hybridfree/eevblog-posts huggingface dataset:
MASTECH MS8218 versions - Page 1
Forum section: electronics / testgear

author: mskobier
author_rank: Regular Contributor
timestamp: May 30, 2015, 10:34:57 pm
content: All,As I posted before, I purchased a MASTECH MS8218 from an -bay seller that arrived broken. I did eventually get a refund. I ended up purchasing another through Amazon for a much reduced price. Both models are marked MASTECH MS8218. During the course of events, it has come to my attention that there is at least two different versions of the MS8218. The two versions I am aware of are as follows. The one that has been reviewed here and other places has an optical port and RS232 interface to the matching computer program. The second one has a USB port and interfaces to the computer through an USB port. However, that is not where the differences end. The first one I purchased had a USB interface, used captured screws to hold the battery cover in place, and different fuses with fuse covers that isolate the fuses from the battery compartment. The original one has the little plastic keepers that hold the back cover in place, and fuses that are exposed when the battery cover is open. Other than that, they are identical. The earlier version I ordered through Amazon which is the one I currently have, has been checked out and appears to be fully functional and accurate.I also checked the MASTECH web page. That company does not even list a MS8218 in their line up of DMM's. I do not know if it is an obsolete model or what. Just that it is not listed as one of the models they manufacture.Mitch
Tektronix 494AP Spectrum Analyzer Repair - Page 1
Forum section: electronics / testgear

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: May 30, 2015, 02:23:43 am
content: Hi Group,Time to share a repair that I made to a Tektronix 494AP Spectrum Analyzer.A friend gave me the SA to repair, it would not work at all, it would blow the main line fuse at the back of the unit.SchematicI did some poking around with a meter and I found that one the rectifiers in the bridge was short-circuit (CR3096 or CR4094). In addition one the main electrolytic capacitors was short-circuit (C6101 or C6111).The rectifier was easy to repair, I used a 1N5408 3A diode.Electrolytic ReplacementThe original capacitor in the spectrum analyzer were manufactured by Aerovox. They have a 5 pin base. This was probably chosen by Tektronix for mechanical stability.I decided that I would make some adapter boards, so that I could use two pin snap-in electrolytic capacitors as a replacement.I went to all this trouble with the adapter boards, because the end of the capacitor pokes through a hole in the chassis. The replacement capacitor has to be in the same place as the original.Working againThe Spectrum Analyzer works fine now that the capacitors and the rectifier have been replaced.I found the Service manuals at:http://www.ko4bb.com/manuals/Regards,Jay_Diddy_B

author: w2aew
author_rank: Super Contributor
timestamp: May 30, 2015, 03:53:05 am
content: Sweet!

author: Muxr
author_rank: Super Contributor
timestamp: May 30, 2015, 04:10:48 am
content: Very cool.

author: photon
author_rank: Frequent Contributor
timestamp: May 30, 2015, 09:42:44 pm
content: Thanks for posting. I always find such repairs very instructive.

author: Vgkid
author_rank: Super Contributor
timestamp: May 30, 2015, 10:31:16 pm
content: Very cool, those are the same style of caps used in the 3456A's infamous power supply. I just used a radial cap, and bent the pins for best fit.
Where Can a Guy Find a Low Tolerance Inductor as a Standard? - Page 1
Forum section: electronics / testgear

author: TheRuler8510
author_rank: Regular Contributor
timestamp: May 28, 2015, 11:58:52 am
content: Where Can a Guy Find a Low Tolerance Inductor?I have good and cheap capacitance standards, like 0.05% tolerance, and resistors at 0.01%, but I can't seem to find an inductor for less than $60.Any suggestions? The cheapest currently on eBay are $60 and don't even quote a tolerance.Thanks,

author: HighVoltage
author_rank: Super Contributor
timestamp: May 28, 2015, 12:42:21 pm
content: There are some on ebay from time to time, but they usually start at $400I had the same challenge a few years back and I made my own.Bought a few temperature stable toroidal cores and wounded them myself with good quality insulated copper wire.Then I had then certified at a calibration lab.They turned out to be extremely stable in regards to inductance, even with changing temperatures.Using a toroidal core is the only way, that I found to get them stable and this way, you can even mountthe inductor in an aluminum housing, without influencing the inductance at all.

author: SArepairman
author_rank: Frequent Contributor
timestamp: May 28, 2015, 04:01:35 pm
content: Quote from: HighVoltage on May 28, 2015, 12:42:21 pmhow many ppm TCL (temp co induc) did you get with this home technology

author: owiecc
author_rank: Frequent Contributor
timestamp: May 28, 2015, 06:13:37 pm
content: I can help with a Keysight E4990A if anyone wants to test their inductor.

author: HighVoltage
author_rank: Super Contributor
timestamp: May 29, 2015, 11:09:08 am
content: Quote from: owiecc on May 28, 2015, 06:13:37 pmHello owiecc,I would take you up on the offer.PM sent, Thank you.

author: TheRuler8510
author_rank: Regular Contributor
timestamp: May 30, 2015, 09:04:42 pm
content: Quote from: owiecc on May 28, 2015, 06:13:37 pmHello too, owiecc.I would also like to take you up on your offer. I'll send a message.Regards,
plugged test leads - Page 1
Forum section: electronics / testgear

author: artag
author_rank: Super Contributor
timestamp: May 30, 2015, 03:48:10 pm
content: A number of test leads I've bought recently have plastic plugs in the ends.What are these for ? They don't seem to offer any useful protection either to me or the leads, and I can't imagine anyone would bother to replace them after use.

author: jeroen79
author_rank: Frequent Contributor
timestamp: May 30, 2015, 05:16:18 pm
content: They can keep dust and other rubbish out of the shrouded plugs.

author: retiredcaps
author_rank: Super Contributor
timestamp: May 30, 2015, 05:51:28 pm
content: Quote from: artag on May 30, 2015, 03:48:10 pmRepairing Fluke inner jack shrouds of course!http://mrmodemhead.com/blog/fluke-banana-jack-repair/PS. Yes, I sent some to modemhead.

author: artag
author_rank: Super Contributor
timestamp: May 30, 2015, 08:02:24 pm
content: That's a good use for them !Modemhead is probably right - I've got other probes that have been stored tightly wrapped, and the barrel is no longer round. It recovers eventually but might be awkward to plug in when first received in the mail.Not sure about the dust and dirt. I don't keep my leads in dusty, dirty places

author: con-f-use
author_rank: Unknown
timestamp: May 30, 2015, 08:04:21 pm
content: Yes dirty, grime and chemicals. Also deformation during transport.
Hantek 6022BE - Page 1
Forum section: electronics / testgear

author: jwells
author_rank: Newbie
timestamp: May 29, 2015, 07:37:12 pm
content: I can't seem to get any measurement over 5v and the scaling dropdown does not seem to work. I've read the manual and can't seem to find the answer. Does anyone know what I'm doing wrong?

author: MatthewEveritt
author_rank: Unknown
timestamp: May 29, 2015, 08:15:42 pm
content: The slider on the probe needs to be set to 10x to measure anything over 5V. Other than that it should just work.
Configuring your multimeter leads  - Page 1
Forum section: electronics / testgear

author: VK5RC
author_rank: Unknown
timestamp: May 29, 2015, 08:14:21 am
content: I have always tended to use my multimeter with the negative lead with a clip and the positive as a point, I thought it would be interesting to see how others use their dmm.

author: Ian.M
author_rank: Super Contributor
timestamp: May 29, 2015, 08:36:06 am
content: It purely depends on what you are doing. Even for my little pocket DMM I have a selection of clips and adapters that fit on the 2mm probes, including 0.025" square pin adaptors for breadboards, ribbon cable connectors etc.Two probes - Checking mounted components with power off etc.One probe, one clip - general voltage & signal testing, checking reasonably sized loose leaded components.Two clips - Anything high energy, or difficult to access or needing extended monitoring.

author: rob77
author_rank: Super Contributor
timestamp: May 29, 2015, 09:03:14 am
content: it really depends... i'm using virtually all combinations of tips, clips and plugs depending on what measuring.

author: McBryce
author_rank: Super Contributor
timestamp: May 29, 2015, 09:39:34 am
content: Usually two points unless of course I'm doing a 4-wire measurement which tends to be easier with kelvin clips.McBryce.

author: tautech
author_rank: Super Contributor
timestamp: May 29, 2015, 11:05:52 am
content: Want to check the HV on a CRO @~minus 2.5 kV.... better get that right for the sake of your meter.........

author: VK5RC
author_rank: Unknown
timestamp: May 29, 2015, 12:17:41 pm
content: I do use an assortment as well, in fact I have a little tray of clips and probes etc that lives on the desk that I can swap easily but I typically use the clip-probe combo for most. For HV, like tautech, I definitely use clips, get out the safety glasses and stand back from the bench! (Makes chicken noises) HiHi.

author: robrenz
author_rank: Super Contributor
timestamp: May 29, 2015, 01:02:26 pm
content: I have used the Deluxe Pomona test lead set that I got when I got my fluke 87 about 37 years ago. Love the ability to plug on whatever is most appropriate instantly. The pic below is the modern version of the set I have.
Minipro Tl866 help trying to read an Eeprom chipset. - Page 1
Forum section: electronics / testgear

author: dell12345
author_rank: Newbie
timestamp: June 02, 2015, 12:57:19 am
content: I got a Minipro Tl866 programmer and I'm using its software Minipro V6.10 to read an Eeprom s93C56 chip and it read fine but, it's giving me a blank screen.

author: MrAureliusR
author_rank: Unknown
timestamp: June 02, 2015, 04:43:57 am
content: Hi there!I've had a MiniPro for a while now, and I've had the same problem with some older EPROMs. Is it a windowed EPROM (ie, UV-erasable)? If so, I've found that sometimes it doesn't read them correctly, and it rarely can generate the necessary voltage to program them.I haven't used that exact chip before, but if you can provide some more detail I can try and help.

author: wd5gnr
author_rank: Regular Contributor
timestamp: June 02, 2015, 12:38:12 pm
content: If you have Linux you might try qtl866 (which uses minipro as a back end). Seehttps://github.com/wd5gnr/qtl866andhttps://github.com/vdudouyt/miniproIt is likely that if it isn't the actual hardware, that software would work. If it is actually something in the hardware, it is probably going to be bad on both sets of software.

author: dell12345
author_rank: Newbie
timestamp: June 02, 2015, 12:59:54 pm
content: I tried it on two separate chips. Both are soldered to the board thought and that might has something to do with it? Between I'm using Window 7 and using a soic clip to read the chip off the board. Maybe I should de-solder the chip from the board and read it that way...

author: wraper
author_rank: Unknown
timestamp: June 02, 2015, 01:18:53 pm
content: Quote from: dell12345 on June 02, 2015, 12:59:54 pmDon't assume you can easily read IC's soldered to the board.
Fast WiFi SSID scanner - Page 1
Forum section: electronics / testgear

author: davorin
author_rank: Unknown
timestamp: May 28, 2015, 02:25:29 pm
content: Does anyone know of a small device or a linux application which can scan and update a list of active WiFi SSIDs fast to be able to detect if a certain SSID was only visible for a few seconds?Something which would help in a IoT project involving WLAN on a small linux device...

author: Muxr
author_rank: Super Contributor
timestamp: May 28, 2015, 02:46:28 pm
content: Quote from: davorin on May 28, 2015, 02:25:29 pmhttp://www.security.securethelock.com/find-hidden-ssids-using-backtrackkali-linux/You could possibly run the tools on a Rasspberry Pi.

author: miguelvp
author_rank: Super Contributor
timestamp: May 28, 2015, 06:15:53 pm
content: Android WiFi Analyzer perhaps?

author: ConKbot
author_rank: Super Contributor
timestamp: May 28, 2015, 06:27:59 pm
content: A wifi adapter with promiscuous mode (I believe thats what its called? Whatever ones are popular for wifi sniffing) and wireshark or traffic logger of choice, configured to only log beacon packets?

author: davorin
author_rank: Unknown
timestamp: May 28, 2015, 06:29:50 pm
content: No..I don't like Android (o;But the airmon-ng seems to be interesting....have to grab out a RPi tomorrow and have a test run...Ubuntu doesn't know this package...My preferred setup would a AJAX driven web page where appearance/disappearance is time logged....down to seconds if possible with the airmon-ng....

author: dom0
author_rank: Super Contributor
timestamp: May 28, 2015, 06:38:16 pm
content: airmon-ng should be in aircrack-ng (probably community repo).
multimeter_ut51 problem - Page 1
Forum section: electronics / testgear

author: mahin
author_rank: Newbie
timestamp: May 27, 2015, 08:27:52 pm
content: Hi guys!I have a problem with my multimeter_ut51.I do not know how the pins were standing. Would anyone get a photo of it, opened I would be grateful.Sorry for bad english

author: retiredcaps
author_rank: Super Contributor
timestamp: May 28, 2015, 03:39:55 am
content: Do a google search UT51 image. You will findhttp://219.153.51.229:8085/index/dXQ1MeS4h%2BeUqOihqOivtOaYjuS5pg%3D%3D.html

author: mahin
author_rank: Newbie
timestamp: May 28, 2015, 06:27:45 am
content: thank you, you're the king. I sentimentally attached to the instrument

author: retiredcaps
author_rank: Super Contributor
timestamp: May 28, 2015, 06:32:42 am
content: Glad you got it working again.The search by image is something I frequently use when a text search fails to bring up anything.
Spectrum Analysis Basics, hp AN-150 - Page 1
Forum section: electronics / testgear

author: Rupunzell
author_rank: Frequent Contributor
timestamp: May 25, 2015, 06:44:07 am
content: For those interested in spectrum analysis and spectrum analyzers in general.http://cp.literature.agilent.com/litweb/pdf/5952-0292.pdfShort interview with Blake Peterson, the guy who wrote this.http://www.engineeringtv.com/video/Blake-Peterson-Microwaves-RF-Li;2013-ETVThe basics matter and still apply.Bernice

author: pascal_sweden
author_rank: Super Contributor
timestamp: May 25, 2015, 08:45:27 am
content: Nice document! Definitely something to keep as reference.Winning team: Application note from Agilent together with Rigol DSA800 spectrum analyzer

author: Blue_Alien
author_rank: Contributor
timestamp: May 28, 2015, 10:03:57 pm
content: Hey! I helped update the AN150 a few summers ago when I was interning for Agilent(Keysight). I also wrote some webapps to demonstrate spectrum analysis fundamentals.Frequency vs. Time DomainDisplay DetectionSwept Tuned Spectrum AnalysisDynamic Range for Third Order InterceptYou can get all of these on the App Note 150 Resource Toolkit. Plus a whole bunch more training programs written by Blake Peterson
8753A supercap replacement - Page 1
Forum section: electronics / testgear

author: Howardlong
author_rank: Super Contributor
timestamp: May 27, 2015, 10:36:26 am
content: Has anyone any experience or information in replacing the battery backup supercap in an 8753A by any chance?

author: KJDS
author_rank: Super Contributor
timestamp: May 27, 2015, 10:54:30 am
content: I've not used one in years, but have one arriving next week so will keep an eye on this thread.
DSA1030A-TG 9k-3G, not really - Page 1
Forum section: electronics / testgear

author: donmr
author_rank: Regular Contributor
timestamp: May 26, 2015, 04:13:54 pm
content: A little while ago I purchased a Rigol DSA1030A-TG and have been happly using it for various RF tasks above 100 MHz. Yesterday, I pulled some IF filters from a friend's radio that are suspected of being bad. No problem, their freq of 455 kHz is well withing the specs of my SA right?Hooking up the TG to the input (with suitable Rs) etc, I was surprised to see no signal. Is the filter that bad? No, there is nothing coming out of the TG. I finally put the SA into zero-span mode and checked the output with a scope, no signal!A close reading of the spec for this unit says the Tracking Generator is "10M-3G, 9k-settable". I'm not sure what that last part is supposed to mean, but the first is pretty clear, it only works from 10M up, not 9k.Looking at the output of the TG, its amplitute drops off below 100M, it stops being a sin wave below 25M, at 10M its a square wave and below that it just goes away. There are some small glitches at the programmed freq, but they are pretty fast spikes and ringing, not just a low freq signal filtered by too small caps.Even more frustrating is that the "lower end" DSA815 is speced to go down to 100 kHz.Don
HP 66312A dynamic measurement DC source software - Page 1
Forum section: electronics / testgear

author: wreeve
author_rank: Unknown
timestamp: April 08, 2015, 05:43:37 pm
content: Hi, just picked up a HP 66312A for use in measuring current consumption for a number of projects! It works great; precise and calibration spot on. However I can't find any PC software which will do simple logging 'vs' time. Any pointers as to where to look would be great. I was hoping keysight might have some software for this task. There is a RS232 serial data link on the back or I could connect GPIB if I had to.

author: dadler
author_rank: Unknown
timestamp: May 03, 2015, 11:22:54 pm
content: Bumping this back up--anyone know?

author: mzzj
author_rank: Super Contributor
timestamp: May 04, 2015, 12:05:54 am
content: Have been using Realterm to send measurement command Every x seconds to the meter and write results to log file. Works with many sorts of equipment.

author: dadler
author_rank: Unknown
timestamp: May 26, 2015, 04:41:32 am
content: Quote from: mzzj on May 04, 2015, 12:05:54 amThanks.Agilent offers(ed?) this gem at the low, low price of $1964:http://www.keysight.com/en/pd-852417-pn-14565B/device-characterization-software-with-test-automation?nid=-536902309.389074&cc=US&lc=eng
THANK YOU!!! - Page 1
Forum section: electronics / testgear

author: allen.gordon
author_rank: Contributor
timestamp: May 27, 2015, 03:32:39 pm
content: After doing my own research and combining that information with the very resourceful information provided by members of the forum, I purchased my first-round of test equipment.Rigol DS1054Z DSO - more scope than I currently need, but will grow into it!Siglent SD 805 AWG - WAAAAYYYYY more generator than I currently need, but the price was comparable to an Audio Signal Generator, so I invested in my future with electronics!Rigol DP832 DC Power Supply - Again, WAAAAAYYYYY more than I currently need, but I can say that I shouldn't be limited in the power supply needs!I found MANY questions from prior threads, and noticed that most, if not all, seemed to just move on after their needs were met.I thoroughly enjoy the multitude of information available on or through this forum and Dave's YouTube channel!As such, I wanted to thank you for all of your positive support and for the information you each shared with me!THANK YOU!!! You are greatly appreciated!!!Sincerely,AllenP.S. - I will get back to 'scoping all AC devices in my home!!!

author: Electro Fan
author_rank: Super Contributor
timestamp: May 27, 2015, 03:51:05 pm
content: Beautiful and Congrats! Let us know what you learn/build

author: Muxr
author_rank: Super Contributor
timestamp: May 27, 2015, 03:53:48 pm
content: Nice kit you got there. I would be stoked if I just got all that gear for the first time too. Have fun!

author: xenocide702
author_rank: Contributor
timestamp: May 27, 2015, 04:27:51 pm
content: Wow, that signlent AWG looks like GREAT bang for buck...Congrats on the great starter lab setup! Now what about soldering gear?

author: allen.gordon
author_rank: Contributor
timestamp: May 28, 2015, 04:35:53 am
content: I've got a 5-year old Weller WESD51 that's still melting lead rather well! I understand that more recent models have shoddy quality.The weak-point of this system is the connection of the pencil iron to the solder station. I keep it clean with De-Oxit and pipe cleaners.I have noticed that the quality of replacement tips have seemingly diminished as well. I just replaced one of my ETA-model Weller tips and there is a considerable weight difference between the older tip and the new one.

author: macboy
author_rank: Super Contributor
timestamp: May 28, 2015, 01:14:27 pm
content: Buying better than you need today is smart. It ensures that you won't immediately outgrow your gear, which turns an "investment" into an "expense" or worse, a "waste".
General Resistance DV-4107 manual? schematic? - Page 1
Forum section: electronics / testgear

author: VintageNut
author_rank: Frequent Contributor
timestamp: May 25, 2015, 03:55:43 pm
content: I am awaiting shipment of a DV-4107. Looking for operation, calibration, service manual(s) and schematic.

author: Vgkid
author_rank: Super Contributor
timestamp: May 25, 2015, 04:04:23 pm
content: email Prime Technology, they might still have a manual.Internet:Main E-Mail : sales@primetechnology.com
Noise on Rigol 1054z - Page 1
Forum section: electronics / testgear

author: j.a.mcguire
author_rank: Contributor
timestamp: May 24, 2015, 09:58:32 pm
content: Is it normal to have this much noise on a Rigol 1054z scope.I tried hooking the scope up to a clamp meter to probe 240V 50hz on the primary. The clamp itself outputs somewhere in the region of 5mV on the secondary but its hard to tell you're reading anything on the scope display because of the junk signal present on the screen.First picture is with the probe connected to scope but nothing attached to end of the probe.http://postimg.org/image/kihrzn0zb/Second picture is probe disconnected, still quite a bit of noise present on the display.http://postimg.org/image/rphop06d9/Just wondering what your thoughts are, reckon its normal?

author: Muxr
author_rank: Super Contributor
timestamp: May 24, 2015, 10:10:52 pm
content: Quote from: j.a.mcguire on May 24, 2015, 09:58:32 pmLooks normal to me. You're picking up random noise from your environment.

author: ebastler
author_rank: Super Contributor
timestamp: May 25, 2015, 02:52:37 pm
content: To really assess the input noise of a scope, you should short-circuit the input under investigation, or connect e.g. a 50 Ohm terminator straight to the scope, instead of the probe lead.In your second picture, I assume you have selected a 1:10 probe, and the scope is actually set to its highest sensitivity (1mV/div)? If that's the case, then the noise level seems perfectly OK.

author: Fungus
author_rank: Super Contributor
timestamp: May 25, 2015, 03:11:49 pm
content: "Why Digital Oscilloscopes Appear Noisy" - part 1"Why Digital Oscilloscopes Appear Noisy" - part 2
FLIR e4 resolution upgrade - Page 1
Forum section: electronics / testgear

author: sinbad
author_rank: Newbie
timestamp: March 07, 2015, 11:27:01 am
content: Hi, I'm trying to upgrade the resolution of the e4 following the instructions found on this site but am unable to get ftp access. Have set to RNDIS. The next stage is to connect via ftp. However there is no IP address of 192.168.0.1 or gateway 192.168.0.2 to connect to and using filezilla it just times out. Any help appreciated

author: tmbinc
author_rank: Frequent Contributor
timestamp: March 07, 2015, 01:07:22 pm
content: - Make sure the device is set to RNDIS+UVC or RNDIS (seems you already did that)- Make sure you have installed the Flir device driver. (Otherwise it doesn't detect the USB device as a RNDIS, but Serial port).- The IP address can be 192.168.0.2 or 192.168.250.2; I don't know how the cam decides on its address.- Auto configuration never worked for me, so I had to manually set 192.168.250.1 as the local IP address. Use 255.255.255.0 as the network mask, and don't set a gateway or DNS.Make sure the cam can be ping'ed. ("ping 192.168.250.2" for example). Only if that works try to connect with an FTP client.(FYI "Gateway" doesn't matter; the cam does not provide internet. 192.168.x.2 isn't the gateway IP address, but the IP address of the cam.)

author: JIMMYZ
author_rank: Newbie
timestamp: May 24, 2015, 01:19:40 am
content: HI ALL,INSTALL OF UPGRADE TO A 2.3.0 CAM SEEMED FINE, UNTIL I GET ECCONREFUSED WHEN TRYING TO CONNECT. I CAN PING THE CAM, WHAT AM I MISSING? THANKS IN ADVANCE, JIMMYZ

author: Skimask
author_rank: Super Contributor
timestamp: May 24, 2015, 03:20:42 am
content: A single press of the caps lock button

author: JIMMYZ
author_rank: Newbie
timestamp: May 30, 2015, 09:59:10 pm
content: Thanks for the tip skimask, Sorry to offend with the c-lock.my network guy says everything looks like it does in the fubar guide, until filezilla produces the "ecconrefused error"can ping at will.any ideas helpthx jimmy
DSA815 dead pixel - Page 1
Forum section: electronics / testgear

author: dadler
author_rank: Unknown
timestamp: May 06, 2015, 04:53:51 am
content: Hi all-Just received a brand new DSA815 from tequipment.There is a "screen test" function, which cycles background colors. It reveals a dead pixel (it might be two dead pixels) on the screen.Anyone else experienced dead pixels on Rigol products before?I'm tempted to return it, as I paid for a fully functional device. The other 4 (much cheaper) Rigol products I own all have perfect screens.

author: Spork Schivago
author_rank: Frequent Contributor
timestamp: May 06, 2015, 04:58:39 am
content: I ordered a Rigol DP832 power supply but it hasn't come yet. If it was me, I'd contact TEquipment. Before I ordered my power supply, I talked to customer service via a chat window and they seem to really care about the customer. I'm sure if you explained everything to them, they'd accept the return and offer you a replacement.

author: dadler
author_rank: Unknown
timestamp: May 06, 2015, 06:08:54 pm
content: You were correct - they took it back and gave me a pre-paid UPS label.The DSA815 is now with the UPS man back to Tequipment, and they said they will ship a new one out when they receive it.At least I'm not out of pocket, though I do get to wait for another shipment California->NJ, and then NJ->California, which should take a little over two weeks. Lame.Oh well, at least I won't have to live with the dead pixel(s).I was going to try to deal with it, but black pixels in the menu area were quite obvious whenever I looked at the screen.Thanks Tequipment

author: dadler
author_rank: Unknown
timestamp: May 22, 2015, 04:33:46 am
content: Received my replacement DSA815 today, screen is good on this one. Came with FW 00.01.12 and main board 00.08, rf FPGA 00.05, digital FPGA 00.05.Apparently there is an approximate 1 week delay after they receive an RMA'd item before they ship out a replacement. They claim this is for "verification". I was not happy with this particular policy (especially since the original CS agent told me a replacement would be shipped out immediately). After complaining, they offered to upgrade the return shipping to 3 day, which I accepted.Thanks tequipment

author: videobruce
author_rank: Frequent Contributor
timestamp: May 22, 2015, 09:56:57 pm
content: TEquipment I would highly recommend. Generous 30 day return policy. Some sellers (dealers) have none.
Rigol DP832 measures "ghost" current - Page 1
Forum section: electronics / testgear

author: Milentije
author_rank: Contributor
timestamp: May 22, 2015, 07:42:23 pm
content: Hello to everyone!My DP832 finally arrived 3 day ago. And, immediately after opening I had a problem. The fan was dead on arrival and I couldn't turn on any of the outputs. Because I didn't want to wait for another month, or even more, for RMA I opened the unit and replaced the fan. After that the power supply allowed me to turn the outputs. NICE, I thought.BUT, now there is a new problem.Problem is in channel 1 and 2, channel 3 works fine.Problem appears when there is NO load on the channels 1 and 2. As you can see from the picture that I linked above, power supply reads the current of 50mA on channel 1 and 150mA on the channel 2. Problem stays there even if I set the current limit at any level higher than 50mA for CH1 and 150mA for CH2.If I try to set the OCP for CH1 lower than 50mA, power supply turns that channel off because of OCP.Same is happening if I set OCP at the value lower than 150mA for CH2.Problem disappears when there is any kind of load. Even a single green LED with 1k resistor solves the problem (@ >3V). With that load readings are as expected on both channels.What could be a reason for this?Thanks in advance,M.EDIT: I apologize to moderators for opening a new thread but I couldn't find the right one to put this in.EDIT 2: I forgot to mention this:Problem disapperas on the CH 1 when the voltage is set to 20V or more, but there is no change on the CH 2 even if the voltage is set to 30V.

author: dadler
author_rank: Unknown
timestamp: May 22, 2015, 08:30:53 pm
content: I would send it back and get a new, fresh one.

author: XFDDesign
author_rank: Frequent Contributor
timestamp: May 23, 2015, 12:54:50 am
content: He decided to crack it open and void the warranty. He's rooted.In all probability, from very limited information, I would guess this never go through QA/QC and Cal. The "ghost current" is likely an offset error that needs to be trimmed. Either way, it's probably a paperweight now, without more extensive work being performed.

author: Skimask
author_rank: Super Contributor
timestamp: May 23, 2015, 01:04:07 am
content: Or...search for that particular 'issue' here and find the solution.

author: Milentije
author_rank: Contributor
timestamp: May 23, 2015, 07:20:14 am
content: Quote from: XFDDesign on May 23, 2015, 12:54:50 am"Warranty void if broken" sticker is in one piece, and there is no evidence of opening (except this thread).So, there is no problem about that.Quote from: XFDDesign on May 23, 2015, 12:54:50 amI think the same. I highly doubt about validity of cal. certificat.Quote from: XFDDesign on May 23, 2015, 12:54:50 amIt will be sent back.Thank you all for your answers and help. It is going back.
Trainer / Book for Oscilloscope? - Page 1
Forum section: electronics / testgear

author: signal
author_rank: Regular Contributor
timestamp: May 20, 2015, 07:52:40 pm
content: Can anyone recommend a good trainer (PC Board likely) and/or book that takes you through a really good understanding of using an oscilloscope?

author: GreyWoolfe
author_rank: Unknown
timestamp: May 20, 2015, 08:30:13 pm
content: Start with Tektronics' XYZs of Oscilloscopes. You can download it here:https://courses.physics.illinois.edu/phys193/Labs/XYZs_of_Oscilloscopes.pdfNot knowing your country, if you were in the US, you could go to Radio Shack and get some of Forrest MImms' Engineers notebooks. You could build the circuits and check the wave forms depicted. Many, Many references on the interwebs to look at.

author: signal
author_rank: Regular Contributor
timestamp: May 20, 2015, 08:36:16 pm
content: Yes I have the Forest Mims books. I was hoping someone made it easy by building a pre-built PCB/circuit(s) that you could just follow along so your just focusing on learning the scope. I saw Vellemen has a trainerhttp://www.amazon.com/Velleman-EDU06-Oscilloscope-Tutor-Kit/dp/B00BY8LJA2But I was hoping there may be something better out there.I will download that book for sure.

author: DC912
author_rank: Contributor
timestamp: May 21, 2015, 03:07:17 am
content: B&K Precision also has a helpful "Oscilloscope Guide" in the support section on its website. It's a good introduction to scopes if you prefer text over video.

author: ez24
author_rank: Super Contributor
timestamp: May 21, 2015, 04:36:02 am
content: http://www.amazon.com/dp/B00NQBR9G8/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=20I1QUYFF3Q7D&coliid=I3L6GEMMQ057SOfor about $400 there is another one on the market that puts out "bad" signals to find- I just do not know who makes it or what your budget is

author: radioFlash
author_rank: Regular Contributor
timestamp: May 22, 2015, 01:40:23 am
content: Look for "oscilloscope demo board". They generate various kinds of signals you can use to try out on an oscilloscope. Rigol makes one, the DS6000-DK. I also saw one from Keysight and GW Instek.http://www.tequipment.net/Rigol/DS6000-DK/Analog-Demo-Board/
linear reg input voltage stability - Page 1
Forum section: electronics / testgear

author: SArepairman
author_rank: Frequent Contributor
timestamp: May 21, 2015, 05:39:16 am
content: I once heard that for optimum stability you should run linear regs on voltages significantly higher then the dropout. Like running a 5V rail at 10V.i understood the consequence as there being more thermal drift but a higher PSRR.

author: montemcguire
author_rank: Regular Contributor
timestamp: May 21, 2015, 07:31:03 am
content: The data sheets for some regulators provide graphs of their input rejection (PSRR) vs. input voltage above output voltage (sometimes called 'headroom voltage'). It's hard to be specific, since it depends upon the actual regulator, but in general, there will be a region of 'basic functionality' at the dropout voltage, and then as the input voltage to the regulator is increased, the regulator will perform better (i.e. have better rejection of input voltage variations) up to some point where it improves no further.The Analog Devices ADP7142 data sheet has a graph of PSRR vs. frequency for various 'headroom voltages', and that is essentially the data you want. For that regulator, the PSRR improves from 600mV headroom on up to 3V headroom, above which it apparently does not improve further. However, the graph is very informative, and it shows exactly how PSRR improves over frequency with additional input headroom.If this is not specified by the manufacturer, you could always wire one up and test it for yourself, but yes, it's sort of tedious unless you have some nice gear like an Audio Precision test set. Still, you aren't writing the data sheet, so you really only have to test where it's important to your circuit, so you could do this with a sine wave generator, a variable DC supply, an AC voltmeter, and a simple breadboarded regulator circuit.

author: montemcguire
author_rank: Regular Contributor
timestamp: May 21, 2015, 07:37:38 am
content: What I didn't address: yes, the cost of extra input voltage is extra power dissipation, so a ridiculously high input headroom voltage could cause a large portion of the overall circuit's power dissipation to be in the regulator, perhaps with little practical benefit. That's why the curves are useful to see, so that you can make a good tradeoff for the expected input voltage range and the PSRR that you need to make things work well.
DER EE DE-5000 LCR Meter Fails CAL - Page 1
Forum section: electronics / testgear

author: TSL
author_rank: Regular Contributor
timestamp: May 20, 2015, 07:40:33 am
content: Hi all,I turned on my DE5000 to measure some L today and I notice that it now has a standing 12pF on the display with no test leads plugged in.So I ran CAL on the meter and it fails at the first step!Switching between C, L & R I find that on the R scale it read 8.350 Mohm. Blowing some dust off it the value dropped to 2.667Mohm and the cap value has dropped to 2.4pFI don't think I zapped it measuring anything, hope not anyway.Has anyone had theirs break ?Has anyone had cause to repair one ?Has anyone a schematic or service manual ?Any help appreciated.In the mean time I'll pop the case open and see if any crap got in the sockets to weird me out.thanksTim

author: Co6aka
author_rank: Unknown
timestamp: May 20, 2015, 01:18:48 pm
content: Were you previously LCR-metering with sweaty hands?

author: KedasProbe
author_rank: Frequent Contributor
timestamp: May 20, 2015, 03:03:38 pm
content: Low supply voltage? (although I assume you checked that)

author: dfmischler
author_rank: Frequent Contributor
timestamp: May 20, 2015, 03:09:09 pm
content: Quote from: TSL on May 20, 2015, 07:40:33 amJust the power circuit in mine.

author: TimFox
author_rank: Super Contributor
timestamp: May 20, 2015, 06:24:45 pm
content: What battery indication are you getting?

author: TSL
author_rank: Regular Contributor
timestamp: May 21, 2015, 01:12:39 am
content: Well I'm a goose !I believed the on screen battery indicator.Insert a fresh Duracell and its all good.The unit is only 6 months old and still had its original "Golden Power" battery in it; its OC terminal voltage is 8.5v. Testing the battery with 100mA load reduced it to 8.4v, so its not too bad.So it seems that the DE requires a higher terminal voltage to operate correctly.regardsTim

author: georges80
author_rank: Frequent Contributor
timestamp: May 21, 2015, 02:26:40 am
content: Well, I just ran mine at 6.8V (below that it display batt and powers off after hooting).So, I find it extremely hard to believe it needs >8.5V to operate correctly.At 6.8V mine powers up properly and measures some caps just fine.Maybe removing and re-installing the battery reset your unit??I have a 9V duracell in mine, I try to not use the no-brand batteries that come for 'free'...cheers,george.

author: TSL
author_rank: Regular Contributor
timestamp: May 21, 2015, 02:30:30 am
content: Ok.... then further testing of my unit is required.thanksTim
Old Test Gear - Page 1
Forum section: electronics / testgear

author: PsychoMaster
author_rank: Regular Contributor
timestamp: May 20, 2015, 10:06:09 am
content: Hi FolksI have come across some old test equipment for sale on the side of the road a Evershed Megger Series One set from 1906 which is really not all that old for stuff in these parts and wondered wether it,s worth spending my hard earned on ? £20.

author: smjcuk
author_rank: Frequent Contributor
timestamp: May 20, 2015, 10:18:52 am
content: I wouldn't bother. You might be able to sell it on ebay but its virtually no use these days. Very primitive devices.Edit: if you put steampunk in the auction title its a winner

author: -jeffB
author_rank: Regular Contributor
timestamp: May 20, 2015, 02:43:13 pm
content: Are you sure about "1906"? Some quick Googling indicated that the Series 1 dates from the early 1950s...?

author: PsychoMaster
author_rank: Regular Contributor
timestamp: May 20, 2015, 07:48:25 pm
content: Yes there is some odd information about this and it was still available in the sixties but I,m pretty sure it,s been about since 1906 ,I have seen one dated from 1933.Just look how it,s made. I don,t think I am going to bother with it as it is really for a collector. Old scopes are a different prospect though.
LitePoint IQultra WiMedia Test System - Page 1
Forum section: electronics / testgear

author: SparkyBruce
author_rank: Contributor
timestamp: May 13, 2015, 08:28:40 pm
content: Hello,I have just bought one of these off ebay and I was wondering if anyone here has ever used one. (I don't know if it is the 100 or 300 version as the label was torn off).I have contacted LitePoint to see if I can get any software for it.The only list price I have been able to find was $55K back in 2008 for the IQultra300 system.I am hoping to be able to use it as a more general purpose analyser, or worst case do a tear down of it to post here.ThanksBruce

author: SparkyBruce
author_rank: Contributor
timestamp: May 18, 2015, 03:30:14 pm
content: The unit has turned up in good condition so all I need now is the software drivers.Inside is nice and clean and it has the three wideband receiver boards which means it is the expensive model.I will post some pictures later , but for now it is just an expensive powered USB hub.Bruce

author: tmbinc
author_rank: Frequent Contributor
timestamp: May 18, 2015, 08:42:15 pm
content: Certainly very interesting specs, as far as I could find. I would love to see photos.

author: daqq
author_rank: Super Contributor
timestamp: May 19, 2015, 05:11:31 am
content: I too would love to see some innardsBy the way, how much did you pay for it if you don't mind my asking?

author: SparkyBruce
author_rank: Contributor
timestamp: May 19, 2015, 07:21:14 am
content: Well for the system that I have with the three processing boards the list price was $55,000Ebay seller wanted £500 and accepted my offer of £100 given the unknown condition of the unit or even if it was the single or triple processing version. (including postage).Here is a quick shot of the top of the unit showing the front analogue board connected directly to one of the processing boards , with two almost identical ones stacked on top with different fit options. They use sata/SAS cables to get the signals from the front end to the processing boards so I assume the high speed ADC's are on the front analogue processing board under the metal cans.The processing board has a big Virtex 4 fpga together with a smaller Spartan one and four high speed 18Mbit SRAMS (512K x 36 bits 167Mhz) Cypress CY7C1380D's.The three processing boards sit on a USB interface board that as well as a USB hub , has the USB to PC interface for all the processing boards.When plugged into a PC the PC sees the USB hub , and an Unknown device for which it needs a Windows device driver (which I am trying to get from LitePoint at the moment).My hope is to be able to use the API's for the system to do analysis from the 3.1Ghz up to 10.6Ghz bands for more general purpose spectrum analyser applications (I have a signal hound which processes 250Khz bandwidth at once , so going to 1.6Ghz at once is going to be a big improvement).I will post some more pictures later on.ThanksBruce

author: daqq
author_rank: Super Contributor
timestamp: May 20, 2015, 08:52:39 am
content: Wow, that's some serious power for just 100 GBP. If you can hack it, then it's an epic win...
Any comment for Siglent SDS1102CML Digital Oscilloscope 2CH 100MHZ 1GSa/s 2Mpts - Page 1
Forum section: electronics / testgear

author: get-trade-hk
author_rank: Newbie
timestamp: May 19, 2015, 12:25:58 pm
content: https://youtu.be/vBuASZzQsZAThe youtube video shows this scope is good. Any comments ??I am wondering I should buy Hantek DSO5202P or Siglent SDS1102 CMLany comment ??

author: ion54
author_rank: Contributor
timestamp: May 19, 2015, 02:30:01 pm
content: I have the Siglent SDS1102CML. Using a BNC to BNC cable and 50 Ohms termination I verified a bandwidth at 3 dB of 138 MHz. I can still see the signal at 175 MHZ but it is down about 10 dB.For me the price and a larger memory sealed the deal. Hantek has a better screen resolution, 200 MHz bandwidth, but only 40K points memory.Depending of your location you might find that for a lower price than Hantek you can get a Rigol DS1054Z.If I would be in the market again for a scope that will be what I will try to get. It has 4 channels, much larger memory, better screen than Siglent, good firmware and it is easy to make it run 100 MHz bandwidth.

author: get-trade-hk
author_rank: Newbie
timestamp: May 19, 2015, 03:56:42 pm
content: You 're nice! thanks for your comment
XY Mode on Tektronix 7000 Scope - Page 1
Forum section: electronics / testgear

author: Electro Fan
author_rank: Super Contributor
timestamp: May 18, 2015, 11:55:11 pm
content: I was trying to figure out how to use XY mode on a Tek 7000 series scope and received this very helpful info from David Hess.There are three ways implement X-Y mode on a 7000 series and the 7B92/7B92A will not do any of them:1. Use two vertical amplifiers with one in a vertical slot and one in a horizontal slot.2. Use one of the several timebases which support X-Y mode; these include the 7B50, 7B70, 7B80 with option 2, 7B50A with option 2, all variations of the 7B53A. The 7B53A is the most common timebase for this.3. Use a 7D20 digitizer.Note that the 7B53A X-Y mode is pretty complicated. The X input can either come from the front panel BNC like you expect or it may come through the internal trigger path from the trigger output from one of the vertical plug-ins.I went for #1 and moved one of two 7A26 plug-ins from the normal vertical slot to one of the horizontal slots. Then just connected a couple BNC cables from a sig gen and voila!Thanks David!EF

author: miguelvp
author_rank: Super Contributor
timestamp: May 19, 2015, 12:24:01 am
content: I use option 2 using the 7B53AYou have to move the timebase to AMPL and use the AMP IN BNC connector, but it's good to know about option 1.

author: Rupunzell
author_rank: Frequent Contributor
timestamp: May 19, 2015, 05:39:40 am
content: The Tek 7104 has a horizontal BW of 350Mhz with very little phase shift relative to the vertical channels.In the four slot main frames, one channel of vertical and one channel of horizontal can be used as X-Y along with one vertical plug in and a time base displayed together using chop-alternate on the horizontal. This gives a time -vs- amplitude with X-Y display in the same display.Bernice
WANDEL & GOLTERMANN SPM-19 POST BP - Page 1
Forum section: electronics / testgear

author: IZ1FID
author_rank: Newbie
timestamp: May 18, 2015, 01:27:39 pm
content: Hi to all I already have an SPM-19 but I saw for sell an SPM-19 that report a factory BN 853/02 IEE488 interface marked POST BP, this POST BP is reported also on the front panel near the W&G logo.My question is :1what means?2how this affects the operation of SG-4 Display UnitThanks. Federico IZ1FID federico_baldi@alice.it

author: 128er
author_rank: Regular Contributor
timestamp: May 18, 2015, 02:04:12 pm
content: Where did you buy it?Thought you already bought itIs it a Sticker? Horn symbol anywhere?My guess is, that it is maybe a Sticker of the "Deutsche Bundespost". Former federal mail of germany. It is typical for governmental institutions to label their test equipment. My Tektronix scope also has labels "BUND". It was used by the german army. Wandel & Goltermann was a typical TM supplier for german institutions. Like Siemens or SEL (Standart Elektro Lorenz).A picture would be good.Found that:http://kleinanzeigen.ebay.de/anzeigen/s-anzeige/wandel-u-goltermann-selektiver-pegelmesser-spm-12/298907866-168-2472?ref=searchThe pictures are quite small. But you can see the sticker. If it's the same label as on your device, I would defenitely say it's from the german federal mail.
A handheld analyzer KC901S with vector network analysis function. - Page 1
Forum section: electronics / testgear

author: bg8npk
author_rank: Newbie
timestamp: May 10, 2015, 01:35:38 pm
content: Hi,I'm BG8NPK from Guangdong Province in China, Our team build an vector network analyzer KC901S.KC901S is a "RF multimeter". It supports the analysis of single port vector network analysis and dual port scalar network analysis, extended spectrum, intensity and signal generator functions.it a powerful and useful handheld instrument of many RF designer.Features• -Test frequencies up to 3GHz with 1Hz resolution and stability better than 1ppm.• -Vector measurement on S11 with 0.01 phase resolution and 0.01db amplitude resolution.• -With vector measurement capability of S11, it shows the smith chart, RL(Return loss), characters of phase position, and frequency.• -In S21 scalar measurement, it has the function of single frequency S21 within range of 100dB.*• -With its non-volatile calibration data built-in, on site calibration is not necessary if performing a qualitative measurement. While performing rigorous test, you may use the SOL to enhance the calibration.• -A handy field strengthen meter with a wide dynamic range.• -Built in DDS, audio signal source function.• -Data can be saved in the Memory Card or be transferred into PC via USB.• -3.5 inch color-display• -Excellent response speed with accurate key feeling, less than 3s ready to use.• -Functions are stable and reliable with the excellent hardware/software design.• * in accordance with Technical parametersApplications- Transmission test (tuning diplexer and filter, testing amplifier and inspecting the directivity of antennas)- Vector reflection test (examining quality of antenna system and feeder system, a tracking receiver is used to improve the noise performance)- Spectrum display and field strength detection (inspecting radio frequency emissions / searching interference sources)- RF and AF sourceIf you are interested in our products please click this urlhttp://www.deepace.net/kc901s-rf-multimeter/for more details.Thanks,

author: all_repair
author_rank: Frequent Contributor
timestamp: May 19, 2015, 11:40:10 pm
content: Questions are raised in this post:https://www.eevblog.com/forum/testgear/a-new-antenna-vna-from-china-kc901s/It shall be helpful if you can answer.