Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 836832 times)

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Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2875 on: October 17, 2017, 02:42:38 am »
Yes indeed. Did A level chemistry here and our teacher really didn't give a crap what we took out of the store. That was until we blew the fume cupboard out with picric acid. About 50g of it went off that we were trying to extract to set off on the field. It showered my good friend and accomplice in glass. Good job he had a face shield on. He learned that when he lost half his hair the previous time  :-DD

Tip: never move a shock sensitive explosive by convincing your lab partner that it's ok to scrape it off the drying rack with a spoon.

You have to embrace danger a little bit to be aware of it. This is also why I didn't end up a chemist. They actually left me in a lab full of chemicals once in my summer job between college and university and I must have stolen about 10kg of oxidising agents :D

Never did get my hands on some Toluene.

That little meter is pretty safe compared to the above :D
I always knew you was a bit of a rebel, so normal gunpowder wasn't good enough for you then, you wanted to make some TNT. "You was only supposed to blow the bloody doors off"  :-DD
Who let Murphy in?
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2876 on: October 17, 2017, 02:47:18 am »
Chemistry is boring unless it does something. That did lots of loud things. I think that was the attraction. We only wanted TNT because the synthesis process was a little less dangerous than RDX :D

You'd surely end up in prison if you did this now!

Really I wanted to do play around with stuff in a chemistry lab. This came to an abrupt end when I got caught booking expensive NMR time in that summer job to see if the Kolbe process worked. It did. Also got caught smuggling about 100g of raw aspirin out. Turns out they didn't like that and I didn't get a reference. Whoops!

Electronics was far less dangerous!
« Last Edit: October 17, 2017, 02:52:59 am by bd139 »
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2877 on: October 17, 2017, 03:01:48 am »
Have some help: http://www.eevblog.com/forum/contests/uk-geek-car-boot-sale-(i-e-a-hamfest)-kempton-park-november-5th-10am/  >:D

This is literally 10 minutes up the road from me. I'm screwed.
You guys knock yourselves out there then, it's to far away for me to make it  :phew:
Who let Murphy in?
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2878 on: October 17, 2017, 03:16:57 am »
I was considering more the fact that I will have to explain my purchases when I get home. The first thing coming out of the car will get a raised eyebrow. It's the ones after that...

What would be ideal is a TM500 mainframe because it looks like one thing :-DD
You could always do this :popcorn:
Who let Murphy in?
 

Offline Cubdriver

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2879 on: October 17, 2017, 03:21:35 am »
Yes indeed. Did A level chemistry here and our teacher really didn't give a crap what we took out of the store. That was until we blew the fume cupboard out with picric acid. About 50g of it went off that we were trying to extract to set off on the field. It showered my good friend and accomplice in glass. Good job he had a face shield on. He learned that when he lost half his hair the previous time  :-DD

Tip: never move a shock sensitive explosive by convincing your lab partner that it's ok to scrape it off the drying rack with a spoon.

You have to embrace danger a little bit to be aware of it. This is also why I didn't end up a chemist. They actually left me in a lab full of chemicals once in my summer job between college and university and I must have stolen about 10kg of oxidising agents :D

Never did get my hands on some Toluene.

That little meter is pretty safe compared to the above :D
I always knew you was a bit of a rebel, so normal gunpowder wasn't good enough for you then, you wanted to make some TNT. "You was only supposed to blow the bloody doors off"  :-DD



-Pat
If it jams, force it.  If it breaks, you needed a new one anyway...
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2880 on: October 17, 2017, 03:28:18 am »
I was considering more the fact that I will have to explain my purchases when I get home. The first thing coming out of the car will get a raised eyebrow. It's the ones after that...

What would be ideal is a TM500 mainframe because it looks like one thing :-DD
You could always do this :popcorn:


I've nearly been there. I had a fully stacked Sun SPARCserver 1000E for a desktop for a year until I got fed up of the electricity bill. This was basically a cut down Cray 6400 with less slots. This was tossed in a skip because it was obsolete no less than 4 years after it was purchased for half a million quid. It was replaced by a standard dual pentium rack mount box which was faster. I untossed it from that skip and ran away laughing maniacally, well staggering; it was bloody heavy.

This was about the time I got married so it had to go as well.

Found a video:



Incidentally when I sold it on Yahoo Auctions (remember that?) I only got £190 for it! That's depreciation!
« Last Edit: October 17, 2017, 03:34:42 am by bd139 »
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2881 on: October 17, 2017, 03:40:10 am »
On the other hand it also doubled as house heater  :popcorn:
Who let Murphy in?
 

Offline AF6LJ

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2882 on: October 17, 2017, 06:24:41 am »
It's considerably less bad than some of the kit my father had and he was a professional EE. They didn't do safety back then at all :D
What your father had back then was better built, I have some of that here...
The old gear wasn't built from floor sweepings and, and was designed to a higher standard.
I wouldn't touch one of those HF DMMs if it was the last meter on the planet.
I had one once; I could have crushed the case in my left hand. (I am right handed).
I got rid  of it as soon as I could.
Sue AF6LJ
Test Equipment Addict, And Proud Of It.
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2883 on: October 17, 2017, 06:38:04 am »
Hmm. Live exposed conductors on the probe jacks, no earth, 400v in exposed terminals. I’ll take my suspect cat III rating instead...
 

Online neo

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2884 on: October 17, 2017, 08:05:33 am »
I take all too much pleasure winning and i'm OK with that.  I won uncontested, best feeling i have felt in months.

Now i absolutely must stay clear of ebay before the wallet lynches me.
« Last Edit: October 17, 2017, 08:19:54 am by neo »
A hopeless addict (and slave) to TEA and a firm believer that high frequency is little more than modern hoodoo.
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2885 on: October 17, 2017, 08:30:28 am »
I take all too much pleasure winning and i'm OK with that.  I won uncontested, best feeling i have felt in months.

Now i absolutely must stay clear of ebay before the wallet lynches me.
Congratulations, you got it for a bloody good price as well!  :clap:

It's at times like this that I begin to worry a little bit incase I missed something that was so glaringly obvious to everyone else that they decided not to bid. Then I'm like  :wtf: until it arrives and either confirms my worst fear or I go  :phew: and then start  :-DD but so far I have not really purchased anything that was complete crap so its been great on Ebay for me  :popcorn:
Who let Murphy in?
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2886 on: October 17, 2017, 09:05:08 am »
Shortly after writing about it I came across an ebay-offer of an HP 3437A and won it tonight (with only one arm.. ;))!  :)
The triax 3-lug input connector requires an adapter or a matching cable worth a multiple of the price including shipping I paid. :palm:

Who does think I was lucky because I've got the whole day to look after & bid for TEA-worthy gear doesn't know the whole story, by the way:
I had no success bidding on an agilent 8110A nor on HP 8116A's nor on a differential probe and I was even outbid on a weller PCB holder mounting frame.  |O
Where's the compensation for my aching broken arm..?  :rant:
The time being off for recovery isn't willing to correlate with my supposed time of increased number of bargained test equipment.
Bad for my TEA but good for my bank account.  :-DD

That should have a standard C13 IEC socket on the back; if it doesn't somebelly probably hacked it. A power cable off any old PC should fit; if not, they're cheap on fleaBay.

You've spent enough on test gear for one day; time to spend a little on flowers for the missus. ;)

I would consider it an embarrassment for someone who worked in the electronics field to be seen in the same room with one of those meters.  :palm:

I work in the field, and I had a box full of 'em in my office for about a month (what it took to accumulate 30-40 pieces). HF was having a "One item every day for a month" special; I went to 3 different stores whenever I had a chance and took the coupon with me. When it was all done, I donated the box to my model airfield for noobs who didn't have a meter.

What's the best meter in the world? The one you have WHEN YOU NEED IT.


mnem
"Yes, dear..."
« Last Edit: October 17, 2017, 09:15:19 am by mnementh »
 

Offline bitseeker

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2887 on: October 17, 2017, 09:25:26 am »
I take all too much pleasure winning and i'm OK with that.  I won uncontested, best feeling i have felt in months.

Congrats, neo! Now I'll be waiting in suspense until you report back on how it is in person — after you've swapped those two plugins, of course.
You don't acquire TEA. It acquires you.
 

Offline CalMachine

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2888 on: October 17, 2017, 10:13:46 am »
I picked up an Instrulab 4221 Thermometer.  It's got accuracies of a few PPM!  I'm in the process of refurbing it

Wow, you're in.  >:D

Never heard of an Instrulab 4221. Googled it. Impressive according to the datasheet.  :-+

Yeah, you're going temp-nuts..  :-DD

I'm looking forward to you presenting it here, will you?

Digikey parts arrived today!!  Should be getting to the thermometer here, tonight
All your volts are belong to me
 
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Offline Cubdriver

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2889 on: October 17, 2017, 03:14:20 pm »
After running up against a wall a week or two ago when I realized I didn't have a decent operational power supply capable of driving the recently acquired Lucent rubidium standard, I went off to the 'bay (this will doubtless be shocking to everyone here, I'm sure) and snared a rather rough looking HP 6289A 0-40V, 1.5A variable power supply for a decent price.  It arrived a few days later, and was just as ugly in person as it was in the listing (sporting a nice collection of labels, tape and magic marker, along with a few dents, but, to my delight also with its original HP emblem).

Initial testing showed a dirty voltage control pot, but it began behaving after a few back-and-forth rotations.  The rest seemed to be happy.

I took the panels off and cleaned them up, cleaned out the dust, got the crud and magic marker and stickers off of the front panel, hosed out the controls, hammered out the dents and put it all back together.  A quick check of several of the electrolytics inside showed them to be in good condition, within spec on their values and with good ESR readings.  Pretty good for a 45-plus year old power supply (it appears to have been manufactured in late 1971).  A quick-and-dirty load test (a power resistor I scrounged, but not a particularly high power or low resistance enough one for a good test; I need to dig some more for one better suited) showed no visible ripple on the output when monitored on a scope.

Here is is as it arrived on my doorstep:





And here it is after it's 'spa' visit (hard to believe it's the same one; rest assured that it is):





And finally, posing with the freshly cleaned and reassembled Fluke 8200A (apparently some idiot took a tag off the top right using a chisel :rant:):


I'll connect up the rubidium standard in the next few days and see how it behaves.

Some more photos of the dismantling and cleanup are here: https://pmanning.smugmug.com/Electronics/HP-6289A-0-40V-DC-Power-Supply

-Pat
If it jams, force it.  If it breaks, you needed a new one anyway...
 

Online Vgkid

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2890 on: October 17, 2017, 03:23:44 pm »
Nice job on the cleanup.
Jesus , those are some huge resistors mounted to the back . I wonder what those are for , I haven't looked for a manual.
If you own any North Hills Electronics gear, message me. L&N Fan
 

Offline Cubdriver

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2891 on: October 17, 2017, 03:41:19 pm »
Nice job on the cleanup.
Jesus , those are some huge resistors mounted to the back . I wonder what those are for , I haven't looked for a manual.

They're series resistors which, in combination with Q7 act as sort of a pre-regulator and minimize the power that Q6 (the series pass transistor) must dissipate.  At low output voltages, Q7 is completely off and all the current passes through the resistors, dropping the voltage and lessening the load on Q6.  As the output voltage is increased, Q7 is turned on progressively to bypass the resistors and provide higher voltage at the input to Q6.



-Pat
If it jams, force it.  If it breaks, you needed a new one anyway...
 

Offline bitseeker

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2892 on: October 17, 2017, 05:02:50 pm »
Pat, great job on restoring that supply. Glad to see that it still had its badge! I didn't know that the single-range supplies like yours had pre-regulation. That's really neat.

My first bench power supply was an HP 6200B and it's still running. Unlike your supply, mine has to be switched between 20V and 40V (and can only provide 1.5A in the 20V range). Unfortunately, its serial number plate was missing when I got it, but one of the transistors has a 1979 date code on it. The only problem I've had is with the pilot light's housing (it's separate from the power switch). It's held tight against the face plate with a flat spring retainer on the rear. Earlier this year, the combination of age and stress cracked the plastic housing on the inside, so I've had to replace the retainer with some silicone to both hold it together and retain it.

You don't acquire TEA. It acquires you.
 

Offline Cubdriver

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2893 on: October 17, 2017, 05:39:06 pm »
Thanks!  I was very pleasantly surprised with how well the front panel cleaned up.  Some patient rubbing with denatured alcohol soaked paper towels did an excellent job of removing the black marker, and the knobs cleaned up nicely with a good soaking with Windex wetted paper towels.  The downside is that that usually removes the painted pointers from the knobs.  The voltage ones were pretty easy to redo, as the 'pointer' spot is recessed slightly, so a dab of paint and then a skimming with a toothpick or popsicle stick will clean the excess nicely.  The one used for the meter range switch, on the other hand...  Its pointer is slightly raised, and it was a battle to get the paint on it and clean the excess off under the microscope using toothpick.  I've had good success with that kind of knob in the past, but last night just didn't have the touch - it took about three or four tries, and I'm still not completely happy with it.

A close look showed that the badges are just glued in place, and the two holes are only for some little alignment nubs, not retaining posts as I'd originally thought (but never bothered to actually check), so it's a bit less of a surprise that they're so often missing - probably doesn't take much to wipe one off if the adhesive gets old and brittle as that seems to be all that's holding it on.  (I still want to find a case of NOS ones, nonetheless!!)

I don't have too much experience (yet) with this series, but plan to keep an eye out for some more of them.  There's also a 6024A in the queue; I got it cheap a while back as it seemed to be dead, showing a current limit light whenever it was powered up.  Turns out the current limit pot was set too low, and the voltmeter movement is sticky.  Tweaking the I limit pot up got the current limit light to shut off and voltage to emerge from the terminals, but the voltage meter, she no work.  I plan to take the meter apart in an effort to free it up; failing that I suppose I could put a digital readout in there.  I'd like to keep it as original as possible, though, as it's a 200W supply and the current capabilities drop off as the voltage goes up, and the current limits vs voltage are shown on the meter (and the V vs I ones are shown on the ammeter).  That one maxes out at 10A@20V, sliding down to 3.3A@60V

HP certainly did a lot of creative things to make good, reliable power supplies, didn't they?

-Pat
If it jams, force it.  If it breaks, you needed a new one anyway...
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2894 on: October 17, 2017, 06:05:43 pm »
Those are ridiculously nice power supplies in that series. I had a couple of them many years ago and am constantly on the lookout for some on eBay but they hardly ever show up in Europe.

Got me an Hp 6215A a while ago but it was smashed to bits in the post :(
 

Offline bitseeker

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2895 on: October 17, 2017, 06:19:54 pm »
... the knobs cleaned up nicely with a good soaking with Windex wetted paper towels.  The downside is that that usually removes the painted pointers from the knobs.  The voltage ones were pretty easy to redo, as the 'pointer' spot is recessed slightly, so a dab of paint and then a skimming with a toothpick or popsicle stick will clean the excess nicely.  The one used for the meter range switch, on the other hand...  Its pointer is slightly raised, and it was a battle to get the paint on it and clean the excess off under the microscope using toothpick.  I've had good success with that kind of knob in the past, but last night just didn't have the touch - it took about three or four tries, and I'm still not completely happy with it.

Wow, I'd have never known had you not said anything. It turned out great — worth the effort.

Quote
A close look showed that the badges are just glued in place, and the two holes are only for some little alignment nubs, not retaining posts as I'd originally thought (but never bothered to actually check)...

Heh, I never bothered to check before, either. Well, that does explain all the missing ones.

Quote
There's also a 6024A in the queue ... but the voltage meter, she no work.  I plan to take the meter apart in an effort to free it up; failing that I suppose I could put a digital readout in there.  I'd like to keep it as original as possible, though, as it's a 200W supply and the current capabilities drop off as the voltage goes up, and the current limits vs voltage are shown on the meter (and the V vs I ones are shown on the ammeter).

HP certainly did a lot of creative things to make good, reliable power supplies, didn't they?

Yeah, I like the supplies in that series because of the meters. It was really neat the way they put the available voltage markings on the current meter and vice versa. I've seen it done on some non-HP gear, but it's rather rare. If you do have to go digital, then do the segmented LED as that's what the successors to those supplies had, IIRC.
You don't acquire TEA. It acquires you.
 

Offline Cubdriver

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2896 on: October 17, 2017, 06:20:52 pm »
Those are ridiculously nice power supplies in that series. I had a couple of them many years ago and am constantly on the lookout for some on eBay but they hardly ever show up in Europe.

Got me an Hp 6215A a while ago but it was smashed to bits in the post :(

 |O :palm:

That sucks.  Was it at all salvageable?  (I have one like that too - a 3-D puzzle for some day when I'm bored and feel like playing with glue.  They're nice little supplies, but the enclosures have become somewhat brittle over the years, and they don't appreciate being smashed about.)

I wish shippers would realize that what they're shipping is going to get tossed about like a football while it's in transit, and package it appropriately!  Stuffing something relatively heavy in a box with some crumpled newspaper does NOT qualify as adequate packing.   ::)

-Pat
If it jams, force it.  If it breaks, you needed a new one anyway...
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2897 on: October 17, 2017, 06:34:09 pm »
Unfortunately not. The case was smashed, the meter smashed and the neon disintegrated. It had one layer of bubble wrap around it. If it had a few more it'd be fine. The plastic gets quite brittle but brittle enough to disintegrate to that level if it was well packed.

Then the seller started to be a dick, so I just claimed it.
 

Offline Cubdriver

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2898 on: October 17, 2017, 06:49:56 pm »
Unfortunately not. The case was smashed, the meter smashed and the neon disintegrated. It had one layer of bubble wrap around it. If it had a few more it'd be fine. The plastic gets quite brittle but brittle enough to disintegrate to that level if it was well packed.

Then the seller started to be a dick, so I just claimed it.

Bummer.  :palm:  I hate packaging morons.
 
-Pat
If it jams, force it.  If it breaks, you needed a new one anyway...
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #2899 on: October 17, 2017, 07:00:43 pm »
Me too. I’m a feedback bastard though. Bad packaging and it survives, neutral feedback. Bad packaging and it doesn’t, negative feedback.

If it’s a small value item I won’t bother to claim because the claims process allows the sellers reputation to remain intact if they refund. They could sent a hundred things out that were destroyed and still get 100% positive feedback.

I’ve sent 290 items as a seller.  Not one return and none damaged in transit! It’s not hard. Unless you’re an idiot and idiots don’t deserve a good feedback outcome otherwise what’s the point. Oh filling ebays pockets is the point! :(

Edit: perhaps I should set up an independent site for TEA :)
« Last Edit: October 17, 2017, 07:05:39 pm by bd139 »
 


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