Some obscure test equipment I got in an auction... - Page 1
Forum section: electronics / testgear

author: Codemonkey
author_rank: Regular Contributor
timestamp: September 18, 2014, 03:23:11 pm
content: My employer is currently in the process of relocating our office to smaller premises, and as a result due to impending reduction of lab space, they opted to auction off some of the lesser/unused bits of test equipment.Below are two of the more obscure bits that I ended up winning that I intend to try and sell off at some point to cover the cost of the stuff I really wanted (HP8595E and Agilent ESA-L1500A spectrum analysers), however given their obscurity I'll be surprised if I get a buyer any time soon! (Please excuse the poor photo's!)So, they are:1) A Sony/Tektronix model 370 Programmable Curve TracerI've no idea why we had this bit of kit, I know it was used for a short time when the lab dwellers were doing characterisation on a device but other than that it spent most of its life occupying bench space (probably due to the fact it weighs about 37Kg, no one could be bothered to move it!).It has many knobs and dials, and I believe the compartment in the lower right accepts a bubble memory module (not present) for saving/restoring data. Its also programmable via GPIB.and a compartment to plug in adapters for different types of devices, which then gets covered by what can only be described as a "blast shield" which disables the test voltages when raised to prevent numpties poking their fingers into potentially high voltages (I think it goes up to about 2KV). The blast shield bears the stain of some previously released magic smoke from a DUTI believe its in full working order, just not calibrated.2) Agilent OmniBER 719. This bit of equipment I never once saw powered on during my 8+ years there. It sat unloved under the bench together with another almost identical device.First time I've ever seen it powered up:It has quite a few connectors down one side, and even a floppy disk drive!Options fitted:Again, I believe this to be fully working. Both items are obviously for very niche markets. Anyone used either ? Know much about them ?

author: MarkPalmer
author_rank: Regular Contributor
timestamp: September 18, 2014, 04:02:01 pm
content: The curve tracer you'll have no trouble unloading at all, plenty of guys drool and go all ga-ga over those things, even really vintage ones. That Tek is somewhat "newer," so to say.The Agilent 719 is one of these specialized computer com test rigs that E-Bay is flooded with and they seem to be worth more for internal parts than they are for any practical use- just too much of that type of equipment on the used market virtually no one wants.-Mark-

author: timb
author_rank: Super Contributor
timestamp: September 18, 2014, 04:09:20 pm
content: I'd be very interested in that Curve Tracer if you're in the US and willing to ship? Okay if I send a PM?Sent from my Smartphone

author: biot
author_rank: Regular Contributor
timestamp: September 18, 2014, 04:11:58 pm
content: Quote from: Codemonkey on September 18, 2014, 03:23:11 pmThis would have been hot stuff 10-15 years ago. It's used for analyzing problems with long-distance telco lines, in this case optical fiber up to 2.5Gb/s. However these days people tend to throw ethernet on everything, and of course 2.5Gb/s isn't all that much anymore (in telco land at least).So I can't really see it being very useful.

author: madires
author_rank: Super Contributor
timestamp: September 18, 2014, 04:28:39 pm
content: Quote from: biot on September 18, 2014, 04:11:58 pmThat line tester is fitted with a STM-1 SM (single mode fiber) card and supports ATM and POS (Packet Over Sonet). Nothing fancy and totally outdated. My guess is that the tester is 15+ years old.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 18, 2014, 06:48:45 pm
content: Quote from: MarkPalmer on September 18, 2014, 04:02:01 pmMe being one of the drooling guys.Sigh. Too bad that although I do have cash at the moment, it's all going to go on ticking things off a list. And a curve tracer isn't urgent enough to be on that list. Sob.But yeah, you'll have nooooooo trouble selling that.

author: SeanB
author_rank: Super Contributor
timestamp: September 18, 2014, 07:07:44 pm
content: Would love the curve tracer as well, but postage from UK to ZA or even NZ would be bleeding expensive. As it is 37kg it has to be sent courier service, limit for postage to NZ is 20kg. Double whammy there, you get to pay to send it along with paying to get it.

author: MadTux
author_rank: Frequent Contributor
timestamp: September 18, 2014, 07:23:47 pm
content: That Tek 370 high power curve tracer can yield several 1000€ if sold correctly (e.g. shown to be fully functional and displaying traces of transistors). Shipping to mainland europe isn't that expensive, so I would really like to buy it, in case you decide not to keep it.

author: philpem
author_rank: Frequent Contributor
timestamp: September 18, 2014, 07:44:45 pm
content: Quote from: MarkPalmer on September 18, 2014, 04:02:01 pmThe interesting thing about it is the serial number implies it was made in England (the GB serial number prefix). I had no idea Agilent had manufacturing facilities over here -- most of the HP/AGI kit I've seen with "new style" serial numbers has been either US (that one's obvious!) or MY (Malaysia).

author: Codemonkey
author_rank: Regular Contributor
timestamp: September 18, 2014, 08:05:28 pm
content: Interesting comments! The OmniBER is definitely getting on a bit. Was probably used when my employer designed some IP for ASIC's a few years before I joined them. Its sat unused ever since and looks almost new as a result. If I can't sell it, I'll tear it apart and post photos of its inners.As for the curve tracer, sorry, I should have stated I'm in the UK. I wouldn't be interested in shipping overseas, too much hassle and likely very expensive due to size and weight. I appreciate its worth a few quid (did a few eBay searches before bidding!)I'll have to have a read up on it and try and get some nice plots displayed, should keep me busy for a bit! I found a website with a manual so that's a start.I also got a few other items, one of which is a Eurostat TOM600 Tera ohm meter which I believe is for testing anti static floors etc. It comes with 2 big heavy electrodes that are placed on the surface to test. Looks like its never been out of its little carry case.

author: Excavatoree
author_rank: Frequent Contributor
timestamp: September 18, 2014, 08:16:55 pm
content: Quote from: TerraHertz on September 18, 2014, 06:48:45 pmI'm another. Although, with a 577 and two 575s, (Jeri Elsworth approved) I couldn't justify it even if the overseas shipping wasn't prohibitive.

author: baljemmett
author_rank: Unknown
timestamp: September 18, 2014, 08:49:20 pm
content: Quote from: philpem on September 18, 2014, 07:44:45 pmMaybe not made in England specifically - I think they only have sales and support offices somewhere Bracknell/Reading way - but they do have a R&D and manufacturing facility near Edinburgh. We might find that prefix needs to be crossed out in the morning

author: coppice
author_rank: Super Contributor
timestamp: September 19, 2014, 03:28:52 am
content: Quote from: philpem on September 18, 2014, 07:44:45 pmHP used to have a lot of R&D and manufacturing in the UK. Their canteens were famous for being the only works canteens in the UK that served actual food.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: September 19, 2014, 05:17:52 am
content: Quote from: Codemonkey on September 18, 2014, 08:05:28 pmI might be interested in the OmniBER, of course depending on your asking price. Send me a PM.QuoteWhat hassle? Aside from the shipping costs (which are paid by the buyer anyways so not really your problem!) there is*no*difference wether you ship inside the UK or abroad (you have to package well anyways no matter where the parcel goes to). Done that an uncountable amount of times.Shipping costs to abroad are also usually very reasonable with services like Interparcel which gets discounts with shipping providers like UPS.

author: EEVblog
author_rank: Unknown
timestamp: September 19, 2014, 06:03:08 am
content: I've wanted a curve tracer for a long time, you lucky bastard! Rare as hens teeth here.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 19, 2014, 08:16:37 am
content: Codemonkey, please do mention how much you end up selling that curve tracer for.Just so I know exactly how much to cry.

author: tggzzz
author_rank: Super Contributor
timestamp: September 19, 2014, 10:56:01 am
content: Quote from: coppice on September 19, 2014, 03:28:52 amAt one time in Bristol, the canteen would occasionally serve frogs legs (nice, like chicken) and suckling pig, courtesy of a French chef.And then you went to HP Grenoble, and found the canteen had racks red wine and the food included fresh oysters. Wasn't worth going out to a restuarant!

author: Codemonkey
author_rank: Regular Contributor
timestamp: September 19, 2014, 03:46:22 pm
content: I'm genuinely interested in what you would all use the curve tracer for ? Matching transistors ? What makes them so desirable ?If/when I sell it I'll be sure to update this thread and post the sale price ;-)

author: MCCSolutions
author_rank: Contributor
timestamp: September 19, 2014, 07:37:19 pm
content: I would get rid of that OTDR ASAP because it will serve as a expensive book weight soon. I mean single mode fiber is not going away but between the new multiplexing and etherent integration for SONET systems it will be obsolete. I have a similar one at work and it never gets used on the SONET because we have T-Bird ones now that support the modern SONET and ATM systems....

author: Excavatoree
author_rank: Frequent Contributor
timestamp: September 19, 2014, 08:21:26 pm
content: Quote from: Codemonkey on September 19, 2014, 03:46:22 pmI'm sure someone will add to/correct this, but I've found that curve tracers are used for:1. Quick check of diodes and transistors - These curve tracers are overkill for that application, most "troubleshooting" curve tracers, such as the huntron tracker, only use two leads and display the v-i characteristics of one transistor junction or diode. A dedicated curve tracer can also be used like this, just don't use the base/gate drive circuits. I built a crude one that I used as a technician at the TV shop.2. Matching components. Visually matching characteristic curves is one way to get two devices with close enough characteristics. I'm not familiar with the high end type like the OP has. I did use a 576 at University for lab circuits that required matched transistors. Many Tek models have two connection point sets, and an A-B switch so two devices can be compared.3. I've used mine to evaluate diodes, and determine the best tradeoff between light output and current consumption. It's a quick and dirty variable (swept) power source with many different series resistors and graphic representation of voltage and current. (looks like the OPs has digital read-outs as well. I have to count spaces on my 575)

author: MarkPalmer
author_rank: Regular Contributor
timestamp: September 19, 2014, 08:25:20 pm
content: Quote from: Codemonkey on September 19, 2014, 03:46:22 pmCurve tracers are popular mostly among the audio crowd. They will use them to match output transistors, and/or they make modified jigs to use them to match vacuum tubes. Ones like yours are very comprehensive for the task. I have a Peak/Atlas DCA75 semiconductor tester that does "poor man's" curve tracing through software, but one big advantage to it is that it goes in the drawer when I'm not using it rather than needing half the shop for it to take residence in-Mark-

author: Codemonkey
author_rank: Regular Contributor
timestamp: September 20, 2014, 08:06:50 am
content: Wuerstchenhund, you have a pm!

author: Codemonkey
author_rank: Regular Contributor
timestamp: September 20, 2014, 02:02:01 pm
content: Had a chance to play with the curve tracer today. Fortunately the user manual has some handy step by step instructions for getting you going, so I followed a few of them to check all is working:First of all is to insert a 1K resistor and show the V/I characteristics for that which results in the following:So, with 1V per horiziontal division and 1mA per vertical division, R=V/I = 5V/5mA = 1000ohms, looks good so far!Next is to insert a silicon diode (I used a 1N4148)Then twiddle the knobs and dials to generate a nice curve showing the forward voltage characteristics which resulted in this:Looks pretty much what you would expect with the diode starting to conduct at about 600mV, so next we move on to a Zener diode (8.2V in this case) and choose an ac "collector voltage" to show both forward and reverse bias characteristics which resulted in this:0V is at the centre of the display, forward biased is to the right, reverse bias to the left. Can clearly see the reverse breakdown voltage of around 8V, all good so far!Next is to have a go with an NPN transistor, in this case a BCU81. Initially I ended up with this:Unfortunately its not really comparable to the curves shown in the datasheet, so I fiddled a bit more and eventually ended up with this:which when compared with the datasheet curves for collector current vs collector-emitter voltage:Each curve represents a 1mA increase in base current, so looking at the 3rd trace from the bottom which represents a base current of 2mA (the very bottom one is 0mA), it shows a collector current of just over 800mA at Vce=1V, looks like a pretty close match to the datasheet! I didn't go for the full 5A collector current since its a quite small TO92 package which I suspect would pop pretty quickly when dissipating up to 5W without any heatsinking!All in all, its a pretty impressive bit of kit. Capable of generating +/- 2000V for the collector voltage, I'm guessing its pretty easy to let the magic smoke out of any DUT if not careful

author: David Hess
author_rank: Super Contributor
timestamp: September 27, 2014, 01:40:32 pm
content: Quote from: Excavatoree on September 18, 2014, 08:16:55 pmI just have a Tektronix 7CT1N. *cries*Quote from: Codemonkey on September 19, 2014, 03:46:22 pmI usually match transistors based on Vbe or hfe at a specific current which just takes a power supply and voltmeter.The only significant thing I have used a curve tracer for is finding obscure problems with transistors and diodes that a simple gain or junction test would miss. Each time this has saved hours to days of troubleshooting time though and it is nice toknowthat the problem is solved.

author: SeanB
author_rank: Super Contributor
timestamp: September 27, 2014, 01:57:52 pm
content: Just looked at the prices on fleabay, and there is the 5CT1N I want, just the price...........Just bought the cheaper kit though, to do it myself like I was promising for a while.

author: Excavatoree
author_rank: Frequent Contributor
timestamp: September 27, 2014, 03:20:48 pm
content: Quote from: Codemonkey on September 20, 2014, 02:02:01 pmFlagged for porn.

author: David Hess
author_rank: Super Contributor
timestamp: September 27, 2014, 03:43:49 pm
content: Quote from: Codemonkey on September 20, 2014, 02:02:01 pmWith apologies to Will Smith, I have got to get me one of these!

author: SeanB
author_rank: Super Contributor
timestamp: September 27, 2014, 04:11:26 pm
content: Search Ebay for curve tracer, and get one. Bit pricey though, and delivery will be a tad expensive, though there is one there for $200, ex NASA or so it is listed. The cheap n Thai ones look more like in my price range.

author: David Hess
author_rank: Super Contributor
timestamp: September 27, 2014, 05:00:43 pm
content: Quote from: SeanB on September 27, 2014, 04:11:26 pmI will survive with my 7CT1N for now. It can switch between polarities easy enough but showing four quadrants instead of one would be nice some of the time. I was not really aware that any real curve tracers supported this.

author: free_electron
author_rank: Super Contributor
timestamp: September 27, 2014, 06:01:06 pm
content: that omniber is worthless.that curve trace on the other hand.. i know people that would cut of one of their balls to get one of those ...especially the 370... a very priceypiece of kit. even used.

author: Codemonkey
author_rank: Regular Contributor
timestamp: September 27, 2014, 07:55:35 pm
content: Lol, well I don't take balls as payment, only cold hard cash

author: Martin.M
author_rank: Frequent Contributor
timestamp: September 28, 2014, 10:23:23 am
content: my oldie is still workingTek 575 mod122c (400V Option). This instrument can load up to 200W to the Transistor.Fore more, there is an additional power extender.I can not: write backward (for Thyristors and tunneldiodes very useful)Tek575 may be the source of a lot of the old data sheets

author: Codemonkey
author_rank: Regular Contributor
timestamp: February 18, 2016, 11:03:01 am
content: Well I forgot to update this, so here goes...I managed to sell both the curve tracer and the "worthless" OmniBER on eBay, both sold as collection only.I got £1200 for the curve tracer. Probably could have got more if I'd been prepared to ship it, but that would have involved me having to get some form of packing crate for it and risk it getting damaged in transit. It went to a fairly local company that already had a number of older Tek curve tracers which they used for testing IGBT packs. The company owner collected it and said they'd be able to automate a bit of the testing since the 370 has GPIB, so at least its getting some use and not just gathering dust somewhere. I paid just £60 for it!I sold the OmniBER to an engineer that uses them to align microwave links. He'd already got one but it had apparently "gone up in smoke". Got £120 and I paid just £6All in, I more than doubled the money I spent on all of the equipment combined, and I still have left the HP 8595E (cost £300) and ESA-L1500A (cost £200) spectrum analysers, as well as a biconical EMC antenna with tripod and a TTi bench PSU, all of which I will be keeping.

author: ralphrmartin
author_rank: Frequent Contributor
timestamp: February 18, 2016, 01:31:37 pm
content: Why do curve tracers go for so much then? Why not get yourself a Peak Atlas DCA75 for just over £100? I suppose it is because it only does low voltage and current, and while that is enough for most things I do, there are always people who like to play with mains and stuff...

author: Codemonkey
author_rank: Regular Contributor
timestamp: February 18, 2016, 02:20:13 pm
content: Peak Atlas DCA75 test signal range +/- 12V, Tektronix 370 +/- 2000VIf you're doing device characterisation and need to be able to specify reliable figures in a datasheet, I guess you have to empty your wallet a bit more!

author: kfnight
author_rank: Regular Contributor
timestamp: February 18, 2016, 10:40:07 pm
content: That curve tracer takes me back to my community college days when I would characterize ~50 BJTs looking for matched pairs to be used in my discrete op-amp circuit.

author: Keysight DanielBogdanoff
author_rank: Unknown
timestamp: February 18, 2016, 11:11:46 pm
content: Quote from: philpem on September 18, 2014, 07:44:45 pmWe have some different manufacturing locations for smaller run-rate products. Not sure if that's the case here or not.

author: rrinker
author_rank: Super Contributor
timestamp: February 18, 2016, 11:55:03 pm
content: Wow, that curve tracer... I've only ever seen one other one before, and it was a much lower end model than that. At my first job we had one, for no real good reason other than when my boss was hired there, he talked them into buying a ton of stuff they didn't really need to do the job at hand, but made for nice test gear. I can't remember the make, this would have been a mid 80's vintage piece, but the most use it got was to do what a simple transistor checker would have been able to do - we had EDM machines with banks of 2N3055 power transistors in parallel to drive the high current outputs. We also had an IC tester that you could throw pretty much any digital IC in, any family, TTL, CMOS, LS-TTL, anything at the time, up to and including most 8 bit microprocessors, and it would identify the chip and then test it.