Electronics engineer with over 35 years of design experience. PLAYLISTS : Teardown and Repair Electronics Fusion 360 skolen (Danish) 3D Printing, and 3D design youtube.com/@TeardownOZ2CPU youtube.com/@TeardownThomas
Hello ,I'm reaching out to you as I've been following your RU-vid Channel and I'm impressed with your content. Your video quality is much better. But I found some issues with your channel. If you don't fixed your channel problems, you will never grow your brand on RU-vid.
I don't see any issues with his channel, people that are really interested will for sure find their way. Your comment gives me scam vibes, "contact me, or otherwise your channel won't grow"...
@@jb5631 I checked his channel, the videos are not SEO friendly. His videos have no video tags, very few channel tags. Which is not ranking his videos on RU-vid. That's why the videos are not getting views
You can see the market pressure in this product. They had no time left to make it fancier inside. It could have been a very nice product given just a bit more time.
@@TeardownOZ2CPUIt may be that at some point, maybe late in their company history, they had few customers and getting anything sold was big priority. Or there was competition pressure. Those are all hypotheses, but I’ve been in that situation more than once. One has to then hope that the product will work well in the field because keeping all those “one-offs” documented is a pain. Or at least was in the times when high quality digital pictures weren’t common. Today a phone and good lighting allows great during- and post-production documentation. At least so that the poor soul who later has to service it in the field knows ahead of time what they’ll deal with :)
It probably pained their engineer(s) to release it in this state - it would have pained me. But if the alternative was to get bankrupt, sacrifices had to be made.
@@absurdengineering I´m a consultant, I design electronic products for companies, from startups to larger places, it is always a thing to make stuff fast to the marked, see how it handle sale and real field use, then make it better, it is super funny to see other designers work from various life cycle states.
The resistance wire is insulated, and wound around an insulated copper wire former. Then the inner insulation is removed to expose the inner wire to make contact. Have had a few fail from wear, that wiper either wearing through, or it wearing out the fine wire. The insulation determines voltage rating, very few, despite power dissipation ability, are recommended for over 50V in adjustment during operation, as the contact will otherwise arc, even with 1000V insulation resistance, because of the wiper bouncing between turns. The wire also shows why they are not really made above 100k, way too fine a wire to wind then, and too fragile. The cermet ones are a lot more resilient, but a little less accurate, and have a much lower contact current rating. 2W rating for the entire element, but also a 20mA contact current limit, which is why you only see them as a sense unit in a power supply for current limit, across the main shunt. Output voltage sense no problem.
First oscilloscope I worked with at my first job, 42 years ago. Even though it was just 10MHz, it has very trustworthy. Beautiful, bright and sharp trace, and all switches were very snappy and given a great click and feedback. The silk screen of the panel was very clear and controls were very well positioned.
I have an AVO bridge which I restored last year. It's well worth replacing the old electrolytics but the rest of the components I would leave as they are unless you have a definite fault
I bought such a scoop in 1980 and it worked fine then. I've had it sitting in the box since about 1990, so I wonder if it still works? Are there any capacitors that have become old, tired and leaking or can I expect it to work?
i recommend to open and perform deep going visual inspection, check for leaked caps, if all is fine, take a soft paintbrush and compressed air, and clean it, then try it out, also check the trigger wire mentionened in this video, and see if your trigger works
At my first engineering job I used this equipment to test wow and flutter of record players. The tests are done by playing reference DIN test tecords containing a 3150 Hz tone. The same for tape decks using reference tapes. Actually it measures drift, wow and flutter separarelly.
Opinion wanted: Replace these fabric tubed wires with modern silicone wire and heatshrink, especially when they got sticky or are anywhere near mains voltage, if you intend to restore devices for use, or keep them for the sake of originality...? I keep finding that stuff not vintage but just nasty....
you are right, some fabric coated wires crack, makes the unit very dangerous, some of them the internal plastic type under the fabric, turn to goo or slime, maybe due to humidity or other types of chemicals nearby, maybe not designed to last 70-80 years !! but teflon wires will last 1000 years..
Always having mixed feelings when radiomuseum is given a shout: On one hand, their curation of materials is great, on the other hand, them hoarding that information behind a members-only/request-only wall might ultimately be detrimental to the community and/or be in the way of better archive sites being established.
you are perfectly right to have feelings about this, I often dont have any other options for information, sorry it is a payment site, but informaton is worth money and they figured that out, I dont blame them.. you can however as a non paying member still get some info x times pr day or how it is.
I came across your channel by accident and then I saw the AVO. My dad (who was an electrical engineer) had one of these and I remember him showing me how to use it when I was a kid in the 1960s. He passed on in the late 1990s so thanks for the memory!
Nice bridge. Can't be many of them out there anymore. for continued working I guess the old caps would have to go, it is however impressive that it still works after so many years. I haven't seen this unit from AVO before. Thanks for showing on YT. Have a nice summer holiday 😀
The crystals remind me of potassium hydroxide from a leaking NiCd battery. If that's the case the only reason it hasn't eaten through the pins is because of the gold plating. RS92N is a series of foil resistors from Vishay which are still in production.
Wow, that's some awesome design work in there! Especially after watching Frankie's power supply repair, you should watch that, you're going to lose your mind lol
I have recently become interested in Instrumentation Amplifiers. I have been considering building my own from scratch. I have realized that obtaining high level specifications with discrete components will be difficult. Therefore, I believe I will use an all-in-one chip, to do the serious work. I would like 1) to see you putting this unit back in working order, 2) for you to fully explain the circuit's operations and 3) you using it to do some testing with any minimal voltage source that you wish to assemble. Meaning, finding a particular sensor to test is not so important. Please and thank you. If anyone has a suggestion for an Instrumentation Amplifier all-in-one chip, I would appreciate it. Cheers.
Love to own that device, I could really use that test equipment for my bench. Great looking meter my friend. Keep up with the awesome videos. God Bless 73's Hope you having a Great week. 😁
Interesting little oscillator, Trio also used that case design for an oscilloscope, so maybe there is a range of gear in like boxes. I'm guessing the power transformer is on a raised section as they were concerned that the mounting bolts were extending too low, so they could either do this, or fit taller feet, however taller feet would make this unit look out of place when set next to other like cased instruments.
I have this PSU, what I didn't understand is why I can't really adjust the current? in my mind, you set voltage and max amperage but doesn't work. So what's the amperage adjustment for then?
but a 10 ohm resistor big heawy type on it, turn up the voltage to 10V you should see the current is now 1A, now keep the voltage dail untuoched, and slowly dial down the current until you get 500mA, now you see ? your are using the current regulation, mostly it is used for protection, like you have a good idea what is the max usage or safe level of what ever you work with today, then set the current limit to a point a little bit over that, and you can save your construction from causing too much extra damage, when something go wrong
The pedestal the transformer is mounted on is simply for mechanical clearance on the bottom of the chassis. Producing that feature isn't very difficult, a set of dies are used on the top and bottom and it's punched. There might be a series of a couple of dies to form it in steps, reducing stress in the steel as it's formed. I've seen the technique used quite a bit over the years. The knob turns backwards because they didn't want to spend the extra few cents to put an intermediate roller between the knob and the tuning cap shaft to correct the rotation.
i think this punching is super interesting, since the lifted part needs more length material, to get that, it mush streech the material using very high force, the hold bottom plate straight force at the same time, must be crasy high
@@TeardownOZ2CPU The dies keep everything perfectly straight. Imagine the top die and bottom die are the same shape as the 'strap' less the thickness of the metal it's made of so it's squeezed perfectly between the 2 dies. Because it does have to stretch the 'sides' quite a bit, it may have been done in 2 steps, I'm not that familiar with punch press operations. I know the old school ventilation louvers that used to be common on stamped equipment cabinets were stamped with a single die set so you can displace a fair bit of metal before it starts to tear. I love the simplicity of this old equipment. You can just look at it and figure out roughly how it works.
Alternative theory for transformer mounting... They wanted the transformer to be removable, i.e. screw mounted. The screws have to be undone from inside the unit because you don't want idiots undoing them from the bottom and the transformer dropping off and breaking things. Self tapping screws are best, otherwise nuts can be undone from underneath. You don't want the points of the screws sticking out beyond the bass plate. Solution? Bend the chassis. Incidentally, Trio is normally pronounced tree-oh
thanks a lot for your comments, it sure look like an odd way mount the transformator, there must be a good and smart idea behind it, you could also be right :-)
Makes sense to me! I'm thinking they mounted the transformer that close to the PCB because they needed the metal near the edge to make that bend properly maybe?
Yep, that was my idea as well, no screws sticking out to scratch your bench. They need to press with a lot of force anyway to punch the holes. That is probably done in a single stamping operation.
Den bro transformatoren står på er ganske let at lave. Man standser ud i siderne og presser broen op på samme måde som når man fremstiller F.eks. en gryde eller en stålvask.
Ah, nostalgia. We used Unigors (not sure which model) at school late 80's / early 90's in the Netherlands. They are nice. I only do not like the parallax 😉
Just found one of these somewhere for cheap. Doesnt produce anything else than a low hum so ill be checking out the tubes tomorrow. I dont have an osciloscope and was wondering if matching impedence is important when using this on a speaker? Also does it even need to be amplified or is the signal strong enough? Was planning on using it as a weird synth when plugged into a guitar amp lol
Hi Thomas, After months of hesitation, consulting tutorials, training to desolder and re-solder QFNs (from out of order PCB's), I finally managed to change the input IC HMC1118. It wasn't easy, but it's done and the result is there: the spectrum analyzer is working again. Cost of repair: - hot plate: €5 (Ali...), - HMC1118: €20 (Mouser). That's €25 compared to the €1369 asked by Siglent for repair. Of course, I was already equiped with hot air gun, flux and solder paste and magnifying glass. I have performed the most of tests according the Siglent Service Manual. All are OK. Conclusion: It's worth persevering! And thank you again for your advice. 73 de Dominique F4FEI
Comparing measurement procedure to the hp334a: Did you try to further minimize distortion reading using the balance after adjusting filter frequency? Your impedance meter setup is excellent. Frequency sweeps and graphical output make the characterization coherent. I could afford a hp4192, but I don't want to make the space for it!
Finally you got the real one, Thomas. Unfortunately, yours has had a very hard life in the past. Otherwise the 6e, at 1% in all voltage and current ranges both DC and AC, I think is the most accurate analog multimeter in existence. The one I got was totally dead when I got it. It turned out, all its electrolytic condensors were gone. After I exchanged them and set back its chopper frequency to 205 Hz it was as accurate as brand new. Your electrolytes seem to have been exchanged already. Originally they had green tantalum drops and yours has blue ones. Maybe you have to readjust the chopper also to get back full accuracy. There is an excellent service Manual for the 6e, but it is unobtainium. At least there is a user manual at elektrotanya. Capacitances are measured with a chopped up internal current source source, so you do not need external AC for that and the voltage drop across capacitances is a few mV except in 1 and 10 nF range, so you can measure capacitances in circuit most of the times.
I might try to scan the back gor the future. Perhaps it could be laser etched or something along those lines when in the future it could use a reprint.
Fixed a Metravo 2H recently where the whole current measurement part of the circuit was more or less board-mounted ashes - carbon resistors where none were installed initially, if you will. Somebody must have connected it to mains on current range and left it connected :(. Impressively, the plastic housing wasn't damaged severely, no damage visible from the outside.
Great Meter , used it for decades ! BUT ...if the day comes ,the meter shows you " -2", you are out of luck ! Because then the the A/D converter is gone , and there is no replacement . Also the inner parts of the knobs tend to break over the decades.
