hybridfree/eevblog-posts huggingface dataset:
Tektronix 145 Pal Gen Lock test generator: What is it and what is inside? - Page 1
Forum section: electronics / testgear

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: January 10, 2018, 08:27:25 am
content: There is a local guy that is selling a Tektronix 145 Pal gen Lock test generator. For the price he is asking I'm thinking of getting it just to see what is inside and if there are any usefull components I can harvest (seems to have a lot of BNCs that are 50 ohm, rather to my suprise. Would have expected everything to be 75 ohms).Anyone have any clue what this thing actually does or what I will find inside? I can't seem to find much information on the net.

author: iainwhite
author_rank: Unknown
timestamp: January 10, 2018, 02:32:51 pm
content: My guess would be that it generates PAL signal test patterns for Television sets

author: ogden
author_rank: Super Contributor
timestamp: January 10, 2018, 02:38:04 pm
content: You can see what's inside w/o buying it (loads of metal-can opamps or transistors):https://produto.mercadolivre.com.br/MLB-709641140-tektronix-145-m-generator-signal-pal-m-gen-lock-test-_JM

author: vk6zgo
author_rank: Super Contributor
timestamp: January 11, 2018, 01:19:08 am
content: "Gen lock" is so that you can switch sources without the receiving device losing syncs momentarily due to the two source syncs being out of phase.This was used a lot in the days before frame stores, & was still important for inline devices such as the Tek 145, well after that time.Analogue TV used "50 Ohm" sockets with a 75 Ohm system because they were cheap, plentiful & durable, whilst not causing any appreciable mismatch at low HF frequencies like 5MHz.With the advent of "digital video", Studios racks were rewired with "true 75 Ohm" sockets.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: January 11, 2018, 03:20:50 am
content: Can I harvest those little gray caps on the ends of the levers?These commonly fall off from vintage Tek stuff.
Fluke 287 vs 189-II - Page 1
Forum section: electronics / testgear

author: Helix70
author_rank: Unknown
timestamp: January 06, 2018, 10:50:49 pm
content: Does anyone know the difference between the Fluke 287 and the Fluke 189-II (can't find it on Fluke's website, here is an Ebay listing:http://r.ebay.com/tqApiP)?I have seen a couple of these now, but know nothing about them.

author: Terry01
author_rank: Frequent Contributor
timestamp: January 06, 2018, 11:14:14 pm
content: search "Fluke 189ii vs 289" on google and you'll get bits and pieces buddy.Hope you get the info your looking for.

author: retiredcaps
author_rank: Super Contributor
timestamp: January 07, 2018, 12:05:43 am
content: If I'm not mistaken, the Fluke 189 II is the predecessor to the 287/289 models. Dave did a review of the 189 II way back in #15.

author: Electro Detective
author_rank: Super Contributor
timestamp: January 07, 2018, 01:31:10 am
content: AFAIK a 287 is a 187-11and a 289 is a 189-11187 and 189 models without the '-11' are the previous style and look different in style and functionAll these 6 meters are awesome btwand a definite but pricey upgrade from the Fluke 87 series, or any series!

author: PA4TIM
author_rank: Super Contributor
timestamp: January 07, 2018, 07:40:28 am
content: For575675 dollar I would buy a new Keysight instead of an antique Fluke,

author: Electro Detective
author_rank: Super Contributor
timestamp: January 08, 2018, 05:41:18 am
content: $675 would get you two good used -antique- Fluke 287sand two strong lattes to enjoy, whilst waiting for them to be packed at the vintage auction room

author: Helix70
author_rank: Unknown
timestamp: January 10, 2018, 08:20:45 am
content: For bench meters, Keysight. For hand held, you would need to pry my Fluke 287 from my cold dead hand. Or my Fluke 87-V for that matter.Thanks for the info, confirms my thoughts.
Tek 2465A "Var" knob source? - Page 1
Forum section: electronics / testgear

author: usuthu65
author_rank: Newbie
timestamp: January 10, 2018, 12:47:14 am
content: Hi all,I have done a search and didn't find the answer. I just acquired a beautiful Tek 2465A and it's missing the inner variable knob on the time knob ("Sec/Div"). From looking at pictures, this appears to be similar to the "VAR" inner knobs on the two Volts/Div.Anyone know of a good source for this knob? It's the only thing this scope is missing, really. I can turn the inner shaft with my thumb so I know it works OK but it would be nice to complete it.Also, the scope reports > 11,500 hours operation time. How does that stack up?Cheersusuthu65

author: edavid
author_rank: Super Contributor
timestamp: January 10, 2018, 01:40:20 am
content: Quote from: usuthu65 on January 10, 2018, 12:47:14 amYou can get it from Qservice:https://www.qservice.tv/vpasp/shopexd.asp?id=13506Be sure to check eBay as well.QuoteIt doesn't mean anything, since it can be reset.

author: usuthu65
author_rank: Newbie
timestamp: January 10, 2018, 01:45:56 am
content: Thanks - I think Qservice has a few of them. Looking forward to keeping this analog wonder alive.

author: james_s
author_rank: Super Contributor
timestamp: January 10, 2018, 01:50:50 am
content: Typically a CRT is good for about 30,000-50,000 hours of service, but that depends heavily on how hard it is driven. The condition of the CRT is probably the best indication of how much life is left in the instrument. If it has plenty of brightness and doesn't get blurry when turned up brighter than you'd want it for regular use then that suggests it's in good shape.

author: usuthu65
author_rank: Newbie
timestamp: January 10, 2018, 02:23:02 am
content: No problem with focus/blurriness when turned up way past my normal usability range. I think I've got a winner here. Time will tell!

author: Old Printer
author_rank: Frequent Contributor
timestamp: January 10, 2018, 03:03:01 am
content: Congrats on the scope, I look forward to having one someday. There is a teardown thread a couple pages down on this forum (Test Equipment). There are a number of age related issues with those scopes that if caught in time can save a lot of grief in the long run. Fortunately that series is very popular and Tek made a bunch of them. The problem spots and fixes are well documented. God luck with yours!
ssa3032x reflection bridge alternative? - Page 1
Forum section: electronics / testgear

author: rfspezi
author_rank: Regular Contributor
timestamp: January 09, 2018, 07:55:31 am
content: I am in search for an alternative to the original reflection bridge (RBSSA3X20) that goes up to 3,2 GHz.In the datasheet the insertion loss is given with 5 dB typ. and the directivity with 20 dB typ. .Those values seem to confirm that it is a reflection bridge and not a directional coupler.The question is if it is possible to use an e.g. Minicircuits directional coupler aswell or can anybody suggest an appropriate alternative?

author: RFDUK
author_rank: Regular Contributor
timestamp: January 09, 2018, 12:44:06 pm
content: One of the best value bridges in this frequency range I've found to be a second hand Wiltron 60N50. Can be found for about £200 on ebay.They are specified for 5 ... 2000 MHz, but the two we have here are very good to 3.2GHz.Specification is 40dB directivity for the standard bridge, 46dB for an option.These here do 35dB to 3.2 GHz. 13dB insertion loss.We are waiting on an SSA3032X, impressed by the general performance of the ones we've tried.
EEVblog 121GW Disassembly? - Page 1
Forum section: electronics / testgear

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: January 09, 2018, 08:40:52 am
content: How on earth do you remove the little brass insert?

author: andtfoot
author_rank: Unknown
timestamp: January 09, 2018, 10:32:34 am
content: There's a circlip style thingie (e ring/clip) behind the circuit board that keeps it retained on the front housing.

author: EEVblog
author_rank: Unknown
timestamp: January 09, 2018, 10:52:23 am
content: Once you undo the screws holding down the PCB, the PCB should just lift out (may need a bit of a lever) leaving the brass insert behind in the case.You do NOT have to remove the plastic clip in order to get the PCB out of the case.
In love with the EEVBlog Differential Probes - Page 1
Forum section: electronics / testgear

author: forrestc
author_rank: Unknown
timestamp: January 08, 2018, 08:05:51 am
content: Micro-review:I bought a couple of the EEVblog differential probes. Figured it would be nice to have a set of decent ones.My last experience with differential probes was less than positive. Always replacing batteries. Questionable accuracy. Low bandwidth. Odd artifacts. I'm sure it's because I got something inexpensive from a questionable seller. But when I bought them it was pretty much all that I could afford. Definitely a waste of money in hindsight.These are completely different. I don't even notice that I have the differential probe in the circuit, well except for the fact I just gained differential measurements. Accuracy is high enough that I can trust the amplitude of the signals on the scope. And, the 70Mhz bandwidth is well above my needs. I'm finding that having these has changed the way I approach troubleshooting/design validation in a very positive manner, since I am able to look at signals referenced to multiple points in the circuit. I added 9VDC regulated supplies and no more battery issues.I liked them so well, I bought two more. I now have 4 of them, one for each channel on the scope. I added some colored heat shrink to each connector and also at the cable entry into the electronics box to match the colors of each of the channels on the scope, so it is easy to tell which leads go with which channel.About the only gripe is of course how much ANY differential probe costs. But, it's hard to gripe about this seeing as how inexpensive these are when comparing specs to other similarly priced probes.

author: Electro Detective
author_rank: Super Contributor
timestamp: January 08, 2018, 11:35:17 pm
content: Headscratching whether to go the same wayor an isolated inputs 4 channel DSO with true isolation from power earth/groundNot cheap either way
RF Field Intensity Measurement - Page 1
Forum section: electronics / testgear

author: RCHRDM
author_rank: Regular Contributor
timestamp: January 14, 2018, 01:59:11 am
content: I have become interested in measuring RF fields around ham radio transmitting equipment.I bought a couple of vintage instruments and am learning about how these measurements are made.I have a Holaday HI-3002 Broadband Isotropic Field Strength meter and an Aitech/Stoddard NM-17/27A EMI/Field Strength Meter, so far.Is anyone familiar with this area or the test equipment?Richard
Agilent Keysight 34465A or Fluke 8846A / Tek DMM4050 ?  - Page 1
Forum section: electronics / testgear

author: djnz
author_rank: Regular Contributor
timestamp: November 17, 2016, 04:15:35 am
content: For the same price, would you buy a Keysight 34465A or a Fluke 8846A (also sold as Tektronix DMM4050). Could someone help me understand the areas where one is better than the other? For which applications would these differences matter?Edit: I guess both manufacturers have authorized distributors in my city, who say they will help with any warranty / service matters should the need arise.

author: TheSteve
author_rank: Unknown
timestamp: November 17, 2016, 07:28:29 am
content: Which is easier to get serviced in your country should the need arise?I'd rather have the 34465A, mainly because I have lots of other Keysight equipment and it is easier to just use gear from the same company. I also prefer the LCD screen to the VFD.

author: nctnico
author_rank: Super Contributor
timestamp: November 17, 2016, 12:21:34 pm
content: I looked into both when I needed a accurate DMM and I went for Keysight. Even though they are equally accurate the Keysight offers more features and has a TFT screen which makes the DMM much more usefull (think about screendumps which can be copied into a report directly).

author: tangram
author_rank: Contributor
timestamp: January 09, 2018, 09:14:01 am
content: had exactly the same question, djnz. Thanks TheSteve and nctnico for helping make up my mind too. :-)

author: HighVoltage
author_rank: Super Contributor
timestamp: January 09, 2018, 09:30:59 am
content: I used to have a Fluke 8846A and it was a very good meter.But the display (VFD) is totally outdated, when you compare it with a 34465AThe 8846A can also do a trend chart on the screen, but when you comparethe two DMM on this aspect alone, you will never use the 8846A again.I would definitely go with the Keysight DMM.
Oscilloscope noob - Page 1
Forum section: electronics / testgear

author: Charlie86
author_rank: Regular Contributor
timestamp: January 05, 2018, 08:39:18 pm
content: Hi,Like I mention I am total noob in using Oscilloscope. Just bought Rigol DS1054Z to start learning. When I attache probe to point for probe calibration and press auto button I get nice square signal. But if i press auto button without probe attached to test point I get some noise signal. Is this normal?https://imgur.com/a/lMYNK

author: Paul Moir
author_rank: Frequent Contributor
timestamp: January 05, 2018, 08:45:45 pm
content: Yes. When you press the Auto button the 'scope tries to detect what signal is present on the probe and adjust it's parameters to show you a display of it. If it's only detecting noise, that's what it will display for you.If you look closely at your two pictures, you'll see the top one has the horizontal timebase at 100us (micro seconds) per division while the second one is at 5.00ms per division. That's a clue that they're completely different signals.

author: Charlie86
author_rank: Regular Contributor
timestamp: January 05, 2018, 08:57:43 pm
content: Thank you very much for yours information.

author: David Hess
author_rank: Super Contributor
timestamp: January 06, 2018, 02:36:41 am
content: The second signal looks like interference from a 50 Hz TRIAC phase control dimmer.

author: Charlie86
author_rank: Regular Contributor
timestamp: January 06, 2018, 08:58:08 pm
content: Not shure about Triac interference, like I said I am beginner.Have to more questions. What is default pass and user for web interface and what is best programs to communicate with oscilloscope.Thank youBR

author: David Hess
author_rank: Super Contributor
timestamp: January 07, 2018, 02:26:35 am
content: Quote from: Charlie86 on January 06, 2018, 08:58:08 pmDo you have a light dimmer somewhere nearby? If so, try adjusting it while watching that waveform on the oscilloscope.

author: Charlie86
author_rank: Regular Contributor
timestamp: January 07, 2018, 01:24:30 pm
content: I have 3 led bars under it, but even if I unplug them, noise is still on display.
What is inside the Keysight  M8196A 92 GSa/S Arb? - Page 1
Forum section: electronics / testgear

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: January 07, 2018, 01:10:13 pm
content: Hi guys,I am aware of very fast ADC architectures, and how once you get past say a few GSa/S you tend to start time-interleaving to go higher. Higher still you often work with mixing to get more samples (such as in the teledyne 100 GHz scope). But I am not that familar when it comes to DACs, and from what I can tell, the keysight M8196A is one of the fastest DACs on the market right now (or at least contains?). Does anyone have any idea what makes these things tick? What special-sauce they use to get these sample rates? (InP? GaAs?).https://www.keysight.com/en/pd-2583267-pn-M8196A/92-gsa-s-arbitrary-waveform-generators?nid=-33319.1139580&cc=BE&lc=dut

author: 0xfede
author_rank: Regular Contributor
timestamp: January 07, 2018, 03:32:52 pm
content: I don't know for sure, but a quick look on google and IEEE shows some papers of ultra fast DACs (up to 100-Gs/s) using SiGeC or InP HBTs.Can't ever imagine one of these ARB in my lab...Best,0xfede
SysClk LWLA1034 (and others) FPGA Enhancements - Page 1
Forum section: electronics / testgear

author: Scratch.HTF
author_rank: Regular Contributor
timestamp: December 05, 2017, 03:55:46 am
content: I've read athttps://sigrok.org/wiki/Sysclk_LWLA1034that different FPGA bitstreams can be reloaded with Sigrok, and I believe that incorporating the following is possible in the LWLA1034 (and possibly with the LWLA1016 and LWLA2034 which uses the same FPGA) while retaining data compression and State Clock functionality:* Qualifier capability (record data only on qualifying conditions)* If-Then-Else sequencer with full conditional structure (up to a certain number of levels) for the logic analyser* Multiple state trigger words* Range recognizer* Selective data acquisition functions* Programmable STOP conditions* Option to combine logic ports to extend number of points (e.g. 34-16-8-4-2-1 bit for 256K-512K-1M-2M-4M points) and define segment size* 64 bit (probably less) FIFO stream trigger (good for triggering on I2C and SPI)* If possible, enable an option to capture data on either edge (rising and falling edges) of the State ClockFor the host software, there should be an option for automatic retriggering while retaining previously captured data.

author: abraxa
author_rank: Frequent Contributor
timestamp: December 05, 2017, 11:14:26 am
content: Certainly, there are a lot of things that are possible. Do you intend to work on implementing these features?

author: Scratch.HTF
author_rank: Regular Contributor
timestamp: January 06, 2018, 07:32:45 am
content: My strength here is contributing realistic and viable ideas.
"nktech nk-51h" - proper way of installing battery/fast look inside - Page 1
Forum section: electronics / testgear

author: IAmBack
author_rank: Regular Contributor
timestamp: January 04, 2018, 02:49:18 pm
content: Hi.I've purchased this meter on ebay for... $1. And it just arrived! Unbelievable (no matter how cr***y this toy will happen to be). But I have one problem: what is the proper way of installing battery? Meter has two contacts (like for AA/AAA batteries, but 9V battery has to be installed) and no single mark of polarity...Anyone has experiences with this unit?

author: casinada
author_rank: Frequent Contributor
timestamp: January 04, 2018, 03:55:31 pm
content: There is an opening that shows the pcb and there is a "-" sign in the solder mask that is the negative side.

author: IAmBack
author_rank: Regular Contributor
timestamp: January 04, 2018, 09:53:51 pm
content: Thank You for help.I've opened this meter and made several photos.The "-" sign on PCB is not the marking for negative terminal, but anyway - it works.Big fuses I see
Leybold-Heraeus Thermovac TM202 thermocouple vacuum gauge controller - Page 1
Forum section: electronics / testgear

author: ChristofferB
author_rank: Frequent Contributor
timestamp: January 06, 2018, 06:49:16 pm
content: Not sure if this goes here, but strictly speaking itisabout test gear.Hi! Getting into high vacuum stuff, and i've got a cheap offer for a 80's (i think?) Leybold-Heraeus Thermovac TM202 - without the gauge head.Now, it has a non-standard tube socket as probe connector with two fat and 4 slim pins, and the probes look a bit non-standard:https://www.ebay.ca/itm/LEYBOLD-THERMOCOUPLE-VACUUM-GAUGE-89672B1/263415925632?hash=item3d54d00b80:g:dhgAAOSw4A5Y03EZthose thermocouple gauges are pretty simple to drive, but considering how bulbous the detector is, I fear most of the magic might be in there. Is the TM202 then worth picking up, to see if I can modify it for std. thermocouple gauges? Does anyone KNOW this piece of gear?Thanks in advance!--Chris
Rigol DP821A Dual Output 140W Programmable DC Power Supply Impressions - Page 1
Forum section: electronics / testgear

author: MedSpark
author_rank: Contributor
timestamp: January 04, 2018, 03:33:25 am
content: We're considering the purchase of a Rigol DP821A DC Power Supply and I'm wondering if anyone on this forum has any good/bad/ugly experiences with them. We're looking for something that has at least one channel at >50V+ @ >1A. Thanks in advance for the help!

author: MedSpark
author_rank: Contributor
timestamp: January 04, 2018, 04:59:19 am
content: Quote from: blueskull on January 04, 2018, 04:54:54 amAre there any drawbacks? Also, I thought that the 832A was only essentially a 2.5 channel unit, or am I mistaken?

author: MedSpark
author_rank: Contributor
timestamp: January 04, 2018, 05:23:29 am
content: Quote from: blueskull on January 04, 2018, 05:18:15 amThanks for the info. I'll consider it.
Ballantine 5500A counter, seeking info or manual - Page 1
Forum section: electronics / testgear

author: zike
author_rank: Contributor
timestamp: December 30, 2017, 08:42:43 pm
content: [sorry for re-post, evidently I put this in the wrong forum topic at first]Also known as the "Accumetronic" (!). Hoping someone has a manual gathering dust to loan/scan/sell. Docs for similar 5500B (later, non-Nixie tube, 110 MHz) may serve. Usual boat anchor manual sources came up dry.Thisbrochureindicates the unit is "fully programmable" by way of a connector on the rear panel, but it turned out this option is not present. Banana jacks found in the place of that connector were for an external "elapsed time" TTL input.OTOH, aforementioned brochure indicates 6 digits with 7 optional, whereas my unit has 8 functioning nixie tubes (!?). It also appears to trigger well past 70 MHz. So maybe this is a later "A" model.Also curiously, while Ballantine was/is in New Jersey, my unit was evidently built in Germany. Both problems I've found so far are "West Germany" labeled electrolytics that failed in a dead short, one in the 5V supply (mains fuse protected the rectifiers, fortunately) and the other timing a multivibrator in the gate system (gate wouldn't close).I'm still trying to track down a problem with the front end; all functions appear to work with TTL-level inputs, but she won't fire on anything smaller than 2 volts. Hard to troubleshoot without proper schematics.Hope someone can help,Zike

author: zike
author_rank: Contributor
timestamp: January 03, 2018, 10:11:10 pm
content: Status update (success!):- Ballantine responded right after the holiday. They do still have the original manual and offered to sell me a copy; but they actually scanned and emailed me a full set of schematics and parts lists (8 triple-fold B-size pages) for free!- It is evidently not indexed, did not come up in search, but Oliver Pogensee has the full manual for the later5500B. This has 7-segment LED figures instead of Nixie tubes, and thus, e.g., a different readout board and no 200 VDC supply; but it is otherwise very similar.(Interestingly, this download bears the K4XL "BAMA" mark, but is absent from the preserved mirror of that archive...?)- The "MHz" enunciator bulb was burned out. I bodged in a red LED and a resistor ;^)- Once in a while the clock oscillator seemed to just quit. I reflowed joints in that section of the main board and it hasn't recurred.- Trigger issue was a failed (open) "preset" switch on the A trigger level pot. Bypassing this (and rebalancing the front end) gives me solid triggers on 50 mVrms sine up to ~120 MHz, and on 300 mV pulses down to about 7 ns width. Better than spec.- While I was in there... added a wire from "RESET" back to the (unpopulated) remote interface connector plate, and installed a second pair of banana jacks. So now I have both "elapsed time" and "reset" remote inputs on the back panel.- Counter is fully working now. Not about to replace my 5316A; but them nixies sure do look purty.zike
Please Help Identify a Mystery Device! - Page 1
Forum section: electronics / testgear

author: RCHRDM
author_rank: Regular Contributor
timestamp: January 03, 2018, 07:33:49 pm
content: I bought a nice, old rack mount cabinet at an electronics swap meet last year. Inside it was a mystery box made by Sierra Electronics. (I made the purchase for the cabinet, not what was in it.)The only number stamped on the name plate on the front panel is "691." It has tubes and what looks like tuned circuits with a separate circuit for 2, 4, 10, 20 and 30 MC (MHz).Does anyone have an idea of what this device is? Maybe a signal generator?It has no chassis-mounted inputs or outputs but one of the coax cables on the back is longer than the rest and perhaps connected to another piece of equipment.I have attached front and back pictures. The space on the lower left on the back view had five band pass filters of various cutoff frequencies.Richard

author: Simon
author_rank: Unknown
timestamp: January 03, 2018, 08:47:39 pm
content: Please don't double post.
Rigol DS1054Z menu question - Page 1
Forum section: electronics / testgear

author: raptor1956
author_rank: Frequent Contributor
timestamp: January 05, 2018, 01:20:38 am
content: I have the aforementioned scope and there's one thing that I'd like to know how to do. If I connect up the probe to a signal and press the "Auto" button to get a baseline set of settings the right-hand list of menu options includes, fourth from the top, the icon to view the falling edge of the trace versus the normal/default rising edge. But, if I press that icon to view the falling edge that menu disappears and I can't so easily switch back to rising edge. I could pres the "Auto" button again and that will return the menu that includes the rising and falling edge icons but doing so means any other setting change I may have made is reset to whatever "Auto" comes up with. I'v poked around looking for a way to return the menu but can't find it. Any ideas?Brian

author: rbm
author_rank: Regular Contributor
timestamp: January 05, 2018, 02:17:43 am
content: When you press Auto key on the console, it sets the menu items to a few that are commonly needed, like positive and negative going slope trigger selection and long/short timebase. These same functions are available on their respective menus. The Slope functions are available in the Trigger menu. The long and short timebase settings are available by rotating the horizontal timebase selection knob.I hope that answers your question.

author: raptor1956
author_rank: Frequent Contributor
timestamp: January 05, 2018, 02:55:20 am
content: Quote from: rbm on January 05, 2018, 02:17:43 amYeah, I found it in the trigger menu -- it's a different set of icons but it does what I need. Thanks for the tip...Brian
VNA3p 1-60MHz  (SP2SWJ/IW3HEV ?) - looking for PC software - Page 1
Forum section: electronics / testgear

author: Yansi
author_rank: Super Contributor
timestamp: June 22, 2015, 08:37:52 pm
content: Hello,I am looking for software compatible with this old "VNA 1-60MHz" device. It is almost same (only minor changes) as this:http://www.sp2swj.sp-qrp.pl/IW3HEV/VNA3p/On this link there is a zip with a software, but the VBasic monster crashes like rock instantly after start. "Runtime Err 19, type mismatch". (wXP 32b OS, nothing new)It is connected via LPT, not serial port like the more modern version which works up to 120 or 180MHz or thereabout.But I smell that if a working software will be ever found, it still won't help cause my PC does not have LPT on the MB, I have only expansion card, the LPT sits on exotic address $E800 and PC software programmers usually don't think much, so I suspect only LPT1 ($378) hardcoded into the sotwareThank you for your help, if you now where the software is...EDIT: I'm in contact directly with SP2SWJ now. He's quite communicative and answeres fast. So I've already figured out problems with software for this old VNA. And - for all user of this thing with LPT port, there is a possibility to make a serial/USB interface for it. I'll add more info later!

author: OK1FSX
author_rank: Newbie
timestamp: January 02, 2018, 12:39:41 pm
content: H?llo everybody, if somebody looking for USB interface for this old LPT VNA3p, I have one spare and I can offer it for some bucks. You can contact me here via email. I was very frustrated when working VNA with old LPT NB only, so I decided to build the USB interface and I have made 2 pieces, 1 can be yours. 73 de Tom OK1FSX

author: Yansi
author_rank: Super Contributor
timestamp: January 02, 2018, 01:13:49 pm
content: I have also rebuilt that for the USB interface. But either way, the USB software for it aren't much better. I haven't bothered using this VNA since then. The software is not very intuitive and as far as I remember, there was an issue of the DDS output frequency being different than what the software expected. No way to calibrate or change the ref. frequency. It just didn't work.Maybe one day I will build myself a custom VNA with much better resolution, that will work indeed as VNA. As thins thing is only a VSWR reflectometric bridge, that can't tell the sign of the phase. The AD8302 detector has a symmetric phase response and rather large phase uncertainty around 0° and 180°, which is kind of annoying.Y.

author: OK1FSX
author_rank: Newbie
timestamp: January 03, 2018, 12:48:03 pm
content: Hello Yansi, isn´t that mismatch error caused by wrong regional setting or setting of decimal separator in WinXP?,see this page:http://www.sp2swj.sp-qrp.pl/VNA3p2/VNA3p2.htm#_Instalowanie_oprogramowaniasection 5.1.2 of documentBy the way, the schematic of my USB interface is here:http://www.sp2swj.sp-qrp.pl/VNA_IF/VNA_IF.htmHope something there is usefull for you.Best 73, Tom OK1FSX
Teardown of the Duoyi DY294 transistor/component tester - Page 1
Forum section: electronics / testgear

author: PA4TIM
author_rank: Super Contributor
timestamp: January 03, 2018, 10:03:26 am
content: I bought this thing a few months ago and because I wanted to change the connectors so I opened it and used the opportunity to make a review of it. On my site you see all pictures and calibration results. I did not make adjustments. There are a few trimpots so if someone wants to do that it is possible.Soldering is not great. I resoldered everything and removed some of the component connectors and replaced them with banana sockets. I added a resetable 650 mAfuse in series with the caps input.I also made a video.It is usable as transistor/fet tester. It can measure Vce(sat), hFE, Iceo, Vbr. It can generate several base currents. That makes it a useful tool.It is very handy as zener (Vbr upto 1600V) , led tester (Vce with 4 currents) or MOV tester (Vbr) . It kan generate 270V and 1600V for isolation breakdown voltages. The Ice reads uA's and generates 26Vdc. It is usable to measure leakage current of capacitors. I tested a 25V 100 uF that showed 4 uA on the display, the real leakage was around 1.5 uA. At higher currents it is better. I tried to place pictures here, but the filesize was to big. But you see them on my sitehttp://www.pa4tim.nl/?p=6022https://youtu.be/7_oBBoEkQSI
HP Logic Analyzer - Fine pitch 30 pin/2 row connectors - Page 1
Forum section: electronics / testgear

author: calmissile
author_rank: Contributor
timestamp: January 03, 2018, 06:19:09 am
content: Have been trying for weeks to find the vendor and P/N of the 30 pin (2 x 15) connectors that are used on many of the Test Interface Modules. They are the same series that are also used for inter-board connectors when you are using multiple analyzer boards of the same type. It may also be the same connector that was used for the Intel 30 pin JTAG (TAP) connectors. Anyone have a clue what these are and where to purchase them? HP is no help!

author: abraxa
author_rank: Frequent Contributor
timestamp: January 03, 2018, 08:28:01 am
content: http://download.intel.com/support/processors/pentium4/sb/31337301.pdfChapter 3.11, Mechanical Specifications says it's a Samtec BSH-030-01. Is this the one you're after?
Looking for handheld calibrator 10V, 20mA, RTD and TC K - Page 1
Forum section: electronics / testgear

author: Magnum
author_rank: Regular Contributor
timestamp: December 19, 2017, 02:40:30 pm
content: Hello,I am looking for a reasonable priced handheld calibrator. It should be able to measure and source (simulate) up to 10V, 20mA, RTD PT100 and PT1000 as well as thermocouple type K.I know there are nice calibrators available from Fluke, but they seem to be really expensive (>EUR 3.000).On Ebay I found some Chinese brands for EUR 300-400, but I am not sure if they are good and if a calibration manual is available.I would like to spend less than EUR 500 if possible, it can be a good used unit, too.Any suggestions?Thanks.

author: PTR_1275
author_rank: Frequent Contributor
timestamp: December 19, 2017, 03:57:21 pm
content: I have quite a few process calibrators, the one that comes to mind that will do what you want is the fluke 725.The 724 is more aimed at thermocouple testing and calibration, but will not source current. It will source upto 10v, but only measure mAThe 725 will do all of the 724 functions, plus it will source mAIf you are patient enough, cheap ones do come up for sale. The 725 I have was new in box and cost less than you are wanting to spend. I looked at Chinese units but decided to be patient and wait for a good deal to come up.

author: Magnum
author_rank: Regular Contributor
timestamp: December 19, 2017, 04:42:03 pm
content: The Fluke 725 was the one I was looking at. New price is EUR 3.150,- here in Germany :-(Seems I'll have to wait a little to get one cheap.

author: Magnum
author_rank: Regular Contributor
timestamp: January 02, 2018, 11:16:16 pm
content: I was lucky and found a used GE Druck DPI 880 for a good price. It has approx. the same specs as the Fluke 725. If someone is interested:https://www.gemeasurement.com/test-calibration/calibrators/dpi-880-multifunction-calibrator
Yokogawa DL1540 CRT power supply - Page 1
Forum section: electronics / testgear

author: davorin
author_rank: Unknown
timestamp: January 02, 2018, 04:03:41 pm
content: As stated in another post I recently acquired a Yokogawa DL1540 scope...not only as it reminds me to my first Mac 512k Reflex (o;Does someone know if the CRT has its own power supply or does it feed the logic part as well?Reason for asking: Tend to replace the old CRT with a LCD screen ;-)And there seems to be now useful service manual available...
New Rigol DP832 doa? - Page 1
Forum section: electronics / testgear

author: mitchty
author_rank: Newbie
timestamp: December 31, 2017, 03:37:32 am
content: So I just got myself one of those Rigol bench power supplies to upgrade me beyond my kit built power supply. But it appears a bit DOA or at least not entirely alive, more zombie on arrival maybe.I double checked that I've selected my right voltage at 115, the fuse is definitely in place and the right fuse for 115 as well according to the manual, and isn't blown. But this is all I get out of it, I left it on for an hour and got some taquitos in case it was just me being impatient and also because I was hungry, but this is all it does outside of look like something out of star wars with the fancy fins. I pressed pretty much every button, and nothing appears to be coming out of any channels either, so I'm assuming the lack of the display means kablamo.Did I manage to acquire a $500 fancy green light and fan paperweight? I'm thinking I should release this one back to the the wild, its not fully formed yet.Video of the situation:https://mitchty.net/misc/dp832.m4a

author: cncjerry
author_rank: Unknown
timestamp: December 31, 2017, 03:54:28 am
content: looks like you have green panel lights with no display? Can't tell for sure on the video but it looks like the display is dead at a minimum.

author: Monkeh
author_rank: Super Contributor
timestamp: December 31, 2017, 03:58:27 am
content: Have you considered, oh, asking the seller to replace it as it's faulty?

author: SkyMaster
author_rank: Frequent Contributor
timestamp: December 31, 2017, 03:59:02 am
content: I do not have experience with the DP832, but the first Rigol DS1054Z that I received kept freezing/crashing.Hopefully you bought your DP832 from a professional seller that will exchange it at no additional cost to you.

author: Pinkus
author_rank: Frequent Contributor
timestamp: December 31, 2017, 11:43:23 am
content: $500 is about the price for a new DP832 so I assume you purchased it as a new item.Just send it back for a replacement.Only if the seller gives you a written OK, you may remove the warranty seal and open it to check for a connector which might became loose during shipping. There is nothing more you can do.

author: mitchty
author_rank: Newbie
timestamp: December 31, 2017, 03:26:36 pm
content: Yep purchased new, this is basically out of the box. And also yes the display does nothing. Figured I'd ask in here while I wait on the response in case there was anything facepalm obvious that I missed.

author: 2N3055
author_rank: Super Contributor
timestamp: December 31, 2017, 03:59:38 pm
content: Quote from: mitchty on December 31, 2017, 03:26:36 pmNope, it's dead, return it...
New low cost meter with temperature  - Page 1
Forum section: electronics / testgear

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: December 29, 2017, 08:17:16 pm
content: There's now an Aneng AN8009 on Ebay that has temperature measurement, which the 8008 lacked. Have to get Dave to give it a thumbs-up, down, sideways, or something..Might get one myself as it's small and handy to put in the toolbox.

author: Russ
author_rank: Regular Contributor
timestamp: December 29, 2017, 08:34:05 pm
content: Interesting. I just ordered this unit for the tool box.Auto Ranging Digital Multimeter TRMS 6000 with Battery Alligator Clips Test Leads AC/DC Voltage/Account,Voltage Alert, Amp/Ohm/Volt Multi Tester/Diode and Continuity Test HZ Backlight LCD Displayhttps://www.amazon.com/dp/B06ZZG2F2N/ref=cm_sw_r_cp_api_KzQrAb0RC6QTKRuss

author: barry14
author_rank: Regular Contributor
timestamp: December 29, 2017, 10:23:21 pm
content: There is already a long thread on this meter in this forum.

author: Fungus
author_rank: Super Contributor
timestamp: December 29, 2017, 10:43:15 pm
content: I'd get the ANENG AN860B+.It's not so small but it's rubberized/tougher and has probe holders on the back - big advantages for a toolbox.It's also cheaper than the AN8009.PS: Chop a mobile phone screen protector to the right size and stick it on the screen, you'll be glad you did.

author: ez24
author_rank: Super Contributor
timestamp: December 29, 2017, 11:07:55 pm
content: Quote from: Russ on December 29, 2017, 08:34:05 pmMy goal in life is not to buy anything that uses 9v batteries. As far as AN860B+ vs AN8009, I got both.

author: Russ
author_rank: Regular Contributor
timestamp: December 29, 2017, 11:37:14 pm
content: Quote from: ez24 on December 29, 2017, 11:07:55 pmWhy are so many put off by the 9v batteries? Just curious?ThanksRuss

author: ez24
author_rank: Super Contributor
timestamp: December 29, 2017, 11:44:57 pm
content: Quote from: Russ on December 29, 2017, 11:37:14 pm$$$ and I like Eneloops

author: GreyWoolfe
author_rank: Unknown
timestamp: December 29, 2017, 11:48:41 pm
content: Quote from: Fungus on December 29, 2017, 10:43:15 pmActually, the AN860B+ is the same price as the AN8009 on Banggood.com. I have both the 8008 and 8009. I really wanted the small size. I don't want to carry a meter the size of a Fluke 87V. Both meters are in the case/bag that them come in. The 8009 is in the 8008 bag in my tool bag and the 8008 is in the 8009 case in a tote as a spare. I have 2 full sized meters, a Velleman and a Fluke 27/FM. Both are way too big for my use.

author: Russ
author_rank: Regular Contributor
timestamp: December 29, 2017, 11:50:11 pm
content: Quote from: ez24 on December 29, 2017, 11:44:57 pmI have Eneloops in my Brymen and all of my cameras and flash units. Been using them for years.Russ
Neon bulbs for HP 3420B/419A optical chopper  - Page 1
Forum section: electronics / testgear

author: perdrix
author_rank: Frequent Contributor
timestamp: January 06, 2018, 04:53:42 pm
content: After many attempts to get the chopper circuit in the my HP 3420B working correctly using many different neon bulbs, I was sent a few GT-NE6H1925T neon bulbs by George Kerber.I took two out of the packet at random and installed them in the the optical chopper. Powered on and was delighted to see the correct waveform at test point TP1 on the A2 board. I had almost given up on this so am really delighted. I think the problem was the the neons I had been using previously (e.g. A2B) had too low a strike voltage and were both firing simultaneously. These have a strike voltage of about 95-100V (depending on how you measure it) and a sustain voltage of about 68V.A huge thank you to George!Happy New YearDave

author: Tony_G
author_rank: Super Contributor
timestamp: January 06, 2018, 05:28:30 pm
content: Awesome - Available right now on Mouser for US$0.44TonyG
Searching for straight testleads - Page 1
Forum section: electronics / testgear

author: zed65
author_rank: Contributor
timestamp: December 30, 2017, 09:11:47 pm
content: Looking for standard testleads to my multimeter with straight connectors at the multimeter end.Like this ones but not the 90 degree connector.More like this onesDo any of you know where I can find such leads?

author: blacksheeplogic
author_rank: Frequent Contributor
timestamp: December 30, 2017, 09:20:34 pm
content: Quote from: zed65 on December 30, 2017, 09:11:47 pmhttp://www.pomonaelectronics.com

author: glarsson
author_rank: Frequent Contributor
timestamp: December 30, 2017, 09:25:39 pm
content: Probemaster.This series, for example, has eight types of connectors to choose from.http://probemaster.com/8000-series-test-leads-only/

author: donkey77
author_rank: Regular Contributor
timestamp: December 31, 2017, 12:17:06 am
content: Go for the probemaster BOOBS ;-) I know, sorry, being childish!
Universal-Pegelmessgerät UPM550 - Page 1
Forum section: electronics / testgear

author: Charlie86
author_rank: Regular Contributor
timestamp: December 10, 2017, 12:10:15 am
content: Hi,For what kind of measurements was used this device? Does is still useful in this days (I am guessing it is pretty old)?https://www.radiomuseum.org/r/sennheiser_universal_pegelmessgerae.html

author: SparkyFX
author_rank: Frequent Contributor
timestamp: December 10, 2017, 04:47:03 pm
content: Well, the text says it´s a level meter 10Hz-1MHz, 30µV-300V AC input, 1kHz calibration source included. Probably used to test audio amplifiers for gain-bandwith.A spectrum analyser or most modern oscilloscopes with an FFT mode will show a signal in that range with a wider bandwidth, concurrently with the other ranges.

author: Charlie86
author_rank: Regular Contributor
timestamp: December 27, 2017, 09:07:47 am
content: Thank you for yours answer.
Tek 2465B DMM Test failure - Page 1
Forum section: electronics / testgear

author: SteveRosenlund
author_rank: Regular Contributor
timestamp: October 09, 2017, 12:19:32 pm
content: Hello,On my Tek 2465B DMM, i'm getting an error on startup regarding the DMM. The error is "DM Test 76 Fail 01". This means that most likely one of the two fuses on the DMM has opened. One is external and one is internal. Do any of you know where the internal fuse is?From the service manual: DMM FUSESThe DMM has two fuses, in series with the HI inputconnector, to protect the DMM circuitry from current over-load. One of the fuses is on the DMM front panel and theother is inside the instrument cabinet. Only the front-panelfuse is operator replaceable; if the internal fuse opens,refer the instrument for fuse replacement or repair to aqualified service technician.If the DMM does not make measurements after apotential current overload condition has occurred, turn offthe instrument, remove the probes, and check the front-panel fuse. If it has opened, replace it with a fuse of thesame type and rating. Otherwise replace the fuse in itsholder and turn on the instrument. If the internal fuse hasopened, the message DM TEST 76 FAIL 01 will appear onthe crt readout during instrument power-up. In this case,refer the instrument to a qualified service technician forrepair.

author: med6753
author_rank: Super Contributor
timestamp: October 09, 2017, 02:53:59 pm
content: I have a 2465 with the DMM and according to that manual a Test 76 Fail 01 is defined as "Malfunction of DMM, or if this is the only failure, V/F Input Multiplexer U5020 input, pin 2". So apparently there have been changes/updates with the 2465B.Anyway, the 2nd fuse right there on the front of the DMM board.

author: SteveRosenlund
author_rank: Regular Contributor
timestamp: December 27, 2017, 07:02:42 pm
content: I fixed the issue. Turned out to be just a loose ribbon cable from the dmm board.
What is the difference between a Hameg 408 and a 408-1 - Page 1
Forum section: electronics / testgear

author: Specmaster
author_rank: Super Contributor
timestamp: December 27, 2017, 02:10:39 pm
content: Can anyone tell me what the differences are between the 408 and 408-1, both are 40MHz storage scopes but appear to have different back covers
DS1054Z X-Y mode slow - SOLVED - Page 1
Forum section: electronics / testgear

author: idecable
author_rank: Newbie
timestamp: December 27, 2017, 04:21:28 am
content: On latest firmware 00.04.04.SP3 the X-Y mode at scale of 1ms makes the screen refresh about twice per second.Older firmware worked better in that mode, after seeing youtube videos of others using DS1054Z with X-Y mode with scale at 1ms at descend speed. I think latest update added the fullscreen mode..The device is not allowing downgrade.I am fully aware that I can take a previous firmware release, open a hex editor and carefully increment the end of the version by a single digit at the top header, making the scope believe it is truly getting an upgrade.. But I feel like that's playing with fire (even with doing factory reset beforehand), and would break warranty.I'd like to hear what you guys think! Should I refund and find another scope? Or should I really attempt force downgrade with higher firmware version at the header?I don't think there's a unbrick tutorial for this scope

author: Fungus
author_rank: Super Contributor
timestamp: December 27, 2017, 05:02:54 am
content: Quote from: idecable on December 27, 2017, 04:21:28 amI never heard that trick before.But there doesn't seem to be any danger, all the code and data will be the same.Quote from: idecable on December 27, 2017, 04:21:28 amI doubt anybody would even bother to check the firmware version if there's an obvious, visible hardware fault.

author: idecable
author_rank: Newbie
timestamp: December 27, 2017, 05:20:45 am
content: It is brand new.Is there another 4 channel at 100mhz that would be a step up from this one. I don't mind putting an extra $100 or $200 on something that works.

author: Fungus
author_rank: Super Contributor
timestamp: December 27, 2017, 05:29:48 am
content: I just checked on mine and the refresh speed in XY mode depends directly on memory depth.Go to the "Acquire" menu and set memory depth to something faster.nb. This happens in other modes as well, whenever you see very slow screen refresh you probably need to look at the memory depth.

author: idecable
author_rank: Newbie
timestamp: December 27, 2017, 05:59:40 am
content: Quote from: Fungus on December 27, 2017, 05:29:48 amSOLVEDthank you!! Yes 100% working now! Awesome!
Instek GDS-2072E for $222 - Page 1
Forum section: electronics / testgear

author: rhb
author_rank: Super Contributor
timestamp: December 27, 2017, 05:25:02 am
content: I just ordered one from Amazon. It said "one left, more on order". I have no idea how long they will honor that price. It runs the Xilinx Zynq Linux distro, so it's a great candidate for an open source scope. "Some assembly required." I bought it for testing so I don't have to risk bricking my MSO-2204EA, which is a great scope except for the FW.