hybridfree/eevblog-posts huggingface dataset:
Teardown and RE of a cheap OCXO - Page 1
Forum section: electronics / projects

author: wan hung lo
author_rank: Newbie
timestamp: July 04, 2021, 02:15:35 pm
content: Hello folks,I decided to open the can of a cheap OCXO marked OSC5A2B02.I must admit I am quite puzzled with the circuit. Is the "501" IC a micro, or ASIC? I think it is something programmable, because the controll loop of heater transistor seems like good PID. But I am puzzled by the oscillator circuit between pin 6 and 14 almost as much as that strange LLC thingy connected to pin 15 and 16. And why the 4V (reference?) is connected to two pins of the IC?The output to the base of the power transistor is purely analog, no PWM, so if it is a micro, it must have an DAC able to source a couple of milliamps.Any opinion will be welcome." alt="" class="bbc_img" />

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 04, 2021, 03:45:25 pm
content: Apparently you've already spend some time reverse-engineering the circuit.So start by drawing a decent schematic from that circuit, and then post the schematic.Quad opamps usually have 14 pins instead of 16, so it's probably not a quad-opamp.While reverse engineering, you should start by verifying continuity between the power input and the power of that IC (Apparently Freescale makes some P1011 "Communications processor" but that is probably not it)Probing a picture with a DMM for continuity is unlikely to give satisfactory result.So do the basic work, draw a schematic and post that.

author: magic
author_rank: Super Contributor
timestamp: July 04, 2021, 05:38:53 pm
content: Do they sense temperature with a thermistor hanging off of the 5V supply or is there more to it?

author: wan hung lo
author_rank: Newbie
timestamp: July 04, 2021, 08:04:55 pm
content: Here is the schematics I've made. Unfortunately it does not make me any wiser. I can only identify the oscillator output pin, ADC in and DAC out. Maybe somebody have a clue?

author: wan hung lo
author_rank: Newbie
timestamp: July 04, 2021, 08:07:08 pm
content: @magic: I was confused too at firstNo, they read the thermistor from the other terminal - from the voltage divider via pin 11, see the schematics above.

author: Smile2016
author_rank: Regular Contributor
timestamp: September 04, 2024, 02:43:39 am
content: Have you had any luck reverse engineering this 10MHz OCXO? My heater broke, so I opened mine up and compared it to your schematic. I've attached an image showing the differences. It seems like the 501 chip is a simple custom IC with just a few basic components inside. I’ve identified an NPN transistor with biasing resistors around the oscillator and an operational amplifier on the temperature compensation side. I can create a schematic if anyone is interested. My goal is to repurpose the entire setup for a 40MHz OCXO that I need for some experiments.
Teardown and test of a Ferguson "Mini Line Tamer" power conditioner - Page 1
Forum section: electronics / projects

author: intabits
author_rank: Frequent Contributor
timestamp: December 12, 2017, 11:22:25 am
content: I've just done a teardown and test video of one of these:-It's a Ferguson brand "Mini Line Tamer" power conditioner.It provides an almost constant output voltage over a very wide range of input voltage.At no load, it works down to 40v input, but for a 200W load, it needs more like 120v. So it can output the nominal voltage even with only 50% around input voltage.The video is here:-Some earlier videos I did looked at another ferrorresonant transformer, from the power supplies of an IBM 4341 mainframe's computer:-https://www.youtube.com/edit?o=U&video_id=T5Je6l-OaoQ
Teardown & Detailed Analysis of Qualcomm's 60GHz Multi-Panel Phased Array WiGig - Page 1
Forum section: electronics / projects

author: Hugoneus
author_rank: Frequent Contributor
timestamp: May 22, 2022, 09:04:44 pm
content: Hello everyone,I don't often get a chance to post here (mostly due to limited time), but I thought you might enjoy my latest video since it dives into some content you don't typically find on YouTube:youtu.be/JI9fvAcNpdkI hope you enjoy it.

author: mawyatt
author_rank: Super Contributor
timestamp: May 23, 2022, 02:00:28 pm
content: Superb video!!Do you know what process for this chip, you mention 65nm CMOS (which might be TSMC), but suspect it's a smaller feature process?Integrated Phased Arrays have come a long way since the Invited IEEE Proceedings paper in 2005, "Smart Phased Array SoCs: A Novel Application for Advanced SiGe HBT BiCMOS Technology", which created much interest and was key to getting our small research company acquiredhttps://ieeexplore.ieee.org/document/1495911Wish we could attend the IEEE IMS and RFIC sessions, but health issues prevent attending. Have fond memories of the RFIC dating back to 1995 when we were invited to participate in the original IMS panel sessions on such.Best,

author: Hugoneus
author_rank: Frequent Contributor
timestamp: May 26, 2022, 02:17:08 am
content: Quote from: mawyatt on May 23, 2022, 02:00:28 pmThanks! I hope that you can attend IMS/RFIC in the future. I'll be presenting a paper and workshop this year. We will also have alive demo!

author: KE5FX
author_rank: Super Contributor
timestamp: May 26, 2022, 08:30:52 am
content: What microscope model is that? Looks amazing.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: May 26, 2022, 06:33:18 pm
content: Quote from: KE5FX on May 26, 2022, 08:30:52 amI’ll make a video about it.
teardown of $100000 server....check out the pcbs - Page 1
Forum section: electronics / projects

author: Section8
author_rank: Contributor
timestamp: September 04, 2016, 09:27:16 am
content: hey chums,stumbled across this tear-down on youtube last night. Check out the thickness of the PCBsBuilt like a brick dunny, as Dave would say

author: rs20
author_rank: Super Contributor
timestamp: September 04, 2016, 09:36:10 am
content: Old news sorry! (Handy hint: google search for "eevblog cucLQF3TqOg")https://www.eevblog.com/forum/reviews/extreme-teardown-pr0n-$100k-server/

author: Section8
author_rank: Contributor
timestamp: September 04, 2016, 09:42:18 am
content: Oh. I did do a search for the url first and didn't find anything.I'll search for just the video ID in the futurecheers

author: Section8
author_rank: Contributor
timestamp: September 04, 2016, 09:46:55 am
content: apparently I only searched this sub-forum.....

author: Fungus
author_rank: Super Contributor
timestamp: September 04, 2016, 10:43:22 am
content: Quote from: Section8 on September 04, 2016, 09:46:55 amOn the bright side: A lot of people will watch that video today.Impressive stuff. Where would you even begin designing something like that? It must take a whole building full of people.I wonder if the software quality is up to the hardware quality?

author: zapta
author_rank: Super Contributor
timestamp: September 04, 2016, 01:38:00 pm
content: Quote from: Fungus on September 04, 2016, 10:43:22 amWe need a time mark for that thick PCB.

author: m98
author_rank: Frequent Contributor
timestamp: September 04, 2016, 01:48:38 pm
content: Quote from: zapta on September 04, 2016, 01:38:00 pm40:00

author: rdl
author_rank: Super Contributor
timestamp: September 04, 2016, 02:03:36 pm
content: I think 17:50 is when it first zooms in on a board to show the thickness.

author: zapta
author_rank: Super Contributor
timestamp: September 04, 2016, 03:23:15 pm
content: ThanksWow! I wonder what kind of yield they get with that number of layers.

author: Fungus
author_rank: Super Contributor
timestamp: September 04, 2016, 04:07:44 pm
content: You can get a basic spec one on eBay for, like,$400.Shipping is probably prohibitive though.

author: AF6LJ
author_rank: Unknown
timestamp: September 04, 2016, 04:52:59 pm
content: Holy Crap. WoW.....

author: dom0
author_rank: Super Contributor
timestamp: September 04, 2016, 05:03:12 pm
content: Hm, almost sad, an M5000 is still a useful machine even today. Not that old, actually...Quote from: Fungus on September 04, 2016, 10:43:22 amSolaris is a very good OS
Teardown of a Eaton PowerWare 60kVA UPS system - Page 1
Forum section: electronics / projects

author: madsbarnkob
author_rank: Frequent Contributor
timestamp: August 09, 2018, 10:38:38 am
content: This is the teardown of a large 2x 60 kVA Eaton UPS system, first is the teardown video and below are some pictures and a little description of the components.Here is a picture of a single 60 kVA system installed with battery and inverter cabinets: attachment 1I am not quite sure if this was really a 60 kVA or a 90 kVA unit, as the cabinet had both stickers on it: attachment 2The cabinets were unfortunately badly damaged from crane handling when they were thrown out into the junk yard. I managed to scavenge input rectifier, capacitor bank and 5 inverters from the system.attachment 3, 4, 6The inverter boards consisted of 10x FS35R12W1T4 IGBT 3-phase full-bridge modules, 6 of them used for the output and 4 of them for the intermediate / battery charge inverters. For details of the boards see the video at the top.The inverter boards were pure with only IGBT and DC bus capacitors, so they are suitable for hacking into something else, maybe it is just the relatively low 70 A peak current handling of the modules that limits its use for other applications.

author: jbb
author_rank: Super Contributor
timestamp: August 09, 2018, 11:26:16 pm
content: Shame about the crane damage.I think the 3-terminal magnetic components on the board were for combining the outputs of half-bridge modules. If you switch the IGBTs simultaneously, you just use some inductance (and winding resistance) to help current sharing.If you switch the IGBTs with a phase offset in the PWM carrier, you use the magnetics as autotransformers to turn the 2 level outputs from the half-Bridges into a 3 level output. This approximately halves the size of the output inductors.More modern UPS systems will use three-level IGBT (or SiC MOSFET) modules directly. They offer reduced switching losses (or higher switching frequency for same losses) and reduced output filter sizing. The packaging is also getting very interesting, for example Semikron MiniSKiiP.

author: madsbarnkob
author_rank: Frequent Contributor
timestamp: August 10, 2018, 07:34:54 am
content: Quote from: jbb on August 09, 2018, 11:26:16 pmYes I agree, I just call them output inductors, but you are right there is a difference between a output inductor for a single line and then inductors used for combining multiply parallel lines.Running 3 phase modules with all three half-bridges in parallel is properly getting a much cheaper and easier option than using either more expensive largers bricks or many TO247 parts.After I was done with the video, I found out that the modules are quite interesting, they can be pried off the PCB with a large screw driver, as the pins sit in tight sockets inside the module and the pins then remain soldered to the PCB.
Teardown of a medium voltage fuse (7200 V / 200 A) - Page 1
Forum section: electronics / projects

author: madsbarnkob
author_rank: Frequent Contributor
timestamp: December 18, 2017, 11:50:23 am
content: I got my hands of a old NEBB (Norsk Elektriske Brown Boveri) medium voltage fuse, rated for 7200 V, 200 A and 350 MVA. My best guess from the company name is that it originates from before 1988 where NEBB was merged with ASEA into ABB.Medium voltage fuses are used at the secondary side of distribution transformers, which are often the link from the transmission grid to the distribution grid.Here is the video of the teardown and below are some of the pictures, which also are used in the video.The fuse implements a Striker system that is a series of trigger mechanisms to let a spring loaded pin fly out of one end, in case of a fuse failure, to activate a mechanical shutdown or electrical feedback when there is a blown fuse due to over-voltage, over-current or too high temperature.Here the disassembled fuse can be seen, the blown fuse element and the single small parts of the chain that has blown apart nice and evenly.* imagine pictures of fuse element here *The still intact fulgurites from the melted fuse element can be seen here in greater detail. It is really interesting to see how the inside is now a insulated glass tunnel and the small silver beads have been pressed out and fused with the sand. The structure of the fuse element creates fulgurites that has alternating white stribes containing silver beads and yellow stribes that is only sand/glass.* imagine pictures of fulgurites here *
Tearing Effect signal on touch display - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: September 24, 2024, 11:22:17 pm
content: Hi,first time using this type of touch display (datasheet attached) and I am planning to use it with a STM32 micro (still not decided which one).The touch display has a Tearing Off output pin. After a bit of searching it looks like I need to connect it to the micro. I would have thought a micro using MIPI-DSI would have an option with a dedicated pin for this as it seems it is for synchronising the image refresh so it would need to be high speed and sychronised... but I cannot find such option on the micros I looked at.Do I really need to connect that to the micro?And how do I use it exactly?Thank you

author: Smokey
author_rank: Super Contributor
timestamp: September 25, 2024, 12:55:18 am
content: "High Speed" is relative when you are talking about LCD refresh rates. It's probably like 60hzYou would use that signal to known when the display driver is done doing a screen refresh so you can write new data to the buffer. If you write data to the buffer while it's refreshing, you will see a line that looks like it's tearing across the display.

author: ricko_uk
author_rank: Super Contributor
timestamp: October 04, 2024, 04:42:11 pm
content: Thank you @Smokey,Because I am planning to use DMA, I was trying to figure out how to use it so the hardware uses it directly.Thank you
TECBOND 7718 on PCBs, anyone else used it? Looking for some reassurance. - Page 1
Forum section: electronics / projects

author: Psi
author_rank: Super Contributor
timestamp: August 31, 2025, 12:48:46 am
content: Hi, I'm looking for some reassurance around the use of TECBOND 7718 on PCBsTECBOND 7718https://docs.rs-online.com/5a7e/0900766b80371993.pdfWe got a PCB returned with some corrosion below the TECBOND glue, see photo below,And there has been some internal discussion around what caused this damage.My view is that it's obvious water ingress/damage. Water got inside the unit and onto the PCB where it found its way under that area probably due to it being a sort-of 'water trap' where water can find a spot to stay retained due to surface tension. Hence explaining corrosion in this spot.But there's also another concern held by a company director, mainly due to the comment in the TECBOND 7718 datasheet about it absorbing some moisture from the atmosphere. They're worried that TECBOND 7718 might be causing this corrosion and worry that we should stop using it. It seems fair to want some reassurance around this, since it's being used on all units atm.(I think they had one of those old KRK Rokit speakers which died due to moisture from the black gunk used on the pcb. Dave once did a video on that. So you can understand their concern.)So I thought I'd post here and get some other engineer's opinions on TECBOND and its safe use.Anyone else use TECBOND 7718?A few things of note- I have an older RnD PCB that has the same TECBOND 7718 on it. No signs of any corrosion under it or around the TECBOND.- This is the only PCB we have seen with corrosion in this area.- The unit with the corrosion was only 2 months old. I reckon if it was glue moisture related it would take way longer than this.- The datasheet says water absorption "does not affect the performance and all test data relates to fully saturated material." and this stuff is intended for electronics encapsulation.- The TECBOND 7718 we use was obtained from a legit supplier.

author: Whales
author_rank: Super Contributor
timestamp: August 31, 2025, 01:14:46 am
content: Are those relays underneath? Might be worth cutting them open and having a look, just in case they became filled with water at some point and slowly leaked out.The waterline around the edges of the glue on the PCB is interesting, looks like it was a single wetting event with decent volume rather than a gradual seepage or repeated episodes.

author: Psi
author_rank: Super Contributor
timestamp: August 31, 2025, 03:25:26 am
content: Quote from: Whales on August 31, 2025, 01:14:46 amThanks, I had not noticed that yet, but yes it does indeed look like a water line.They are DCDC modules, and are potted from underneath from factory so nothing inside to look at sadly.I've not got the PCB in my hands yet, just the photo. It's being shipped back atm.

author: Simmed
author_rank: Frequent Contributor
timestamp: August 31, 2025, 08:57:01 am
content: my guess is that the screw started it
Tech with scope needed in Palm Harbor, FL - Page 1
Forum section: electronics / projects

author: JohnnyP
author_rank: Regular Contributor
timestamp: July 23, 2013, 01:04:59 am
content: Is there anyone here from the Palm Harbor, FL area with a scope that would like to look at coil signals on a Lamborghini Aventador?I make an ignition timing controller. The installer says everything is ok until they turn on the nitrous, then the ignition seems to "break up".I can PM the installer's name and cell number if you are interested in helping.Thanks for any help.JohnP, J&S Electronics

author: eKretz
author_rank: Frequent Contributor
timestamp: July 23, 2013, 04:55:27 am
content: Hmm, would love to help with this if I were closer, but I'm in Indiana. They wouldn't do something so silly as to run the nitrous solenoid from the same power wire as your ignition controller I presume? Or have the controller so close to the solenoid that the EM field is screwing with it? Did the n2o system go on at the same time as the controller or did it work fine until the controller was installed? Did they change ANYTHING else?

author: eKretz
author_rank: Frequent Contributor
timestamp: July 23, 2013, 05:09:07 am
content: Heh, I just checked out your website, saw you had a blurb from Todd at Protomotive. A good friend of mine used to work for him; do you know Ben Strader from EFI University?

author: JohnnyP
author_rank: Regular Contributor
timestamp: July 23, 2013, 07:37:21 am
content: What a small world. I've never met Ben, but we have talked a few times on his efi101 forum.I told the installer to check this thread. It's possible there is an install issue as you suggest.

author: eKretz
author_rank: Frequent Contributor
timestamp: July 24, 2013, 03:31:03 am
content: Well, that would be my first avenue of investigation, anyways.Yeah it is pretty neat how you can run into people you didn't realize were that close to your circle pretty much anywhere. I grew up with Ben, he lived on the next street over from me when we were kids. I went out to visit him at his first shop before he started the EFI101 thing.Any news back from the installer yet?
Technical documents on electronics - How to know/find them? - Page 1
Forum section: electronics / projects

author: chimerahitman
author_rank: Contributor
timestamp: January 16, 2013, 09:00:35 pm
content: I watched Dave's latest video, #410, and I saw that he pointed out some standard: IEC or IEEE or something like that.How does one go about this knowledge? I am supposing that you do not have to mentally store all the numbers with related information, and that somewhere on the web there is a browser similar to Google that you can type in a search term, i.e. "ICE Debugger", and receive a list of related documents.Is this correct?Reason I ask is because I want to find out, this time around, for distances between copper traces at different voltages. I say this time around because I would like to be pointed out how to look up this information by myself and not rely on having to ask the forum each time.Thank you for your time,SRR

author: free_electron
author_rank: Super Contributor
timestamp: January 16, 2013, 10:27:13 pm
content: IPC2221 is the offical spec. IPC765 also has info. there is newer version that succeeds 2221, 2456 i believe ... i need to look it up.You can get them at IPC .www.ipc.orgThose are the 'gold standards'As for knowing where to find this stuff . that's called experience ... as for 'mentally store all the numbers with related information,' that's exactly what happens over time.same goes for pinouts of commonly used parts. i can give you the pinouts of most 74 and 4000 series off the top of my head. same for lots of other components i have used.

author: Neilm
author_rank: Super Contributor
timestamp: January 17, 2013, 07:26:08 pm
content: Quote from: chimerahitman on January 16, 2013, 09:00:35 pmIf you are making a commercial product then the chances are that there will be international safety standards. These will probably produced by the IEC and then are enacted by each country into the local law. This might mean minor changes (for what ever reason usually references to local regulation). For instance, one standard you will see a lot on this forum is IEC61010. This is the international standard for test and measurement equipment and all multi-meters, clamp meters etc must meet it.The difference between the IEC and the IPC is that the IPC is an industry association. The IEC is an international regulatory body that has representatives of countries national governments or official technical bodies.The clearance data in the IPC2221 standard does not take into account any transients. For instance, the usual mains rating is 300V CATII. The CATII indicates that there could be high voltage transients (2kV from memory) superimposed. If you space it for the transient, then you will have a lot of space between conductors, but if you space it for 300V it will arc over if a transient occurs. This is what is specified in the international regulatory standard.Neil
Technical documents to prepare for hardware products - Page 1
Forum section: electronics / projects

author: fedimakni
author_rank: Regular Contributor
timestamp: April 14, 2025, 02:10:42 am
content: Hello,I would like to create a document which i can use to fill the requirements of a hardware project for software, electronics and mechanical constrains before the start of a project (can be adjusted during design or add points to complete it after finalizing the project).In my mind that document should list PCB size enclosure size, power IN/OUT interface, type of microcontroller, software used, bloc diagrams activity diagrams and all other required details. I can add to it the schematic and source code...I tried to ask chatgpt about documents and he provide titles like:Product Requirements Document (PRD)System Requirements Specification (SyRS)Technical Specification (or Hardware Specification)I tried to look for templates or actual documents shared by manufacturer or engineers on the internet but i was not successfulMy point is i would like to ask what are the documents used to illustrate such requirements and if you can share templates or actual documents i can inspire from them.Note: I know that it depends on the project and it is very vague but i want something to start with to get more ideas rather starting from scratchThank you

author: Smokey
author_rank: Super Contributor
timestamp: April 14, 2025, 02:32:37 am
content: Great job recognizing that something like this is a good idea. Every real company has their own version of this system. They are typically custom for whatever that particular companies design process looks like.You might want to look at ISO9001 templates for engineering companies. That covers a lot of the requirements and process documentation.
Technical Handbook (German) for mechanical engineering - free - Page 1
Forum section: electronics / projects

author: Haenk
author_rank: Super Contributor
timestamp: May 19, 2024, 09:40:22 am
content: https://www.schaeffler.com/remotemedien/media/_shared_media/08_media_library/01_publications/schaeffler_2/catalogue_1/downloads_6/stt_de_de.pdfMainly targeted at mechanical engineering, this might come in handy elsewhere, too.I used it at university back in the days. Now as a 2023 edition; folks in Germany can order a printed edition for free as well.

author: ksjh
author_rank: Regular Contributor
timestamp: May 19, 2024, 10:49:12 am
content: Great, thank you.I just found an English version of this book:https://www.schaeffler.com/remotemedien/media/_shared_media/08_media_library/01_publications/schaeffler_2/catalogue_1/downloads_6/stt_de_en.pdf
Tegra K1 base design - Page 1
Forum section: electronics / projects

author: subzero
author_rank: Newbie
timestamp: December 14, 2017, 01:31:54 am
content: Hi all,Has anyone done any work on a basic Tegra K1 board (bare minimum processor with LPDDR3, power management, boot, JTAG)? I've had a look at the nVidia reference design, but I was interested in looking at a more minimal implementation if one was around.Thanks!

author: subzero
author_rank: Newbie
timestamp: December 14, 2017, 02:26:22 am
content: K1 seems to be the only processor in the Tegra range that is readily available for individual purchase. X1 and X2 are next to impossible to get a hold of for the time being.

author: bobaruni
author_rank: Regular Contributor
timestamp: December 14, 2017, 02:40:40 am
content: Quote from: blueskull on December 14, 2017, 02:33:44 amI wish they were only $200, more like US$499 which is more like A$650https://www.arrow.com/en/products/900-83310-0001-000/nvidia

author: bobaruni
author_rank: Regular Contributor
timestamp: December 14, 2017, 03:08:25 am
content: This won't work for myself but the OP may have a way of doing this

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 14, 2017, 07:08:38 am
content: You can get a complete media player with the X1 chip for $150.https://slickdeals.net/f/11017579-16gb-nvidia-shield-streaming-media-player-w-remote-149-free-shipping?src=sticky
Tek 2445A power supply - should I be worried? - Page 1
Forum section: electronics / projects

author: c4757p
author_rank: Super Contributor
timestamp: May 04, 2013, 12:20:58 am
content: This should be a rather quick question. I just replaced the capacitors in my Tek 2445A's power supply (many of them were getting pretty bad - bulges and leaks and ESR, oh my!).I've never tested it separate from the entire scope before, so I don't know if it was like this before, but after changing the caps and powering it up by itself on the bench, I discovered: 1) It's unstable with less than around 5W load - yes, I know this is perfectly normal. 2) When it's having its unstable, squealing fit, this resistor (marked in attachment) cooks. That means that capacitor that's in series with it is passing at least 24 mA RMS! That seems a bit surprising to me, considering that it's only 4.7 nF. (Yes, the cap is fine, it hasn't shorted.)Should I be worried that I messed something up when I was repairing it, and that it's going to ruin my oscilloscope when I put it back in, or is it perfectly normal for a supposedly good quality Tektronix power supply to not only become unstable when not loaded (this, of course, is normal), but absolutely shit itself and start charring resistors? It does seem to be working fine with a new R1071 and a 5 ohm bit of resistance wire across the +5V output.

author: c4757p
author_rank: Super Contributor
timestamp: May 04, 2013, 01:26:24 am
content: OK, well - feeling a bit reckless, I went ahead and tried it. Yup - works fine. (And the already decent noise floor has improved significantly as well)Still - any thoughts on why it does that?

author: kt315
author_rank: Regular Contributor
timestamp: May 04, 2013, 04:17:59 am
content: Glad it turned out well.

author: SeanB
author_rank: Super Contributor
timestamp: May 04, 2013, 05:30:24 am
content: Probably the power loop was oscillating with no load. Many power supplies will do so with no load, some will just oscillate and some just blow up within seconds as they dissipate power in portions not designed to do so.

author: amyk
author_rank: Super Contributor
timestamp: May 04, 2013, 10:46:34 am
content: Quote from: SeanB on May 04, 2013, 05:30:24 amThe SMPS in the earliest IBM PC and XT would do this and had a very high minimum load - units that shipped without hard drives had a 50W(!) power resistor mounted in its place.

author: c4757p
author_rank: Super Contributor
timestamp: May 04, 2013, 11:57:01 am
content: Huh. I figured it would have some sort of protection against damaging itself. I suppose it doesn't really need it though, considering it's meant to spend its whole life permanently mounted in an oscilloscope!Thank you.
tek 453 scope mod - Page 1
Forum section: electronics / projects

author: m3vuv
author_rank: Super Contributor
timestamp: March 17, 2018, 10:49:56 pm
content: hi all ive a tk 453 scope ive repaired,just out of interest it has a nuvistor front end,just wondered if anyone here has converted one to a fet front end ,dont need to but may be an option if a nuvistor dies,cheers m3vuv.

author: JohnPen
author_rank: Regular Contributor
timestamp: March 18, 2018, 09:10:02 am
content: I haven't converted the Y amp front end nuvistors but have replaced the A timebase nuvistor with the FET equivalent as per 453A. This came about when the A TB nuvistor failed, proved by nuvistor swapping, plus an associated tunnel diode failure. I did look at replacing the B timebase nuvistor but as that one was OK I left it alone. I did investigate whether to update the front end circuitry to FETs but decided to leave well alone. To modify the existing Y board would be quite complex whereas the TB changes were easily modified on the existing TB board. Probably one should create a small PCB with the 453A FET circuitry on it and then replace the nuvistor related components. Maybe someday but I hardly use the 453 these days as it is very much a backup scope in case my regular scope has a problem.John

author: m3vuv
author_rank: Super Contributor
timestamp: March 18, 2018, 09:28:57 pm
content: yup i think i will leave well alone for now,im like you i have an hitachi scope i normaly use,so im using the principal if it aint broke dont fix it.73 m3vuv.

author: Cyberdragon
author_rank: Super Contributor
timestamp: March 18, 2018, 11:22:31 pm
content: Nuvistors apparently have a 50,000 hour life, don't mess with them.
tek 495p help - Page 1
Forum section: electronics / projects

author: KTP
author_rank: Frequent Contributor
timestamp: September 30, 2010, 12:10:45 am
content: I wiped the inch of dust off the tek 495P spectrum analyzer I bought with some other junk (a 2465A) for $200 and change at an auction and powered it up with the 100mhz calibration 50ohm output hooked directly into the 50ohm input. After doing some sort of powerup test, it displayed the 100mhz fundamental and all of the harmonics in decreasing amplitude. So at least it must be working somewhat. There are at least 3 x 10^6 buttons on the front panel and the only one I really know how to use is labled "power"So....does anyone happen to have a pdf of the operators manual, service manual, etc? I really haven't gotten to the point in my EE classes where I have need of a spectrum analyzer, but I wouldn't mind tinkering with it until then.

author: KTP
author_rank: Frequent Contributor
timestamp: September 30, 2010, 12:22:54 am
content: nevermind, I found it online through a link in a really cool document by a John Miles about repairing and troubleshooting 49x SAs.
TEK 7000 MF ...Paris?  - Page 1
Forum section: electronics / projects

author: jonpaul
author_rank: Super Contributor
timestamp: May 24, 2022, 08:52:27 am
content: Hello all:I have a TEK 7L5 spectrum analyzer in Paris.https://w140.com/tekwiki/wiki/7L5I need to test it out, but I have no mainframe...Anyone in or near Paris that has (or knows of ) a working 7000 eg 7603, 7704?We could RDV meet and test the plugin.Please PM me if its possible, I am here until mid July.Many thanks!Jon
Tek DPO - TDS3034 - also guilty of fake standby mode - Page 1
Forum section: electronics / projects

author: tom66
author_rank: Super Contributor
timestamp: August 10, 2012, 11:02:51 am
content: At work we use this fairly old Tek DPO TDS3034 - quad channel 300 MHz 2.5GS/s scope.I noticed that it gets very warm in standby, initially wrote this off as it feels like it uses a "real clunking" mains switch.Then when unplugging it from the rear, I noticed it lasts about 0.5 seconds with no power, but when turning it off from the front, it dies instantly.So I'm pretty sure that the mains switch is fake just like in the Agilent and just controls the REMOTE pin or similar on the PSU. But I'm not allowed to open it to confirm. Anyone else brave enough?

author: Wim_L
author_rank: Regular Contributor
timestamp: August 10, 2012, 12:22:18 pm
content: Haven't opened one, but I can confirm that one left plugged in but turned off for weeks is pretty hot on top. That should really be all the evidence you need.
Tek High Voltage Probes derating with frequency - Page 1
Forum section: electronics / projects

author: PartialDischarge
author_rank: Super Contributor
timestamp: May 13, 2017, 04:10:49 pm
content: For some time I've been curious about the derating with frequency in HV x1000 tek probes. Attached is the derating for one of the first models, P6013A, 12kV@100kHz, newer models have a similar derating. So my question is exactly what are those deratings due to:1) Resistor Voltage gradient2) HF dielectric loses3) Damping resistorI understand #1 (the size and intercapacitance of the ceramic 99.9Mohm resistor voltage limits), but not #2 and #3. And what exactly is the damping resistor? Any help?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 13, 2017, 09:56:30 pm
content: At HF, the main (100M) resistor is bypassed by compensation capacitors, putting all the voltage drop across the series resistors.The series resistors (and the shunt resistors in the compensation box) set the HF resistance, and division ratio, independent of the LF components.Tim

author: PartialDischarge
author_rank: Super Contributor
timestamp: May 14, 2017, 06:02:55 am
content: I wonder if they come up with graphs like these theoretically or experimentally, in the latter case I'd like to see those power HV amplifiers on ebay

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 14, 2017, 09:17:36 am
content: Well, if it were experimental, it would probably be a noisy, sparse data set, interpolated with a curve. Instead, they present a PWL graph. It's a Bode plot derived from the relevant limits (V and P).Easy enough to see. Take this one for example,The RC circuits are simply crossovers, where the high value resistors matter at low frequency, and the low value resistors matter at high frequency.Tim
TEK scope cal near Paris?  - Page 1
Forum section: electronics / projects

author: jonpaul
author_rank: Super Contributor
timestamp: October 01, 2025, 09:53:36 am
content: hello all I Just finished restoring a fine 2465B : Usual A5 SMD corrosion NVRAM , PSU power supply blown RIFA capsIt now works perfectly, but of course out of calibration, especially horizontal and vertical.my lab here in France does not have the Cal fixtures TEK required.If anyone near Paris has the time mark or voltage calibrations fixtures, like TM 501 PG 506 I will appreciate. Perhaps we can arrange to meet and I could borrow the fixtures or bring the scope.Many thanksHave an absolutely fantastic dayjon
TekBox TEM cell – how is it constructed ? - Page 1
Forum section: electronics / projects

author: tomud
author_rank: Regular Contributor
timestamp: April 16, 2024, 09:01:38 pm
content: I am wondering about the design of the TEM cell made by TekBox. They used an interesting solution by dividing the septum into several transmission lines to reduce resonances and suppress perpendicular electromagnetic fields.They used some electronic components to connect the transmission lines. However, they are covered with something, probably to make their identification difficult.Unfortunately, I don't understand how it works and what these elements may be. I found two scientific articles on a similar topic on the Internet (attached). Resistors were used there, but it was not explained why and how the values of these resistors were selected.There are also some speculations about it on the Internet.The first statement talks about using resistors or ferriteshttps://essentialscrap.com/tem_cell/temcell.htmlQuoteThe second statement from this forum talks about using capacitors (topic Parametric TEM cell design):https://www.eevblog.com/forum/projects/parametric-tem-cell-design/msg4068439/#msg4068439Quote from: krokodyl1220 on March 22, 2022, 07:05:26 pmMaybe there is someone smarter than me here and can explain how it works. Alternatively, point me to some scientific articles that will explain the principle of operation and allow me to select such elements when building my own chamber for hobby purposes. Of course, if a working TEM cell is built, the project will be made public for free, including on this forum.Attached is a photo of the septum PCB from the TekBox chamber (from a video on YouTube) and scientific articles I found.

author: tomud
author_rank: Regular Contributor
timestamp: April 19, 2024, 10:58:10 pm
content: For those interested, I found a scientific article that explains this problem a bit (attached).Personally, I'm waiting for the PCB I ordered, so I'm not able to write more at the moment. The PCB is modeled after the TekBox septum - I based it on the photos I found on the Internet (we'll see what the results will be).

author: tomud
author_rank: Regular Contributor
timestamp: April 29, 2024, 09:53:17 am
content: Well, we're slowly starting to start building the TEM cell. Let's see what the results of the test version will be...

author: tomud
author_rank: Regular Contributor
timestamp: May 01, 2024, 04:36:06 pm
content: And the TEM cell is assembledThe effect is as in the attached photosWhen it comes to components, I tested resistors in the 40R - 820R range. They improve the lower frequency band, which is somewhat spoiled by the notches on the Septum PCB. I ended up using 100R - it's possible the choice could have been better, but I didn't have many resistor values in stock.

author: dexar
author_rank: Contributor
timestamp: September 19, 2024, 06:13:25 am
content: Nice build! Can you please share the gerber for the septum and the dimensions of the body.
Tektronics THS720 on screen measurements - Page 1
Forum section: electronics / projects

author: distefanom
author_rank: Contributor
timestamp: May 01, 2023, 11:19:01 am
content: Hi guys!I have a THS720 0scilloscope with a strange quirk.Almost Sure is because of my ignorance. The problem is this.When I activate an on screen voltage measurement (mean, RMS or any other), if the vertical scale puts the track off-screen, the shown voltage indicators are as well the track is shown in a wrong position.See the enclosed images.I'm testing a 19Vdc signal at the CH1 probe. I set-up a vertical voltage measurement @ 5 V/div.In the second I selected 2 V/div. with the very same voltage input.As you can read the measuremens shown are wrong as well the track position in the second image.Why is that?Can anyone explain to me why this happens?

author: shakalnokturn
author_rank: Super Contributor
timestamp: May 01, 2023, 03:26:09 pm
content: This isn't the most appropriate section of the forum for the question.To me this looks like a defect in CH1 input attenuator, does the scope behave the same if CH2 is used for the same measurements?

author: distefanom
author_rank: Contributor
timestamp: May 01, 2023, 03:58:10 pm
content: Yes, it is the same on both channels.Sorry if this isn't the appropriate section.Please tell me where I should put this thread, or if any admin can do this for me, I'll appreciate it. ThanksMario

author: mk_
author_rank: Regular Contributor
timestamp: May 01, 2023, 04:26:17 pm
content: Quote from: distefanom on May 01, 2023, 03:58:10 pmSchematic attached... maybe helpful for deeper diagnosisgood luck

author: TERRA Operative
author_rank: Super Contributor
timestamp: May 02, 2023, 11:44:44 am
content: Check your channel marker, the black arrow/tag labelled '1' on the left hand side of the screen, that's your zero volt reference point for that channel, you have it offset down from the centerline on the graticule.If you count up from the channel marker, your voltages match up.Any other discrepancy could maybe be explained by mismatched probes, a scope that need a calibration/adjustment (Looking at the service manual, it doesn't seem toooo difficult on these units) or the source device not outputting the expected voltage.Do you have another voltmeter you can use to compare?

author: HighVoltage
author_rank: Super Contributor
timestamp: May 02, 2023, 11:50:27 am
content: What probe are you using?
Tektronix 1485R - Page 1
Forum section: electronics / projects

author: Zeitkind
author_rank: Contributor
timestamp: March 27, 2017, 09:57:51 pm
content: Hiho!A friend asked me if I want an old waveform monitor - for a beer. I have some very basic knowledge what a waveform monitor was used for (analog TV is dead), and I'm not into any kind of old analog TV stuff. But, AFAIK, a waveform monitor is more or less a kind of X-Y scope with some more special things around and I wonder if someone hacked/modded an older one for something.. useful?Kicking those units into the trash is.. well.. hmm.. Anyone?For all those DVB-T receiver that will soon flood the dumpsers here, i also look for any useful <whatever>. DVB-T will soon here be dead (forced migration to DVB-T2), so thousands of old receivers will get trashed.Many USB-dongles with RTL chips can be used as nice software defined radio receivers aka cheap spectrum analyzers, but the "normal" receivers?

author: TerraHertz
author_rank: Super Contributor
timestamp: March 29, 2017, 10:57:24 am
content: Analog video is still used for security cameras, and if someone offered one to me I'd gladly accept. (Mine has a CRT damaged in transport.)But I doubt it's worth trying to convert it. You should take it, then offer on ebay for $50.

author: Zeitkind
author_rank: Contributor
timestamp: March 29, 2017, 12:40:01 pm
content: All I have are WIFI-webcams, mobiles and my ancient Sony Digital-8 ^^I watched some infomational videos about waveform monitors and vectorscopes on youtube yesterday, well, no, I don't really need a working unit and if modding isn't a choice, my friend gonna try ebay. Otherwise, the Mount ElectroGarbage will grow again..And also, prob. millions of working DVB-T(1) receivers will be tossed the next weeks here, it's a shame. I will try to get some with dedicated power boards inside and will try to convert them to RasPi-cases or whatever, but well ..
Tektronix 176 tear down. - Page 1
Forum section: electronics / projects

author: harrimansat
author_rank: Regular Contributor
timestamp: September 26, 2016, 07:10:14 pm
content: Hi, has anyone service manual for a Tektronix 176? Mine now works, but I would like to know how it works.http://www.vishay.com/docs/40021/wtintro.pdfWet Electrolyte Tantalum Capacitors
Tektronix 2465B restoration - Page 1
Forum section: electronics / projects

author: jonpaul
author_rank: Super Contributor
timestamp: August 18, 2023, 04:48:33 pm
content: Bonjour a tous:Voila!A very sick 2465B, a 5 years battle: Highly optioned GPIB, CTT, WR.Supposedly "worjing fine but power was fixed" off epay.....in 2018!Was partly disassembled, SMPS power supply, rattling loose inside , all cables disconnected, not starting...dead NVRAM chip, A5 control bd corroded due to leaking SMD lytics and finally multiple strange issues ..turned out to be scratchy pots on front panel...Still needs a full CAL and AUTO trig odd...but all 4 ch and all controls fine, and CRT bright anfd focused.Finally, satisfaction!"Luck and superstition win every time, talent had nothing to do with it""Walked away from another one"(old Pilots jokes..)Your comments appreciated!Jon

author: DavidAlfa
author_rank: Super Contributor
timestamp: August 18, 2023, 07:42:53 pm
content: Congrats!Yes, the PSUs need recapping most of the time, some version have blue caps with red bottoms that love to leak everywhere, sometimes the legs weren't there anymore, held by some sticky residue.The ones with gray caps were all ok.I fixed a dozen of these at my job, mostly the same issue.. others had bad modules, like the preamplifier (Distorted signal) ot the famous... U800? Can't recall right now.And of course... the NVRAM. Which I didn't bother saving, because they all were f*** wrong, the previous guy simply renewed the "Calibrated" sticker, but never did anything to them, so things like showing a 60MHz signal when inputting 50MHz, way off amplitudes, ground moving up/down when changing V/div...Calibration is lengthy and tedious, but pretty simple... but you need a second, fast oscilloscope to do the adjustments, and a pattern generator up to 1ns if I remember correctly.
Tektronix 3001gpx probe connector pinout - Page 1
Forum section: electronics / projects

author: TrooperN
author_rank: Contributor
timestamp: September 01, 2021, 02:15:57 am
content: Hello, I'm not sure this is the correct category to put this so here goes, I have been looking for a pin description for any of the four probe connectors, I have done some googling and haven't been able to find anything on the probes or connector, other than the probe the 3001 uses is the P6490. If anyone has or knows where a pinout can be found and would be willing to post it that would be greatly appreciated!

author: bdunham7
author_rank: Super Contributor
timestamp: September 01, 2021, 02:29:27 am
content: It's not in the service manual?https://w140.com/tekwiki/wiki/3001GPX

author: TrooperN
author_rank: Contributor
timestamp: September 01, 2021, 03:04:14 am
content: I looked in that manual and didn't see anything and I don't think that is the right manual, the picture in it shows a connector that looks like a centronix 50 pin and not like a dual row header that is on the one I have.
Tektronix 3024B network connection - Page 1
Forum section: electronics / projects

author: austnais
author_rank: Contributor
timestamp: January 12, 2016, 01:58:19 pm
content: Hi guys,First post on the forum!I have a Tektronix 3024B oscilloscope with a RJ45 plug. It's connected to the network and by typing the IP in the address-field I'm able to log in to it. So far so good.But then, I want to control it (setting trigger etc..) and I've been told this is possible to do by pressing the control button on the top bar. (see attachement)But all this does, is sending me to the tek.com homepage!! Does anyone know what's going on? I've just updated (with floppy-disk) the firmware to version 3.41, presumably the newest one.Thanks for any input!Cheers,
Tektronix 466 - Page 1
Forum section: electronics / projects

author: TheOscilloscope
author_rank: Newbie
timestamp: July 30, 2012, 02:09:10 am
content: I have a Tek 466 oscilloscope that is in need of repair. There is no high voltage to the CRT. Looking closer I noticed that the high voltage oscillator circuit that drives the CRT was not oscillating. I was wondering if anyone has seen this problem before and might know where I should start to look. So far I have checked a lot of resistors and transistors in the circuit and they all seem good.

author: w2aew
author_rank: Super Contributor
timestamp: July 30, 2012, 03:13:13 am
content: Check the components on the HV side of the transformer, those that create the -2KV bias to the cathode. HV caps and diodes could be at fault, and causing the oscillator not to oscillate. The service manual includes a nice troubleshooting chart for the HV supply. Of course, check all of the low voltage DC supplies that provide power to the HV supply circuit. The +15KV anode voltage is generated off of the cathode supply.These notes are based on the 465B, which should have a similar HV supply.