scope using an Arduino Nano and a Nokia screen. It works but not nearly a good as the one in your video.

[@bobford100]

Just a quick tip for the lad with the Tek 2213 scope issue.... First check the resistor chain in the focus circuitry. Theres a voltage divider consisting of a number of 1M ohm resistors (8 off from memory in a 2213), or 510k in a 2213A. Check the values with your ohm meter. Chances are some are out of spec......

[@stawmy]

At 37:20 Those little jumpers are a typical Siemens design that was taken up by several relay manufacturers, it enabled you to plug in a module next to the relay (across the coil) that contained a cap / filter or even just a LED to tell you it was on. Mostly used in late 90's industrial PLC stuff. I have tons of them ;)

[@dentakuweb]

Those little scopes are useful in modular synthesizers so you always have a way of checking what your audio output looks like. People have made them fit into Eurorack modules.

[@Daveyk021]

@EEVBLOG Hello Dave. Yes, I am interested in a fast DVM in the $150 range, although I would prefer a perfected 121GW, which I pretty much shelved for resistance trouble-shooting. I am interested in it from you because I know there will be updates and software updates. It is fun to be on the bleeding edge of what can be done. Realistically, I am interested in a Fluke 189B type meter, that is not discontinued. it's hard to justify $400+ for a handheld meter. For trouble-shooting a Fluke 17B may be better. If you have another one coming out, I may just wait. Speed to low ohms (not higher ohms) is more important to me. It's a cool trick the DM-950BT does. That trick should be added to the 121GW code, or if nothing else added as an option. i am enjoying your videos as usual; your accent is very pleasant to listen to. I've also learned some of your BritishAutralian slang.

[@HazeAnderson]

I ordered the DSO138 as a kit (pre-surface mounted) and spent several hours one Saturday soldering it together. The instructions were nice and clear but there are a LOT of parts and as a newbie ... it was daunting. In the end I got it right the first time but I am still feeling lucky that I made no mistakes. And I use it all the time as I do not have a proper oscilloscope. It's good for "go or no go testing" of audio signals and some lower frequency digital signals like MIDI. Only one channel however :(

[@markwright5731]

Customer private meters . There were either 50Hz longitudinal pulse or 12Khz tone. Back in the 90's when I was working telephone exchange maintenance. The Alcatel S12 didn't support the 50Hz metering and a local adaption was made. But, it wasn't used that much because there was extra cost involved. The standard line card supported 12Khz metering no extra hardware required or jumpering to special equipment.

[@Sanctustalio]

Interested in your new $150 DMM, would you consider potentially adding an LED to indicate continuity alongside the buzzer. This is a featured that seems to be commonly requested in my office but we've never found one that does this. When under a stage mid rehearsal there is 0% chance of hearing anything, I'd imagine others in live events might be interested in something similar. Cheers Neil

[@lezbriddon]

i 2nd that request, and a decent led that can be seen, we dont all work down caves...

[@DjResR]

Usually the buzzer in DMM has internal oscillator so it should be possible to hack a LED with resistor in parallel to the buzzer._

[@gartmorn]

I'm a bit hard of hearing and don't hear many of the buzzers on meters anyway!

[@EEVblog]

It does that with the display backlight, just like on the BM235

[@ak321]

@@EEVblog Why can't the 121GW do that with the backlight?

[@TrevorClarke]

I've got a JYE scope like that. I build modular music synthesizers and I use it for audio frequency test and tuning. Works great for that, I jumpered the buttons and switches out to a Eurorack panel.

[@VoidHalo]

I guess it's alright for audio frequencies. But I had triggering problems like Dave did on anything shorter than 100us. It led me down a lot of wrong paths in terms of troubleshooting. I'd spend days trying to troubleshoot a percieved problem in a circuit, only to realize it's the scope that was problematic. They're okay as a novelty, but after the problems I had, I wouldn't trust anything it tells me for anything past maybe 10khz. And even then, there's just no way to know for sure without a proper scope to check it against. I just saved up and got an entry level Hantek scope and I've never thought twice about it. You should consider doing the same, if it's possible. You'll be glad you did. Start looking around and get an idea of which scope suits your needs best for its price. Cheers.

[@whuzzzup]

If you are interested in this scope (kit) make sure to get the original JYE Tech. They invested the time to create this stuff, they should get the money. And they are not even more expensive than the rip-offs. And no this is not "open source" in the sense of "just happily copy our design and sell it".

[@englishrupe01]

And if you get them from Banggood they are guaranteed JYEtech approved and the soft/firmware can be updated. If they are fakes from Ebay or AliExpress they will be bricked! Be aware!

[@JerryEricsson]

I bought one of those about 3 years ago, I even sprung for the plexy case. While some of the buttons are a bit clunky, it does protect the unit, and I found an old leather PDA case that I had laying around that it fits in which makes it easy to transport, and keeps the dust and dirt off of it. I have used it probably ten or twelve times, but those times make it well worth the 30 bucks I have into it. I mounted a little 9 volt battery box on the side for ease of power and use a rechargeable battery which again makes it easier to use.

[@steverpcb]

Those torque wrenches are used on car production lines so that if one stage requires 6 bolts to be tightened to torque X then the system checks that all 6 have been done correctly.

[@Psi105]

i use some of those cheap scopes on a manual test jig to check the product output connections are pulsing correctly. Makes things super simple to plug in product and look at scope LCD to confirm output is switching. Works great

[@robbieaussievic]

...... I have one in my P.C. behind tinted glass displaying hard-drive activity. I think it looks cool. I also made a test jig for a coin validator, (displays output pulses).

[@SarahRWilson]

I have a mod for the DSO138, which will allow it to be used on some vacuum tube circuits.

[@Digital-Dan]

Hybrid in this instance refers to the mechanism for carrying baseband voice both ways on two wires. The outgoing voice is subtracted from the overall signal to remove the outgoing voice from the result. The subtraction is not complete in order to create sidetone, a certain amount of the local speaker's volume to control how loudly the user talks. The circuit also acts to prevent echoing the incoming signal back to the output.

[@ChuckyGang]

those DSO oscilloscopes I use it quite often. to see if sound is distorted when repairing Amiga machines. and I guess that is more or less all it can do :)

[@matutolaYT]

Looking forward for the full review of the multimeter

[@joaquins90]

I would pass on the U$150 DMM, but I already have both EEVmeters. About the strain gage in the whire, is for temperature compensation, it's common practice to use an unloaded one next to the loaded one to make the compensated bridge, at least when you only load half of them, in other cases you could load the 4 sides of the bridge in opposite direction and get higher gain from it, but not always mechanically practical. I thought a few times about getting one of those scopes, to use as an isolated one with some safety mods, or to mock around, sometimes it's all you need.

[@GonzaloCobos]

About the cheap DSO, I bought original one for about $20, with the SMD stuff already soldered, and through-hole components included in the kit. The oscilloscope itself, for the price is good enough for most of the DIY stuff, but I recommend to choose always the one with all components already mounted. It will save time and headaches.

[@robbieaussievic]

...... I have one in my P.C. behind tinted glass displaying hard-drive activity. I think it looks cool. I also made a test jig for a coin validator, (displays output pulses).

[@isdeekelis]

And changing opamp to genuine tl074/tl084 reduces distortion a lot!

[@amigochan]

Hi Ethan, thanks for the short demo on the DSO138 Oscilloscope Kit. I am new to this field. :)

[@rockettcrawford890]

I ordered one of these last year just for grins. I had the same problem with a nice sine wave showing what appeared to be cross over distortion that wasn't really there.

[@kevincozens6837]

Ethan, There is a forum post in the EEVblog from a few years ago that you can look at. Someone else had the same problem with the beam focus. See www.eevblog.com/forum/repair/tektronix-2213a-repair/. A user manual for the scope can be found at www.download-service-manuals.com/en/manual.php?file=Tektronix-2518.pdf and the service manual can supposedly be found at ebaman.com/index.php/remository/ELECTRONICS/Test-Equipment/Tektronix/Scopes/2XXX-Series/Tek-2213A-Oscilloscope-ebaman.pdf/

[@VoidHalo]

I used to use one of those JYETech scopes before I could save up enough to buy a real scope and the trigger on them is absolute garbage. It claims it's 10us/div which you CAN set it to, but it absolutely refuses to trigger on any events shorter than 100us. They're ok for measuring a PWM signal or getting a vague idea of what a waveform might look like, but I wouldn't even recommend these for beginners. The problems with the triggering caused me endless confusion, thinking it was me that was doing something wrong. Which as somebody new to electronics, just hurt my confidence in my abilities and led me in the wrong direction in terms of troubleshooting. I spent days trying to build a simple EEPROM programmer because I thought I was screwing up my write pulse generator because the scope wasn't showing anything when I probed it. It was only after a lot of troubleshooting and experimentation that I figured out it was the damn scope. For all the problems it caused, this thing isn't even worth the $25 or so it costs. If anyone's thinking of buying one of these, DON'T. Just save up for a real entry level scope. Cuz you're just gonna have to buy one sooner or later anyways.

[@reidkeevers]

That Telemeter Type 3 is a real beauty! Something I’d love to get my hands on. I have the Telecom Australia installation/service manual for it if you would like a copy.

[@mycosys]

What was the Special Service Network? Googling didnt enlighten me

[@Minimixer112]

The thing counts pulses send over the phone network called ‘ticks’. Similar to a car odometer, the top counter counts the total ticks while the bottom counter can be reset after your call. Way back when they were used for billing shared phones (as far as i know). You wrote down the amount of ticks (duration) you called for. I picked a similar unit at a local thriftshop! (Thought it looked interesting)

[@ewaldikemann4142]

At 38:13: That are no fuses, those are electrolytic capacitors rated 47µF @25V. Manufacturer was ROE (Roederstein)

[@MiniLuv-1984]

Perhaps a video on understanding multimeter specs?

[@booboyBL]

i have a genuine JYE Tech DSO138 scope that i bought way back, before I could afford a proper scope. TBH, I bought it mainly for the soldering practice. The SMD ICs were pre-soldered, but nothing else. I had some fun with it, and found some use for it, but 'it is what it is.' About the same time, I bought a JYE Tech FG085 DDS Function Generator kit, which I still use today. My soldering skill has increased considerably since those days, but unfortunately, my electronics skill level hasn't quite kept pace :-(

[@EdEditz]

That thing at 38:00 might be useful in a DIY synthesizer build project. As for the oscilloscope at 49:30 , I just received one too and it cost me € 17,99 including shipping (assembled but no case). They are useful for audio measurements but not much else. But if you don't have any scope at all , it is at least something. No match for my Rigol DS1104Z though ^___^

[@robbieaussievic]

...... I have one in my P.C. behind tinted glass displaying hard-drive activity. I think it looks cool. I also made a test jig for a coin validator, (displays output pulses).

[@EdEditz]

@@robbieaussievic Oh wauw, that's a really cool idea! I'm planning to build mine into my DIY synthesizer but I need to figure out how to get the switches on the same level as the display. But that's not too big a problem. :)

[@cavemaneca]

I've got one of those kit DSOs. As an electronics engineering student I can't really afford anything better. It works all right for basic stuff.

[@frankowalker4662]

I got one of those scope kits as a laugh, (it was so cheap I thought why not), I used it to trouble shoot my faulty ZX81. It was perfect for letting me know which data/address lines were dead. Happy Xmas to everyone.

[@tetraquark2402]

Great little computer. I built mine from a kit to save a little more money

[@benbaselet2026]

A cheapo logic probe helps too. Might be nice to build one as well.

[@Moragor]

I assembled the oscilloscope kit when I started with electronics as a hobby. It was quite a fun project, but it's really useless for doing oscilloscope stuff.

[@oetken007]

Sometimes the coils on the tube are lose. Repositioning and tightening does the trick in that case.

[@TERRAOperativeOriginal]

For the scope, check and replace the 510K resistors in the focus circuit if present. They are a known failure point on a bunch of the 22xx etc scopes. Also, check the output filter capacitors in the PSU while you have it open too, they tend to dry out and fail.

[@Seegalgalguntijak]

And what is that about EEVBlog multimeters not being available in the EU any more?

[@kennethnilsson6976]

The 121GW is still avaliable at Welectron according to their web. www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth

[@brazeiar9672]

Too much regulation in the EU single market.

[@Seegalgalguntijak]

@@brazeiar9672 Wow, that's stupid.

[@brazeiar9672]

@@Seegalgalguntijak EU creates a lot of regulatory barriers. But in many cases they are so onerous that it is easier to just avoid the market entirely.

[@Seegalgalguntijak]

@@brazeiar9672 That sucks.

[@russellhltn1396]

For a new meter, I want something that has capacitor ESR measurements. I don't need high accuracy, I need functions.

[@NullStaticVoid]

48:27 I got one of those JYE kits. It's kind of crap. Mine was missing parts, and honestly the PCB has some kind of problem with the plating or something that it doesn't solder easily. It's easily one of the most frustrating kits I've ever built.

[@onjofilms]

Got my TTP223N boards to test out. They are really sensitive. Even thick plastic or wood sets it off. A finger sets it off at about 4 mm. I will experiment with reducing the pad size, otherwise these sense pads need to be spaced pretty far apart.

[@flomojo2u]

Would love to see a full review of the meter!

[@johnpossum556]

9:00 I remember making my first touch switch out of a 2N3819 and putting it in my wall as the light switch. It was quite flakey, sometimes it'd go on or off when you just walked by it. That was a 99 cent transistor from RS back then, BTW.

[@VoidHalo]

Sounds like it needed a pull resistor. One of the first things I noticed about using MOSFETs compared to BJTs is they're really wonky if you leave the gate floating without a resistor to pull it down to ground when there's no signal applied (or pull it to VCC). Your story reminds me of darlington pairs. They have such huge gain (about 10,000 for a pair of 2N3904s) that they'll do pretty much the same thing. I've heard of people using them as "ghost detectors" because they pick up damn near any electrmagnetic interference. From what I've tested myself, it seems like it capactively couples to my body and picks up mains interference that my body is picking up. Unless my body happens to generate 60hz signals as well.

[@JasonSobell]

In telephone exchanges they used to use -50V for billing pulses, so that meter most likely listened on the line for the voltage reversal so you could have a home bill indicator, perhaps for businesses? They used -50V because everything else ran at +50V, and it was to prevent spurious connections incorrectly billing customers. I remember spending many unhappy hours testing banks of thousands of those meters in an exchange when I was an apprentice, then some guy would come along with a camera, photograph them all onto microfische, then girls in the main office would manually type all the numbers in using a keypad and reading each one from a microfische projector. Thank god for modern digital recording techniques...

[@petersage5157]

I recently got one of those kit scopes; mine didn't come with any documentation whatsoever. It came with one of those shanky Perspex cases, which really doesn't add much value. (2022 price is about 3x what it was when this video was released - frakking pandemic - but still better value than a typical scopemeter.) Would have been much better value if it came with its own 9V wall wart. Anyway, 200KHz analog bandwidth is perfectly adequate for a portable solution for looking at the waveform of a signal in line level audio gear which may have intentionally produced distortion, e.g. distortion pedals, and with a 100x probe should be just fine for tracing signals in a choob amp. Definitely in my wheelhouse for analyzing music production gear.

[@mechtheist]

I bought one of those little kit Oscilloscopes on Amazon for about $24US and liked it so much I got another one. My main use is audio so the limited BW is no problem. Being so cheap, I don't mind keeping one in the truck for watching power output for the sound system. or devoting one to watching the poser going to various speakers in my home system.

[@WCM1945]

The "hybrid amplifier", at least in US telco terminology, is a bi-directional amplifier, exhibiting gain in both directions simultaneously. It's used to compensate lossy phone lines. Very tricky to set up, lest they begin to oscillate ("ring-around"). They require a very stable impedance on both sides, and also strict adherence to frequency band limits.

[@lasersbee]

55:42... Nah... too many beginners will screw up that fine pitch SMD MCU soldering and get discouraged to build anything else.

[@tomaszwota1465]

For a first timer maybe, but a second or third kit? Eh, it's fine I think. Didn't discourage me, and I've put it together and it worked on the first try.

[@xenonram]

I completely disagree. It's not for people who have never picked up an iron. And, frankly, if you get discouraged that easily, it'll probably save you a lot of time. You won't have to waste your time pursuing further electronics knowledge/skills, only to find it too hard, and end up quitting after investing much more time... and you can continue working at McDonald's.

[@lasersbee]

@@xenonram Well Andrew... seems that you have no clue... You sound like an "Expert" I don't get discourage at a simple to assemble PCB as that one but a beginner that has never soldered a fine pitch IC may very well have much difficulty. BTW... We assemble all are own Through hole and SMD PCBs in house. Perhaps it is you that should continue working at McDonald's... Nice try Trolling... but fail...:-)

[@YCbCr]

The hardest part for me to solder was the BNC socket. :) No high heat capacity tip, so it's just tacked on somehow - some say the bigger the glob, the better the jaaahb. :D

[@NetworkXIII]

YCbCr I had to put a BNC plug in the jack to prevent the center from moving around when the nylon insulator started to melt.

[@jlucasound]

@ 28:18 Do I see a solder ball on pin 6 of the HY3131?

[@diatomsaus]

Dave, you can get a USA address very easily. Simply use a freight forwarding service such as shipito or myus. Whether it's worth it or not, you be the judge.

[@EEVblog]

I have one of those. Not worth it.

[@billallen275]

These are GREAT for Audio, low voltage controls and uP stuff, and automotive with some filtering. It is not every measurement that I need 100 MHZ BW. Needs a case, and a second channel, but for an ISOLATED "visual" A/D / multimeter, adding a shunt resistor, etc., it works. Just don't drop bare wires or molten solder on the board! ha! Kinda gimmicky, but useful on occasion. There's 3'rd party firmware available, too. Cheers!

[@sirdigalot1978]

I bought one of those kit oscilloscopes just to practice soldering

[@petertryndoch8857]

I used to install those 2 wire vf hybrid amps. Some lying around here somewhere. They were used to adjust the gain of a Tie Line which was used to span 2 sites with voice lines. Popular at the time with money markets where speed in making a deal is essential. Or if you had multiple sites and wanted to network your PABXs. These lines could span multiple exchanges and even interstate with the use of carrier. The other use was with Inwatt Lines which were the predecessor to 1800 & 1300 numbers. There was only a small number of exchanges terminating Inwatts, so lengthy runs were common.

[@cryptearth]

1:55 Hi from Germany =D - love your pronounciation of Deutsche Post (wich DHL is also a part of) ... //edit: don't hate our scart - it's still widely used in the retro gaming community as it's rgb output is way better than ntsc composite (wich, to make it worse, was mostly used over rf as early tv sets didn't had direct composite input as it was widely available before the hdmi era)

[@brazeiar9672]

It was designed in France. You can tell.

[@cryptearth]

@@brazeiar9672 he said "SCART's that 'european' thing ..." - so when I wrote "our" I didn't meant "us germans" but "us europeans" - I'm aware that SCART is a french akronym as it was first designed in france for a very strange reason

[@brazeiar9672]

@@cryptearth My point was more that it seems quite designed by committee as seems to be the case with French/EU regs. I'm from the UK so I don't consider myself European, at least in the sense that it refers to mainland EU.

[@cryptearth]

@@brazeiar9672 aside from politics, where EU is european union, in terms of geographics the british isles are as well considered to be part of europe as iceland although iceland was created by a vulcano where the british isles are part of the main european continal plate and the channel is just a flooded canyon formed by last iceage - a bit like the fjords in scandinavia about designed by committee - couldn't find any sources about this - so I can't neither agree nor deny - I just simply don't know and was unable to find any information

[@brazeiar9672]

@@cryptearth Yes I know the geography of the UK, but the term "European" is generally used as shorthand for "Mainland Europe" and often also to mean "EU". Even strongly pro-EU countries like Ireland are not proper European countries because they lack a shared land border. The UK technically shares a land border in mainland Europe in Gibraltar but its only ~2 miles wide.

[@barrymayson2492]

I use one of the little scopes as a visual indicator on a signal tracer. No real measurements are used but just an indicator , works fine for that .

[@bobweiss8682]

The "strain gage" is actually a trimmable resistor network used for nulling the zero output from the internal strain gage bridge. You adjust the value by cutting the various links on the pattern (tongue angle highly critical). Info here:www.micro-measurements.com/press/micro-measurements%C2%AE-bondable-resistors-transducers-now-built-advanced-sensors-technology

[@EEVblog]

Makes sense, thanks.

[@Antoniobeta]

I am almost sure that the load resistor in series with the cable is for temperature compensation of the main cell. In the torque measuring wrench.

[@randomblogger2835]

cheap scope: there is a version available with only the QFP soldered, and all the other surface mount supplied on cut strips, (with one or two spares of each part in-case some get accidentally launched)

[@FurEngel]

Dave, I am in the process of sending you a mailbag care package next week. Finally have it ready for you.

[@EEVblog]

Thanks

[@TheDefpom]

Thanks Dave, hopefully you can track down the printer one day!

[@helltanner3722]

There will be a fixed resistor in the focus cct that has gone very high or open..carefully probe around until you find it ..with the power off and unplugged.

[@Gigawipf]

The Heinz Nixdorf Museum is indeed great. If you are in the region check it out. Had the honor to work with them some time ago and it really takes some time to experience it all. They have pretty much everything related to computer history and also some interactive setups from old to more modern times. On the multimeter 9V batteries are annoying. But apart from that it seems pretty nice.

[@pnjunction5689]

Yes, the Nixdorf Museum is great! I haven't been there in a long time, but 15 years ago or so they really fueled my appreciation (pun intended) for SGI workstations :-)

[@qzorn4440]

i just wanted to see the o-scope 49:00... thanks...:)

[@Coloneljesus]

I have one of those JYE kits. For me, a software engineer who just dabbles in electronics as a hobby, it's great! I can debug stuff that I couldn't with just a multimeter. And building it was fun too.

[@Spongman]

the problem with center-off is that it's really easy to accidentally overshoot to the 10A range when turning it off after measuring voltage. if your stuff is still connected... boom!

[@dewspbru]

No boom, because overshooting to 10A does not move your lead into 10A jack.

[@christerbergstrom8081]

As C Dundee said: Thaaaat's not a knife. THIS is a knife !

[@dudleywin7514]

Would that 100watt resistor at 48:11 has big variable inductance?

[@EEVblog]

Yes, it's not a bi-filar winding.

[@douro20]

Plessey logo on that attenuator board at 40:50. That logo is still in use, btw. Those torque wrenches probably came from the automotive industry.

[@awkbot]

Please, can you bring us a full review of the meter:)

[@dlvnmedia]

So would that JYE scope be ok for building and testing some diy synthesizer gear? I would not mind a Cheap little thing mainly for checking the waveforms as I test out different filter designs and other random effects. Just something to keep right at the breadboard level.

[@englishrupe01]

I think it would be perfect for that.

[@WacKEDmaN]

Welcome to everyone's favourate MAILBAG!

[@onjofilms]

Thanks for the info on that Tontek jobbers. Just bought 20 on eBay for .17 each.

[@jmannUSMC]

Thank you for the TekScopes tip, Dave! I also just bought my first scope and it needs some love, but my troubleshooting tools are limited to a DMM as well 😂

[@superdau]

I have another of the JYEtech scopes (the DSO shell/DSO150 about the same price with similar firmware and specs but much better controls). The crazy thing it that it has taken over 90% of my oscilloscope uses. I repair a lot of stuff for fun and for power supply and audio circuits it's all that is needed, and easy to throw in a bag at the same time. It's even fine for a lot of microcontroller stuff, when you want to check if a signal, clock, data, PWM, you name it, is there and in the expected ballpark. Oh, anf if you do got for the original from JYEtech you can get a kit that hasn't the SMD components soldered either.

[@garnetkoebel8027]

For anyone who doesn't know that AIM academy robot pictures is a First Robotics Competition robot. And I do love the arm on it.

[@JerryDodge]

Speaking of things appealing to kids - just today I for the first time published our company's mobile app to both Apple and Google, for their mobile device stores. During the process of each, plus having to create a privacy policy, I had to address the fact that that app had absolutely zero appeal to kids, and was instead targeted at a niche market. Had to go through that 3 different times.

[@randycarter2001]

The robot is part of USFIRST.org. Fantastic program, and a true blast to attend the competitions.

[@bertblankenstein3738]

Regarding the out.of focus Tektronix scope. I wonder if the deflection coils on the CRT are out of position.

[@stephenbell9257]

Scope tubes like this use electrostatic deflection with internal deflection plates so there are no external deflection coils. However, there is however a trace rotation coil which is used to compensate the effect of the earth's magnetic field to make the trace level. The trace rotation coil has no effect on focus

[@douro20]

D7, the big through-hole diode in that multimeter, is a 6.8v Zener diode. If it only has an ATmega processor in it, then they're probably doing the heavy lifting for the interactive application in the AXP core in that CSR bluetooth module.

[@antoniosantos6442]

Hi, at 38:12... Those are not fuses, but electrolytics in a plastic body...🙂

[@kriswingert1662]

If it is indeed a monochrome CRT, check the deflection yoke as it may have moved causing the focus issue. Seen this before.

[@DHealey]

05:12 You've got 3 hairs growing out the end of your thumb or you've been moving a cactus recently?

[@viperidaenz1]

I have a Uni-T UT136C+ meter and it's pretty fast on the auto-ranging too.

[@tullgutten]

Artifacts on the dso oscilloscope may come from your 12 v supply. It clearly says it must be under 12v. And many people comments its better to have a low voltage. I run mine on 2 18650 in series for a max 8.4v and it works great. Low bandwidth yes but for me it's more than enugh, and i cant justify the 10k price of a proper one

[@andymouse]

I bought one of these a few years ago (JYE) and they had great instructions ...nothing new here.

[@nonsuch]

I have a bunch of DSO138 scopes that I use strictly as waveform displays for synthesizers. They are perfect for that. 👍

[@alek202]

Hi, PartKeepr dev here. PartKeepr is an open source inventory system. Not sure why people reinvent the wheel all the time instead of contributing to existing open source software. 10k subscribers, WTF. My software had about 200 subs when I provided hosting service. I guess it's all about advertisement, it's frustrating.

[@cb2micro]

Thanks for showing the CB2 micro Dave EEVblog ! Oh it was so fun you couldn't even pronounce the name :) I am waiting forward to see Sagan enjoy this with his father. Oh by the way, If you haven't got a SCART, use the composite output (B&W though) on the PCB pad, just to test it. Or build this one cb2.qrp.gr/extensions/#8_Color_composite_videoS-video if you want color composite. The page cb2.qrp.gr has all the info you need to know. Regards :D

[@jco2641]

I'd think the bent pins on the jumper inside that telecom amp were so that if you have the jumper held the right way around, you can't accidentally put it on the pins right next to where you wanted it to go.

[@martinda7446]

Not fuses - electrolytics..popular in the 70s with plastic red cases 38:15