hybridfree/eevblog-posts huggingface dataset:
Signal Generator (my 1st) - Page 1
Forum section: electronics / testgear

author: hmlittle59
author_rank: Contributor
timestamp: August 11, 2013, 08:33:32 am
content: Hello All,First, the Rigol DS2102 is on it's way to me. I have not used a Sig. Gen. for over 20yrs. and want one now for learning and working with the new Scope. I've narrowed it down to the GW-Instek AFG-2225 (3' screen) or Rigol DG4062 (7' screen). I really want the Rigol but the price hurts. Has any one used or test either one of these units? The Rigol may be over kill for now but if its more then work the price for now and the new future, I'll go with that one. But if the "Quality" is bad then, "NO".Thanks for any help.Howard

author: Selectech
author_rank: Regular Contributor
timestamp: August 11, 2013, 11:54:29 am
content: I have a DG4162 for my personal bench and a couple of DG4062 that I got for work. Like them both { along with the DS2102 , DP832 and DM3068 }. They all worked just great out of the box.I have an SDG1010 and that worked fine, but Rigol has better features / spec although more expensive. It was worth it for what I'm doing { analog / digital sensors & signals } so I did the upgrade.

author: hmlittle59
author_rank: Contributor
timestamp: August 11, 2013, 05:05:26 pm
content: Hello Selectech,Thanks for the reply. As this is strictly training for now, I will go with the DG4062. I do want the larger screen also. Looking at the unit, it will be like the O'scope were I can upgrade at a later date, correct? (with software). Will there be any thing else(small connector/cables) that I should get now that will help with the setup?Thanks for any advice.Howard

author: kevinpt
author_rank: Contributor
timestamp: August 11, 2013, 07:10:28 pm
content: If money is tight you would get more bang for the buck by tracking down a used analog signal generator or arb rather than a new one. If all you plan on needing is basic signal generation you'll get much more bang for the buck than the case of scrounging for a used oscilloscope versus new. There are a ton of unwanted Waveteks and other brands floating around on the auction sites. Unless you know for certain you need some advanced feature or tighter specs from a new arb an older unit will be much more cost effective.

author: Sigmoid
author_rank: Frequent Contributor
timestamp: August 12, 2013, 03:57:59 am
content: Just yesterday I scored a Goldstar 0.2Hz-2Mhz sweep generator for $50. It seems someone dumped a crapload of the things nowadays, they are all over eBay for this price.I'm sure it's not the finest signal generator ever, but it's a sweep, has the most important waveforms, and it's cheap.
Rigols DS1052E Run/Stop BUG - Page 1
Forum section: electronics / testgear

author: Bryan
author_rank: Frequent Contributor
timestamp: August 12, 2013, 07:56:36 am
content: Has anyone else experienced this issue with the Rigol DS1052E. Analyzing a waveform and when selecting the Run/Stop button to capture the waveform the vertical voltage of the trace will be divided in 2. For example if scoping a 2v p-p signal, when I select run/stop the display freezes the waveform at 1v p-p. Doesn't happen all the time but fairly predictable. Bug or am I missing a setting somewhere in the scope ?

author: Wytnucls
author_rank: Super Contributor
timestamp: August 12, 2013, 12:12:07 pm
content: Mine doesn't do that.Tried 20 instances of Run/Stop selections, with no variation in voltage on the waveform. My scope runs the original 00.03.01 software version.
Omnitec FG200 Function Generator - Page 1
Forum section: electronics / testgear

author: Deckert
author_rank: Regular Contributor
timestamp: April 29, 2013, 12:15:27 am
content: Hello,I picked up this old Omnitec function generator for about $50. It was sort-of working, but had lots of noise and some of the rotary switches were almost completely stuck. I little WD40 on the rotary switch pillars and some Servisol contact cleaner inside the switches and the unit was fully working again.I had to replace one of the knobs (I'll find a more fitting replacement in due course). There is zero information on the 'net about this model, but I suspect it was actually designed and manufactured in South Africa:Inside, the unit has only three ICs. Two of the chips have their numbers sanded off (why do people do this?!). Looking at the date codes, it seems to have been manufactured in 1981.It uses an Intersil function gen chip that seems to have been fairly popular at the time:The ICL8038 data sheet can be found here:https://www.renesas.com/us/en/search?keywords=ICL8038The spec sheet says the chip can do 0.001Hz to 300kHz, although the unit I got has a range of 1Hz to about 110kHz. It supports sine, triangle, square and positive/negative pulsing. Looking at the signals it generates on the scope, they're very clean indeed. Not bad for a unit more than 30 years old!The frequency counter chip seems consistent with the Intersil ICM7216B counter chip.Edit: a fellow forum user has acquired the same function generator without the numbers scrubbed off. The chip number is actually the ICM7226B (basically the same as the 7216, but with an additional BCD output).It seems that the ICM7216B was also very popular at the time. The data sheet can be found here:https://www.renesas.com/us/en/search?keywords=ICM7226Almost all the functions of the counter chip have been exposed on the unit itself, including period measurement.Having this unit added to my bench means my XR2206-based project will probably move down the list of projects to be completed. Although it only goes up to 100kHz it serves well to play with analogue signals, RC circuits and investigating their properties on the scope. Measuring frequency output with my trusty RACAL-DANA frequency counter shows that the frequency values displayed on the unit match perfectly. There is a little drift in output frequency as the unit warms up, but after about 10 minutes it stabilizes and there's only a few Hz drift every now and then.--deckertEdit: updated with correct chip number and updated the datasheet links.

author: Stonent
author_rank: Super Contributor
timestamp: August 11, 2013, 06:15:49 am
content: I just picked up an XR2206 as well. But I do like that they labeled the pins on most parts, the mosfets and regulators seemed to be marked, good for troubleshooting quickly.
HP 3468B current source troubleshooting - Page 1
Forum section: electronics / testgear

author: kt315
author_rank: Regular Contributor
timestamp: August 10, 2013, 11:45:18 pm
content: Hi,I've bought a used DMM HP3468B on ebay. VDC seem to be accurate. But it does not measure resistance correctly on the two lowest ranges (the higher ranges are fine as far as I can tell).The service guide suggests that the current thru R204 should be the same for all the ranges, and it is indeed the same for the ranges that work, but drop for the ranges that do not. The relevant schematic is on page 135.I went thru the troubleshooting steps in the guide, and it looks like my only hope is that one of Q201-205 transistors is defective.What would be the easiest way to check if it is the case?I am a bit lost at the moment, so any advice would be highly appreciated.The service guide:http://www.home.agilent.com/agilent/techSupport.jspx?pid=3468B%3Aepsg%3Apro&pageMode=OV&cc=CA&lc=eng

author: Unknown
author_rank: Unknown
timestamp: August 11, 2013, 12:08:34 am
content: Apparently Agilent now requires registration before you can download a manual, so I haven't looked at the schematic, but would switching transistors give any useful information? Of course while you're at it, you might as well test it out of circuit for shorts or opens. Did you measure voltages around the transistors to see if they make sense?

author: kt315
author_rank: Regular Contributor
timestamp: August 11, 2013, 01:29:31 am
content: Thank for the ideas.They require the name an email address, they do not require to create an account though.I attached the screenshot of the schematic.I was thinking about checking the voltage across "overvoltage protection" section, I am not sure what the reasonable value would be though. To be totally honest, I am not sure why the voltage on Q201 emitter would change when the range switches ...It is still the same load, and the same current we want to run thru it.
pc program or phone app for signal output? Making lissajou letters in XY mode? - Page 1
Forum section: electronics / testgear

author: superUnknown
author_rank: Regular Contributor
timestamp: August 15, 2013, 02:05:45 am
content: I want to mess around lissajou patterns and what-not. Are there any good programs / apps for output from a stereo headphone jack?I downloaded a couple via google search, but they are old and I can't get 'em working on XP...

author: Rerouter
author_rank: Super Contributor
timestamp: August 15, 2013, 02:28:05 am
content: if you dont want to modify on the fly, audacity for pc will let you generate very clean waveforms per channel,

author: superUnknown
author_rank: Regular Contributor
timestamp: August 17, 2013, 12:49:04 am
content: Cool. Thank you!

author: c4757p
author_rank: Super Contributor
timestamp: August 17, 2013, 01:03:29 am
content: Lissajous! Il est français, les lettres sont silencieux!

author: claude3386
author_rank: Contributor
timestamp: August 17, 2013, 02:16:32 am
content: Rabiscoscopio convert svg file into sound file:http://dalpix.com/rabiscoscopio

author: claude3386
author_rank: Contributor
timestamp: August 17, 2013, 03:55:44 am
content: Rerouter, how do you generate the signal in Audacity?

author: Rerouter
author_rank: Super Contributor
timestamp: August 17, 2013, 05:21:23 am
content: Tracks - Add new - audio track,drag the balance meter to one edge,Generate - ToneEnter The Frequency and waveform type,repeat for the other channel, with the balance reversed,

author: claude3386
author_rank: Contributor
timestamp: August 17, 2013, 12:26:39 pm
content: Thanks for the advice.How do you generate the signal for the letter?
Siglent SDG1010 sinewave phasenoise "issue" - Page 1
Forum section: electronics / testgear

author: rf-loop
author_rank: Super Contributor
timestamp: August 09, 2013, 06:03:47 pm
content: Issue is that HP8568B is not enough good for craracterize this phasenoise.Test setup:SDG1010 (1Q13) With HW:02.... and FW....27Sine, CH1, 50ohm, level 0dBmInternal frequency reference in use.Small (under 12ppm) frequency offset corrected in phasenoise software what use HP8568B via GPIB. Software is KE5FXFrequencies have checked using 53131A and GPS OCXOHP spectrum run (of course) using its own very good OCXO)Result was so good for this kind of function generator that first I think there is something really badly wrong.. but after many many checkings I keep this result reasonable valid. More than 1kHz offset I believe that result is better but here really specrum limits. So there is "phasenoise issue" with this test method with these equipments.
4kHz DSO for $10 XD - Page 1
Forum section: electronics / testgear

author: Sigmoid
author_rank: Frequent Contributor
timestamp: August 08, 2013, 06:08:30 pm
content: This is... uh... well... quite useful I guess!An oscilloscope app that uses the iOS devices' built-in ADC! For low frequency, low power work, I guess it's worth the $10.

author: dfmischler
author_rank: Frequent Contributor
timestamp: August 09, 2013, 12:09:22 am
content: Quote from: Sigmoid on August 08, 2013, 06:08:30 pmI don't see how, myself. I suspect cavemen needed more than 4KHz bandwidth to debug fire.
Hitachi V-1565 Input Voltage - Page 1
Forum section: electronics / testgear

author: losnir
author_rank: Newbie
timestamp: August 08, 2013, 07:48:48 am
content: I can grab this oscilloscope for a good price, however I do not know what is the input voltage (seller did not respond yet). I live in Israel hence I need a 230V capable device.I've seen a photo of a similar model:And you can see it is dual-voltage. Are all Hitachi V-1XXX Oscilloscopes dual-voltage, or there are 115V only units?In the case of the latter, will it be a hard task to convert it to 230V? Do they usually have these dual 115V primary transformers that can be wired in series to get 230V?Like this:Thanks!

author: calmtron
author_rank: Regular Contributor
timestamp: August 08, 2013, 08:06:24 am
content: The operations manual is availablehere, complete with a whole bunch of cute oscilloscope cartoonsIt says 90-250V for the V-1565 so you should be OK!

author: losnir
author_rank: Newbie
timestamp: August 08, 2013, 08:17:56 am
content: Thanks for the manual. It does say "90-250V" in the specification table on the bottom of the sheet, but at the top (fuse replacement instructions), there is a different story:Hmmm...

author: Unknown
author_rank: Unknown
timestamp: August 08, 2013, 08:38:35 am
content: Different fuses because of different regulatory requirements? It's easy enough to replace a fuse.

author: calmtron
author_rank: Regular Contributor
timestamp: August 08, 2013, 08:56:15 am
content: I would guess that it's powered by an universal input SMPS internally. The wide voltage range and the fact that it uses fuses with the same current rating for all line voltages points towards it. I second alms theory on the regulatory requirements for the fuses.See if you can get hold of the service manual for the oscilloscope, you'll probably need it sooner or later.
4mm shrouded straight leads, like this but shorter? (Answer Found)  Thx - Page 1
Forum section: electronics / testgear

author: Electro Fan
author_rank: Super Contributor
timestamp: August 08, 2013, 07:27:08 pm
content: http://www.tequipment.net/FlukeTL221.htmlAnyone know of any leads that would be very similar but shorter? ThanksOr better yet: the type of leads shown in the photo below in a 24-36" or so length.- B&K sells them as part of a kit. The kit is pretty good but the best part of the kit are these straight 4mm shrouded banana plugs with one end being stackable. These plus some accessories provides a lot flexiblity. Any idea who makes this particular configuration (just the leads without the kit accessories)? Thanks again- Preferrably from a source in the U.S. or some place with decent shipping fees (I know beggars and choosers)------UPDATE:Ok, answering my own questions with help from the other similar thread here:http://www.probemaster.com/product_info.php?cPath=2_13&products_id=171&CDpath=2- this will definitely do for the first questionOn the second question it looks like the product is made for B&K's kit by CalTest:http://www.caltestelectronics.com/ctitem/123-plugs-power-supply-kits/CT3374A- just need to see if they sell just the lead without the kitCASE CLOSED

author: M. András
author_rank: Super Contributor
timestamp: August 08, 2013, 07:41:35 pm
content: http://www.sks-kontakt.de/index.php?page=shop.product_details&flypage=flypage_sks_all.tpl&product_id=346&category_id=29&option=com_virtuemart&Itemid=129&lang=enits upto 2m in lenght and up to 2.5mm2 if i remember right

author: Electro Fan
author_rank: Super Contributor
timestamp: August 08, 2013, 09:09:25 pm
content: One more similar item:BK Precision TL 9160http://www.amazon.com/Precision-TL-9160-Stacking-Retractable/dp/B004TMT7ZEnot too long, shrouded, stackable on both ends - nice

author: Unknown
author_rank: Unknown
timestamp: August 08, 2013, 09:34:20 pm
content: Pomona also has them. Don't have the part number handy, check their catalog.
Some should grab this -- $10 GWInstek Function Gen - Page 1
Forum section: electronics / testgear

author: MrAureliusR
author_rank: Unknown
timestamp: August 07, 2013, 06:09:44 am
content: Was surprised to see this -- only a day left!Let's try not to run the price up -- someone who really wants it should bid and let it sit at the 9.99 US. The shipping to Canada is under $30, so you're looking at around $40 total in NA. Pretty amazing!http://www.ebay.ca/itm/GW-Instek-Function-Generator-Model-GFG-8020H-/221264241251?pt=LH_DefaultDomain_0&hash=item3384606263&_uhb=1

author: dfmischler
author_rank: Frequent Contributor
timestamp: August 07, 2013, 10:45:00 am
content: Judging by the panel details, this looks to be the same unit (or a close relative) as the BK 3011B.

author: Stonent
author_rank: Super Contributor
timestamp: August 07, 2013, 02:36:37 pm
content: Quote from: dfmischler on August 07, 2013, 10:45:00 amLooks a lot like a Kenwood I've seen too.

author: MrAureliusR
author_rank: Unknown
timestamp: August 08, 2013, 06:28:48 am
content: Darn, it's up to $38 US now... 10 hours to go.

author: Bored@Work
author_rank: Super Contributor
timestamp: August 08, 2013, 04:22:45 pm
content: Hmm, how should I phrase it? Announcing an auction on such a forum like this is not a very good strategy to keep the price down.

author: Unknown
author_rank: Unknown
timestamp: August 08, 2013, 04:32:10 pm
content: Even without posting on the forum you shouldn't get your hopes up because of a low opening bid. Many people will wait until the end, often a few seconds from the end, to bid. It's currently at $51 but could easily go up by another $20 or more by the time the auction is over.
DM3068 .xdat file format? - Page 1
Forum section: electronics / testgear

author: KedasProbe
author_rank: Frequent Contributor
timestamp: August 07, 2013, 04:08:26 pm
content: The measured data can be stored as .csv or .xdat to USBDoes someone know of an way to open the .xdat files on your PC?I checked the file and I can write some code (C#) to read it but I like to ask first before I put some time in programming this.Reason why I want this:.csv only saves 6 significant digits (text) (should at least be 7, I ask Rigol to fix this, no reply yet).xdat saves the values (IEEE 754 double-precision)

author: KedasProbe
author_rank: Frequent Contributor
timestamp: August 08, 2013, 12:34:21 pm
content: I wrote the code.You can find it here if you want ithttps://www.eevblog.com/forum/testgear/rigol-dm3068-sceenprint-net-general-scpi/Example difference:edit screenshot added of DM3068
Extech Model 380580 Digital Mili-Ohm Meter - Page 1
Forum section: electronics / testgear

author: Terabyte2007
author_rank: Frequent Contributor
timestamp: August 09, 2013, 12:22:48 pm
content: Christmas has come early this year! I scored a brand new (Open Box) Extech Model 380580 Digital Mili-Ohm Meter from eBay for 100 bucks! I carefully ran through all self checks, and it's right on the mark! eBay is a great resource if you spend the time to look and do the research!
Rigol (and Agilent and USB LA) Serial Triggering and Decoding Discussion - Page 1
Forum section: electronics / testgear

author: Electro Fan
author_rank: Super Contributor
timestamp: August 09, 2013, 11:46:04 pm
content: The Rigol approach to managing digital signals looks very straightforward. Plus, it seems - but I don't know for sure, that the approach is very consistent (almost identical?) across their DS2000 and DS4000 series, and maybe the new DS1000Z series.One question is why the scope software makes the user seemingly re-enter some of the same values twice when decoding after triggering. Fore example, why do you need to tell the scope which just triggered on RS232 that it needs to decode on RS232 (it should/could be the default at this point, no?) and why retell it the number of bits, baudrate, partity etc. It would seem like the same fields could retain the most recently entered values and therefore the data could be entered once for triggering and then re-used as the default for decoding. It's possible that Rigol does this for some fields, I couldn't tell for sure from watching the video. Just curious.Also, anyone know if the Aglilent scopes do anything different, better, nicer along these lines? ThanksAlso, back to Rigol (or maybe Agilent 2000/3000 users too) - how is the usability and effectiveness of the the triggering and decoding on these scopes vs how well does triggering and decoding work on the the ~$100 to $500 USB LAs (from Saleae, Zeroplus, Intronix, etc.)?

author: w2aew
author_rank: Super Contributor
timestamp: August 10, 2013, 12:26:15 am
content: Can't speak for the others, but the Tek scopes are very simple - setup the decode once, and it's all set to use for triggering too, if desired.

author: echen1024
author_rank: Super Contributor
timestamp: August 10, 2013, 02:54:15 am
content: Never used one of those USB things, but can tell you that it is quite simple on the Agilent and Rigol scopes. I think the "ask twice between trigger and decode" is a bit redundant, but not that bad. Regardless, I think Tek is the most well-versed in this category.
Scope Probe Compatiblity Question - Page 1
Forum section: electronics / testgear

author: Electro Fan
author_rank: Super Contributor
timestamp: August 06, 2013, 09:47:13 pm
content: Silly question, but any chance this probe:http://www.ebay.com/itm/HP-AGILENT-10073C-X10-OSCILLOSCOPE-PROBE-NEW-IN-BAG-/190874921454?pt=LH_DefaultDomain_0&hash=item2c710829ee#ht_2056wt_1093would work well on a Tektronix 2247A (older analog) scope?

author: c4757p
author_rank: Super Contributor
timestamp: August 06, 2013, 09:56:09 pm
content: Sure. But it's a bit overkill for a 100 MHz scope.

author: Unknown
author_rank: Unknown
timestamp: August 06, 2013, 10:27:38 pm
content: From the Agilent website:Compensation range: 6 - 15 pFI think the 2247A will have approximately 20 pF of input impedance, though I haven't checked. Now the trimmer caps that are responsible for this compensation range are not known for their tight tolerances, so you may get lucky, but you may also not get lucky and then the probe will be unable to compensate to that scope.A fancier probe can sometimes be nice because of the sharper tip, slimmer body and larger number of compatible accessories. If you wanted accessories to probe SSOP packages, for example, you might be able to find something for an expensive Agilent or Tek probe, but not for a $10 ebay special.

author: Electro Fan
author_rank: Super Contributor
timestamp: August 06, 2013, 10:38:30 pm
content: The 2247A is 1M ohm, 20pF up to 400V pk.I know this probe might be overkill for the 2247A, but I see a new scope over the horizon

author: c4757p
author_rank: Super Contributor
timestamp: August 06, 2013, 10:39:37 pm
content: Don't miss the bit about compensation thatImissed.

author: macboy
author_rank: Super Contributor
timestamp: August 07, 2013, 01:43:56 pm
content: alm is spot on about the compensation, the agilent probe, while no doubt a good probes, is not suitable for this scope. It is designed for a scope with less input capacitance than the 20 pF of your Tek.It is also strange that it has a 2.2 M? input impedance rather than 10 M? as is usual for 10:1 probes. This is probably related to the 500 MHz bandwidth which is pushing the limits of a passive probe.
Fluke 23 Series II or HP E2378A - witch one should i get ? - Page 1
Forum section: electronics / testgear

author: bingo600
author_rank: Super Contributor
timestamp: August 05, 2013, 04:46:52 pm
content: GuyzzMy brother got 2 working meters for freeFluke 23 Series IIHP E2378AHe would only use it to measure 230v present or if a wire is broken in a lamp.He insists that i get the better one , but what should i chose.I lean towards the HP , but have absolutely no idea about the specs or performance yet .....I have some neat bench meters , so i'm already covered pretty well.But if he insists ....Hmm seems like the 23 is a 77 (with a yellow case) ... not a bad meter if i remember correctly.The HP can do temp' C , but what probe , and my 3457 prob does it better .../Bingo

author: ModemHead
author_rank: Frequent Contributor
timestamp: August 05, 2013, 06:26:30 pm
content: Yes the 23-II is the same as a 77-II except with the yellow case. I use one quite often as a general-purpose DMM. Beware the yellow cases have a high rate of internal screw post failures from the self-tapping screws. I think the yellow plastic is more brittle than the gray/green.The HP is a Japanese Yokogawa instrument. From pictures, I think HP may have specified more input protection than avery similar Yoko-branded onethat I kludge-repaired some time ago. IIRC, I tested the temp function with a K-type thermocouple with banana plugs, one that came with a Fluke 179.I'm sure you'd be served well by either one. I'm partial to the Fluke myself.

author: bingo600
author_rank: Super Contributor
timestamp: August 05, 2013, 07:06:42 pm
content: Thanx MHI was told that the HP has 100nA LSB , and the Fluke 10uA LSB , else they should be quite equal.Is the "Off" on the fluke a real Off ? ... Meaning i can expect that it doesn't eat 9v Batts if in Off pos.The HP has 2 x AAA , witch are cheaper if the Fluke is a Batt eater ...If the Fluke Off is a real Off , then i guess i might chose my first Fluke now.I have a 34401a or 3457 if i need low amps measurements on the bench./Bingo

author: ModemHead
author_rank: Frequent Contributor
timestamp: August 05, 2013, 07:30:31 pm
content: The 23-II runs Vbat+ through the rotary switch, so it's a "real" Off.Just checked one here, it draws (average) 252uA in VDC, 273uA in VAC, and 707uA in Ohms w/inputs shorted.Not what I'd call a battery-eater. Battery life is spec'ed at 2000 hrs. That's three zeros.

author: bingo600
author_rank: Super Contributor
timestamp: August 05, 2013, 07:47:01 pm
content: Thanx MHYou can say welcome to a "soon" fluke owner then/Bingo

author: retiredcaps
author_rank: Super Contributor
timestamp: August 07, 2013, 06:01:45 am
content: The HP is no slouch in the battery department either. It is rated for 1000 minimum hours using akaline AA batteries.http://cp.literature.agilent.com/litweb/pdf/E2377-90001.pdf
Mini-circuits hybrid as a cheap RLB with DSA815-TG VSWR option? - Page 1
Forum section: electronics / testgear

author: Rory
author_rank: Frequent Contributor
timestamp: August 06, 2013, 03:13:46 am
content: First day out of the box, and learning how to use the Rigol DSA815-TG, trying a few things.While playing with a Mini-Circuits 3dB hybrid splitter, the kind used to connect two receivers to one antenna, checking loss and port-to-port isolation, it occurred to me (when I terminated the common input with 50 ohms and got over 35dB isolation between the two ports) that a hybrid can be used as a return loss bridge, just like the Rigol VB1020.So, I got the chance to try the VSWR option before it runs out of time and before the VB1020 I ordered last week (on 2-3 week back order from Tequipment) arrives. To see how accurate it could be, I tried paralleling a couple of 50 ohm terminators on a BNC tee, and the VSWR software reported 2.09:1 VSWR. A 75 ohm load reported 1.59:1 VSWR. Hooked it up to an 8 element 8-30MHz log periodic antenna and it looked pretty close to the VSWR curves in the manual.I took a random piece of RG-58 coax about 17" long and connected it to the tee in parallel with 50 ohms and looked at the 1/4 and half-wave resonant points by shorting the far end, the frequency response was pretty close to what it physically measured to be. Got return loss measurements of greater than 45dB at the parallel resonant points.A $50 hybrid works almost as well as a $500 return loss bridge. What do you think of that?

author: nctnico
author_rank: Super Contributor
timestamp: August 06, 2013, 04:07:32 pm
content: Mini-circuits also has directional couplers which are very affordable.

author: Neganur
author_rank: Unknown
timestamp: August 06, 2013, 04:45:10 pm
content: Couple of reflection bridge projects:A Baluns and Beads Reflection Bridge, 50 KHz to 1.5 GHzThree-Bead-Balun Reflection Bridge, 250 KHz to 1.5 GHzActive Bridge 10 kHz (outstanding up to 30 MHz) good to ca 300 MHzedit: URLs corrected

author: olsenn
author_rank: Frequent Contributor
timestamp: August 06, 2013, 04:49:41 pm
content: QuoteI'm of the belief that test equipment should be purchased (from a reputable seller) and never built, unless you already have a professional equivalent to test/calibrate it against.

author: Neganur
author_rank: Unknown
timestamp: August 06, 2013, 11:14:28 pm
content: uh, your spectrum analyzer does the calibration / normalization...what are you using that instrument for again?
The Hunt for a New (First-ish) Scope Continues.... - Page 1
Forum section: electronics / testgear

author: jasonbrent
author_rank: Regular Contributor
timestamp: August 07, 2013, 03:01:12 am
content: Folk,I've been seeking a new scope after a hand-me-down tektronix 7603 I had died. This past week I picked up a Siglent SDS1102CML as my first 'real' scope and enjoyed it for about two days.... this evening when I went to power it on, the fan came on but there were no lights nor did the screen come on.... It's been boxed up and is waiting for a pick up on it's way back to amazon.com.So, I'm trying to find another scope to try. I was looking at the OWON SDS7102 but it looks like folk have been having issues with it over time. I've looked at the Rigol DS1102E also... I'm looking for something under $500 USD.I liked the wide screen of the siglent, I liked the zoom functions, I liked the alternative time bases (split time base per channel). I'd like 2 channels and 100Mhz at a minimum. I'm willing to go used. I like digital storage functions. I like on-screen frequency representations. I like the time-tunable persistence of vision for a wave form... Can I get some pointers to other suggestions in this price point and near that feature set?I'm willing to go to the used market and have been scanning ebay for a good deal, but I'm pretty over whelmed by the options. If my budget was double, I'd be able to hit my targets easily it seems... but at $500 it's a little more difficult.Thoughts and suggestions are welcome.-jbl

author: PA4TIM
author_rank: Super Contributor
timestamp: August 07, 2013, 07:43:56 am
content: Let me correct something first, you had a real scope and replaced that with a 500 dollar toyHere is an other option, why not repair the 7603 ? Good documentation, a lot of knowlegde about them available, they are great performing and versatile scopes. I have a very good Hameg 350 MHz MSO but still use my 7603 and 7704A on a regular base.

author: jasonbrent
author_rank: Regular Contributor
timestamp: August 08, 2013, 02:18:29 am
content: I ordered a Rigol DS2072... hopefully here in a week or so.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 08, 2013, 06:20:35 am
content: Quote from: PA4TIM on August 07, 2013, 07:43:56 amI agree,the 7603 has been around for about 30 years,& just now failed.The Siglent died after 2 days-----which is the "real scope"?On the other hand,maybe the OP should have given Siglent another chance,& seen how a replacement unit made out.Two days would not seem very representative for a company which makes many of their competitor's Oscilloscopes as well as their own brand.That said,the Rigol DS2072 looks like a good choice.
Uni-T UT61E Scuffed Shunt Resistor - Page 1
Forum section: electronics / testgear

author: losnir
author_rank: Newbie
timestamp: August 05, 2013, 03:28:00 pm
content: I was curious and tried to measure the shunt resistor inside my UT61E, I used some alligator clips (stupid decision), which left "scuff" marks.Some photos:(click to enlarge)Will it affect my current measurement in any way?I'm starting to get paranoid..Thanks.

author: mariush
author_rank: Super Contributor
timestamp: August 05, 2013, 03:33:42 pm
content: I'm not sure which are the scuff marks.The shunt resistor has some "cuts" in it which are basically the factory way to trim the resistor to be more accurate. I doubt your aligator clips were so powerful to bite into the resistor and remove some of the metal used, in worst case it was probably just compressed or moved around a bit.I wouldn't worry too much about it ...

author: losnir
author_rank: Newbie
timestamp: August 05, 2013, 04:01:28 pm
content: Those "cuts" you see in the photos are actually the marks left by the alligator clips - they are pretty beefy. Those marks were clearly not there before I used the clips.I, too, think the clips only compressed the soft metal and left indentation marks, but can it affect the resistance and\or affect current measurement?Edit: You were right, pictures from other users showed similar marks. Guess I was just being paranoid. Thanks!
Looking for compact DC Power Supply for home bench under $ 75 - Page 1
Forum section: electronics / testgear

author: Rutger
author_rank: Regular Contributor
timestamp: May 07, 2013, 09:15:46 pm
content: Any suggestions? My specs are;1) Compact/Small2) Linear PSU up to 20V DC/ Up to 1A3) Digital readout for voltage (doesn't need dual display), with current limiter4) For US market (120V)5) Kit w/case etc or fully build.Nice to have: 10 turn pot for voltage settings.Thank you for any suggestions.Rutger

author: potatogun96
author_rank: Contributor
timestamp: August 07, 2013, 02:22:15 am
content: I realize that it has been a few months since you posted this, but if you are still looking for a cheap power supply, I found a couple that might work for you.This is a linear supply that follows all your criteria except it only goes to 18 volts:http://www.mpja.com/0-18V-0-3-A-Variable-Benchtop-Power-Supply/productinfo/9600%20PS/This is a switch-mode power supply, but will do 30 volts at 3 amps:http://www.mpja.com/0-30V-0-3A-Variable-Benchtop-Power-Supply/productinfo/9616%20PS/I hope this helps. I am considering purchasing a power supply myself, so if you end up buying one, let me know which one you got.

author: mariush
author_rank: Super Contributor
timestamp: August 07, 2013, 02:31:51 am
content: See CircuitSpecialists' site:https://www.circuitspecialists.com/bench-power-supply-csi1802x.html$49 0-2A; 0-18VDC adjustable DC Regulated Bench Power Supply (this one even has schematic and parts are generic so if you break it you can probably fix it easily)https://www.circuitspecialists.com/bench-power-supply-csi530s.html$83 0-30V / 0-5A Adjustable Linear DC Bench Power Supply , coarse and fine knobs for voltage and current etchttps://www.circuitspecialists.com/csi5003xe.html$89 0-30V/0-5A but not easy to adjust the current limit.

author: robrenz
author_rank: Super Contributor
timestamp: August 07, 2013, 03:37:07 am
content: Look on ebay for a Power Designs 2010, 2020 or 6010 in working condition.

author: Fsck
author_rank: Super Contributor
timestamp: August 07, 2013, 03:44:23 am
content: Quote from: robrenz on August 07, 2013, 03:37:07 am^esprecially since you're american.
HP/Agilent 6632B PSU - Page 1
Forum section: electronics / testgear

author: dexters_lab
author_rank: Unknown
timestamp: August 04, 2013, 02:17:46 pm
content: Cant see anything in the agilent docs about it, but can two 6632b's be setup in series or parallel operation?

author: free_electron
author_rank: Super Contributor
timestamp: August 04, 2013, 03:39:30 pm
content: Series yes, parallel is tricky as these things have a down programmer...

author: Andy Watson
author_rank: Super Contributor
timestamp: August 04, 2013, 04:26:52 pm
content: Agilent's FAQ about the 66xx series suggests that it is possible.http://tinyurl.com/khd4zezI would be interested to know how well it works (or not).

author: dexters_lab
author_rank: Unknown
timestamp: August 04, 2013, 04:39:54 pm
content: Thanks guys, tbh series operation is preferable for me anyway.Tempted to pick up a 2nd unit as kjds still has some available

author: KJDS
author_rank: Super Contributor
timestamp: August 04, 2013, 04:47:43 pm
content: Quote from: dexters_lab on August 04, 2013, 04:39:54 pmI've just bought another 100 of them, so won't run out for a few weeks.Can anyone recommend me an osteopath?

author: senso
author_rank: Frequent Contributor
timestamp: August 04, 2013, 04:49:08 pm
content: 100 6632B supplys?I'm already saving up for at least another one, love the one I've got from you

author: SeanB
author_rank: Super Contributor
timestamp: August 04, 2013, 05:02:17 pm
content: Pity posting it to South Africa will be prohibitive though..... I find going to the local Boots and asking for some Panamor tablets helps a lot. That and Voltaren emugel on the sore spots works a treat.

author: KJDS
author_rank: Super Contributor
timestamp: August 04, 2013, 05:10:24 pm
content: Quote from: SeanB on August 04, 2013, 05:02:17 pm£106 to ship to South Africa, £169 to ship two in one box.

author: MetraCollector
author_rank: Regular Contributor
timestamp: August 04, 2013, 10:33:12 pm
content: I have bought three 6632B units from KJDS and also Keithley 2015THD and I can recommend his shop, instant shipping from UK to CZ.Units are in good condition, perfect for the price.

author: Andy Watson
author_rank: Super Contributor
timestamp: August 04, 2013, 10:51:04 pm
content: I agree with the above. I've purchased a pair of KJDS's units and I'm well pleased. An absolute bargain at the price - I wish I had space for a couple more.
DS2072 buzzing sound - Page 1
Forum section: electronics / testgear

author: leafi
author_rank: Regular Contributor
timestamp: July 30, 2013, 04:02:30 pm
content: Hey everyoneI just got a DS2072 and powered it up and I am hearing a low buzzing sound coming out of the back which sounds like a power transformer. I am not sure if I need to have it serviced or exchange it and I would like to know if this is normal. I took a video with my cell phone at start up so you could hear it but I think I need to have a few more posts on the forum before I can post things. Please let me know what you all think before I try to unlock my scope.Thanks

author: tlu
author_rank: Regular Contributor
timestamp: August 01, 2013, 01:57:37 am
content: It should not sound like that. At least on mine it does not. If it's still under warranty, I would ask for a replacement.

author: leafi
author_rank: Regular Contributor
timestamp: August 04, 2013, 01:18:39 am
content: HelloYes I called Rigol and they sent me out a replacement. I think I need to pay shipping back for the old one but ehhh I got a later serial number scope with the 3300A probes instead of the 3300 probes. Plus I look at it as ok I need to pay for shipping so I get to unlock my scope without feeling bad for it.... I wouldnt have felt bad anyway after all I paid the cost of the parts for the memory and bandwidth so those should be included. Triggering and decoding is nice but come on make it reasonable. They are not selling their products to NASA or the federal government who have the US tax payers money to waste on inflated costs of decoding. Just make the product as best as you can and corner the market. Do you really need to rape everyone for ever last nickle and dime?

author: tlu
author_rank: Regular Contributor
timestamp: August 04, 2013, 11:56:33 am
content: Well, some of these options are now available at your disposal if you know where to look on this forum without burning a hole in your pocket. Check out sniffing the Rigol i2c bus thread and you will know what I mean.

author: leafi
author_rank: Regular Contributor
timestamp: August 04, 2013, 05:22:16 pm
content: Yes thank you I read thru that long post and was able to implemented it on my scope. However now I am having problems with DC offset in the trace even after self cal.
no text - Page 1
Forum section: electronics / testgear

author: daywalkerdha
author_rank: Contributor
timestamp: August 03, 2013, 09:25:28 am
content: no text

author: dzseki
author_rank: Frequent Contributor
timestamp: August 03, 2013, 12:11:02 pm
content: Do you have this manual? It seems pretty decent to me:http://elektrotanya.com/hameg_hm203-7_oscilloscope_sch_2.pdf/download.htmlthe 'get manual' button is pretty small at the end of the page, and you have to wait a bit, but it's free at least...

author: dzseki
author_rank: Frequent Contributor
timestamp: August 03, 2013, 02:44:44 pm
content: What do you want to re adjust? These equipments usually need only minor adjustments (preamp gain adjust, time base adjust) for more advanced calibrations you'll probably need a lot of special equippments.

author: Fraser
author_rank: Super Contributor
timestamp: August 03, 2013, 04:44:31 pm
content: Hameg will supply the full service manual if you request it, free of charge by email. I have such for all my Hameg scopes.

author: firewalker
author_rank: Super Contributor
timestamp: August 03, 2013, 06:42:29 pm
content: Yep, the send my the service manual in couple hours after my email request.Alexander.
Tektronix 465 one channel showing lower voltage - Page 1
Forum section: electronics / testgear

author: edy
author_rank: Super Contributor
timestamp: August 04, 2013, 01:26:06 am
content: Hi folks,I have an opportunity to pick up a Tektronix 465 but seller says the one channel is showing a lower voltage "but can be repaired". I wonder if anyone had a similar issue and knows if it is something common and easy to fix. I will have to check with the owner to see if the traces are accurate and the only thing is the voltage being off... I wonder if this is a problem with the display tube vertical electromagnet or something in the circuitry, higher resistor value on the input somewhere, a calibration pot on the vertical adjustment knob or what have you. I don't know anything about the scope and how difficult or easy it would be to fix.Hopefully, if I pick up the item I can get some help from the forums and fix it, because it is coming at a good price (almost at Dave's famous $50 mark) from a local guy and being my first oscilloscope, for that price I wouldn't mind tinkering a bit with it to fix if you think it is worth it.Thanks for any suggestions....

author: poida_pie
author_rank: Regular Contributor
timestamp: August 04, 2013, 05:12:06 am
content: Have no fear at all.athttp://tech.groups.yahoo.com/group/TekScopes/you will find much help and helpful people.If I was you I'd make an account there and search the posts on the list for your problem. There is a good chancethat someone has seen this issue and worked it through successfully.

author: edy
author_rank: Super Contributor
timestamp: August 05, 2013, 12:37:06 am
content: Good to see there is a lot of support and documentation on Tektronix!I just lost out on a bid for Iwatsu 200mhz scope sold at only $100 with $20 shipping. But now I have a couple of scopes in my sights... Tek 455 and Tek 475, the first $10 with free local pickup and second at $50, also pickup. So if any of these manage to work it will be a charm and I can meet Dave's "mythical" $50 and under for a good ol' analog beginner's scope.Wish me luck! Hopefully will buy one or both, apparently they power on but one seller has no other info on it, and then other told me one channel has lower voltage (it was 475 not a 465 like the thread title suggests).
HP3478A showing C: in the display (eBay item...) - Page 1
Forum section: electronics / testgear

author: senso
author_rank: Frequent Contributor
timestamp: August 02, 2013, 11:19:09 pm
content: God evening, I have been looking for a nice bench DMM to buy and found this one:http://www.ebay.com/itm/HP-Hewlett-Packard-Digital-Multimeter-Multi-Meter-Model-3478A-Used-Condition/221172362527?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D16724%26meid%3D294182029776781058%26pid%3D100011%26prg%3D7905%26rk%3D1%26rkt%3D1%26sd%3D350842433377%26I have taken a look into the manual but it doesn't refer the C: in the display, is it a sign of being uncalibrated?

author: free_electron
author_rank: Super Contributor
timestamp: August 02, 2013, 11:50:09 pm
content: broken display. segments stuck

author: ModemHead
author_rank: Frequent Contributor
timestamp: August 02, 2013, 11:50:40 pm
content: According to the service manual it displays a "C" in calibration mode, and indeed you can see the CAL switch on the front panel is in the Enable position. If someone has been punching buttons with that switch enabled, I wouldn't trust this unit's calibration.

author: senso
author_rank: Frequent Contributor
timestamp: August 03, 2013, 12:06:02 am
content: My first toughs were exactly about maybe dirty zebra strip, worst case dead lcd, and so a no go, even worse if it is callibration kiss it good bye..I would love to live in the USA, so many great deals, add customs and shipping, might as well wait another 6 months and buy it brand new..Thanks for the fast and concise responses guys!
Meter leads and dust caps - Page 1
Forum section: electronics / testgear

author: Sigmoid
author_rank: Frequent Contributor
timestamp: August 01, 2013, 02:03:56 am
content: I wonder why all the better meter leads come with these plastic dust caps jammed in their shrouded banana plug ends... Is there some kind of standard that dictates this? I find it hard to imagine the use of having those dust caps... Maybe if I wanted to store the leads underwater for extended periods of time. XDBy the way I just scored a set of EXtech meter leads on Amazon, for $15 it seems like an awesome buy. The insulation feels really good to the touch, and it just seems well put together.http://www.amazon.com/gp/product/B0012VWUI6/

author: Lightages
author_rank: Unknown
timestamp: August 01, 2013, 02:37:20 am
content: There is no standard for these dust caps. It is just that some manufacturers think it is a good idea and some don't. Yes they an actually prevent a problem if you throw your leads into a tool box that is dirty, or has loose bits of wire and screws lying around, or anything else that could get inside the plug. Depending on the plug shield material they can also keep the shield in the correct shape.The caps for the tips are to protect the tips from getting blunted and also to protect other equipment from the sharp tips.If I am storing my leads for a long time then I am inclined to put in the plugs. If the probes are sharp and able to damage other things then I put the caps on.

author: Bored@Work
author_rank: Super Contributor
timestamp: August 01, 2013, 05:12:25 am
content: The real purpose of these caps is that you have some more small pieces that are easy to lose.

author: retiredcaps
author_rank: Super Contributor
timestamp: August 02, 2013, 08:08:54 am
content: Save the caps. They can help repair the Fluke 80 series multimeters with the inner missing shroud.http://mrmodemhead.com/blog/fluke-banana-jack-repair/

author: SArepairman
author_rank: Frequent Contributor
timestamp: August 02, 2013, 09:22:35 am
content: I don't think its a good idea to do glue repairs if you are using the meter at your job... I could see that being a pickle if you go to some hard to reach location and suddenly a super glue repair snaps off.

author: Terabyte2007
author_rank: Frequent Contributor
timestamp: August 02, 2013, 10:55:38 am
content: I tend to think they are a pain in the butt to remove and replace if you use them often. I just remove them and throw them all in a small plastic bin for some remote possible future use.

author: G7PSK
author_rank: Super Contributor
timestamp: August 02, 2013, 11:07:34 am
content: I always thought that those plastic caps/plugs were to protect the shroud from getting deformed in transit, if the shrouds get squashed they can difficult to insert into the meter.