Test Equipment Anonymous (TEA) group therapy thread

[Saskia]

Yeah I know that but I was looking for an excuse to buy a DCA55 

Anyway back to the Titillating Transgender Transistor Troubles 

Beam me up Scotty. Even our transistors are going transgender. 

I guess that's why Vince is calling them trannyistors.

[med6753]

You old softy. You just can't bring yourself not to help an oscilloscope in distress.

Well it certainly helps if its a Tektronix of course 

I did hear a rumor that hp made oscilloscopes. 

[Specmaster]

You old softy. You just can't bring yourself not to help an oscilloscope in distress.

Well it certainly helps if its a Tektronix of course 

I did hear a rumor that hp made oscilloscopes. 

Nah, thats not a rumor, I had one, a 1740A, nice machine too

[bd139]

Quick YT to prove I’m not going insane. Excuse the focus and exposure issues. Still have no idea how to do video on the Z50 

[med6753]

Quick YT to prove I’m not going insane. Excuse the focus and exposure issues. Still have no idea how to do video on the Z50 

Miss-marked factory rejects somehow made it into the surplus market? 

[Specmaster]

Quick YT to prove I’m not going insane. Excuse the focus and exposure issues. Still have no idea how to do video on the Z50 

The tab on the metal can is also 180 degrees out, so I reckon one is genuine and the other is a fake from China?

[BU508A]

Yeah it’s weird. It’s definitely NPN. I buzzed out a few with diode tester. All the same. These are TI 1970 stamped ones. Will see if there’s a catalogue on bitsavers…

I suppose it’s a good excuse to buy a DCA55 or something 

Could it be a counterfeit part?

[Ice-Tea]

Rather like it... Has a lot of info on the screen, contrary to some other crap (looking at you, Metrix) that has a single line for your entertainment...

[Specmaster]

@bd139
I've found a few datasheets on the web and they all say that it is PNP?

[bd139]

Yeah it’s weird. It’s definitely NPN. I buzzed out a few with diode tester. All the same. These are TI 1970 stamped ones. Will see if there’s a catalogue on bitsavers…

I suppose it’s a good excuse to buy a DCA55 or something 

Could it be a counterfeit part?

I think this was just a Friday afternoon labelling job and murphy doing his thing to me today by handing me the one duff one to play with . I tested all the others and they are all PNP. Just one part was wrong. It does work quite happily as a dual NPN transistor though!

Obviously you should widlarize any parts which can screw with you later so I chopped the top off with some cable cutters.



Fun fun fun.

[Specmaster]

Rather like it... Has a lot of info on the screen, contrary to some other crap (looking at you, Metrix) that has a single line for your entertainment...

Whats not to like, its a TTi product 

[Robert763]

I finally got the Sieg SX1LP mini mill set up today.
Test equipment used was a Mitutoyo Digimatic DTI. Spindle runout was basically unmeasurable. Not set the gibs or trammed the head yet but some trial cuts on a bit of alloy bar from  scrapped Gamma counter gives a nice finish at least. Next step is to get some mild steel bar and make some clamps for the vice. It looks like it will do everthing I want.

Edit: the ER25 collet chuck is not standard but another purchase from ARC Euro Trade.
well worth the cost compared to morse taper collets. Easier to use and more accurate.

[simba15]

So if there is still interest in TEK 465 there are about 5 or so on GCSurplus.  (with shipping available.)

Hope this doesn't drive the prices up.

[tautech]

@tautech will go for that specialized premix husqvarna certified mix that does cost a bit more but comes without all those pesky additives good for the road but bad for the woods ...

Okay as you wish but can't be bothered with such BS here. I know what works, period !
What model Husky do you have, an Autotune one ?

Don't be bullied by this pollution BS as the little each of us use a saw has zip impact on the environment....whereas if we freeze to death think of all the extra lumber required for our deep sleep box or the gas required to crisp us to cinders. 

If big industry were to do their bit, globally, that would make a massive differance to the enviroment but all time when you have the 2 largest polluters China and the USA doing diddly squod, even if we all had EV cars, we are not going to make a significant differance unless industry does their share. 

Don’t get me started on this Globullshit warming, as the data it’s based on is contrived and one day the world might realise we’ve been sold a pup !   

[tautech]

Road trip today. Decided to rescue the Tek 2235 in this CL ad. I know I'm probably in for mucho aggravation due to their known PSU issues but it will keep me busy. 

Full tear down once I get it.

https://newjersey.craigslist.org/ele/d/sparta-tektronix-mhz-oscilloscope/7510713135.html

Drive safe buddy.
Do take notice on Howardlong’s writings on these. 

[AVGresponding]

I did think about buying something like that and decided that it was more fun to make one. Plus it’ll only cost about 2 quid

Doesn't a typical handheld DMM output precise currents of this nature on various ohms and diode test ranges..? Over an even wider impedance range too, I'll warrant...   

Unfortunately not the handheld ones generally. There’s a crude voltage source and series resistance with the resistor under test. Constant current should not be relied on. The bench meters tend to have current sources but aren’t very portable 

Turns out we're both right. The F87V and the F289 can both give a very stable and accurate 1mA, from 0 to about 2k1, it drops past your 5% mark at around 2k3. This is of course with manual ranging set to lowest ohms range. The Metrix puts out 1mA but drops past 950uA at a bit over 1k5. Brymen 869S, Tek 912, Agilent 1401 all use 340uA on the lowest range. The Fluke 8060 seems to use a different method; the current changes directly in relation to the resistance. Haven't put a battery in the F27 to check that.

Manually ranging the F87V or 289 gives progressive decade divisions of 1mA, and are good to hundreds of k; I'd say they could be used for this purpose. Naturally I'd just take my Agilent U1401B with me, since it can source +/-25mA in 1uA steps...   

[tggzzz]

You old softy. You just can't bring yourself not to help an oscilloscope in distress.

Well it certainly helps if its a Tektronix of course 

I did hear a rumor that hp made oscilloscopes. 

Nah, thats not a rumor, I had one, a 1740A, nice machine too

I knew the Czech refugee that designed the early digitisers, back in the late 80s.

[med6753]

So if there is still interest in TEK 465 there are about 5 or so on GCSurplus.  (with shipping available.)

Hope this doesn't drive the prices up.

No interest from me. I have two 465B's which are superior in function and construction to the original 465. Plus shipping across the border would be a nightmare.

[Zoli]

So if there is still interest in TEK 465 there are about 5 or so on GCSurplus.  (with shipping available.)

Hope this doesn't drive the prices up.

There is one 2465B, too. For those interested: shipping by Purolator from Dartmouth to west coast is ~CAD157, so the rest of Canada should be the same or cheaper.

[25 CPS]

A quick look at the local buy and sell sites:

The HP 400FL listed for $75 that was bought from Value Village for $15 which my offer of $50 for was rejected on is still for sale.  The pictures still show the $14.99 Value Village price tag on it.

The Agilent U1253B that I messaged twice and offered full asking price on but never heard back from the seller is still there.  Several weeks later, I got a friend to offer full asking price and would've bought by proxy if it was me the seller had an issue with for some reason, but the friend never got a reply either.  The 13 week old listing now has additional pictures though. 

Beats me.  The first seller would've been up $50 and the second $400 instead of $0 with their advertisements getting older and generating very little interest from other people, if any.  I don't understand it.

[tggzzz]

...
Beats me.  The first seller would've been up $50 and the second $400 instead of $0 with their advertisements getting older and generating very little interest from other people, if any.  I don't understand it.

Incompetent seller can't be ruled out.

Otherwise they or their family might have experineced an "event", or they might be on holiday. That's events as in the possibly apochyrphal...

[SoundTech-LG]

WAF Improvement Project: FINAL UPDATE



I'm just going to lead with the money shot; it's the one most folk would be interested in, even though for me it represents easily a full work week of semi-skilled labor and ~$150 in tools & supplies (more like $300 if you include the woodworking bench bought primarily for this project) and associated back misery from too much time spent vertical.

Also, it's pretty much the only thing I've been doing for the past week.   For those who are interested in some of the details, read on... 



This is how those pieces of the base all fit together; I had to make new locking wedges as one was missing, and it was no longer deep enough to provide correct clamping thickness anyways. The uprights are screwed to the stanchions on the tabletop with 3/8" x 3" lag bolts.




It's hard to see in the finished surface, but these edges had big chunks broken out and huge scars in the surface from mishandling by a moving company over a decade ago. Insurance claim did pay off, but not nearly enough for professional restoration of this family heirloom... so it became a promise, and finally a Anniversary Present to my loving wife who did wait patiently all that time for me to finally get a round tuit.

Now all those injuries are part of the "character" of the table; its history. This table does have some interesting character to the wood as well; I'm glad I didn't refinish it in the original dark mahogany that hid almost all the grain of the wood.




I have no idea  happened here... these gouges were ~10mm deep, and to my recollection, were not part of the original damage. I suspect adolescent male child messing around with my power tools some time over the decade or so it languished in the garage. 



There are somewhere between eleven and thirteen coats of polyurethane... a whole pint... applied to the tabletop. Most of them were due to "just not right" finish, so were sanded smooth with 320-grit and another coat applied... however, all those mistakes did ultimately yield a lovely deep finish, even with semi-gloss polyurethane.

But all that hard work was rewarded more than enough... watching my wife run hands over her father's table, and a wistful smile followed by "It's beautiful, honey..." *kiss*

The things we do for love.



And here's a little reward for those who plodded through all this: Unearthed during this project was my old TENMA/B&K NTSC pattern generator.

The feature set on this one was unusually advanced back in the day, as it provides both RF modulated output and IF (good for troubleshooting tuners), plus it also provided composite and RGB outputs as well, the latter of which could be abused to serve as VGA input to a computer monitor.

IIRC, there was no processor in this thing; it ran off 2 9V batteries as +/- rails and pretty much all 7400 series logic. I plan to open it up in the near future and post lots of pics as atonement for my horribly selfish behavior here.

Cheers!

mnem
We now return you to your regularly scheduled insanity.

Beautiful!!!  Looks like it would hold a 1950 RCA Oscilloscope perfectly!
What kind of wood is it? I just purchased 2nd hand a 9 foot oval table with drop side leaves, and a set of 6 gorgeous chairs. It was way over 3600 for just the table at a local Antique type furniture shop.
I'v been trying to not pile any scopes on it (yet). It's Cherry wood. Needs some finish work as well.

Great Job!

[mnementh]

Just got some good news. It's A-level results day here. Results through. Eldest got her first university choice so day of celebrations  . She's off to study biochem. No soldering irons there but good luck to her 

Waitaminnit... yer daughter is going into biochem...? 



Why am I imagining this scenario in the near future...? 

mnem
welcome to Jurassic World. 

[Saskia]

and here are ze rezultz from ze bajuvarian djurie:

[mansaxel]

Just got some good news. It's A-level results day here. Results through. Eldest got her first university choice so day of celebrations  . She's off to study biochem. No soldering irons there but good luck to her 

I remember a parallel Dell-pile, a.k.a "supercomputer" (~800 Dell bottom-end 1HE servers with only 1GE interconnects) that was for bioinformatics. It was hosted where I worked, but the trans-university bioinformatics centre was at the other uni in town -- as a division of labour.  As the system was used, its speed was completely determined by the bandwidth-delay conditions between the compute nodes and the other university file servers. Oh, and the quality of the Perl interpreter, because most of the software was Perl scripts. (and neither net nor Perl binary were bad -- IIRC the net was never less than 1GE and always below say 2ms latency which was good in those days. )