Greetings: The SSD will speed up all op's especially the initial bootup. (The power reduction of the SSD may ease the burden on the power supplies, too.) A small (
I agree, it's a good idea to upgrade to SSD, but... It probably has an IDE drive, so that could be a challenge. Getting a coverter from IDE to SATA that works under W2000 might be possible, maybe... But a unit like this probably hasn't that many hours on it, and sitting on the bench it would most likely function well for a log time. And as he said, it's not a fantastic scope compared with modern scopes, so when the HDD dies, it's probably time to retire it and get a new one.
I want one just for the bragging rights to being able to play Wolfenstein on my lunch break LoL! You could possibly even use the audio input jack on the back of it as a signal tracer and if you can possibly connect the scope probe to the audio input at the same time, you just might be able to hear what's going on as well as see! Come to think about it, why doesn't such a device exist? I think that there will be situations where this will be extremely useful...
Great video Tony. On the subject of older test equipment, always check that they don't have any of the famous Rifa X caps that like to explode coating the equipment with stinky burnt oil. This happened to my Tek 2465 and a HP function generator. Check this out www.eevblog.com/forum/chat/old-rifa-capacitors-and-a-disaster-story/. Cheers Ian
DBT tester is the #1 tool for old audio geeks, ALWAYS use it when powering up new drag-homes and after any component work on the boards. My dim bulb tester has saved my butt many times. I've got a 40 watt, 60 watt and 100 watt bulb for different amps.
Thank you so much for this video, this is a great addition to all the other videos on dim bulb testers or current limiters and isolation transformers, wich left me with some questions and this video answered them all and thaught me even more. You are a great teacher.
Great Tony , wonder if you have in rush current limiter on your big X-ray transformer?? Or so-called soft starter ? I have 4 KVA toroid transformer with softstart inbuilt so home fuse will not go off when you connect it to main , in Europe (Sweden), we have separate PE cable and Neutral coming to your house , it is not directly connected in your fuse box , and there are Ground protection fuse breaker on it , it is around 30mA . So if you touch live main ground break go off .
Thanks Tony. A while back, I set up a crude single dim bulb tester and needed to unscrew the bulbs of various wattages to check for different current draws. Before I realized that fact, I was testing a flat screen TV and the bulb I used seemed to indicate a problem. The TV would not power up. Once I changed to a different bulb, it came on and I learned another lesson. Always more to learn. JwgK
Hi, Please someone help me, i have microwave 220v 2000w, i want test how many watt Bulb should I use ? Please explain how to calculate the bulb wattage
I use traffic light bulbs. Electrical supply houses still stock them, because so many traffic lights are still using incandescent bulbs. They also have super long life and reinforced filaments.
Hello Tony - That was one very informative and very well explained Dim Bulb system I have ever seen. Thank you. You explained it in a way which made it easy to understand hot it operates. One question if I may, what was hiding under the cloth cover on a piece of equipment on your bench 🤔.
If the bulb is a filament light bulb it will pass a large surge current when the filament is cold. Its rating is not all that consistent between even identical light bulbs, the bulb will get hot, the glass can break and at some point the bulb will burn out. A better solution to limit AC current is to use a large non-inductive power resistor on a heat sink that can be in series with the load or shorted by a switch for no current limit. Usually, the current limit is used as a first step if we surmise the load to be shorted, or nearly so, and this is usually confirmed rather quickly so the current limiting device does not really have time to overheat. The best isolation transformer is a hospital grade toroidal isolation transformer with internal temperature sense and an internal shield. The AC leakage is very small. The down side is a large transformer of this type will have a substantial magnetization surge current. So, the isolated AC power supply must have a start up current limit circuit to prevent overloading the mains circuit breaker or fuse. To protect a mains powered grounded oscilloscope (probe ground at earth) you should isolate the AC power supply output ground. Most AC receptacles will have a ground strap from the ground screw to the metal mounting frame (to ground metal face plates) which means in your design the isolated output connected to a common metal faceplate will also be grounded. The ground between the two receptacles is connected through the face plate. To isolate AC receptacles from the mounting frame panel you need to buy an isolated ground receptacle which will be orange in color. I use duplex receptacles in my isolated AC power supply designs, so I have both an isolated ground duplex and GFCI. Duplex receptacles seem to be more readily available. For trouble shooting AC powered equipment I think the best panel meters are the old Simpson analog type D'Arsonval movements for both current and voltage. I have two AC current meters that I can switch between using a make before break switch (made from a three position 4P4T toggle switch). The advantage is many times you will see a start up current signature with the rather slow moving analog movements that represent what the load is doing in a very informative way. If you work on the same model of equipment frequently many times you can tell what the failure is just by observing the current on start up. This is hard to do with a digital display. A variac output is very handy for testing at high line (also low line), but also testing a very low voltages (you have to fuse or CB protect the output of the variac to about 50% or 60% rated current I can choose from three different magnet/hydraulic CBs) many times you can get a device under test to operate at a very low voltage, which will allow you to do some basic voltage tests and then as you raise the voltage you can watch what the current does, which can help you diagnose the fault. Low line testing can be very helpful. You can use a ground isolated GFCI as a poor mans AC leakage tester. The GFCI ground is tied back to the floating ground (Neutral) on the output of the isolation transformer. Which is essentially acting as a 1:1 pole transformer without a ground rod. So, once you repair the equipment you can move from the isolated duplex to the isolated GFCI and apply power. If the AC leakage is above about 6mA the GFCI will trip. To only real problem I see from your enclosure is that it is made using flammable materials. Most electronic benches are all ground (earthed) referenced for personal safety and ESD. So when trouble shooting I use an isolated variable AC power supply that has the mains and earth ground floating. Then I use all floating instruments as a starting point. I use a Fluke 289 DMM and a 199C Scopemeter, both instruments are battery operated. The two Scopemeter input channels are isolated from each other. Once I know more about a problem I can use more sophisticated equipment like a PicoScope using high voltage probes and current probes. My AC variable isolated AC power supply for trouble shooting is made from two 19 inch rack aluminum/steel enclosures and mounted in a 19 inch steel rack frame on casters. Once you repair a piece of equipment you have to then verify its operating specifications. This is done with a different variable isolated (hot only) AC power supply which generates the AC waveform internally and provides useful information like power factor. The AC output is very harmonically pure (less than 0.1% Current and Voltage THD into a non-inductive resistive load) as opposed to the mains residential power which is usually distorted in some way, and will be further distorted through the isolation transformer and variac.
That is correct. As a matter of fact, most of the commercially available isolation transformers still carry the earth ground lead to the output. This provides isolation for noise purposes, but you still have a path to neutral return, because the neutral is bonded to the earth ground at the breaker box. These types of ISO transformers have to be modified for what we will be using them for. Thanks for bringing this up!
@@xraytonyb I seem to recall that some medical-grade isolation transformers do not have the earth bond. I guess you, Tony, would know for sure, but maybe we should be looking for old medical iso transformers ??? Thanks for another interesting video.
I built a Velleman Power amp kit (now discontinued) back in 2003. They had you put a 60W bulb across two "test" terminals on the circuit board to test for proper PS wiring and instructed the user that if the bulb stayed "bright" to immediately disconnect the unit. That was my first experience with dim-bulb testing. Still using those mono 60W 7293 based amps.
Xraytonyb, great,great video, You have help reconsidering how I use my DBT on all am 5 radios, I am glad that there are people like you that share your knowledge with those who want to learn, thank you kindly for this award winning video, I will continue watching your channel, have a nice day....):
Tony, can that scope be upgraded to Windows 10? If so, and if necessary, it could emulate Windows 2000 to run the existing programs assuming you can get installation files. Not sure any of that is worth the trouble, though.
16:20 - JFTR: there are comparatively many more countries in the world that have a standard of 230 V mains than those with 240 V. I mention this because I live in a country (NZ) where the mains is 230 V, yet I see way too many people refer to it as 240 V. Why they do this I am not sure. The mains has never been 240 V here. Excellent video for those just learning. I've been doing electronics for 40+ years.
*OK... 240VAC . IT IS LIKE THIS (THE POWER-PLANT) MAKE 250VAC* *AND AT THE END .. THE USER HAVE ABOUT .."240VAC + -"...* *BEFORE THERE ONLY WAS "220VAC" BY THE USERS...* *SO 240VAC IS BY MOST PEOPLE ... (SOME YEARS AGO) THE AC* *WAS UPGRADED .. TO ABOUT "240VAC"...*
@@netautorisationnetautorisa545 That may be the case in a small number of countries. These days the mains network is well controlled, and if the nominal voltage is 230, that's about what most people will get. Here in NZ, the mains is generated and distributed at 230 volts. There may be some loss in remote areas but this isn't common. There is no 'about' when it comes to the power - 230 volts is what it is.
But can’t 1 amp at 120 volts still kill you? At least you get to go out with a flash of light! 😂 I think the trick is not to create a grounding circuit with your body such that the current can flow through your chest, where by it can potentially stop your heart. Based on that idea, I think using only one hand to touch the circuit/probe while using a grounding tether on your wrist with say a 1k ohm resistor on that same hand would be ideal, because in the case of a ground short, the current will simply pass through your hand into the ground wire and while still painful, it at least won’t kill you. You can always buy another oscilloscope, but you can’t buy a new heart. 😂
Firstly, regarding a random video, any time spent with you is time well spent! Regarding your pinball machine example of an isolation transformer, I think that it is important to note that the example transformer, while isolated, drops the voltage on its secondary output. Your xray machine transformer is 1:1, meaning it outputs 120V. You know these things, but maybe your viewers do not. If you (only) have two identical voltage dropping transformers, you can hook them up back-to-back (Mains AC to Primary of Transformer #1 - Secondary of Transformer #1 connected to the Secondary of Transformer #2 - Primary of Transformer #2 to DUT.) to create an 1:1 isolation transformer. Its current capability will be that of the transformer type that is used. As for incandescent bulbs, I am using Halogen bulbs in the "G9" size. They are much smaller and easier to mount. I am using multiple 40 watt bulbs to get a 1/3 amp per bulb bracket. So, in about the space of two common bulbs, I am mounting 12 bulbs, for a total of 4 amps. Finally, I am not an electrical engineer. Use this information at your own risk. It may be incorrect, or incomplete.
When I built my setup I had two Transformers from a Guitar Amp that output around 60Volts. I just connected the secondaries together and got 120. I also made it very fancy by using two normal electrical light switches. One as a bypass for the bulb and one to turn the Transformer ON/OFF. I got a Variac and a Kill-a-watt on it. I'm thinking to replace the outlet with a Smart Outlet that can tell me the Watts, Amps, Volts and Power Factor. That Scope is pretty nifty. I have a HP 16500C that uses a type of HP/UX on the backend. Doesn't have a VGA port but with the magic of Linux I can have it display over the network via a X11 session on my Desktop. I don't use it very often, it's loud and takes twice as long to boot up then your Tektronix does.
Thanks, Tony. I'm building my Iso-trans/variac/dim-bulb tester now. No where near as huge as yours but should do the trick, I hope. Nice scope, BTW. Maybe you can put a modern SSD in it and make that sucker fly through its boot up!
For an AC supply made of individual components - an isolation transformer, an autotransformer and a dim bulb current limiter - , what should be their arrangement? I have mine as the isolation transformer, to the autotransformer, to the dim bulb current limiter, to the fuse, to the DUT. Is there a better arrangement and, if so, why? Hmm... As my isolation transformer is subject to voltage droop, maybe it would be better to have the autotransformer before it. This would mean that I could make up for the droop by increasing the supply to the isolation transformer, by increasing the autotrans above 120v, instead of increasing the draw from the isolation trans, as it is arranged now. Maybe it is all the same...
Looking at the transformer diagram, the 2 RED wires are marked SECONDARY wires and the Gray / Yellow / Blue / Black are the PRIMARY wires. It looks like the transformer could be wired for 240V in ( with the windings in series or 120V with the windings wired in parallel. It looks like it is wired for 120V in as the output is 120V and not 240V. I believe that if you were to wire the yellow to blue liuke the top diagram shows it with 120V on the 2 red wires you'd have 240V on the gray and black. That could be a bummer. In this case it works It out the same in the end but it's confusing.
I got the tds2002c on a trade a few months ago right after I had gotten a nice siglent to replace my old hantek dso5102p and it's only 70mhz but it's super fast.
That scope has probably still have a IDE harddrive, if you upgrade it to a Sata SSD drive with a IDE to Sata adapter, then the bootup time and response would be much faster.
Great info and very well explained. Why do newer isolation transformers have the earth ground connected? They have the three pronged receptacle in the output.
I have earthed wall sockets everywhere in the house. I suppose I could use an isolation transformer to connect an vintage early 70's amplifier (with an unearthed round plug ) - using the isolation transformer as a isolated bridge - to the earthed wall sockets... But then again, would the ground from let's say an connected vinylplayer of same age that is connected to the phono ground on the unearthed amplifier break the galvanic isolation?. And the residential circuit breaker would not work in case the amplifier then short circuts, I understand that, but I guess one should then choose an isolation transformer with some kind of over current protection.
Tony, if you are what's considered a test equipment junkie... Is there an actual word to describe Paul Carlson? He's like the man who owns a shop that just can't sell anything to anyone because the merchandise is to beautiful to let go of.... What scares me is that I totally get it! My collection of test equipment is slowly slipping out of control but only because it's expensive and people just don't leave stuff like that on the kerbside... I did once come across a kerbside vacuum tube oscilloscope but didn't get it because it looked in pretty bad shape and I didn't know enough about it at the time but I have ever since regretted it... But audio equipment! I'm amazed at what people throw out!!! I literally have no more room for more so I try to avoid looking at something on the kerbside as I drive past... It's a hard habit to break LoL. And that isolation transformer! Nice 👍 X-ray Machines... They are the gift that keeps on giving, even after they have been decommissioned! Excellent isolation transformers, excellent capacitors... Who knows what else they have that can be recycled? Well I guess that you do and that would make an interesting video for discussion, sourcing used components from such machine's... One thing that you didn't mention which seems to be an unknown in the electronics repair world is that there's basically two different types of isolation transformer! Just going off and purchasing an isolation transformer will usually result in owning a medical grade isolation transformer, these things are not what is needed for what we do! These things still have their ground connection passed right through to the device under test... They can be used but only after the ground has been disconnected from the output, so a modification is needed! I personally picked up one of those things! I knew exactly what it was as soon as I layed eyes on it (well not really as well as I thought at the time), it was extremely heavy! And as I had been looking for one on eBay, they were expensive but this thing for $50Au and I believe it had a 3kw rating... Clearly the guy at the Ewaste didn't know what he had so I got it as fast as I could drag it... Man! The toroidal transformer in this thing was huge!!! It looked like a birthday cake that I always wanted but never got! But to my shock and horror! It's output was ground connected! I initially thought that if this thing was good enough for a hospital! Then it should be perfect for here! So I thought that I should test it first before I put it into service, I basically made a dimbulb tester on the live wire and a live probe on the other end and after poking around a junk piece of equipment realised that the earth had to be removed from the output socket... I ended up looking around for isolation transformer videos on RU-vid and found that others have had the same problem. One guy who had been using his one for years had no idea until he put his scope ground in the wrong please and the lights went out! These medical grade isolation transformers are great but they weren't designed for the sort of thing that we do and it's important that we remain vigilant in reminding people who are new to the game that all is not what it seems! I don't know if there's an actual proper name for what we need, but I do know that a name is needed to easily distinguish the difference between the medical grade and the tech grade isolation transformer.. one will kill you while the other won't... Anyway... I love the new oscilloscope.. I saw something similar for sale some time ago but it was expensive... I actually kinda like the idea of it... I wonder if it's possible to run a media player in the background? Apart from being able to listen to music while working, you would be able to play pre recorded sine waves and sweep's while seeing the results on the scope which would be kind like those newer ones which have a built-in functions generator! It would be a little bit how ya doin... But it could get you through until the budget allows for the real thing... But alas, eye! Tis was a great video none the less... As usual, no shenanigans... Just grrrreat content frrrrom a grrrreat lad.
Hello, Yes I'm a total newbie - there it's out and I own it. I'm trying to learn all this to begin to work on older audio gear. I'm on a very tight budget (thanks covid), and I'm gathering the basic test equipment. 1.) Ok, please let me know where I can buy a suitable Isolation Transformer for this? 2.) How much will it cost? 3.) Or if I can find a used I.T. what is the rating I'll need - for instance is one rated at 3.5amps enough? 4.) And finally are there ones that can be made into I.T. ?( thinking used again) Thank you for your advice. Regards, Jack
You can get isolation transformers used on eBay. Prices vary, of course. Some of them, especially the medical ones, need to be modified, before they are suitable to use with "hot chassis" radios. There is info online how to do this. New isolation transformers can be expensive, especially if you want one with high current capability. For radio work, a 3 to 5 amp transformer will be just fine. You can also make one by putting two identical transformers back-to-back. For instance, if you have two 12 volt 3 amp power transformers, you can connect the 12 volt secondaries of the two transformers together. When you feed the 120 volt mains into the primary of the first transformer, you will get a little less than 120 vac out of the primary (now acting as the secondary) of the second transformer. There will be some voltage drop because of the transformer losses, but that could be a good thing, as mains voltages were a bit lower back when the tube radios were built. Hope that helps
@@xraytonyb Hi, Thank you very much for taking the time to reply, and your suggestion on the 12 volt build idea, greatly appreciated. There are many YT authors who don't seem to respond. The basic idea of a simple transformer isn't to hard to get. But there are so many different types. It can be confusing when you're an average Joe trying to get a handle on it. Best Regards, Jack
I don't think you have to worry about that on this unit. Back when they made this thing, Marconi was still inventing wireless and Al Gore was still inventing the internet ;)
@@xraytonyb It looks high end gear, and back then I had a Win 98 tower that looked for a network to connect to. Yes it's only 5 bits /sec or whatever but any local teen hackers love to play. Just right click net icon on the right of taskbar to check status, then properties and disable network adaptor. While your at it turn off windows update. Maybe I'm paranoid but they could still be out to get me. I'll get back in my Faraday cage now : )
As you describe the outlets as power strips, I take it that each fixture has multiple sockets. If so, please know that the isolation transformer is only protecting you from making a connection to earth ground. You can still be shocked by your isolated supply, by crossing up line and neutral. The likelihood of making that mistake goes up, if you are running multiple devices on the isolated supply. I hope that helps.
@@t1d100 yes I used to work in a tv repair shop. I only plug the device under test in the white strip. O scope closer iron etc goes to the grounded strip.
Tony, You could isolate your entire house with that transformer. I know that is probably not a good idea. Thanks for the video, it was a good refresher for me.
Hi Tony, When you lit up the bulb with your scope ground, that tells me that you do not have a GFCI in line with your supply, right? Wht not? Also, when isolation transformers are used, GFCIs are kind of useless, right? But also not really required as no fault to ground could cause a short. Do you think that isolating say a SMPS, would allow to be safer than using a non isolated supply but with GFCI? Thank you for the interesting video. Now I'll continue watching... Cheers Mark
GFCI protected outlets are usually reserved for areas like kitchens and bathrooms. You usually won't see them in the other parts of your house, as they can be prone to false-tripping when connected to inductive loads, such as AC motors. GFCI's don't protect you from being shocked between live and neutral, but rather from being shocked between earth ground and live. A GFCI would prevent your scope from frying in this instance, but it would still trip the breaker. In addition, you could still receive a shock of up to 5 milliamps at line voltage before the GFCI would trip. This wouldn't be deadly in most cases, but could still give you a bite. This was a great question. Thanks!
@@xraytonyb Thank you Tony, Yes, in Canada we used to also only use them for such purposes, though where I live now (Germany) they put them right below the meter and fuses in the distribution/service box. I had the idea to put one ahead of my workbench electric system and thus upstream of the isolation transformer, dim bulb, and variac. I'm sure that it's overkill, and sometimes dubious protection systems can lull one into a sense of complacency and lack of attention to the dangers lurking on the bench... Beautiful transformer! You won't use your Uni-T power meter anymore? Its such a cool device.... Cheers Mark Cheers Mark
@@xraytonyb could a GFCI be used on the isolation transformer secondary! Imagine being able to install a GFCI on the secondary side that has a built-in trigger that when tripped, with trigger a recording of the Bee Gees Staying Alive song? LoL... In all seriousness though... Technically if you were being electrocuted in which you took the one hand out of your pocket and came across both live and neutral rail's... What's there to stop it from killing you apart from the fuse in the device under test? And going by some of those amplifiers that you have worked on in the past! Their fuses would have lit you up like a Christmas 🎄 before they caved in! Some medical grade isolation transformers have circuit breaker's built-in which are usually rated lower than 10A, but even if it's 5A! I would hate to come across half that let alone 5A... It wasn't that long ago when I didn't have an isolation transformer and I was working on a set top box which had a built-in SMPS, my the back of my hand brushed across the top of the exposed tops of the capacitors and it got me! Wasn't a bad shock, maybe I'm just used to it as I have been playing around with electricity since I have been a child (some people might say that I still am lol).. but I did have the one hand in pocket rule applied when it happened and yet I still felt it... I would have thought that it would have been a great design decision to at least please a sticker over the top exposed part of the capacitor like I have seen before in other circuits... But there you go... GFCI on the output of an isolation transformer... That's exactly what I would love to know!!!
@@PeterMilanovski no that would not help. That is not what that type of breaker was designed for. So take up to 5 amps to trigger well past the danger zone. The are designed to prevent fires not electrocution.
NO NO NO! Microwave oven transformers are not a 1:1 ratio. They put out upwards of 3000 volts and can kill you instantly! An isolation transformer is a specific type of transformer that does not step the power up or down. Instead, it only provides isolation from neutral and earth ground.
@@xraytonyb unless he's thinking about using two of them back to back? Where the two primaries are connected together! Which sorta works but it's not ideal... Uncle Doug has done a recent video over on his channel where he showed why it's not a good idea... And I think from memory he touched on the topic of medical grade isolation transformers and why you should be careful if you have one of those things... Great video, highly recommend watching...
Thank you for explaining the dim bulb in such detail . I use one with a 300 watt bulb and I did not fully understand how it works until today, thank you so much ! That scope is amazing! I've never seen anything like it ! What an incredible find ! I've been saving to get a decent scope, not like the little$20 Amazon scope I have , and I'm going to look around for a used one . While watching the video it dawned on me that I could get a little more bang for the buck if I find a working , Used one . Thank you Tony . I hope you and yours have an awesome week !
