hybridfree/eevblog-posts huggingface dataset:
That is rdgs/s measurement speed - Page 1
Forum section: electronics / testgear

author: Bloch
author_rank: Unknown
timestamp: August 28, 2016, 06:55:02 pm
content: That does150 rdgs/s measurement speed mean ?http://www.siglent.eu/siglent-sdm3045x.html

author: egonotto
author_rank: Super Contributor
timestamp: August 28, 2016, 07:08:39 pm
content: rdgs/s = readings/smeans measure per second.

author: Bloch
author_rank: Unknown
timestamp: August 28, 2016, 07:17:51 pm
content: Thank you egonotto.As in display update or write to memory ?

author: Dave
author_rank: Super Contributor
timestamp: August 28, 2016, 07:35:27 pm
content: To memory or USB/LAN.There isn't a human being on this planet that would benefit from having 150 different values show up on a screen in a single second. Assuming the LCD would even be capable of such a refresh rate.

author: David Hess
author_rank: Super Contributor
timestamp: August 28, 2016, 10:20:04 pm
content: Quote from: Dave on August 28, 2016, 07:35:27 pmBut 150 readings/second may apply when statistics are being calculated and displayed although only at lower resolutions.If rejection of 50/60 Hz is important, then more than 50/60 readings per second may not be possible and the incomplete datasheet acknowledges this.From the SDM3055 user manual:1. Three reading rates are available for DCV, ACV, DCI, ACI and 2-Wire/4-Wire Resistance: “Slow”, “Middle” and “Fast”.2. There is a linkage for both reading resolution and reading (measurement)rate.3. 5 reading/s belongs to 5.5 digit resolution.4. Both 20 reading/s and 123 reading/s belong to 4.5 digit resolution.Notice that there are two different speeds listed for 4.5 digit resolution. The slower speed will have good rejection at 60 Hz but I wonder if this speed is different when 50 Hz AC power is used.Based what I see in the documentation, I am not convinced Siglent knows what they are doing. Are these rebadged designs?

author: tautech
author_rank: Super Contributor
timestamp: August 29, 2016, 05:25:59 am
content: Quote from: Bloch on August 28, 2016, 07:17:51 pmThe display update rate noticeably increases with the higher rdgs/s settings, at least it does for the SDM3055.I'll have a 3045X in the next few days and check it has the same behaviour, it should do.When the 3055 was first released the readings/s and display update rate was poor and it was fixed in new FW quite rapidly.

author: tautech
author_rank: Super Contributor
timestamp: August 29, 2016, 05:31:40 am
content: Quote from: David Hess on August 28, 2016, 10:20:04 pmNo.https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/

author: tautech
author_rank: Super Contributor
timestamp: August 30, 2016, 10:09:23 am
content: @BlochJust unpacked a new demo SDM3045X today and a short summary of what's obvious:Visual display stability is better than 3055, maybe only having to display 4 1/2 digits helps.FW seems a different series than 3055.No Filter setting for volts.Minor front panel differences in the fonts used.GUI looks the same betweens both models.3045X boots noticeably faster.Different feet with locating lugs for safer stacking.
For Dave - Soar 1000 multimeter/scope - upgrade from your 1st meter ME-533 - Page 1
Forum section: electronics / testgear

author: retiredcaps
author_rank: Super Contributor
timestamp: August 18, 2016, 04:16:22 pm
content: Dave's first multimeter was a ME-533.This meter/scope function is an upgrade to his ME-533 meter, but includes a scope.This is NOT my ebay auction and I have no affiliation with seller. Just posting for Dave's interest. It looks like the lcd screen might be dead?http://www.ebay.ca/itm/291849550868Note auction is for "as is, parts".Pictures from auction included.

author: retiredcaps
author_rank: Super Contributor
timestamp: August 18, 2016, 04:18:00 pm
content: More pics.

author: Tainer
author_rank: Contributor
timestamp: August 18, 2016, 05:45:51 pm
content: Looks great, I'd love to see a teardown of this thing.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 19, 2016, 03:23:25 am
content: That thing looks sweet.

author: EEVblog
author_rank: Unknown
timestamp: August 19, 2016, 03:48:11 am
content: Quote from: retiredcaps on August 18, 2016, 04:16:22 pmCorrection, my first digital multimeter.

author: EEVblog
author_rank: Unknown
timestamp: August 19, 2016, 03:48:42 am
content: What an interesting beast!
Firmware Update U1232A - Page 1
Forum section: electronics / testgear

author: richardpath
author_rank: Newbie
timestamp: August 22, 2016, 01:54:52 am
content: Hello for everybody.I have checked in Keysight´s site about a firmware update for DMM U1232A and so, I tried.Before that, I installed the driver for IR/USB interface and tested it using the Agilent data logger software. It worked fine.However, when I tried to update it, I don´t know what happened. The DMM does not work anymore and the display shows "Pro". Sometimes, trying update it again, it shows "Prou".Did somebody has the same problem? (The firmware is the same for any U123xA model (U1231A, U1232A and U1233A).Somebody knows how to recover the multimeter?ThanksRichard Path

author: richardpath
author_rank: Newbie
timestamp: August 22, 2016, 02:17:03 am
content: Hello.After some thoughts about it, I decided to try the procedure using other computer (the first one was an Acer Laptop CoreDuo). Using a new computer, I was able to conclude the procedure and update the firmware.FYI: I used a DYI optic interface / Windows7.Best RegardsRichard Path

author: MosherIV
author_rank: Super Contributor
timestamp: August 22, 2016, 02:10:49 pm
content: HiSo what is the difference now that you have managed to re-flash the firmware please?Has the auto range been improved/sped up?Thanks
Tek 2335 No power help needed Please - Page 1
Forum section: electronics / testgear

author: radioman56
author_rank: Newbie
timestamp: August 18, 2016, 04:14:06 pm
content: I picked up a Tektronix scope model 2335 I plugged it in went over it good No power.opened it up checked all fuses they test ok. is there something I am missing to check any help is greatly appreciated Thank you.
Rigol DS1074Z rotary buttons acting like CH4 button - Page 1
Forum section: electronics / testgear

author: georgste
author_rank: Newbie
timestamp: August 17, 2016, 07:44:48 am
content: Hi All,My DS1074z appears to have developed an odd problem with the intensity button press. It appears it is now operating as the ‘CH4’ button. If entering text or trying to select and item ie (Probe multiplication, DC Coupling, or any other menu as it appears to do the same).When entering text it will submit the character, however will exit out of the menu and still turn channel 4 on/off.So far I have done the following• Upgrade from 04.01 to 04.04 (no change in behaviour)• Perform factory default (5th button pressed/released continuously while booting) – unit reset to Chinese so it worked. (no change in behaviour)• Insert USB stick on boot and pressed/released help continuously while booting to force firmware and re-applied. (no change in behaviour)• Uninstalled all options (no change in behaviour)Does anyone else have any clues on this one? The unit is over 2 years old with under 50 hours on the clock so not expecting problems like this. The button hardware appears to be fine as it still works, but with new firmware and reset to factory defaults, cannot narrow it down to anything.Thanks in advance.Steven

author: georgste
author_rank: Newbie
timestamp: August 17, 2016, 10:13:34 am
content: Quick Update* This problem actually seems to relate to all the buttons of the rotary encoders doing odd things. (Pushing the Trigger, large horizontal, small horizontal, large vertical and small vertical) rotary also changes channel 4 on/off status.* To be clear a Self Cal was completed after each firmware upgrade.Now that it appears to be all of the rotary encoders its looking more like hardware. Possibly one of the column/row lines not operating correctly.

author: pascal_sweden
author_rank: Super Contributor
timestamp: August 18, 2016, 10:56:12 am
content: How old is your scope? Is it still in warranty? I would send it back!

author: georgste
author_rank: Newbie
timestamp: August 18, 2016, 10:59:37 am
content: Yeah, I thought it was only one year, but a look around tonight it appears it might be a 3 year warranty. I'll be calling Emona Instruments tomorrow to confirm.Thanks
Need help ID'ing a DMM - Page 1
Forum section: electronics / testgear

author: cncjerry
author_rank: Unknown
timestamp: August 17, 2016, 05:59:52 pm
content: I'm looking for a DMM I've seen show up off and on. I think they are made in Japan and the name begins with an 'H'. They made scopes as well that had more of a vertical format, sort of ugly. The DMM I am thinking of was hi-end, somewhat expensive. I can't find them for the life of me. Not hioki. Any ideas?

author: Jwalling
author_rank: Unknown
timestamp: August 17, 2016, 07:12:50 pm
content: Quote from: cncjerry on August 17, 2016, 05:59:52 pmSure it's not Yokogawa? Or Hitachi if it really begins with an H. But I don't know if Hitachi made DMMs.Jay

author: boffin
author_rank: Unknown
timestamp: August 17, 2016, 07:19:16 pm
content: Quote from: cncjerry on August 17, 2016, 05:59:52 pmIwatsu ?Kikusui ?

author: SeanB
author_rank: Super Contributor
timestamp: August 17, 2016, 07:26:04 pm
content: Hioki?

author: cncjerry
author_rank: Unknown
timestamp: August 17, 2016, 08:04:59 pm
content: I don't remember but I've been told I have the best memory. Yes, Yokogawa, no 'H' after all.What do people think of their DMMs? My primary is a U1252b today though I have about 30 including bench types. I love meters and was thinking of adding a Yokogawa to the collection.Thanks.
Hantek 6022BE Windows 7 drivers...again! - Page 1
Forum section: electronics / testgear

author: francoisphil
author_rank: Newbie
timestamp: August 16, 2016, 08:20:32 am
content: My scope was working well , on my laptop , and on my 2 different desktop systems but now it works only on one of my desktop systems , and when i try to install the driver , it appear as unknown device in the devices manager, and it does not find any acceptable drivers in my downloaded drivers folder.What is that?
Does anyone know of a hackable themocouple thermometer - Page 1
Forum section: electronics / testgear

author: RogerClark
author_rank: Contributor
timestamp: August 16, 2016, 12:53:30 am
content: Hi guysDoes anyone know of any hackable thermocouple thermometers ?I'm looking for one that has a processor which I could load with custom firmware.It would have to be one which has a free compiler, as having to spend thousands of dollars on IAR etc would outweigh the cost saving on buying an existing meter.I've seen lots of meters on AliExpress, costing from $4 upwards, but ones like the "HYELEC" which have 2 buttons would be what I was looking for, as I need some buttons for UI.The TASI-8620 would also fit the bill, (etc)But short of buying one of each and taking them apart I have no way to know whether it would be possible to re-purpose them.(Note. I don't think there is any point contacting the vendors on AliExpress etc, as I don't want to buy thousands of these, but I could need 10's or potentially hundreds of them, and repurposing a pre-made meter is going to be far cheaper than attempting to make one from scratch)
Korad 3305 P & D version - Page 1
Forum section: electronics / testgear

author: frsittle
author_rank: Newbie
timestamp: August 15, 2016, 04:51:49 pm
content: Hi,I recently purchased a Korad KA3305D version and realized (afterwards...) the D version was NOTprogrammable.(even though the picture on Reichelt www was showing USB + DB9 connector ... it was a picture of the P version which IS programmable).I saw some post about people trying to talk directly to a 3005D PowerSupply MCU board (24 bytes protocol) but at the end I don't know if they succeed or not...Any hint appreciated - I can easily write a bridge to control the Power Supply, but I must be sure the Main MCU doesn't accept commandsTxs

author: hexreader
author_rank: Frequent Contributor
timestamp: August 15, 2016, 07:27:09 pm
content: Some info here:http://sigrok.org/wiki/Atten_PPS3000_seriesCode for talking to Velleman 3005P WITH RS232 (single supply version) is here:http://libstock.mikroe.com/projects/view/1016/easypic7-control-velleman-ps3005d-power-supplyNo idea whether this matches what is sent to PSU mainboard, but it is 24 bytes - so just maybe...Code is probably of no use, but the comments in the .c file might give some cluesHere is the 24 byte buffer part of the code: Send a message with the appropriate values to set Volts, Amps etc, look at the 24 bytes returned to find out information from the PSU.txt_out = 0xaa; // header - synchronisationtxt_out = 0x20; // header - addresstxt_out = volts/256; // ch1 voltage x 0.01 high bytetxt_out = volts&0xff; // ch1 voltage x 0.01 low bytetxt_out = milliamps / 256; // ch1 milliamps high bytetxt_out = milliamps & 0xff; // ch1 milliamps low bytetxt_out = 0x00; // (ch2 v)txt_out = 0x00; // (ch2 v)txt_out = 0x00; // (ch2 mA)txt_out = 0x00; // (ch2 mA)txt_out = 0x00; // (ch3 v)txt_out = 0x00; // (ch3 v)txt_out = 0x00; // (ch3 mA)txt_out = 0x00; // (ch3 mA)txt_out = 0x01; // reservedtxt_out = 0x01; // 01 for output on, 00 for output off (bits 1 and 2 are CH2, CH3)txt_out = 0x01; // 01 for alarm allowed, 00 for no alarmtxt_out = 0x00; // reservedtxt_out = 0x00; // 01 for OverCurrent Protection on, 00 for offtxt_out = 0x00; // ( 0, 1, 2 for independant, series, parallel )txt_out = 0x00; // reservedtxt_out = 0x00; // reserved 0txt_out = 0x00; // reserved 0checksum_out(); // calculate a real checksum for byte txt_out
Heathkit IB-2A Initial inspection and test - Page 1
Forum section: electronics / testgear

author: jcrubin
author_rank: Frequent Contributor
timestamp: August 01, 2016, 06:19:52 pm
content: This movie documents the initial inspection and testing of the unit. As shown, some components will need to be replaced to continue to the next stage, but all in all quite impressive.

author: BMack
author_rank: Regular Contributor
timestamp: August 10, 2016, 05:41:22 pm
content: I can't watch right now but i will later.I love the old Heathkit stuff, we have several at the shop...older than me and still work perfectly.

author: Seekonk
author_rank: Super Contributor
timestamp: August 10, 2016, 05:57:22 pm
content: I used to sell a rebuild kit for the heath C3 capacitor tester. Don't know why people loved these so. It added a gain of three (using the rectifier tube) and fixed some of this units issues. It all used free parts from work and was just a lark. Still I sold three dozen kits. Even with free parts it wasn't worth the time. I still have the details if anyone is interested. I'll start a new thread for it.

author: jcrubin
author_rank: Frequent Contributor
timestamp: August 15, 2016, 12:52:10 pm
content: SeekonK, Maybe you should start a new thread since your content has absolutely nothing to do with what i'm posting.Better yet, why did you even post that into this thread at all? Clearly this is not a C3. Was it to take a poke at Heathkit in a Heathkit thread?This continues with the initial calibration and goes through DC testing of resistors through AC testing of capacitors up until using Q for deriving Capacitance but not calibrating Q, thats for video 4As for content relevant to the thread. Here is the third movie in the series

author: jcrubin
author_rank: Frequent Contributor
timestamp: August 19, 2016, 02:06:59 pm
content: This is the last video in the repair and demonstration series
Tek USB Scope on the horizon? - Page 1
Forum section: electronics / testgear

author: testmode
author_rank: Regular Contributor
timestamp: August 14, 2016, 07:15:44 pm
content: Stumbled on this info today from what seems to be a profile of a Tek Engr from that business-oriented social networking website:"Define detail specification ofTek USB scopebased on customer requirement and Tektronix technical advantages"Are we expecting a Picoscope contender from Tek soon? I do hope so!I'm not aware they have any USB scope offerings so far...I've been actually contemplating to sell off my DPO2024B for a Picoscope* lately so knowing a Tek USB scope is coming in the horizon, I might wait for it a bit more to see what they have to offer. Makes me wonder if the other big names are working on something as well.* I've used Picoscope at work and although it has it's shortcomings against a "real" bench scope (yes, lack of knobs!), I could set those shortcomings aside for the convenience of having the scope interface right in your desktop. It takes a little getting used to but I find it a worthwhile once you get familiarized with it.
How much power an oscilloscope can handle as input - Page 1
Forum section: electronics / testgear

author: freebil
author_rank: Regular Contributor
timestamp: August 13, 2016, 10:21:07 pm
content: Hello. I have a raspberry 3 and I transmit AM signals withrpitx. The transmitted power does not exceed 200mW. Is it possible to plug the raspberry output directly to an oscilloscope probe?

author: N2IXK
author_rank: Frequent Contributor
timestamp: August 13, 2016, 10:50:57 pm
content: If you are feeding a 50 ohm scope input, there should be a power dissipation rating on the input resistor, perhaps even written on the scope input jack.On a standard 1M input, as long as the peak output voltage is within limits, no problem.

author: freebil
author_rank: Regular Contributor
timestamp: August 13, 2016, 11:26:49 pm
content: Quote from: N2IXK on August 13, 2016, 10:50:57 pmThanks for the answer. I see in other pages that rf signal require rf sampler before the oscilloscope. Why?

author: N2IXK
author_rank: Frequent Contributor
timestamp: August 15, 2016, 12:55:04 am
content: A sampler is useful when monitoring a high power transmitter, as it reduces peak RF voltage, and provides some isolation to the scope input. It generally goes into the transmission line, and permits normal operation of the transmitter into the antenna or test load.At the 200 mW level, not much of a concern. What are you trying to see in the RF envelope? Do you actually want to see the RF, or the modulation imposed on it? If the latter, then you really want a broadband detector probe.

author: Stray Electron
author_rank: Super Contributor
timestamp: August 15, 2016, 03:00:03 am
content: Quote from: freebil on August 13, 2016, 10:21:07 pmIt depends. Are you using a 1 to 1 probe or a 10x attenuator probe? The maximum input voltage and power varies by the scope brand and model. My HP 54510 will safely handle 250V AT THE SCOPE INPUT but only when set for 1 M Ohm input impedance. At the 50 Ohm input it will only handle 5 volts before damage may occur. The input impedance should be relatively constant across the scope's rated frequency range so you can calculate the power if it's not in your scope's specifications. A 10x or 100x attentuator probe will raise the allowable input (at the probe) by 10 or 100 times.You'll have to look up the specification for your model scope to see what the maximum allowable input voltage is.
New to me Hitachi V-650F Oscilloscope, link to manual inside. - Page 1
Forum section: electronics / testgear

author: UnsatisfactoryResult
author_rank: Newbie
timestamp: May 24, 2015, 01:31:56 am
content: I got this for about $25, just arrived today. No pics yet, but it's clean enough. Powered it up, shows a trace, all buttons and switches accounted for. The switches will need a cleaning as some were a bit finicky. Prior to getting this I was trying to track down a manual for it online, but the closest thing I could find was the service manual for the V-1050F. Well this came with the user manual in very nice shape. It's not a huge manual at all, but it does have schematics. I don't have any pics of the machine, because I spent the day scanning the manual when I wasn't putting together our new patio furniture. It's a big file, pages were scanned at 2500x1600, and schematics at 5000x3200.Link to the manual on my Google drive:https://drive.google.com/file/d/0B_7JqBK1MAV1SnBJTlpEemdDRDA/view?usp=sharingI'll post some pics of the machine in the next few days when I pull it apart.Edit: Shrunk the bloat a bit on the manual, and darkened it up for easier reading.

author: tautech
author_rank: Super Contributor
timestamp: May 24, 2015, 03:33:16 am
content: Welcome to the forum.Thanks for sharing the manual.Might I suggest you upload it to one of the manual repositories, you'll find a good selection in the first thread in the Repair board.

author: Russfer
author_rank: Newbie
timestamp: August 14, 2016, 04:16:09 am
content: Hey, you did better than I. I paid $100.00 including shipping from New Mexico to Utah. I made a few minor mechanical repairs but heard a suspicious rattling sound made by a blue and white wire tied with a small cap and small and large ground lugs that seem to tie them together. I guess I'll have to go over the schematics carefully to see if I can find where they should be attached. Looks like they come from the trace rotation pot but I can't be sure. Anyway I hope to use this scope for the building of an electron microscope and need it to be working well. Again, thanks for your reply. Funny where you find friends, isn't it?Russ Ferguson (AKA Russfer)
Tektronix 2235 with no feet - Page 1
Forum section: electronics / testgear

author: Back2Volts
author_rank: Unknown
timestamp: August 15, 2016, 12:17:17 am
content: I got a used 2235 which apparently was mounted somehow, it did not come with rack ears, but has a running aluminum profile in the back, including an aluminum shield for the tube. Handle and feet where removed and are gone. My concern is if I place it on a table or shelf, do the feet play a role in the ventilation/cooling or should I not worry.If I have to put some new feet on it, does any one have an idea of the approximate size of the original ones?

author: radhaz
author_rank: Regular Contributor
timestamp: August 15, 2016, 02:30:09 am
content: If there are no vents on the bottom, it should be fine sitting on a bench.
Preamble 1855 diff. amplifier trouble... - Page 1
Forum section: electronics / testgear

author: ivaylo
author_rank: Frequent Contributor
timestamp: May 20, 2016, 04:58:26 am
content: Got myself on eBay one of those Preamble 1855 differential amplifiers (LeCroy still seems to be selling them as DA1855A) at a price I thought is OK for a second hand working unit. Played with it, nice instrument... Trouble is, that when it warms up (~10 min) the output turns from a flat line with no signal on the inputs (both switched off) to a triangular 130Hz, 30mV pk-pk (see picture). Scope is properly terminated at 50Ohm and all. The attenuator has no effect on this. The gain when on x10 doubles it (what's on the picture is x1). I think the thing is messed up, but stand to be corrected. Any chance this to be easily repairable (not finding schematics anywhere online)? I can still return it, but in case it's something trivial. Appreciate your help...

author: ivaylo
author_rank: Frequent Contributor
timestamp: May 21, 2016, 02:29:00 am
content: When I set gain to x10 and the "-" channel to Vcomp it's very clearly leaking a sawtooth signal from somewhere.

author: rx8pilot
author_rank: Super Contributor
timestamp: August 12, 2016, 04:19:53 am
content: Did you ever resolve this issue? I just got two of these and one works, the other does not. The internal construction looks unnecessarily difficult.

author: ivaylo
author_rank: Frequent Contributor
timestamp: August 12, 2016, 07:06:12 am
content: I did not, the nice eBay seller took it back. Got another one since and that one works. What are your symptoms, similar to what I had or different? Post here (or another thread) if you don't mind and we'll have a record and hopefully fixes, these seem to be popular devices. The fact that you have a working one to compare is also to your advantage.

author: ivaylo
author_rank: Frequent Contributor
timestamp: August 12, 2016, 07:24:51 am
content: Never mind, noticed your other thread.
Multimeter Chipsets what's new and what's available!? - Page 1
Forum section: electronics / testgear

author: edpgc
author_rank: Newbie
timestamp: August 13, 2016, 08:58:27 am
content: Hi allI've got a little project and I want too hook up a custom board to a Micro with a few gpios and a uart, I want to measure voltage, ohms, capacitance, (all over a few ranges) and diode-test over a single pair of ports. I don't need current measurement. Can anyone recommend a chipset that can let me do this without loads of relays as I don't want any physical controls on the device (I.e no rotary switch). Even better if I can buy the chips in the 100s or less quantity!Thanks allEd

author: Kalvin
author_rank: Super Contributor
timestamp: August 13, 2016, 10:06:31 am
content: Quote from: edpgc on August 13, 2016, 08:58:27 amHave you checked the $20 ESR Transistor tester project? It can perform those measurements. Just tweak the code so that it can use the serial port to dump the measurement data and receive commands to perform the required measurement. Pretty straight forward.Ps. You can drop the LCD and the buttons, so the bill of materials cost will be reduced to less than $3. However, you may need a serial to USB adapter which costs from $1 upwards. In total, you should be able to build the measurement unit close to a $5.Pps. If you take a look at the Arduino Nano modules from eBay containing the atmega328p, you can purchase those modules at price range of $3 which contain also the requred serial to USB adapter built on the module already.
Where to find Option 001 External Clock Reference board for Agilent 33120a ? - Page 1
Forum section: electronics / testgear

author: matthieu.e
author_rank: Regular Contributor
timestamp: August 08, 2016, 07:44:20 pm
content: Hi,I am looking for the Option 001 External Clock Reference board (33120-80001 timebase retrofit kit) for my Agilent 33120a. Do you know where I can find it in Europe ? Thanks

author: matthieu.e
author_rank: Regular Contributor
timestamp: August 10, 2016, 08:02:56 am
content: Hi,I wrote to Keysight, they ask me my company name and the 33120A serial number.Do you think it is a good solution to go with them ? I think they will ask me a lot.

author: Orange
author_rank: Frequent Contributor
timestamp: August 10, 2016, 09:39:14 am
content: Your best bet is probably eBay or you could try Helmut Singer or RosenKranzhttp://www.helmut-singer.de/http://www.rosenkranz-elektronik.de/The other option is to make it yourself, but there is one component that might be tricky, that is the VCO module, which is an HP part.

author: bitseeker
author_rank: Super Contributor
timestamp: August 11, 2016, 04:14:22 am
content: The only third-party source I've seen during the past year or so ishttp://www.sglabs.it/en/product.php?s=hp-agilent-33120a-opt-001&id=1504. They had a listing on eBay, but I don't see it anymore. It was over $200. So, if you're handy with building circuits, might as well make one.

author: matthieu.e
author_rank: Regular Contributor
timestamp: August 11, 2016, 07:39:52 am
content: Thanks for your answerI will probably make the board if I find nothing on Ebay.Do you know if someone have already make the board itself ? Is there any gerber file or schematic ?I could not find any schematic of the option on the 33120 service guide.

author: TheSteve
author_rank: Unknown
timestamp: August 11, 2016, 04:38:47 pm
content: You can find the schematic and parts list at the end of the operating guide:http://exodus.poly.edu/~kurt/manuals/manuals/HP%20Agilent/HP%2033120A%20Opt.%201%20User.pdf

author: HighVoltage
author_rank: Super Contributor
timestamp: August 11, 2016, 05:14:10 pm
content: I have seen them on ebay Germany and even bought one a few years ago.But that takes patients to wait.If Keysight is asking for the Serial Number that is, because there are two different versions available.It was the same with the 33220A, it also had two different versions of extensions boards for the external clock.
Alternative to DS203 nano - Page 1
Forum section: electronics / testgear

author: engineering@njrelectronic
author_rank: Newbie
timestamp: August 13, 2016, 06:49:27 pm
content: Hi guys,I have read some posts saying the DS203 nano is to say the least naff (which I at least partly agree with). I can see that it's input circuitry leaves a lot to be desired. It's also, as some have mentioned DC coupled effectively from the inputs to the USB. I also don't like the MCX connectors and think SMA or SMB would have been a better idea.However is there anything better in the form factor? I have a 350MHz 4 Channel Tektronix for the lab, and need something ideally pocket sized for other purposes. 2 channels would do for most of what I would need it for EG fault finding on serial busses etc (CAN and RS485) and the odd SMPSU.Any suggestions that don't cost a fortune?

author: Fungus
author_rank: Super Contributor
timestamp: August 13, 2016, 07:40:16 pm
content: Quote from: engineering@njrelectronic on August 13, 2016, 06:49:27 pmIn that form factor at that price? AFAIK that's the best there is.They're actually quite useful, given their physical limitations and price.Horrible user interface? Yes. Poor bandwidth? Yes. (Only about 5Mhz in reality). Terrible bang per buck compared to (eg.) a DS1054Z? Yes.They're obviously no substitute for a desktop oscilloscope, but ... theydoworkandthey fit in your pocket and run on batteries. That's worth something.There's a few gadgets that promise to turn your phone/tablet into an oscilloscope but I don't know anything about them. Maybe you could look there if the DS203 isn't suitable.
Interesting scope on eBay - Page 1
Forum section: electronics / testgear

author: Jwalling
author_rank: Unknown
timestamp: August 10, 2016, 10:01:40 am
content: http://www.ebay.com/itm/Vintage-Calico-California-Instruments-Monitor-Oscilloscope-Model-7101-3-CRT-/191937797520?hash=item2cb0625d90:g:H0QAAOSwARZXonzQNever seen one like this. Kind of like a wide screen scope for the 1970s (guessing on the date, might be earlier...)Jay

author: chris_leyson
author_rank: Super Contributor
timestamp: August 10, 2016, 10:31:02 am
content: Looks like a "panadaptor" of some sort.

author: pascal_sweden
author_rank: Super Contributor
timestamp: August 10, 2016, 10:34:46 am
content: What I always wonder about these small scopes with CRT screens is how the linearity is respected.Some small oscilloscopes, like the one from Sinclair I believe, used special tricks to keep the depth limited of the device, but it required special techniques.But with all these tricks, it must have impact on the linearity, and if the refraction of the beam is not as expected, it would result in improper readings on the graticule.Or is this compensated internally. Anybody who knows?

author: batteksystem
author_rank: Regular Contributor
timestamp: August 10, 2016, 01:05:31 pm
content: At the back it said "Do not touch! Working" I wonder it means do not touch the casing when the device is operating, or instruction to tell the cleaner not to throw it away.

author: Jwalling
author_rank: Unknown
timestamp: August 10, 2016, 02:51:38 pm
content: Quote from: batteksystem on August 10, 2016, 01:05:31 pmMight have been working, until those pins got damaged.Jay

author: N2IXK
author_rank: Frequent Contributor
timestamp: August 10, 2016, 03:05:47 pm
content: Looks like a record/playback monitor scope for an old analog instrumentation recorder. I have an old Ampex 9 channel rackmount unit that uses 2" round CRTs for each channel.

author: batteksystem
author_rank: Regular Contributor
timestamp: August 11, 2016, 04:07:55 am
content: Quote from: Jwalling on August 10, 2016, 02:51:38 pmThen they should update the label with a new version.Alternatively, we can buy this item, then claim that it is SNAD (Item not as described)

author: Jwalling
author_rank: Unknown
timestamp: August 11, 2016, 09:43:04 am
content: Quote from: batteksystem on August 11, 2016, 04:07:55 amIt sold for about $25 total. Pretty much not worth returning, and it would have been fun to try and get it working (or do a teardown).Jay
What is a Psophometer - Page 1
Forum section: electronics / testgear

author: mhilton2013
author_rank: Newbie
timestamp: August 03, 2016, 10:15:09 pm
content: Hi there,I recently came across a piece of test equipment I had not come across before, the Psophometer. After a little reading it seems to me that these rare items are basically distortion analysers. Is this the case or am I missing something? And if they are not, why are they so rare?

author: ebastler
author_rank: Super Contributor
timestamp: August 04, 2016, 04:24:58 pm
content: Rather a noise meter, in my understanding. The psophometer does not measure distortion (i.e. share of harmonics, relative to a desired sinusoidal signal), but r.m.s. values of noise or other unwanted (additive) voltages. For use in telecommunications, the ITU has defined specific spectral weighting curves:https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-O.41-199303-S!!PDF-E&type=items

author: CJay
author_rank: Super Contributor
timestamp: August 04, 2016, 04:49:31 pm
content: Very interested to know this too, I've got a Farnell/Sayrosa/Wayne Kerr automatic modulation meter and to say the instruction manual is scant on information would be an understatement.The best I can come up with is that it's for use with CCITT standards but nothing on why/what/how etc.It's not that I *need* it, I have no idea if I do or not

author: mhilton2013
author_rank: Newbie
timestamp: August 10, 2016, 02:12:21 pm
content: I think you're right eblaster. I got hold of a manual for one and this one was used for measuring interference on post office telephone lines. I do find it strange how these things are so rare though...
Electronic Load - Page 1
Forum section: electronics / testgear

author: jayd
author_rank: Newbie
timestamp: August 07, 2016, 06:02:01 pm
content: Can anybody tell me how CV mode works?

author: trophosphere
author_rank: Frequent Contributor
timestamp: August 07, 2016, 06:47:41 pm
content: The output of Op-Amp U1B (being closed loop) will attempt to do whatever is necessary to make the voltage difference between the inputs zero. If you imagine the switches SW1 and SW2 to be in the CV positions then note the following: (1) That the negative input of the op-amp is being fed by a reference voltage formed by a voltage divider from the 12v supply rail. (2) The positive input of the op-amp is being fed by a scaled version of Vin.The output of the op-amp is connected to the MOSFET Q1 whose channel resistance is adjusted based on the voltage present on its gate as dictated by the op-amp. If one assumes that the power source under test has a output current limit then it can be theorized that once you start shunting enough current, the voltage will drop as its current limit is approached. When that happens, the voltage being fed into the positive input of the op-amp drops and the voltage on the output of the op-amp decreases thereby decreasing the voltage present on the gate and increasing the channel resistance leading to less current being shunted.There are a lot more details/exceptions than what I have mentioned above but that is the gist of it without going far into it.

author: jayd
author_rank: Newbie
timestamp: August 08, 2016, 05:49:33 am
content: thank you
Entry level DC analyze - Page 1
Forum section: electronics / testgear

author: tapsa
author_rank: Newbie
timestamp: August 06, 2016, 11:01:43 am
content: These days more and more hobbyist make software for low power embedded boards and try keep them work with battery. So it is natural that they need also make power analysis for their devices to see when and how much that device take power. Example at my case I want know how much power and mAh my ESP8266 project take and get some kind plot of it so that I can optimize my code and circuit.Anyhow I did not find any article of EVVblog video what concern this article.Currently I know that I have 2 option:a) Take oscilloscope, shunt resistor and manually calculate from record that how many mAh and mWh each period consume. It is time consuming but cheap approach to problem.b) Make recorder from Arduino and some kind software what can draw graph and calculate totals from given time frame.So my question is that a) what is right term for this kind analysis if I want google tools and videos for it? b) Is there helper features for this at any entry level scope? c) David, Can you make some video of that topic what give good tips and tricks? I think I am not alone with this question. At least I should not be a lone with this questionIf I am, it means that there is not enough hobbyist who care how much their diy dooms day devices and Iot gadgets hog battery.

author: nowlan
author_rank: Frequent Contributor
timestamp: August 06, 2016, 11:18:52 am
content: Last time i asked about this, the Keysight 34461A meter was suggested, as it had logging etc. Out of reach of hobbyist.Doesnt do power, but can measure current etc.

author: nctnico
author_rank: Super Contributor
timestamp: August 06, 2016, 02:15:34 pm
content: If you write remote control software for an oscilloscope or DMM you can easely write it yourself using the oscilloscope and DMM as analog frontend. Both DMM and scope have their pros and cons. An oscilloscope can catch narrower peaks but it's accuracy is around 3% and the dynamic range is limited. A DMM cannot capture narrow pulses but had a wider dynamic range and much higher accuracy.

author: David Hess
author_rank: Super Contributor
timestamp: August 06, 2016, 02:55:02 pm
content: Why not build the power monitoring into the embedded project itself? Then the code can profile its own power usage.

author: _Wim_
author_rank: Super Contributor
timestamp: August 06, 2016, 04:02:29 pm
content: Switch off the power to the main PS-cap (large one), and watch how long it takes for the voltage to drop below a certain level on the main PS-cap. If you know the size of the main cap, you can calculate the power consumed during that period. To test your code, you do not even need to calculate the power, just measure the time...
HP 1631D and 1663C Logic Analyser - Page 1
Forum section: electronics / testgear

author: deanflyer
author_rank: Contributor
timestamp: August 06, 2016, 09:29:37 am
content: I picked up a HP 1631D and HP 1635D Logic Analyser from an auction. Im just getting started in electronics and purchased these to understand more about CPU logic, i'm an old CBM 64 8 bit enthusiast.The 1631D comes with a set of 4 x 10271A and 2x 10272A pods and a single set of probes.The 1663C came with 1 pod populated, with a couple of probe cables.Both power up and work okay.For low speed work (1MHz 6510 CPU) im assuming either would do the job. Ill try and sell one to pay for probes etc. for the other one. Should I keep the 1663C as its newer and faster? Is there anything the 1663C has that the 1631D doesnt or vice-versa?Should I try and make my own probes? Was reading about impedance etc, so should I just buy the official HP probes/grabbers. They dont seem to be cheap.Sorry for all the questions, hopefully someone can help.DeanPS I also bought a Gould 4072 which powered on for 30 seconds and then the PSU expired in a puff of smelly smoke. Apparently a common fate! Ill try and fix it if I can.

author: TAMHAN
author_rank: Frequent Contributor
timestamp: August 06, 2016, 11:45:42 am
content: Hello,went over it a little bit. I did not use these two units personally, but was in the mood for some datasheet googling. I would definitely keep the 1663C. It does not have the "oscilloscope" of the 1631C, but the deeper memory IMHO more than makes up for that.Also, please keep this in mind:AFAIK, these maintenance advices also apply to your two HP Logic analyzers. Also, this is likely what is bringing your Gould scope down...

author: deanflyer
author_rank: Contributor
timestamp: August 06, 2016, 01:42:59 pm
content: Thanks for that. The Gould EMI RF capacitors look to be the initial culprit. WIll replace these and see what happens.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 06, 2016, 02:22:08 pm
content: I used to own a 1631D with the disk drive. It was my first DSO. I replaced it with the 1663C which I still have.

author: TAMHAN
author_rank: Frequent Contributor
timestamp: August 06, 2016, 02:22:58 pm
content: Hello,I would simply gib all the caps on the PSU of the Gould. No sense fixing four, and then the others do you in a week later - new ones cost like, jackshit.Also, given that we had smoke emission. Try to check which cap is shorted - it might have taken some other components with it.
Agilent E4406A 100MHz span - how? - Page 1
Forum section: electronics / testgear

author: perdrix
author_rank: Frequent Contributor
timestamp: August 04, 2016, 04:01:59 pm
content: I have an E4406A with option BAF (W-CDMA) installed.When I select span and enter any span larger than 10MHz I get an error message saying:"Data out of range value clipped to upper limit"and the span stays the same at 10MHz.Dave

author: 1design
author_rank: Regular Contributor
timestamp: August 04, 2016, 05:39:50 pm
content: I would say it works as advertised, it is specified as max. 10MHz span. It is a VSA not a SA.BR

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 04, 2016, 06:06:53 pm
content: Quote from: 1design on August 04, 2016, 05:39:50 pmNot quite right. The W-CDMA option increases the standard max span from 10MHz to 100MHz, but only in W-CDMA mode, and only for specific measurements (can't remember which ones, and am too lazy to check).

author: harha
author_rank: Contributor
timestamp: August 06, 2016, 03:24:48 am
content: You choose baf mode-next intermodulation.Hardy

author: perdrix
author_rank: Frequent Contributor
timestamp: August 06, 2016, 08:32:31 am
content: Thank youDave
Can I request service on Keysight free gift accessories? - Page 1
Forum section: electronics / testgear

author: blueskull
author_rank: Unknown
timestamp: August 05, 2016, 03:39:56 pm
content: At the title says, I have an extra U1168A test lead kit, provided for free for all high end hand held DMMs (https://www.keysight.com/main/editorial.jspx?cc=US&lc=eng&ckey=2720930&nid=-32916.1090989&id=2720930).The kit has a ultra fine probe that is DOA (and costed me 10 minutes ti find out!). Can I return it for a replacement?Edit: wrong part number. Should be U1168A.

author: retiredcaps
author_rank: Super Contributor
timestamp: August 05, 2016, 05:36:57 pm
content: Quote from: blueskull on August 05, 2016, 03:39:56 pmYes, I don't see why Keysight would reject your claim. DOA is DOA regardless whether you got it for "free" with the DMMs.
A really crappy Klevin clip - Page 1
Forum section: electronics / testgear

author: LazyJack
author_rank: Frequent Contributor
timestamp: August 05, 2016, 08:38:48 am
content: I was asked to investigate why this cheap Chinese Kelvin clip from eBay won't work in 4 wire mode.Well, spot the problem!Neither of the black leads are connected to anywhere. The end of the wire is even neatly covered in heatshrink. So this is by design. Amazing! Absolutely amazing!

author: nctnico
author_rank: Super Contributor
timestamp: August 05, 2016, 10:37:16 am
content: I got the same ones and they are fake indeed. The wiring is shielded though so you have 2 conductors and it should be possible to make it work properly with a little bit of effort.

author: mikerj
author_rank: Super Contributor
timestamp: August 05, 2016, 12:10:53 pm
content: They are properly cheap and nasty looking things, place them in the round filing cabinet.

author: LazyJack
author_rank: Frequent Contributor
timestamp: August 05, 2016, 12:29:01 pm
content: Yeah, it's not a big deal to fix it. They should have soldered the shielding to one half of the clip and leave a bit longer the inner conductor and solder it to the other side. Heck, it's even pre-tinned there!So I'm just amused that really they did not save anything on this, but whoever did it, does not have the slightest idea on how a Kelvin clip works.

author: edpalmer42
author_rank: Super Contributor
timestamp: August 05, 2016, 03:27:43 pm
content: These clips were discussed a couple of years ago.https://www.eevblog.com/forum/testgear/kelvin-clips. Concensus was that the clips were cheap but usable. A little repair work should get you a decent set of cables.Ed

author: LazyJack
author_rank: Frequent Contributor
timestamp: August 05, 2016, 03:37:41 pm
content: Quote from: edpalmer42 on August 05, 2016, 03:27:43 pmYeah, the clips seem to be of decent quality. I just fixed it, using a short piece of wire routed in the inside to the other half of the clip.Actually, the leads are not that bad either, they had a surprisingly thick inner conductor.This makes it even more strange that someone managed to get the assembly so wrong. As nothing points to an intentional ripoff, it's not like some expensive part is missing or something. Someone just did not have a clue on how this supposed to work.
Does anyone have any experience with the Uni-T UTP305 0-30V 0-5A Power Supply? - Page 1
Forum section: electronics / testgear

author: drdanke
author_rank: Contributor
timestamp: August 01, 2016, 01:02:03 am
content: I'm talking about this $70 Ebay special..eBay auction: #http://www.ebay.com/itm/New-Precision-Variable-Adjustable-DC-Power-Supply-Digital-Regulated-Lab-Grade-/361089176129?hash=item5412979241:g:jbcAAOSwY45UR0ZkI'm just wondering if it's any better than all the Ebay no name power supplies, for light benchtop duty that doesn't require utmost precision? I know Uni-T doesn't give a vote of confidence in build quality, but I'm hoping that it doesn't have the "no name power supply" voltage spike during power on.Anybody use this power supply, or know of anyone that has any experience with one? Is it worth the money spent, or not worth the red paint on the housing?

author: electr_peter
author_rank: Unknown
timestamp: August 01, 2016, 04:56:13 pm
content: Have you seen this review?PSU seems to be half decent for the price. Not great on thermal side of things, but at least it should be safe enough (with respect to earthing and wiring quality).

author: drdanke
author_rank: Contributor
timestamp: August 01, 2016, 05:12:05 pm
content: Thanks, and yea, that's the only review I could find. Guess that it's just not that popular for some reason, because I can't find any more information about it, even on the Uni-T website. The fact that it's not even listed on the Uni-T website (even in past/discontinued products), means it is probably just a china bootleg, not even made by Uni-T...

author: pascal_sweden
author_rank: Super Contributor
timestamp: August 01, 2016, 05:31:23 pm
content: Uni-T seems to use a red housing for all their T&M equipment lately. Either you like it, or you don't.It's not my favorite color for a housing, I must say

author: Rob Sims
author_rank: Regular Contributor
timestamp: August 05, 2016, 02:02:43 pm
content: Hi, I have this powersupply. Up to now it's working good. Pot's feel good and it's readings are exactly the same as my multimeter. For now I don't use it very often. Only problem I discovered is that at some point a relay is oscillating (fast clicking) and you have to raise or lower voltage or current setting.. This rarely happens and i'm still figuring out why it's happening. Other than that it is a very good powersupply. All the low end powersupplies on the internet are made by a few Chinese companies and they rebrand their units for different big companies I think. This powersupply is also rebranded. Check this website.http://www.bstcaltek.com/catalog2/index.php/dc-power-supply/http-www-bstcaltek-com-catalog2-download-cp-pdf.htmlA variant of this powersupply is also on the UNI-T website.I have also ordered a second powersupply, the Tekpower TP3005T. Very good reviews on Amazon. This one is also rebranded for circuitspecialists.See website herehttps://www.circuitspecialists.com/csi3005t.html