hybridfree/eevblog-posts huggingface dataset:
GSM 3G Modem - tear down / dead ZTE USB stick MF636 - Page 1
Forum section: electronics / general

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: October 25, 2011, 12:03:20 pm
content: If you never had the chance to see the internals of one USB 3G modem , today is you lucky day.Looks like true nano electronics to me, not serviceable by humans.It is dead, some sort of boot loader corruption, that no one are able to handle, speaking about repairing it.It does not detected by any computer, because it does not boot as USB device any more, even if it gets power and the LED turns on in five seconds after connecting it.Just enjoy the pictures.And yes it is double - triple tested that it is damaged!!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 25, 2011, 12:43:42 pm
content: Keep going! those shield covers will just clip off.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: October 25, 2011, 12:48:20 pm
content: If you are willing to repair it, I will send it to you..

author: Achilles
author_rank: Regular Contributor
timestamp: October 25, 2011, 04:11:30 pm
content: Quote from: Kiriakos-GR on October 25, 2011, 12:03:20 pmOh come on, all you need for a repair is thisNo honestly, you aren't curious what's under all the metal??
Reed ST-9919 pics - Page 1
Forum section: electronics / general

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: October 28, 2011, 01:24:55 am
content: Since I didnt find anything on the net, I took my Reed DMM apart for pics! It arrived last week fromwww.tequipment.netThere was 9 screws holding the board to the front so I did not bother to get to turn it over. This works fine for what I need to do... shrug.front;battery, two brass screw holders (nice) and golden pineapple (bzzzzt)cracking it open, 6 of these babies, and I already lost one of those little black washers!These are raw into the plastic. no brassthe inside is fairly clean;the chip is an ES 51966Pwe have a 500ma and 10A ceramic fuselook at the state of these grey fellas!oh it gets better! 3 resistors covered in solder wired together.. and just about touching the one underneath!!!!

author: FenderBender
author_rank: Super Contributor
timestamp: October 28, 2011, 02:05:21 am
content: Looks kind of like that Extech Dave had in the $100 shootout. Whether that's an Extech design or Extech stole it from someone else...I don't know.

author: vl400
author_rank: Regular Contributor
timestamp: October 28, 2011, 05:16:26 am
content: And a Jaycar QM-1541 which has been discontinued.

author: ciccio
author_rank: Frequent Contributor
timestamp: October 29, 2011, 05:07:05 pm
content: I've checked the EXTECH video, and the PCB has some slight differences.It seems a different revision or a smart copy..

author: somlioy
author_rank: Regular Contributor
timestamp: October 29, 2011, 05:39:59 pm
content: Looks like one of Elits multimeters aswell:I dont like it. Too slow on the auto-range detection imo.

author: BloodyCactus
author_rank: Frequent Contributor
timestamp: October 29, 2011, 06:44:17 pm
content: Yeah, its obviously a design that is shopped around for house brands and the like. There is no name silkscreened on the PCB that I saw, it had a revision date of 2005. DT9919-6 05-11-15..So a november 15 2005 revision...

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: October 29, 2011, 11:19:07 pm
content: Yes looks to be an OEM production of CEM China.More details herehttp://www.cem-instruments.com/en/pro/sort7-1.htmlAll those OEM designs have acceptable built quality, but not speed ,and this is normal, for low cost real multimeter s.
RF Porn!!! Microwave site pics - Page 1
Forum section: electronics / general

author: Wartex
author_rank: Frequent Contributor
timestamp: October 19, 2011, 04:57:28 am
content: https://imgur.com/a/2Uj7U

author: vk6zgo
author_rank: Super Contributor
timestamp: October 19, 2011, 08:25:11 am
content: Takes me back!I can almost smell it!VK6ZGO

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 19, 2011, 08:42:17 am
content: That's plumbing not electronics

author: Wartex
author_rank: Frequent Contributor
timestamp: October 19, 2011, 01:02:14 pm
content: Quote from: mikeselectricstuff on October 19, 2011, 08:42:17 am

author: Zad
author_rank: Super Contributor
timestamp: October 19, 2011, 04:18:11 pm
content: To be fair, it is plumbingandelectronics. Not so much porn as gynaecology

author: IanB
author_rank: Super Contributor
timestamp: October 19, 2011, 05:48:05 pm
content: If a fibre optic is a "light pipe", is a wave guide a "radio pipe"?
Tour inside HP5245L - Page 1
Forum section: electronics / general

author: norEL
author_rank: Contributor
timestamp: October 18, 2011, 06:49:32 pm
content: Here is a tour inside my HP5245L frequency counter.Specs.Range: dc to 50MHzGate time: 1us to 10sec in decade steps.Accuracy: +- 1count +- time base accuracy.Period average measurements.Range: dc to 1MHz for single period; dc to 300KHz for multiple period.Periods averaged: 1 period to 100 000 periods in decade steps.Accuracy: +- 1count +- 1 time base accuracy +- trigger errorMainframe measurement functions: frequency, period, period average, ratio and scaling.Signal inputSensitivity: 100mV rms.Coupling: AC and DC.Impedance: 1Mohm in parallel with approx. 25pF all ranges.Attenuation: step attenuator provides nominal sensitivities of 0.1, 1 and 10V rmsTrigger level: continuously adjustable over +- 3V multiplied by the setting of the sensitivity switch.Time base: 10MHz oscillator, aging rate <3 x 10000000000/day.Display: 8digits.Operating temperature range: -20*C to +65*C.Weight: net. 14,4kg (32lb) without plug-in.Size: 133H x 425W x 416D mm.Price when it was new: $5000The tour is two parts, one from above and one from underside.Part one:Part two:

author: tekfan
author_rank: Frequent Contributor
timestamp: October 18, 2011, 07:20:25 pm
content: Nice one! I've got the same counter with the 0.3-3GHz plugin. Very nice and useful retro counter (sadly not reciprocal). Not a single IC in this one. Only discrete transistors. The digit storage was done by means of neon lamps and selenium? photocells. There are about 10 lamps hidden in the black plastic behind each nixie tube. The last digit receives the full 50MHz so it is a special selected module.Amazingly mine was made in England around 1975. Imagine that HP still made completely discrete counters when high speed logic was already available for some time.Wen was your HP5245L made

author: norEL
author_rank: Contributor
timestamp: October 18, 2011, 09:06:30 pm
content: Quote from: tekfan on October 18, 2011, 07:20:25 pmIt's a very nice counter! It is hard to find a production date on mine, the pcb's got different dates on them, but the earliest date is OCT. 1972. But if it was made in 1972??I have a plug-in on mine too, but not absolutely sure about the specs. hard to find some info.. What is the model number on your 3GHz plug-in?

author: tekfan
author_rank: Frequent Contributor
timestamp: October 18, 2011, 09:28:03 pm
content: This is a very nice site for old HP and Tek test equipment:http://www.barrytech.com/Go to: HP components > countersThere's a nice list of many HP counters and pluginsI've got the 5254A plugin.I think this is the manual for your plugin:http://www.kennethkuhn.com/hpmuseum/scans/hp5262a.pdf

author: norEL
author_rank: Contributor
timestamp: October 18, 2011, 09:56:02 pm
content: Quote from: tekfan on October 18, 2011, 09:28:03 pmThank you for the link`s!! I have tried to find some info on the plug-in since I got the counter. So I am very happy now! Now I have to read and learnMy plug-in is 5263A but look`s identical too the 5262A.
Low Frequency Auto Trigger, Agilent vs Tektronix - Page 1
Forum section: electronics / general

author: Michael J. Linden
author_rank: Newbie
timestamp: October 26, 2011, 03:34:23 pm
content: We picked up an Agilent MSOX3014A as our first Agilent scope. At first, the auto trigger behaved in a problematic manner similar to that described in the following thread,https://www.eevblog.com/forum/index.php?topic=4415.msg58597So, I upgraded it to the latest firmware which was supposed to improve auto trigger operation. What I've now found is that it won't auto trigger on a signal below approximately 20 Hz at all. However, all of our other scopes (Tektronix, Cleverscope, BitScope, etc.) easily auto trigger on signals down to 5 Hz.I spoke with Agilent about it. Their statement was that the MSOX3014A's auto trigger behaves essentially the same as their other scopes. They state that it's not intended for use on signals below ~50 Hz and that normal trigger mode should be used in such cases. From their perspective, my description of the auto trigger behavior seemed normal to them.So, here's my question. Are Agilent scopes known to exhibit this behavior. In other words, they don't auto trigger on signals below 50 Hz or so? Even though Tek's do?Thanks, Michael

author: ToBeFrank
author_rank: Regular Contributor
timestamp: October 26, 2011, 04:06:14 pm
content: Here is the response from Agilent I got about this. He says auto trigger should work on anything >= 20Hz. If it's not, file a bug!Quote

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 26, 2011, 04:28:16 pm
content: I wonder why scopes never seem to provide any adjustment of auto-trigger behavoiur - I find that my MSO6000 tends to ba a bit too keen to auto-trigger even in the presence of a stable signal.A simple control to adjust the timeout between a trigger signal and auto-trigger kicking in would be useful.

author: Michael J. Linden
author_rank: Newbie
timestamp: October 27, 2011, 11:57:58 am
content: Quote from: ToBeFrank on October 26, 2011, 04:06:14 pm

author: Rufus
author_rank: Super Contributor
timestamp: October 27, 2011, 12:52:26 pm
content: Mine auto triggers OK on a 1Hz signal providing the timebase is 200ms/div or slower.Looks like the auto trigger 'wait' time is something like 120% of the current acquisition time with a 50ms minimum limit.Perhaps it could work better but if you have something to trigger on you don't need auto anyway.
HIOKI 3804-50 multimeter teardown - Page 1
Forum section: electronics / general

author: zaoka
author_rank: Frequent Contributor
timestamp: October 12, 2011, 09:19:25 pm
content: This is HIOKI 3840-50 multimeterIt cost $75 on eBay, othervise it retails for about $120US.9999 counts0.09% for DCSampling rate: 7 times for V/A, 14times for diode, ohm, continuityMeasure capacity up to 10000uF, sampling rate 4 times per second.Please note that this is completely new design from the old HIOKI 3804.Comparing to Agilent U1272A DC readings and ohms are mostly the same, speed is about the same. Very fast auto-ranging, almost instant for DC.View angle and display contrast are one of the best I have seen so far. Display is also protected by thick plastic shield.Rotary switch is using balls and springs and feels very very nice! It comes with amazing rubber cover and test leads. 3805-50 is also RMS.I think this meter is candidate for best meter under $100.As for design its using gold plated contacts for the switch and buttons, soldering is top of the line.How good is design I dont know. Im sure Dave can tell from the pictures.I use this meter every day and for some reason I like it more than Fluke 79IV, probably because its a bit faster and have better contrast.

author: Spiro
author_rank: Contributor
timestamp: October 13, 2011, 06:40:59 pm
content: What e-bay? e-bay.com or some other because I can't fin it.HIOKI 3840 or 3804? I searched for both with no result.

author: retiredcaps
author_rank: Super Contributor
timestamp: October 14, 2011, 06:44:41 am
content: http://www.ebay.com/itm/Hioki-380450-Multi-function-HiTester-Digital-Multimeter-/190579472305?pt=LH_DefaultDomain_0&hash=item2c5f6bf7b1#ht_1949wt_707

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2011, 07:04:54 am
content: Where is it made?Dave.

author: zaoka
author_rank: Frequent Contributor
timestamp: October 14, 2011, 11:28:03 am
content: I got 2 meters from this guy:http://www.ebay.com/sch/techdeals_4all/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p3686Its made in Taiwan, 2010 design.
The Agilent U1272A  looks to have a Taiwanese opponent  - Page 1
Forum section: electronics / general

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: October 05, 2011, 11:25:31 pm
content: Yes it looks that it does..The APPA 505http://www.appatech.com/appa_product_home.php?pdid=2009091810044515198&&kindid=2005081003113623241More in depth specshttp://www.appatech.com/upload/product/techdata12532396949505.ASix times sampling ( but they do not say if it as at 10.000 or 100.000 counts)And double internal memory capable for 20.000 data logging entries.The Taiwanese APPA 505 got in the Russian market at 10700 Russian Ruble that is about 246 Euros or 330 USD.APPA looks to use even their own data logging software.Just by looking the specs on paper I feel confused.Maybe one more expert than me, he could spot how close they are about their internals.Externally the Agilent it is superior, or better said I like it as is.

author: firewalker
author_rank: Super Contributor
timestamp: October 06, 2011, 07:32:14 am
content: The specs are tempting!

author: qno
author_rank: Frequent Contributor
timestamp: October 06, 2011, 07:59:54 am
content: Guess who is selling them in The Netherlands!http://www.nieaf-smitt.nl/installatie-portfolio/draagbare-test-en-meetapparatuur/digitale-multimeters/

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: October 06, 2011, 02:38:47 pm
content: Quote from: qno on October 06, 2011, 07:59:54 amohhh re-branded too !! ,what a surpriseEven so there is no 505 model to them, and not a word about the pricing.
Kinect teardown - Page 1
Forum section: electronics / general

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 02, 2011, 10:37:33 pm
content: Recently (several weeks ago), I got a Kinect to play with. One of its main downsides is that it needs its own power supply. I opened it up to see if I can make it powered from USB.(Please look athttp://openkinect.org/wiki/Main_Pagefor background information.)You'll note that R4 is circled. That sets the UVLO for the 12V input, which is regulated down to 3.3V before anything uses it. The 3.3V buck regulator (a ST L6728) is capable of operating from 5V, but there's an external UVLO that prevents operation at that voltage. Simply add a 4.7k resistor in parallel with R4 and the Kinect will operate from a 5V supply. Current draw is about 700-800mA. A USB 3.0 port will power it, but since all of my PCs only have USB 2.0, that would require two USB connections for reliable operation. I left it running from 5V for a few hours and nothing is getting warmer than when it's running from 12V. Just to be safe, however, I rewired the fan to an always on 5V line. (That will decrease operating temperatures, prolonging lifetime and reducing sensor noise.)Some interesting observations:* There is a thermal fuse mounted to the IR projector. I'm guessing the developers had one melt down and decided to add the fuse just to be safe. It also looks like it was added after the sensor board was designed since it isn't directly connected to the sensor board as might be expected.* There's a processor on the sensor board for video processing and a seemingly more powerful processor for audio processing. Why they would need such a powerful processor for audio is something I'm not understanding.* The TI USB controller is actually for the auto leveling motor and accelerometer, despite it being labeled as an audio controller. I'm not sure why they didn't just use a generic USB microcontroller or a few GPIOs on the audio processor.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 08, 2011, 03:43:14 pm
content: Quote from: NiHaoMike on October 02, 2011, 10:37:33 pmUnless the audio processor is doing something, it never gets hot enough for the fan to start.QuoteThe Peltier under the laser actually heats it at room temp, so maybe to trip if the temperature feedback is lostQuoteBecause it has several microphones, and does lots of clever processing to detect where the sound is coming from. ISTR it's a very meaty ARM running at several hundred MHzAsus do a similar device without the audio and motor, whic is USB powered :http://www.asus.com/Multimedia/Motion_Sensor/Xtion_PRO/It is also possible to run just the front sensor board on its own - ISTR it needs 5V and 3.3V, although I think the peltier module still takes the power draw over the 500mA USB limit.Unfortunately I think last time I looked the connector was unobtainable in small quantites.
Precision Gold LCR meter M195 - Page 1
Forum section: electronics / general

author: PStevenson
author_rank: Regular Contributor
timestamp: September 24, 2011, 11:36:41 pm
content: I got this thing years ago, I can't remember where from but it was most probably Tandy, I remember wanting to build radios so I thought "I need an inductor meter" and this was the only one I could afford. Anyway I thought I would take it apart for you nice people because I just love the insides of it.I also included a picture of my guitars with my Dave T-Shirt next to them, why? for the hell of it.

author: Kibi
author_rank: Unknown
timestamp: September 27, 2011, 09:19:02 pm
content: Cool retro style. All descreet components. I like itNice guitars too.

author: PStevenson
author_rank: Regular Contributor
timestamp: September 28, 2011, 02:06:29 pm
content: yeah I do love discrete circuitry, I've got an old scope that is all transistors, I think there was only one IC in it which was part of the onboard squarewave generator. that is a work of art.I love my guitars and indeed my new dave T-Shirt

author: saturation
author_rank: Super Contributor
timestamp: September 29, 2011, 01:52:53 pm
content: I have such an oldie myself, but with those glass fuse types one need to give some thought to using it for mains work to higher CAT required safety.

author: PStevenson
author_rank: Regular Contributor
timestamp: September 29, 2011, 03:21:46 pm
content: it doesn't have a voltage/amp facility it's purely just LC and R. I have a "Dave Correct" Fluke 87 for anything that isn't inductance measurementin fact I've got a few different Flukes - they are great meters
APC SURT1000XLI - teardown - Page 1
Forum section: electronics / general

author: hacklordsniper
author_rank: Frequent Contributor
timestamp: September 28, 2011, 05:04:00 pm
content: So the first one arrived. I was surprised when removing the batteries it was still pretty heavy (it has 27 Kg, so its not a usual carry as you wish UPS)Batteries are consisted of 4X12V 7.2 Ah in series. It has 2 fans, one is blowing the air in the heatsink and on the other side second fan is pulling that air out.I'm surprised how silent it is. A Viewsonic VOT120 nettop computer running on minimal fan speed is still significantly louder. Did not have chance to test it toughly, will do that when i move in.Its not fancy with a LCD like cheaper alternatives but simple and elegant row of leds does the job. However the only bad thing is you get only 2 power cables and you don't get the line power cableEnjoy
Anyone have an Agilent U1732B? - Page 1
Forum section: electronics / general

author: alexwhittemore
author_rank: Frequent Contributor
timestamp: October 04, 2011, 05:04:17 pm
content: I'm curious about the board-to-board comparison of the U1732B and the U1731B LCR meter that I just got. If anyone has the former (higher end, ~$350 US model) could you post high-res pictures of the PCB? I'm particularly interested in the area around the main micro.
High Voltage Probe - Page 1
Forum section: electronics / general

author: rkungl
author_rank: Newbie
timestamp: September 25, 2011, 03:04:03 am
content: I'm looking for a high voltage probe to use with a tektronix TDS3032 up to say 5,000V or up to 10,000V.I found the P6015A but its like $1000, anyone know of anything cheaper?

author: tekfan
author_rank: Frequent Contributor
timestamp: September 25, 2011, 11:05:30 am
content: If you want to measure DC then you can get away with one of those HV probes and a multimeter.If you want to measure AC then the only option is a HV oscilloscope probe like the P6015A. There was also the P6015 (without the A) model that required a freon dielectric to safely meaure beyond 12 KV. These quite often come up on ebay but don't expect to pay below 300 USD

author: Unknown
author_rank: Unknown
timestamp: September 25, 2011, 11:27:52 am
content: I believe someone on the TekScopes list tested a HV probe designed for DMM's, I think the bandwidth reached somewhere in the kHz range.The Tek P6013, which is basically the same as the P6015 without the almost unavailable freon, may also be available used. I would be vary careful with trusting cheap knock-off probes with these kinds of voltages. Maybe HP/Agilent or Lecroy have similar products? Of course you'd also have to inspect a used probe carefully before exposing it to dangerous voltages.Watch the voltage derating of probes, even a P6015A is not designed for 10kV RMS at 10MHz.

author: rkungl
author_rank: Newbie
timestamp: September 26, 2011, 06:51:09 am
content: What about a probe that'll measure up to 500V? The probe I am currently using is rated to 150V. The signal will be approx 40-200V, 1-10khz, various waveforms (square, sine)

author: Psi
author_rank: Super Contributor
timestamp: September 26, 2011, 07:20:04 am
content: wasn't there a video on here a while back about building your own high voltage probe ?

author: Lightages
author_rank: Unknown
timestamp: September 26, 2011, 01:46:21 pm
content: Quote from: rkungl on September 26, 2011, 06:51:09 amWell that is quite the drop from 5kV!I have a couple of these:http://www.dealextreme.com/p/250mhz-oscilloscope-probe-max-1200v-35610and they seem well enough made but I have no way to test their safety or voltage rating.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 27, 2011, 02:39:18 pm
content: Quote from: rkungl on September 26, 2011, 06:51:09 amIf the signal is 40-200V,why do you need 500V?Ordinary 10X Tektronix 'Scope probes are commonly used at around 400V or so.The original 5-10KV requirement is available for DMMs at a reasonable price,but once you get to those levels with Oscilloscope probes,the cost goes up steeply.VK6ZGO
Tektronix 2225 Probe Adjust - Page 1
Forum section: electronics / general

author: Mat
author_rank: Contributor
timestamp: September 24, 2011, 01:34:58 am
content: Hi!I've got a Tektronix 2225 and something seems a little odd :The probe adjust signal is a negative pulse square wave (from 0 to -0.5 V).Can anyone tell me if this is normal? In his review, Dave only tests the probe adjust on AC coupling...Thanks,Greetings,Mat

author: Psi
author_rank: Super Contributor
timestamp: September 24, 2011, 01:49:48 am
content: Have you checked if the channel has invert enabled?

author: Mat
author_rank: Contributor
timestamp: September 24, 2011, 09:58:14 am
content: I remember that this happened on both channels and there is no invert on channel 1.

author: TheEENerd
author_rank: Contributor
timestamp: September 25, 2011, 07:28:12 pm
content: Don't worry, my 2225 is doing the same.

author: Mat
author_rank: Contributor
timestamp: September 25, 2011, 10:41:50 pm
content: OK thanks!! One less thing to fix on this scope!I am waiting for a power switch (only the black plastic rod going from the front to the mains input board on the back) and some missing case screws.When I receive them, I'll post some pics!Because you know what Dave says on the EEVblog : Don't turn it on, take it apart!!!TheEENerd : Thanks again!M.

author: TheEENerd
author_rank: Contributor
timestamp: September 26, 2011, 07:00:30 am
content: You r welcome. I picked up my 2225 locally here in Sydney. Got it calibrated, and now waiting for some new accessories.
Help deciding between scopes: Owon SDS7102 OR Hantek DSO5000B - Page 1
Forum section: electronics / general

author: Kernel SegFault
author_rank: Newbie
timestamp: September 24, 2011, 10:07:12 am
content: I finally have saved up some money to get a new scope to replace me slow USB scope. I've browsed these forums and others, read whatever reviews I could find, and flipped through some manuals but I cannot decide which I should go with between the Owon SDS710 and the Hantek DSO5000B. If I got the Hantek I would apply the 200Mhz patch. I have watched marmad's reviews of both of them, but that only helped a little as he spent more time going over the Owon. Since I can't decide with what I know and I have some other questions if anyone knows. I am between these as I would like to have the larger screen.Has the Owon has any FW upgrades released since it came out? Some people say that they are sent to owners and not openly published?Which company is more likely to release FW updates more often, I assume Hantek?The Owon has no fine adjustment correct?Does the Owon have the windowed view?Any other reasons to choose one over the other that I may have missed?Thanks for your help.

author: Bored@Work
author_rank: Super Contributor
timestamp: September 24, 2011, 12:11:15 pm
content: Throw a dice. Because both have their quirks and both are a compromise of cost vs. quality. You are wasting your time with trying to find an optimum.

author: dimlow
author_rank: Frequent Contributor
timestamp: September 24, 2011, 03:07:43 pm
content: pick the owon, it has the highest numer, ie starts with a 7

author: saturation
author_rank: Super Contributor
timestamp: September 24, 2011, 04:39:25 pm
content: I think marmad did a superb review as unlike many reviews, he briefly had all 3 scopes to compare by himself. You have to weigh things that are nontechnical too: which is easier to buy? Which seller is likely to give you an easy time returning it if it malfunctions? What if the Hantek dealer charges far less than the Owon, or the other way around? I prefer local vendors so I can return it easily, not one based outside the country. Amazon.com for example often pays for the return shipping too, but it varies by product and who is the actual seller.Once hacked, it may not be returnable so keep it in mind, even if you reverse the hack; you could also brick it in the process.Formally, when we buy large systems we put a checklist of needs or features, prioritize it on a scale from 1-10, and then look at the item to buy and score it based on how well it meets those needs; add it all up and whomever meets your score wins.As BAW said, they all have pros and cons, which pros do you prefer? which con can you not live with? If you are looking for a general purpose scope and the pros and cons are unclear to you, then its probably clear either will do as you don't have a specific need that needs be met and can differentiate the strengths and weaknesses of either.
Protek DMM calibration procedure? - Page 1
Forum section: electronics / general

author: IanB
author_rank: Super Contributor
timestamp: October 01, 2011, 03:02:30 am
content: This seems to be one of those pieces of "secret" information that I can't find by Googling. I bought a Protek 6500 DMM that reads 4.9986 V against a 5.000 V reference. It is within the accuracy spec of ±(0.03%+6 digits), but the lack of exactness still offends me. I would like to tweak the calibration to make it read at least between 4.999 and 5.001 V, but I can't find out how. Does anyone have this information, or know where I might look?For calibration the meter has a push button on the rear covered by a calibration sticker. I imagine that pressing this button puts the meter in a calibration mode in which the front panel buttons get different functions. But I don't want to experiment. Since it is an inexpensive meter for hobby use I also have no interest in paying for professional calibration. If I could read the calibration instructions I could at least decide whether to have a play or leave well alone...

author: Unknown
author_rank: Unknown
timestamp: October 01, 2011, 10:26:05 am
content: What's the uncertainty in the reference? Are you actually improving accuracy or just making your equipment consistent, which may decrease accuracy?Sorry, no clue about the calibration procedure. Did you try asking Protek?

author: Neilm
author_rank: Super Contributor
timestamp: October 01, 2011, 05:30:38 pm
content: I would be wary of trying to adjust the instrument you have so it reads 5.0V on your 5.0V referance. It might very well make the instrument go out of spec elsewhere.Neil
Video Demo - 9-DoF AHRS Sensor Board and RGB LED Matrix - Page 1
Forum section: electronics / general

author: Hugoneus
author_rank: Frequent Contributor
timestamp: September 18, 2011, 05:44:48 pm
content: In this (experimental) episode Shahriar demonstrates two embedded-electronic circuits available for purchase from Sparkfun Electronics. The demos illustrate some of the capabilities of these circuits along with a short instruction on how to interface and operate them. All the code for the AHRS demo and the RGB Matrix demo are available to download.The first demo is of a 9-degree of freedom (9-DoF) sensor board equipped with three dimension of linear acceleration (accelerometer), angular acceleration (gyroscope) and magnetometer. Using the combined information from these sensors an Attitude and Heading Reference System (AHRS) data can be extracted. The demo shows this system in action using customized Matlab functions.The second demo demonstrates the ease of use of an RGB LED Matrix equipped with an SPI interface. A sample C code written for a Microchip PIC18F2455 is used to draw some simple animations.This is an experimental episode to judge the level of interest in these type of demo videos. Please leave feedback!Please visit:http://www.TheSignalPath.com

author: Hugoneus
author_rank: Frequent Contributor
timestamp: September 18, 2011, 07:04:21 pm
content: I had forgotten to provide the URL. It is included now.
Video Review: Amprobe AM-270 - Page 1
Forum section: electronics / general

author: FenderBender
author_rank: Super Contributor
timestamp: September 27, 2011, 02:58:21 am
content: Hey guys,Got dedicated after sk00l today and decided to make this video. I know it's long as hell...almost an hour. But I tried to make the best comments I could and my real opinions. I don't think the video is done processing yet, but when it is, here is the link:Yes you get to hear my cute little voice. Don't hate.Good meter for the price, really.Enjoy.

author: BravoV
author_rank: Super Contributor
timestamp: September 27, 2011, 03:37:41 am
content: Why I'm getting "This video has been removed because it is too long." when I tried to play the video ?Is it only me ? How long is that video ? Never experienced like this before on youtube.

author: FenderBender
author_rank: Super Contributor
timestamp: September 27, 2011, 03:47:40 am
content: Fixing the problem. I'm reuploading it because I didn't have my account set up for videos longer than 15minutes.Should be up in about 20 minutes.

author: IanB
author_rank: Super Contributor
timestamp: September 27, 2011, 04:30:11 am
content: Didn't get very far through the video, but the PC interface is an extra cost option, USB-KIT3; scroll down to the end of this page:http://www.tequipment.net/amprobepricelist.asp?page=4PC interfaces are normally activated by pressing buttons on the meter--the rotary switch does not turn to that position.

author: FenderBender
author_rank: Super Contributor
timestamp: September 28, 2011, 02:53:46 am
content: Yeah I realized that much. Sorry I was mumbling the whole video. You wouldn't miss much if you muted it. Still not a clue where the serial connection would be made...

author: IanB
author_rank: Super Contributor
timestamp: September 28, 2011, 03:41:44 am
content: Quote from: FenderBender on September 28, 2011, 02:53:46 amIt's an optical connection. It might look a bit like a TOSLINK socket on an audio system. It won't be very big.
Cool new LCD tech from Sharp - Page 1
Forum section: electronics / general

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 08, 2011, 08:16:40 am
content: Just got some of these really coolMemory LCDs from SharpInsanely low power cosumption and amazing contrast.A bit like E-Ink but available, and faster

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 08, 2011, 10:39:42 am
content: you're always cool mike. still cant find it in ebay. where did you buy this?

author: deephaven
author_rank: Frequent Contributor
timestamp: September 08, 2011, 10:42:18 am
content: Quote from: Mechatrommer on September 08, 2011, 10:39:42 amTry putting LS013B4DN01 into the FindChips window.

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 08, 2011, 10:48:19 am
content: ahh! FindChips! old style die hardedit: mouser sells LS013B4DN01 96x96@$15 hmm

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: September 08, 2011, 12:28:41 pm
content: interesting LCD design, screen updating speed, and operating temperature limits,needs some extra exploration.

author: saturation
author_rank: Super Contributor
timestamp: September 08, 2011, 01:25:11 pm
content: Very nice, thanks for these leads, will look into them!

author: John80
author_rank: Contributor
timestamp: September 08, 2011, 06:09:27 pm
content: I saw your video!!!! Really good!!!!

author: deephaven
author_rank: Frequent Contributor
timestamp: September 08, 2011, 07:17:17 pm
content: Thanks for the great video, Mike. What boards are you using to drive the displays?

author: gregariz
author_rank: Frequent Contributor
timestamp: September 08, 2011, 09:58:14 pm
content: Thanks Mike,Would you be able to say how viewing compares in sunlight?

author: EEVblog
author_rank: Unknown
timestamp: September 08, 2011, 10:24:29 pm
content: Yes, they are cool.I've got one earmarked for use in my new µWatch2 project.See an upcoming issue of EEweb's Pulse magazine.Dave.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 08, 2011, 10:32:15 pm
content: Quote from: gregariz on September 08, 2011, 09:58:14 pmThey are very visible in all lighting condas & when I see some sunlight it would be interesting to see if the silver one would actually reflect an image of the display onto a surface...

author: EEVblog
author_rank: Unknown
timestamp: September 08, 2011, 10:55:34 pm
content: The small one I'm looking at using is marked as transflective, so I'm assuming it can be backlit?Dave.
B&K rebadging RIGOL scopes? - Page 1
Forum section: electronics / general

author: ElektroQuark
author_rank: Unknown
timestamp: August 29, 2011, 09:50:28 am
content: It looks like a RIGOL:http://www.bkprecision.com/products/model/2530B/25-mhz-500-msa-s-digital-storage-oscilloscope.html

author: johnboxall
author_rank: Unknown
timestamp: August 29, 2011, 10:32:06 am
content: Atten ADS1022?

author: FenderBender
author_rank: Super Contributor
timestamp: September 15, 2011, 10:02:02 pm
content: I heard is was a Tek 2000-type.
Hey Dave...question about USB scopes - Page 1
Forum section: electronics / general

author: nzo
author_rank: Regular Contributor
timestamp: August 24, 2011, 01:04:20 am
content: Dave - in one of your early "Setting up a workshop" vids, you passed over USB scopes in favour of a conventional hardware scope.I see you have some ads on your blog for several USB scopes (Pico and Cleverscope).Are these worthwhile and useful tools in the electronic workbench, when hardware scopes are not available or way too expensive?If you have time, please comment

author: KuchateK
author_rank: Regular Contributor
timestamp: August 24, 2011, 04:03:59 am
content: Dave explained everything in one of the first episodes...I've checked some numbers and the prices from those websites...Rigol (or similar) scope is a lot better. It has 5x analog bandwidth, 10x sample rate than their offers. It is also half or one third the price they want. 800USD for pico? 1200USD for cleverscope? This is crazy and insane when checking specification. Cleverscope didn't even bother to write analog bandwidth in the spec.

author: EEVblog
author_rank: Unknown
timestamp: August 24, 2011, 12:31:56 pm
content: Quote from: nzo on August 24, 2011, 01:04:20 amTo me, PCB based scopes are more of a specific niche tool than an everyday scope - very useful for datalogging, or high dynamic range (>8bit) sampling etc that you don't readily get on bench type scopes. You'll find those available from the likes of Pico and Cleverscope. That's why I let them advertise on my site, they don't make useless products.But for general purpose use, bench scopes rule in almost every area, and any USB scope manufacturer who claims otherwise is spinning you a yarn - unless you have a specific need that USB scope covers that a bench scope won't.Bench scopes are now pretty darn CHEAP! Rigol's go for $350, and the new Agilent 2000X kicks arse at just over $1K.But if you have no bench scope for whatever reason, then yes, a USB scope is of course better than having no scope at all.Dave.

author: seattle
author_rank: Contributor
timestamp: September 09, 2011, 04:32:32 am
content: I think the other thing to keep in mind is how much SW development do you do? If you aren't doing any SW development, then the need for a logic analyzer isn't huge and the issue comes down to the exact things Dave mentioned.However, if you are doing a lot of SW development and you need a logic analyzer, and you also need a scope, (and especially if you need to do debugging of SW and HW together, decoding of protocols., etc), then trying to do that on a standalone device is very tough.I have a Rigol on my desktop, and it's the first thing to get turned on when I'm confused. But if that confusion lasts for more than a few minutes, then the Rigol gets turned off and the USB scope + LA gets turned on. And stays on.
A Beautiful Transistor... - Page 1
Forum section: electronics / general

author: blackdog
author_rank: Frequent Contributor
timestamp: August 31, 2011, 06:13:35 pm
content: Look at this clip on youtube.com, NXP unbreakable transistor...Beautiful!!!Bram

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: August 31, 2011, 09:21:06 pm
content: The title is not relative with the video.Even so my Kenwood KA-7020 (2 x 115W RMS) , with gold plated connectors, are also immortal because he has electronic short circuit detection on the speakers.And no mater what, it shutdown by it self.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: September 01, 2011, 03:59:07 am
content: Nice video.LDMOS was invented by my supervisor's supervisor from when I used to do my PhD! It is impressive that the device survives going through 50Ohm to open/short with 10% extra supply.
Looking for 100 MHZ DSO - Page 1
Forum section: electronics / general

author: dbs
author_rank: Newbie
timestamp: August 23, 2011, 03:56:31 am
content: Hello to all,I've been reading posts for a while and find the information on this site to be very useful. I'm looking at the Hantek 5102B and the Owon PDS 7102T or the SDS, don't know the difference yet.I think I read that the Owon has a red trace on channel one and am wondering if that is really the case and if so can the color be changed? I don't see red or green very well. Also wonder who does the warranty repairs on the Hantek's and Owon's if purchased from Morton Controls. Haven't been able to get them on the phone and no answer to email as yet. Thanks in advance. Dave

author: rf-loop
author_rank: Super Contributor
timestamp: August 23, 2011, 05:29:38 am
content: Quote from: dbs on August 23, 2011, 03:56:31 amSDS have mx 1Gsa/s PDS have max 500Msa Markable difference.SDS have10Msample full speed memory, Pds have only 6k (this is really big difference)SDS have 800x600 8" TFT, SDS7102T have 640x480SDS have (S)VGA out for external monitor. (of buy look this option is)Colors (SDS) can not change in FW what is today.btw, my Rohde&Schwartz originally extremely expensive spectrum analyzer have default trace colors. RED and yellow.I have changed all "thousends" color combinations... quess what I use... red and yellow.I get SDS, first I think that I do not so much like this CH1 red and CH2 yellow. Well, after 15 minute testing I forget this color question totally.Traces: CH1 red, CH2 yellow, some math light blue and green. FFT clear green.And what is best, you do not use your powerfull working time for tweaking colors or other dingle dongles.I'm not people who have just buy his forst oscolloscope and hen tell that it is worlds best becouse I select it and can not tell that my selection was wrong. I have tens of different scopes and other mostly fully professional middle and high end test gears.I can tell that for normal use, if conventionally capturing but new modern DSO is enough in this speed clas this IS good scope.I have not yet experience about its longevity but seems not bad if compare building quality to Rigol Or Hantek.If really need fast realtime DPO this is not for you. Then buy Agilent about 1.5k$I have not made my testings ready for SDS and it takes in my timetable least 1 month. Now I can only "preliminary" tell.Freq response is good and -3dB point is over 130MHz and -6db point is over 220MHz, Risetimes of course with those values as all gaussian freq response scopes.

author: dbs
author_rank: Newbie
timestamp: August 23, 2011, 12:12:33 pm
content: Thank you for the information RF-LOOP. I guess the only question now is about warranty repair and I'll try to contact Morton Controls again for that information. Thanks again. Dave
Rigol DM3051 5-3/4 Digit Multimeter - Page 1
Forum section: electronics / general

author: nukie
author_rank: Frequent Contributor
timestamp: September 11, 2011, 03:12:46 pm
content: This build quality is much better, and it has a proper quality Caddock 1776 resistor decade network. Probably based on FET reference voltage. Pictures copied from chinese EE forums.

author: Unknown
author_rank: Unknown
timestamp: September 11, 2011, 04:31:43 pm
content: Interesting that the cheaper model appears to have better build quality and parts (and least the resistor network).

author: Unknown
author_rank: Unknown
timestamp: September 11, 2011, 04:50:59 pm
content: the caddock part is 10$ bulk at digikeywhat on earth were they hoping to gain by using a no-name part on the higher model?
Presentation 30V 30A hand made PSU  (1991)  - Page 1
Forum section: electronics / general

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: August 26, 2011, 01:44:34 am
content: This is an old and simple build for an adjustable 3-30V 30A PSU.Yes I did itThe concept is simple, there is an 3-30V circuitry with one 2N3055 as output transistor,that drives 8 X 2N3772.There is a 40A metal bridge (rectifier) and 4 X 15.000mF at 50VAll the output transistors they are connected in parallel, and its one haves an 15W resistor in the output,so to balance the inner resistance of the transistors, they must be 0.22 Ohm.I method that I had use at 1991 about the cooling, today looks amazingly correct,even if it was made by a boy that was just 22 years old at that time.Yes I fill proud about it even today that I am 42 years old.This item still is an performer, and I have even manage to use it so to power up the starter of my motorcycle,that needs about 42A at 14V.Enjoy the pictures.

author: Unknown
author_rank: Unknown
timestamp: August 26, 2011, 09:47:49 pm
content: I would use a larger bridge rectifier if you were to do this again. 30A DC is about 57A AC on average, and the peaks are much higher since the filter caps are only charging during peaks. Bridge rectifiers tend to blow up after a while if run near their rated capacity.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: August 26, 2011, 11:24:05 pm
content: Those days that I had build it, I was in need to power up the output stage of my FM transmitter ,that was a broadband circuit with double MRF317 , the idea was to add another one like it so to have the final output of 500W.The single PCB with the dual MRF317 was need 14A at 30V, I never got the second PCB that in total they would be four MRF317 in action,and this would lead to 24A of load.For the application that I had in mind, I did overbuild it.But you are correct up to a point.Another common solution was the use of double bridges in parallel.But the specific German one, looks even today to be able to handle any task up to 40A ..Basically this device does not have any made in China part, and the transformer is Greek, from a local company in my town,just 1Km away from my shop.It is a sample of well made European parts from the old days.
Bitscope hardware-How can it be improved/updated? - Page 1
Forum section: electronics / general

author: djsb
author_rank: Super Contributor
timestamp: August 20, 2011, 10:01:02 pm
content: I keep going back to the Bitscope site and looking to see if the design has been updated/improved. Apart from a AWG and new logic analser software the core design hasn't changed much.It is meant to be an "OPEN" design. Does this mean anyone can take the hardware and improve it? Any thoughts?David.
Tek MSO3054 vs Agilent MSOX 3054 User input please? - Page 1
Forum section: electronics / general

author: three_jeeps
author_rank: Contributor
timestamp: August 22, 2011, 08:27:36 pm
content: I am considering purchasing the 500 MHz version of one of the above scopes.While I am a practicing EE, well versed in the use of scopes made prior to 1998, I have not used the newer generation of scopes, other than a brief 1.5 hr 'demo' of each unit, so in some respects, I consider myself a 'newbe'.I'd like some input from ppl that have used one or the other (preferably both) scope to provide some comments about pros and cons, especially the negatives. I have read through the numbers in comparisons, and the Agilent seems to have a noticeable edge in basic capability (I don't consider the integral FG any sort of an advantage, so I do my evaluation not considering that functionality).I addition to pros/cons, I am also seeking input on 'useability'...e.g. how easy or hard is it to do signal capture and analysis. I know this is subjective, but if you ran into road blocks, had to adjust 20 settings just to analyze a trace, etc. that frustrated you, I'd like to hear about it.I kindly thank you for you time in responding.BTW, I saw the 32 page thread on the 'review' of the new Agilent 2000x and 3000x, but the thread had two or three themes: numbers comparison, advertising games wrt cost, and how can this scope be hacked... All of which are interesting but very few posts addressed my questions.Also, this scope is intended for a design engineering workbench addressing both analog (not rf) and digital (logic, MCUs, and FPGA based designs).best regards,-John

author: chscholz
author_rank: Regular Contributor
timestamp: August 23, 2011, 01:04:59 pm
content: I'd go with a LeCroy WR606Zi.600 MHz, 10 GS/s sampling rate, 4ch, 16 Mpts per Channel, WXGA Display and the usability/GUI is second to none.Chris
[Teardown] Greisinger GFTB100 thermometer, hygrometer, barometer - Page 1
Forum section: electronics / general

author: Richard W.
author_rank: Regular Contributor
timestamp: August 22, 2011, 07:57:04 pm
content: Hi,I've taken some photos of whats inside a combinated thermo-, hygro-, barometer.It measures air pressure , temperature [°C,°F], relative humidity [% rH].The values for dewpoint, absolute humidity and wet bulb temperature are calculated.temperature accuracy is about +/-0,5%;humidity accuracy is about +/-1,5%;air pressure accuracy is about +/- 1,5mbarthe temperature sensor is a Pt1000, the sensor for humidity is a capacitive one, the sensor for air pressure is a piezo-resistive hybrid.The power consumtion is as low as possible, the datasheet says 75µA at one measurement per second, 30µA at one measurement per minute.I'm surprised, except the sensors and a microcontroller there's not much in it. Everything is done by the software.The price is about 174€ (~250 US$) and it's made in Bavaria

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: August 22, 2011, 10:47:52 pm
content: Quote from: Richard W. on August 22, 2011, 07:57:04 pmI prefer the Bavarian BeersNice presentation, thanks Richard