hybridfree/eevblog-posts huggingface dataset:
A sincere help explain the function of C - Page 1
Forum section: electronics / testgear

author: abdulbadii
author_rank: Frequent Contributor
timestamp: July 04, 2022, 05:41:07 am
content: Anyone outright understand then sincerely help explain the function of C4in Q4 E (C6on Q5 E) ?

author: ataradov
author_rank: Super Contributor
timestamp: July 04, 2022, 06:02:43 am
content: This is a bypass capacitor that is often used in a common emitter amplifier. It drastically increases voltage gain and lowers input impedance of the amplifier.There are a lot of articles describing how the common emitter amplifier works and formulas to calculate the values for given amplifier parameters. Just search for "bypass capacitor in a common emitter amplifier" and you will find a lot of articles.Series resistor is less common, but it can be used to limit the gain.

author: iMo
author_rank: Super Contributor
timestamp: July 04, 2022, 06:16:01 am
content: C4 and C5 lowers the impedance in emitter thus increasing the transistor's stage gain with frequency (the higher the frequency the lower impedance of the capacitor C).Without the capacitor the stage gain will be reduced and given by the ratio of collector vs. emitter resistor values.The higher the frequency the lower the emitter impedance with the capacitor (and the higher the stage gain).In your case the impedance in emitter will go from 330ohm (stage gain aprox 4) at low frequencies (around DC) to 30ohm (stage gain aprox 40, 330ohm parallel with 33ohm) with high frequencies.Tip: learn the LTSpice simulations, LTSpice is free and handy..

author: tooki
author_rank: Super Contributor
timestamp: July 04, 2022, 03:56:58 pm
content: Think of those caps as short-circuits for AC that are simultaneously open circuits for DC. This lets you bias the transistor (with DC) where you want it to be, while letting it get optimal AC gain.

author: ledtester
author_rank: Super Contributor
timestamp: July 04, 2022, 04:40:47 pm
content: You can find the original presentation and discussion of this design (from 2012) here:https://eevblog.com/forum/projects/5-transistor-esr-meter-design/
B&K Precison and Siglent Handheld scopes identical - Page 1
Forum section: electronics / testgear

author: j_omega
author_rank: Contributor
timestamp: July 03, 2022, 11:48:05 pm
content: I was shopping around for handheld oscilloscopes and notices that B&K Precision and Siglent have identical case moldings for their handheld oscilloscope lines. Is one of these a rebrand of the other or are they both a rebrand of a third-party source?

author: tautech
author_rank: Super Contributor
timestamp: July 03, 2022, 11:54:34 pm
content: Siglent is the OEM for both of those, the SHS800 series now with a newer X version that few of us have seen as yet.https://siglentna.com/handheld-oscilloscopes/Some of BK's bench scopes are also of Siglent origin.

author: bdunham7
author_rank: Super Contributor
timestamp: July 03, 2022, 11:57:08 pm
content: Actually BK Precision's whole line appears to be rebadged Siglent with the exceptions of their analog CRO and this oddball which I can't place:https://www.bkprecision.com/products/oscilloscopes/2553-70-mhz-2-gsa-s-4-ch-digital-storage-oscilloscope.html

author: tautech
author_rank: Super Contributor
timestamp: July 04, 2022, 12:08:18 am
content: Quote from: bdunham7 on July 03, 2022, 11:57:08 pmhttps://siglentna.com/digital-oscilloscopes/sds1000cfl-series-digital-storage-oscilloscopes/

author: bdunham7
author_rank: Super Contributor
timestamp: July 04, 2022, 12:48:55 am
content: I guess the trim is a pretty good disguise. I didn't realize that line went to 300MHz.

author: tautech
author_rank: Super Contributor
timestamp: July 04, 2022, 12:58:41 am
content: Quote from: bdunham7 on July 04, 2022, 12:48:55 am4ch CFL have been around for some years and they are old school designs and like many of the A brands with very small memory depth although they were 2 GSa/s.The so much more powerful SDS2000X Plus models like you have consigned these old designs to history.

author: j_omega
author_rank: Contributor
timestamp: July 04, 2022, 03:05:09 pm
content: I also noticed that although they are externally different, the firmware for the Tektronix THS3000 series seems to be almost identical to the Fluke 190 series. Here is a post suggesting that the Tek is a re-brand.https://www.eevblog.com/forum/testgear/scope-suggestions-solutions-with-floating-isolated-inputs/msg3929744/#msg3929744Does the Tek scope also borrow hardware from the Fluke 190 model?

author: tooki
author_rank: Super Contributor
timestamp: July 04, 2022, 03:54:08 pm
content: Well Fluke and Tek/Keithley have the same parent company (and have for many years) so it’s not at all surprising they’d do internal rebadging. They did it in the past with some Fluke and Tek bench meters, too.
Tektronix P6245 Active Probe issues with config data - Page 1
Forum section: electronics / testgear

author: snoopy
author_rank: Frequent Contributor
timestamp: March 03, 2017, 12:11:24 am
content: HiJust got a 2nd hand Tek P6245 Active Probe. Probe seems to work but the scope (TDS784A) cannot read the configuration data from the probe and as such cannot run a probe compensation procedure which results in "Probe comp failed".I note that the probe has TDS500/600 written on it but I thought the newer scopes would still be able to read the data. What data is stored in the EPROM ?Any thoughts ?Cheers

author: snoopy
author_rank: Frequent Contributor
timestamp: February 12, 2022, 12:07:55 pm
content: For those interested in this probe I have uploaded all of the information I have on it which includes schematics, EEPROM dumps etc.cheers

author: d37duck
author_rank: Contributor
timestamp: May 20, 2022, 03:11:25 pm
content: Hi snoopy,Thanks for the Tek 6245 data download, nice work. Please tell us what equipment you used and your procedure for recording the data.Regards,

author: snoopy
author_rank: Frequent Contributor
timestamp: July 04, 2022, 09:10:31 am
content: Quote from: d37duck on May 20, 2022, 03:11:25 pmIt was a while ago but I picked up a small EEPROM programmer from ebay I think called CH341A programmer and used that to read and write the data on the probe EEPROM (24C02). From memory I may have used EZ hooks connected directly to the pins on the probe scope connector whilst it was not connected to the scope of course. Supply required.cheers

author: Mechatrommer
author_rank: Super Contributor
timestamp: July 04, 2022, 10:11:50 am
content: mind to tell what was the issue with config data? i have the Tek P6245 probe but dont have a Tek scope. was bought faulty with some ribbon carbon traces broken... i wonder how Tek scope communicates with the probe? does the Tek scope modify the eeprom content during recalibration?

author: snoopy
author_rank: Frequent Contributor
timestamp: July 04, 2022, 12:52:53 pm
content: Quote from: Mechatrommer on July 04, 2022, 10:11:50 amA couple of the probes had blank data so I copied data from a another working probe. Not sure how they got corrupted but that's how I got them. Oddly enough according to the schematic I mapped out, the WP pin appears to be floating. Not sure if it has an internal pullup ?cheers
Manual for an ESI LRC Bridge 2400 from 1983? - Page 1
Forum section: electronics / testgear

author: JonHendry
author_rank: Contributor
timestamp: July 04, 2022, 08:06:42 am
content: Noticed one of these LCR Bridges for sale on Facebook, but I'd like to find a manual for it.I've checked archive.org, manualslib, bitsavers, and other archive sites, and haven't found a manual.Anyone have a PDF handy or know where I could buy a hard copy?Thanks...
handheld automotive scope HDS272 or 1013d or OSC482 - Page 1
Forum section: electronics / testgear

author: florkk
author_rank: Contributor
timestamp: July 03, 2022, 08:04:30 pm
content: anyone can give any idea what to choose for automotive use? must be good 2 channel and stable trigger

author: Grandchuck
author_rank: Super Contributor
timestamp: July 03, 2022, 08:27:21 pm
content: https://www.amazon.com/Micsig-Digital-Automotive-Oscilloscope-ATO1104/dp/B07M9JJ6ZHI don't have one but it looks good.

author: Fraser
author_rank: Super Contributor
timestamp: July 03, 2022, 08:58:38 pm
content: Love my Micsig ATO1102Datasheet….https://www.batronix.com/files/Micsig/ATO1000/ATO1000-Datasheet.pdfhttps://www.batronix.com/shop/oscilloscopes/Micsig-ATO1102.html?gclid=CjwKCAjw_ISWBhBkEiwAdqxb9qoAwFi_5r9akiAYGMvhTd7BV_7i4b7n3XfOPITEAnO0EPd35Q2k7hoCFsYQAvD_BwEFraser

author: florkk
author_rank: Contributor
timestamp: July 04, 2022, 07:01:55 am
content: ye but im looking for some 200$ range and thinking one of this three models HDS272 or 1013d or OSC482
New UNI-T UT210E PRO clamp meter - Page 1
Forum section: electronics / testgear

author: odarek
author_rank: Newbie
timestamp: February 21, 2021, 12:12:45 pm
content: Hello,is there anybody here who has UNI-T clamp multimeter "UT-210E PRO" - a newer version of UT-210Ecould somebody unscrew the back cover and take some photos with components ids and put them here?so that we can compare the newer version of the meter "UT-210E PRO" with the older model "UT-210E" (without PRO)has anyone already tried to improve (hack) the newer version of this meeter?Best regards,oDarek- Attachments and other optionsNotify me of replies. Return to this topic.

author: anethema
author_rank: Newbie
timestamp: July 19, 2021, 05:20:02 pm
content: I picked one up yesterday I'll take some pictures of the guts later.

author: anethema
author_rank: Newbie
timestamp: July 19, 2021, 07:13:46 pm
content: Appears to be the same ICa as in the later model 210E meters.

author: anethema
author_rank: Newbie
timestamp: July 19, 2021, 07:17:45 pm
content: Sorry hard to see the eeprom

author: rauldm
author_rank: Regular Contributor
timestamp: June 26, 2022, 02:14:04 am
content: Nice pictures, someone has been customized eeprom for this clamp? is similar to ut210e?Regards

author: NoMoreMagicSmoke
author_rank: Regular Contributor
timestamp: July 04, 2022, 02:06:27 am
content: I have this. The standard 210e eeprom settings all worked with no issues.
I am looking for a custom op-amp IC from Advantest R3xxx,  spectrum analyzer. - Page 1
Forum section: electronics / testgear

author: ARF
author_rank: Regular Contributor
timestamp: July 03, 2022, 05:32:14 pm
content: I have been restoring Advantest R3265A for a long time and I need this amplifier.It is applied in several places in the device.Maybe someone has the R3265A IF-board or another Advantest spectrum analyzer for parts from the mid-90s?TOP MARKING - A-7111mark in the service manual - SHB-001655 video amp

author: nctnico
author_rank: Super Contributor
timestamp: July 03, 2022, 05:39:08 pm
content: Can you post the part of the schematic it is in? That could serve as pointers to what kind of part it is. Likely it is a custom part but maybe there are alternatives.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 03, 2022, 05:57:58 pm
content: Looks lumpy, probably a hybrid. Good luck!

author: ARF
author_rank: Regular Contributor
timestamp: July 03, 2022, 06:03:00 pm
content: This is a step amplifier, which consists of four such ICs. I think that pin 3 - gain selection will create a problem with replacing with a conventional amplifier.
HP3563A A38 MEMORY  BOARD EPROM REV_C FILES - Page 1
Forum section: electronics / testgear

author: profun
author_rank: Newbie
timestamp: July 15, 2022, 02:35:31 am
content: This is my first post on the forum!I recently repaired an hp3563a (a tantalum capacitor is broken), a very old instrument, but its function is very powerful. I have been using it for audio analysis. I used MCU tools to extract the system Rom. now I share the files. I hope friends in need can download them.
Does the Siglent SDS2202X-E Fan Run All the Time? - Page 1
Forum section: electronics / testgear

author: cortes
author_rank: Contributor
timestamp: July 02, 2022, 03:41:00 pm
content: I just got a Siglent Technologies SDS2202X-E Oscilloscope. The fan started running right after I plugged it in. I powered it on with the front button and later powered it off. It then went through a shutdown mode. The fan is still running the next day. Is this normal?

author: tv84
author_rank: Super Contributor
timestamp: July 02, 2022, 04:04:06 pm
content: Quote from: cortes on July 02, 2022, 03:41:00 pmI haven't heard Siglent got into the gyroscope world so, it sure seems something is not right.

author: tautech
author_rank: Super Contributor
timestamp: July 02, 2022, 08:45:07 pm
content: Quote from: cortes on July 02, 2022, 03:41:00 pmNew or used ?QuoteNo, it's certainly not normal and when you reply let's work through the next steps to take.
121GW multimeter Bluetooth - Page 1
Forum section: electronics / testgear

author: Monkeyboi
author_rank: Newbie
timestamp: July 03, 2022, 07:23:07 am
content: A question for Dave or the brains trust.Does the 121GW support Bluetooth 3.0 + HS (Atheros) ?The reason for asking is I would like to put my old Toshiba R830 laptop to use and it just can't see the BT on the 121GW.I know the BT on the Toshiba is working and has the latest drivers as it can see and connect to many other BT devices that I have.I also know the BT on the 121GW is working as I can successfully connect to my much newer Asus laptop.Any thoughts or suggestions would be most appreciated. Thanks

author: Kean
author_rank: Unknown
timestamp: July 03, 2022, 01:55:49 pm
content: It uses a Bluetooth Low Energy (BLE) connection, so won't work with a device that only supports BT 3.0.You need an adapter with BT 4.0 at a minimum for BLE support. You could try with a cheap USB BLE adapter.

author: Monkeyboi
author_rank: Newbie
timestamp: July 04, 2022, 03:35:24 am
content: Thanks Kean for the heads up.I will get a Bluetooth 5.0 to USB dongle. Worth the try as they are inexpensive.
BK Precision 1900B For automotive R&D? - Page 1
Forum section: electronics / testgear

author: Esquared
author_rank: Contributor
timestamp: July 05, 2022, 08:47:36 am
content: Hey ya!I was wondering if anyone has experience with the BK Precision 1900B which I'm told is a HCS-3600 that has been rebadged. I am doing R&D work for automotive power electronics and I need something that has that voltage range (0-16V) and a very high current and power rating. It looks like the 1900B is exactly what I need, but I am concerned given it is a switching supply. The ripple of 50mV is nothing in a car (at a set 13.00 volts it is roughly 0.4%) so I don't anticipate that being an issue for the DUT, but I have readhttps://www.eevblog.com/forum/testgear/power-supply-0-16v-with-high-current-and-voltage-sensing/msg3328756/#msg3328756and apparently they don't play nicely with electronic loads? This is pretty important for my use case as I need to be able to validate design & simulations with real-world data and I plan on using an electronic load to simulate different devices such as motors, pumps, etc. If they work fine with electronic loads and that was just one poster's experience I will go for that, but if it is genuinely a problem then it is a deal-breaker. If there are better alternatives in this price bracket then I would appreciate your direction.

author: rdsi
author_rank: Contributor
timestamp: July 06, 2022, 01:22:40 am
content: I have 2 of the 1901B 1 to 32V @ 30A. I bought a new one for the going price $527 and another one that popped up on eBay which I snagged for $91.Both operate just fine & I tested each one using my electronic load with remote sensing – no problems here!

author: Esquared
author_rank: Contributor
timestamp: July 06, 2022, 09:53:00 am
content: Awesome to hear! That one you got on ebay sounds like one heck of a deal!
Marconi TK2374 200MHz zero loss probe for 2730. Can it be used with 2382? - Page 1
Forum section: electronics / testgear

author: brian_mk
author_rank: Regular Contributor
timestamp: July 01, 2022, 03:56:36 pm
content: The TK2374 200MHz zero loss probe was designed for the Marconi 110 MHz TF2370 analyser.My question is: Is it compatable with the later Marconi 400 MHz 2382 (at least up to 200MHz)?From what I've found so far, the Marconi 2388 1 GHz probe designed for the 2382 needs a +/- 15V power supply.The TK2374 appears to use a floating 15v supply from the 2370 which it converts to -7.5v internally.It's not clear to me if you can simply plug a TK2374 into the probe power socket of a 2382.

author: TimFox
author_rank: Super Contributor
timestamp: July 01, 2022, 04:16:53 pm
content: I have successfully used the TK2374 probe with the 2382/2380 spectrum analyzer.I was confused when trying to understand the power connections through the auxiliary cable, but it does work.I measured the THD (at 500 kHz) of the combination, using a Wavetek 98 generator driving 0 dBm into a 50 ohm termination (either the SA input or a terminator at the probe input):Direct With 2374 probeFundamental 0 02nd harmonic -63 0.07 -37 1.43rd harmonic -61 0.09 -46 0.54th harmonic -70 0.03 <-72THD 0.12 1.5dBm % dBm %At 0 dBm/50 Ω = 0.22 V rms, the distortion of the probe is predominantly 2nd harmonic, with a total value of 1.5%. The DDS generator itself is quite clean, despite being at one-half its maximum frequency. The bandwidth of the probe (50 Hz to 200 MHz), should not matter at this frequency.
Recap PS tek 2235 - Page 1
Forum section: electronics / testgear

author: Suzook
author_rank: Contributor
timestamp: June 29, 2022, 10:23:30 am
content: Just picked up a nice 2235. Looks like it led a good life. I want to recap and mod the power supply, before the issues start. Anyone have a part list for just the PS caps/parts? Thanks

author: Suzook
author_rank: Contributor
timestamp: June 29, 2022, 11:12:14 pm
content: Am I posting in wrong area??

author: Old Printer
author_rank: Frequent Contributor
timestamp: June 30, 2022, 03:03:34 am
content: Artek sells very good quality reproductions of the user and service manual. You will be able to download the files. I bought a 2225 with a couple of quirks that needed attention, and I got the manuals from Artek. Well worth what it cost, Tek produced great manuals in those days.

author: bdunham7
author_rank: Super Contributor
timestamp: June 30, 2022, 03:32:08 am
content: I've fixed a few of these and I don't have parts lists because there are a lot of different versions. I can't remember which configuration they originally used in 2235 or what the updates were/are, but here's a good copy of the manual.https://w140.com/tekwiki/images/8/81/070-4206-00.pdfYou'll have to partially disassemble the scope and physically measure the capacitors to get the dimensions and lead spacing right. Someone here or atTekScopes@groups.iomay have more specific and detailed information, but if not it isn't that hard to figure out as you go along. That's what I do because I can't remember all the details from one unit to the next!Some seem to have it all burned into their brains, not me. If you have dimensions and so forth but have questions as to which caps need replacing or what versions to use, post back and you'll get opinions. My first opinion is that if the scope is working properly now, tread lightly and just do a bit at a time.

author: floobydust
author_rank: Super Contributor
timestamp: June 30, 2022, 04:56:58 am
content: I posted a 2235, 2235A recap list here:https://www.eevblog.com/forum/repair/tektronix-an-usm-4882235-high-8-6-v-ripple/msg2539461/#msg2539461The primary cap I upsize because modern parts are on the low value side, and I used the larger B values for the non-A.

author: bd139
author_rank: Super Contributor
timestamp: June 30, 2022, 10:24:17 am
content: Make sure you replace the mains filter and RIFAs on the input filter board as well. Those are fire hazards.
Fluke 199 repair (non booting/corrupt rom) - Page 1
Forum section: electronics / testgear

author: Spekham2013
author_rank: Newbie
timestamp: July 02, 2022, 08:41:03 am
content: Hi,Recently I purchased a Fluke 199 (not B/C model) in a non working state. Listed was that the meter was non-functioning and had suffered a battery leakage. When opening everything was nice and clean with the exception of the metal which was visibly corroded. When connecting power to the system and pressing the power button only a faint beep can be heard (every two presses that is). I checked the flyback converter, which was not getting the on signal. Next I tried to connect to the uart using a simple uart to usb. Here I could get into the mask rom, and test the ram, which worked. Thus also mostly concluding the D-asic is not broken.But now comes the point where I kind of hit into a brick wall. I found the updating utility to v4.08, but I don't know the serial number of the device. So I then just tried a random number and I get the error communication error, caused by corrupted rom or uart communication problem. So I went out and bought a nearly identical pinout rom chip, and soldered it on, and guess what same error. So now I am starting to suspect the problem lies somewhere else, but I am unsure where to look.My two ideas are:- Read out the flash chip directly- Desolder the D-asic and ensure no traces have corroded underneath (I have not yet seen evidence to suspect this)Any help would appreciated, thank in advance!

author: asis
author_rank: Frequent Contributor
timestamp: July 02, 2022, 12:09:59 pm
content: Hi,Follow the linkhttps://www.eevblog.com/forum/testgear/fluke-192-196-199-fw-upgrade/Zip file 28F160 TE28F160B3TA10.zip (510.89 kB) is posted there.You can see the serial number in the address range:001F8080 - 001F80B0 1F8082 = 0801321 (7 - digit) (080132.1) "DM0801321"&001FA080 - 001FA0B0 (double). (1FA082-double) = 0801321BUT!1. Before desoldering the chip, look carefully to see if it has been removed before.2. Chip TE28F160B3TA10 (Intel) has internal copy protection and may be blocked when trying to read / write.3. Back cover with serial number - may be from another scopemetr.Judging by your description, the scopemetr starts the mask verification procedure (UHM - Universal Host Mask v1.0) but does not see the required serial number.There may be other reasons as well.

author: Spekham2013
author_rank: Newbie
timestamp: July 02, 2022, 01:04:57 pm
content: 1. The chip luckily hasn't been desoldered before as far as I can see.2. Noted3. There is no sticker on the back anymoreThe system actually start UHM v2.1 although not sure if that information is relevant. I will see if I can get my hands on a flash programmer/reader.

author: asis
author_rank: Frequent Contributor
timestamp: July 02, 2022, 05:01:07 pm
content: Before you connect the chip to the programmer, read carefully the pdf on TE28F160B3TA10 section 3.3Be sure to write down the checksum the first time you read it.Better yet, find another 28F160 chip and experiment with the dump you downloaded (zip).
Can scope have DC power source instead of mains?..Tenma 72-8225 - Page 1
Forum section: electronics / testgear

author: Faringdon
author_rank: Super Contributor
timestamp: June 28, 2022, 06:18:22 pm
content: Hi,Someones just offered me a Tenma 72-8225 scope for £30https://www.farnell.com/datasheets/1955265.pdf....i would like to use it to scope the primary side of offline PSU...so need it to be battery, or isolated DC powered, not mains....d'you think this scope can be hacked to be like that?(i dont have diff probe or isol txfmr)

author: Gyro
author_rank: Super Contributor
timestamp: June 28, 2022, 07:08:56 pm
content: Unless you can find the service manual, with schematic, I don't think anyone can tell you for sure.I suppose it's pointless for me to remind you that it is not safe to float a scope. At least if you are in a rented caravan in Margate, the additional hazard to others will be minimised.P.S. Note the 5V/div maximum.

author: Faringdon
author_rank: Super Contributor
timestamp: June 28, 2022, 10:02:24 pm
content: QuoteThanks, youre right, defintely dont touch the BNC outputs of the scope while doing it.It kind of makes the mind boggle, say having a battery scope and hooking a 10:1 probe up to the primary high side gate drive of the LLC SMPS......that scope's internals will be batting up and down from 390V to 0V at ~50kHz......with relation to the surrounding earth.... and yet theres no stray capacitive effects........an ex boss had a battery tek-scope which had the scope BNC jacks in plastic, the touchable bit.

author: Gyro
author_rank: Super Contributor
timestamp: June 29, 2022, 09:49:32 am
content: Quote from: Faringdon on June 28, 2022, 10:02:24 pmWhatever else, a 100:1 probe will be mandatory - no Chinese switchable x1/x10.

author: Faringdon
author_rank: Super Contributor
timestamp: June 29, 2022, 10:33:57 am
content: Thanks, but for just the gate drives we will use x10, as its only 0v to 12v gate drive. (i havent yet ordered a 100:1, and will seek cheap)Youre absolutely right though, its better to stick to 100:1 in case of a connection mistake....
Opinions on the Keysight 34470A? - Page 1
Forum section: electronics / testgear

author: dcarolan
author_rank: Newbie
timestamp: June 28, 2022, 03:46:20 pm
content: Does anyone have an informed opinion about the Keysight 3370A?Are there better alternatives out there?

author: Dr. Frank
author_rank: Super Contributor
timestamp: June 28, 2022, 09:00:17 pm
content: 34470A? First post?Please use the search function.
Tektronix DPO7000 disk drive slides? - Page 1
Forum section: electronics / testgear

author: Jwalling
author_rank: Unknown
timestamp: June 27, 2022, 11:10:33 am
content: I must be using the wrong search term, but I don't seem to be able to find these (slides? guides?) anywhere.They are used on the removable 3.5" hard drive. Anyone know where these can be found (preferably on Ebay, but OK if somewhere else in the USA.)Thanks.

author: gslick
author_rank: Frequent Contributor
timestamp: June 27, 2022, 07:33:09 pm
content: A common name for those is "rails". If you search on eBay for "hard drive rails" or "floppy drive rails" you will find a wide variety.The challenge would be finding a set with the mounting holes in the right location and the overall shape of the rails that match your target system. If you can't find an exact match, maybe you can find a set that are close enough that they could be modified to fit without too much modification.

author: mikehank
author_rank: Regular Contributor
timestamp: June 28, 2022, 03:34:54 pm
content: These are excellent candidates for a 3d printer.
Aeroflex  Weinschel 3054 Step Attenuator, DC-6GHz, 0 - 70dB sale price advice - Page 1
Forum section: electronics / testgear

author: FPSychotic
author_rank: Regular Contributor
timestamp: June 28, 2022, 07:38:58 pm
content: Arrived to me an Aeroflex Weinschel 3054 RF Manual Microwave Step Attenuator, DC-6GHz, 0 - 70dB.I have no clue by how much I could sell it.Anyone can say me how much I can ask?It is great and it is in excellent condition.I would invest the money in other basic equipment I need for my learning.Just too good for me.
Whats this cheap HV  Diff Probe (Hantek HT8050) like? - Page 1
Forum section: electronics / testgear

author: Faringdon
author_rank: Super Contributor
timestamp: June 28, 2022, 05:44:18 pm
content: HiDo you know what is this Hantek 8050 diff probe like? $139 = £114https://www.alibaba.com/product-detail/HT8050-Hantek-1-50-1-500_1600120514756.html?spm=a2700.galleryofferlist.normal_offer.d_image.4caa78cdtmqhYT.The cheapest on Farnell etc is TA041 for £319https://uk.farnell.com/pico-technology/ta041/probe-active-differential-powered/dp/1667343
Rs pro desoldering gun a cautionary tale - Page 1
Forum section: electronics / testgear

author: Lafeu
author_rank: Newbie
timestamp: June 28, 2022, 05:30:05 pm
content: Mods feel free to delete lock etc.This type of soldering pump sold by rs components and by the look of it a number of look alikes on aliexpress. Seams to have a potential dangerous problem with over heating. Thanks to my credit card i managed to get a refund.Where on earth is the thermal cut out?
Information on Racal 9065A RF attenuator? - Page 1
Forum section: electronics / testgear

author: EC8010
author_rank: Frequent Contributor
timestamp: June 26, 2022, 06:57:28 pm
content: Today at an amateur radio rally, £15 bought me a Racal 9065A 1U rackmount RF attenuator. Input and output are on N connectors, three decade front panel knobs go from 0 to 200dB in 1dB steps, and taking the lid off suggests a pair of 0 - 100dB attenuators controlled by an alarming 5" x 6" logic board having 50 (!) discrete transistors and some pre-74 series logic. I'm guessing it's to convert the denary code from the three front panel rotary switches into appropriate relay controls for individual attenuators. Mains comes in on afairlylethal connector and the safety earth bond to chassis is the worst I've ever seen.It will clearly need a certain amount of remedial work, so any information that would help justify the time (or help fix faults) would be much appreciated.PS. I did search...

author: EC8010
author_rank: Frequent Contributor
timestamp: June 27, 2022, 03:52:39 pm
content: Well, I was impatient. So I made a mains lead, fixed the earth bond (1.3 ohms and variable) and PAT tested.And it LIVES! I am astonished. I squirted 1kHz square waves through it from a function generator, terminated it properly and saw all the attenuations I expected between 0dB and 80dB. More importantly, I didn't see any low frequency noise/spikes on the square waves or variable leading edge shape (did with an aged R&S purely passive attenuator). Despite what the single reference on the Internet says, it does not go to 200dB. Maximum attenuation is 130dB. I'm guessing that it should be good to 1GHz given the N connectors. No doubt a pair of N to BNC adaptors will each cost as much as the attenuator. But I'll still be happy.
Dick smith Q1803 Oscilloscope - Page 1
Forum section: electronics / testgear

author: samson
author_rank: Contributor
timestamp: June 09, 2022, 07:07:09 am
content: Would any one have a schematic Diagram of the dse Q1803 please as I have a not working crt that I would like to fix.

author: JohnC
author_rank: Contributor
timestamp: June 20, 2022, 04:42:57 pm
content: These were sold under a LOT of different names. This thread will help you heaps...https://www.eevblog.com/forum/testgear/any-experience-with-atten-at7016-1-channel-10mhz-oscilloscope/Schematics there, and heaps of other useful info.

author: sean0118
author_rank: Frequent Contributor
timestamp: June 27, 2022, 03:23:55 am
content: Hey, I have a colleague who has fixed these, their advice is:“Check the fuse for the EHT power supply first. It’s located on the main PCB, close to the middle. If this fuse blows, no EHT, and no trace. I fixed a Q1803 ‘scope a few years back by replacing the fuse for the EHT supply. There were no other faults. The symptom was no trace.”
HP-4140b J113 JFET measurement - Page 1
Forum section: electronics / testgear

author: RichardM
author_rank: Frequent Contributor
timestamp: June 26, 2022, 11:14:33 am
content: HiI have been playing around with an HP-4140b pico amp and voltage source meter as a learning experience.I had a go at tracing Id-Vds characteristics of a J113 JFET but the results suggest something is perhaps wrong with my setup. I have a triax cable with aliigator clips and BNC/alligator clips for the voltage sources. I don't have anything in a shielded box, just open to all the surrounding noise. The curves I get from the HP-4140b are overlayed with the datasheet and as you can see I get an odd dropoff in measured Id current part way through all the tests for different Vgs values ? Is it beacuse I do not have a sheieded test fixture setup ?RegardsRichard

author: Kleinstein
author_rank: Super Contributor
timestamp: June 26, 2022, 12:02:19 pm
content: The currents are not yet that small that one would really need shielding. So the lack of shilding is likely not an issue. Depending on the setup there is a slight chance the FET is oscillating under some conditions. After all the FETs are quite potent high frequency amplifiers and the electronic regulated voltages tend to be not always ideal. With the right amount of inductance one can build an RF range oscillator.For the JFET it may help to add some resistance (e.g. 10 K) in sereis to the gate. This should not effect the quasi DC measurement, but makes oscillation less likely.A frist test for the meter would be to check if a resistor reads correct.

author: G0HZU
author_rank: Super Contributor
timestamp: June 26, 2022, 07:00:04 pm
content: I dug out a J113 and put it into my JFET curve tracer jig and I get the results below if I try and copy your Vds and Id ranges. My jig uses ferrite beads inline with the drain and gate connections to suppress any instability. It supports leaded and SMD JFETs and it is not screened. I do use twisted pair wires for the remote connections to a dual programmable PSU and a DVM.

author: G0HZU
author_rank: Super Contributor
timestamp: June 26, 2022, 07:07:58 pm
content: Here's a recent plot of a BF256B JFET.This is a process 50 JFET (general purpose / VHF amp) and I think the J113 is process 51 (chopper).

author: RichardM
author_rank: Frequent Contributor
timestamp: June 26, 2022, 10:37:38 pm
content: Quote from: Kleinstein on June 26, 2022, 12:02:19 pmThankyou Kleinstein for taking the time to reply. The resistor did the trick. I will see whether I can see any oscillation on the scope, another learning exerciseRichard

author: RichardM
author_rank: Frequent Contributor
timestamp: June 26, 2022, 10:38:19 pm
content: Thanks G0HZUI will compare your plots with mine now
Bridge purpose in connecting the two functional circuit - Page 1
Forum section: electronics / testgear

author: abdulbadii
author_rank: Frequent Contributor
timestamp: June 30, 2022, 01:17:27 am
content: Anyone generous enough explain the function/purpose on connection between the first pin of eachR12and R22? onhttps://www.eevblog.com/forum/projects/5-transistor-esr-meter-design/?action=dlattach;attach=37892;image
How can rsa3030e crack the option? - Page 1
Forum section: electronics / testgear

author: 龚平
author_rank: Newbie
timestamp: June 24, 2022, 09:29:43 am
content: How can rsa3030e crack the option?If anyone knows how to crack it, please tell me how to crack it. be deeply grateful

author: 龚平
author_rank: Newbie
timestamp: June 24, 2022, 09:34:04 am
content: Need to crack

author: coromonadalix
author_rank: Super Contributor
timestamp: June 24, 2022, 10:55:15 am
content: you asked the same question on another thread, please do ne create multiple posts or threads ... ??

author: Fungus
author_rank: Super Contributor
timestamp: June 24, 2022, 11:01:33 am
content: Quote from: coromonadalix on June 24, 2022, 10:55:15 amLook at the number of posts. It looks like he created the account here just to ask that question.

author: tv84
author_rank: Super Contributor
timestamp: June 24, 2022, 06:05:13 pm
content: And, additionally, has an echo problem!
Rigol Customer Research - Page 1
Forum section: electronics / testgear

author: EEVblog
author_rank: Unknown
timestamp: June 24, 2022, 07:16:29 am
content: Got an email from Rigol with a link to a customer survey with some rather odd questions.Where is this 12bit Tektronix for $700? Or this 12bit Keysight for $1000?It's just filled with odd comparisons that make no sense.You might not be able to see it as the link might be unique:https://rcms.rigol.com/PublicPaper/HomeIndex?uid=62883CFF-5A82-40A0-BCC0-5F7E3C706C25

author: tautech
author_rank: Super Contributor
timestamp: June 24, 2022, 07:35:12 am
content: Or the imaginary 2.5 GSa/s Siglent !

author: PartialDischarge
author_rank: Super Contributor
timestamp: June 24, 2022, 07:49:24 am
content: They are just hypothetical and made up specifications and costs to see what users value most when choosing a scope(brand, screen size, sensitivity...etc.)

author: Domitronic
author_rank: Regular Contributor
timestamp: June 24, 2022, 07:56:22 am
content: A few months ago i received a similar survey from Tektronix. No comparison with other brands but also choosing from imaginary scopes. I think it was even more than 10 of those comparisons in the survey.I guess this was a survey to find out which parameter is important and how much more would the customer pay for it. For example is the customer willing to pay more for 12bit, higher sample rate, more memory and so on. Or what would the customer choose if you could either have 12bit or more memory for the same price. So trying to find out which parameter is important and which is not.For your Rigol survey it seems they also want to know how much the brand name is worth i guess?

author: tv84
author_rank: Super Contributor
timestamp: June 24, 2022, 08:00:31 am
content: They better have a very good AI engine behind it to reach some conclusions.

author: switchabl
author_rank: Frequent Contributor
timestamp: June 24, 2022, 09:02:03 am
content: It is called (choice based) conjoint analysis. Has been around for a long time. The combinations are completely fictitious. At the most basic level, I think you would just run logistic regression on the choices. From the weights you can get an idea of the relative importance and the value of the individual aspects. No AI required.
Checking (unknown) ZenerDiodes, when a ZEN50 or two PowerSupplies are not enough - Page 1
Forum section: electronics / testgear

author: PushUp
author_rank: Regular Contributor
timestamp: June 23, 2022, 11:14:06 am
content: Nothing special and most likely well known, but as I have nearly forgotten this solution, it may help some others in the future, when you have access to an Insulation Tester...In order to prove my test setups I obviously took Zener Diodes with known and lower breakdown voltages...I had to check some unknown Zener Diodes, which couldn't be solved by using my ZEN50 - the left one measuring the breakdown voltage only shows >50V:...also, connecting my two cheap PowerSupplies, which are limited to roughly 60V, was useless:Finally, as I had no luck to cope with >60V with the methods from above, the use of an Insulation Tester becomes a very handy and probably easiest solution to do so, due to its self limiting voltage, in order to find out the breakdown voltage of unknown Zener Diodes:Cheers!
Rigol DS1054Z not booting... - Page 1
Forum section: electronics / testgear

author: andyB2022
author_rank: Regular Contributor
timestamp: April 01, 2022, 01:58:33 pm
content: Hi! My scope no longer wants to boot. Before powering it on, on first channel I had connected an Aneng AN8008 in resistance measurement (I just got the meter and wanted to test the wave generator thing...) Then the scope was stuck on RIGOL screen and as I saw that it was no longer booting I'd decided to repower it and now it is stuck at RIGOL logo and starts beeping with the LED's at 2Hz. Here it is a video:https://youtu.be/WRQeZjNPryY(firmware file on USB drive and Help button doesn't work, event tho when I do that the SINGLE button lights up and the CH1 button starts flashing with no beep for 5 6 seconds and then it starts all the LED's and beeping without any other control...)

author: Adrian_Arg.
author_rank: Frequent Contributor
timestamp: April 01, 2022, 05:34:42 pm
content: Hello, I think that when you start the computer, you have to repeatedly press the fifth dark gray button on the left side, and it should reset to factory modegood luckin spanishHola, creo que cuando arrancas el equipo, tenes que ir presionando repetidamente el quinto boton gris oscuro del lado de la izquierda, y debaria resetearse a modo fabrica

author: andyB2022
author_rank: Regular Contributor
timestamp: April 01, 2022, 05:40:23 pm
content: I have already tried that too and it doesn't do anything!

author: Fungus
author_rank: Super Contributor
timestamp: April 01, 2022, 11:05:39 pm
content: I don't see any way it can be the fault of the Aneng 8008. It must have been dead before that.If the help button thing doesn't fix it then either send it back under warranty or open it up and look at the voltages from the power supply.

author: andyB2022
author_rank: Regular Contributor
timestamp: April 02, 2022, 07:08:40 am
content: I'll send it for warranty even tho I was curious why this happened. I contacted Rigol help too, will keep you guys updated on how it will get fixed.

author: andyB2022
author_rank: Regular Contributor
timestamp: June 23, 2022, 07:05:07 am
content: The scope is back from warranty, works now. As I have realised they got inside of it because the seal on the bottom of the unit is different from the one that came from the factory.
Unstable current measurements on PS w/KP184 DC Electronic Load - Page 1
Forum section: electronics / testgear

author: LogicalDave
author_rank: Regular Contributor
timestamp: June 22, 2022, 08:41:23 pm
content: I have a Tenma 72-8795 (Atten PPS3203) linear bench supply and the current metering is problematic(yes, I know the whole user interface is a disaster, but that's not what this post is about).When I connect the supply to a resistive load, the current meter is stable and correct (within 2mA).However, when I connect the supply to a Kunkin KP184 DC electronic load set for CC mode,the power supply current meter fluctuates wildly. The actual current being drawn by theDC load is correct (Brymen BM789 in series reports same current as the KP184).Are others seeing the same thing? Dueling control loops? Any ideas for how to fix this?

author: Hydron
author_rank: Super Contributor
timestamp: June 22, 2022, 09:35:50 pm
content: See what the Brymen says in AC current mode (should be ~0 if the load is working correctly). If it shows zero, double check with a scope + current shunt (to eliminate DMM analogue bandwidth from being an issue). I bet the control loops in the supply and load are interacting and oscillating like crazy around the setpoint, with the supply showing crazy numbers due to doing less smoothing than the load/meter.
Use Agilent 33220A signal generator to supply sine to full wave rectifier ?  - Page 1
Forum section: electronics / testgear

author: electronic_guy
author_rank: Regular Contributor
timestamp: June 22, 2022, 12:36:12 pm
content: Hi,I'm trying to generate a full wave rectification signal out of a rectifier bridge made up of 4x 1N5819 diodes. Instead of using transformer i tried to input sine from signal generator. But the output waveform looks like a half wave rectifier. I checked the ground lead of the BNC output from signal generator and it doesn't show any sine wave going back to signal generator. I might be having a huge misunderstanding here. That's why i need some help with an explanation as to why signal generator output is not the same as transformer output.Is there a way to simulate a transformer output with a signal generator ?Thank you.

author: Grandchuck
author_rank: Super Contributor
timestamp: June 22, 2022, 12:43:30 pm
content: Ground problem? The generator and the scope grounds.

author: wasedadoc
author_rank: Super Contributor
timestamp: June 22, 2022, 03:26:59 pm
content: Quote from: Grandchuck on June 22, 2022, 12:43:30 pmYes, draw a schematic of the four diodes in a bridge rectifier. Draw a connecting line from one side of the input to one side of the output to represent the path through the grounds of the generator output and the scope input. Then, "Doh" time.

author: HighVoltage
author_rank: Super Contributor
timestamp: June 22, 2022, 03:41:49 pm
content: Look at the DC offset from the 33220A and make sure it is 0
Review of the Kyoritsu KEW MATE 2000A & 2021RA DMMs with current clamp - Page 1
Forum section: electronics / testgear

author: RBBVNL9
author_rank: Frequent Contributor
timestamp: June 21, 2022, 06:11:15 pm
content: During a one-month work trip in Tokyo without any equipment with me, I needed a simple DMM for a project and started hunting for one in Akihabara Electric Town, one of the oldest electronics markets in the world.Back home, I am reviewing the Kyoritsu KEW MATE 2000A & 2021RA meters I bought there. As a rather unique feature for such compact meters, they sport an integrated AC/DC current clamp.See below for the video review. Teaser: these meters were not exactly what I expected them to be…Video

author: wasedadoc
author_rank: Super Contributor
timestamp: June 21, 2022, 06:26:46 pm
content: All I see is "This video is private".

author: RBBVNL9
author_rank: Frequent Contributor
timestamp: June 22, 2022, 04:13:32 am
content: Dear wasedadoc,Thanks for letting me know! I think it should be fixed now.If you still get this error, do share it!
HP 54656A/D oscilloscope/MSO CHM file "Programmer's Reference" wanted - Page 1
Forum section: electronics / testgear

author: brouhaha
author_rank: Newbie
timestamp: June 21, 2022, 11:55:15 pm
content: Much to my dismay, the detailed documentation on the SCPI comands accepted by the HP 54645D oscilloscope/MSO was _ONLY_ provided as a Windows CHM file, which was supplied on a floppy disk accompanying the "Programmer's Guide". While copies of the "Programmer's Guide" in PDF form are readily available on the internet, the CHM file doesn't seem to be there. Does anyone have a copy they'd be willing to share?I don't need the PDF files of the "User and Service Guide" or the "Programmer's Guide". I already have those.I also am less interested in the CHM converted into another format. That would be better than nothing, but I'd really like to get the original file.Thanks!

author: oPossum
author_rank: Super Contributor
timestamp: June 22, 2022, 12:10:06 am
content: Attached

author: brouhaha
author_rank: Newbie
timestamp: June 22, 2022, 05:34:11 am
content: Awesome! Thank you!
Searching for Operator/Programming Manual PDF for Tektronix DM2510G Multimeter - Page 1
Forum section: electronics / testgear

author: Mandokahn
author_rank: Newbie
timestamp: June 21, 2022, 04:36:07 pm
content: I am owning some elder Multimeters from different brands.For my Tektronix DM2510G I recently buyed I can't find any manual in the net.Tek is explaining the DM2510G is an OEM model and they don't have any documents to provide....I like to use this DMM with its built in GPIB interface for data acquisition but need some manual to get is working.So I hope that someone within eevblog uses this DMM and has a PDF available for me.Thanks a lotKlaus

author: Kean
author_rank: Unknown
timestamp: June 21, 2022, 05:05:41 pm
content: No manuals for you, but that would be one of three DMMs which were built for Tek by Escort Instruments Corp. in Taiwan.A comparison of the three DMM models is in the catalog pages you can download fromhttps://w140.com/tekwiki/wiki/DM2510User and service manuals for the CDM250 are available fromhttps://w140.com/tekwiki/wiki/CDM250and the service manual mentions Escort (but probably very different internally to the DM2510).

author: Kean
author_rank: Unknown
timestamp: June 21, 2022, 05:13:31 pm
content: FYI, the DM2510G DMM GPIB Programmer Manual is Tek P/N 070-8630-00. My searches for that didn't bring up anything useful other than an old eBay HK listing.