Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

I bid on a 3458, but gave up at, IIRC, 40% of the final bid price. I really couldn't justify that since I have a working Solartron 7081 (probably reading ~20ppm high).

I also have a 7 decade Julie Research KVD, and an ESI  KVD with a 3 decade switch + 2 decade potentiometer. The 7081 agrees with the 7 decade KVM to <3ppm. Not bad for 60yo and 30yo equipment

That blue display reminds of my VW Passat, that had lovely blue instrument lighting, uncommon on cars I think.

Given the choice w.r.t. a £100 7081, I'd prefer a Panaplex display, e.g. a £14 Datron 1061 or £40 Solartron 7075. Must try and resurrect the latter, but I'm not holding my breath.

[Specmaster]

I bid on a 3458, but gave up at, IIRC, 40% of the final bid price. I really couldn't justify that since I have a working Solartron 7081 (probably reading ~20ppm high).

I also have a 7 decade Julie Research KVD, and an ESI  KVD with a 3 decade switch + 2 decade potentiometer. The 7081 agrees with the 7 decade KVM to <3ppm. Not bad for 60yo and 30yo equipment

That blue display reminds of my VW Passat, that had lovely blue instrument lighting, uncommon on cars I think.

Given the choice w.r.t. a £100 7081, I'd prefer a Panaplex display, e.g. a £14 Datron 1061 or £40 Solartron 7075. Must try and resurrect the latter, but I'm not holding my breath.

Yes the Panaplex displays are crisp and clean and clear but they are also very hard to get replacements if you ever need them, but those prices £14 and £40 are really good albeit they are not functioning meters so maybe not good after all?

[HalFET]

Only one Weston cell? Pah. I've got 3, from a local school that was closing down. One is from 1949 and is still good, see
https://www.eevblog.com/forum/metrology/poor-man-gets-his-candies-(6x-weston-cells)/msg1338437/#msg1338437
https://entertaininghacks.wordpress.com/2016/12/28/a-weston-standard-cell-an-introduction-to-voltnuttery/#more-852

One use for saturated Weston Cells is to use them as thermometers. Until you can do that you can't consider yourself a voltnut 

As for (DC) calibrators, I'd go for a calibrated voltage source, and then a 7 decade KVD.

Good choise  I know because I have:
4 weston cells in an ovenized  cabinet including all calibration data from new. 
5 calibrators (or more depending the definition)
2 KV dividers
But I do not have the holy grale of voltnutting, an 3458 (hard to confess as a Keithley fan)

I bid on a 3458, but gave up at, IIRC, 40% of the final bid price. I really couldn't justify that since I have a working Solartron 7081 (probably reading ~20ppm high).

I also have a 7 decade Julie Research KVD, and an ESI  KVD with a 3 decade switch + 2 decade potentiometer. The 7081 agrees with the 7 decade KVM to <3ppm. Not bad for 60yo and 30yo equipment

Having played with a few: don't underestimate the Solartron 7081. It might be crusty, and it definitely doesn't look up to the job when you compare it to the HP 3458A. BUT here's a lot of variation between units, and they have to be running for quite a while before the beast is truly let out of its cage. But when it does come out you can (if you get lucky with the unit at hand) have an incredibly low noise floor down into the ridiculous where it's competing with the 3458A on some ranges, just don't expect it to be quick in doing so.

[Specmaster]

Trouble is with those old meters, just like my Fluke 8505A is that they take up a hell of a lot of bench or shelf space which I don't have my 8505A is currently sitting on the floor on its side unused, shame because I love to see those digits although I really do not need that level of accuracy for what I do.

[beanflying]

Please stop discussing high end DMM's and in particular 3458a's my nervous twitchy index finger keeps hovering over the buy it now button on several nice examples already 

It's already going to be a lean Christmas Day as most of my presents to myself have arrived and been unwrapped and played with. So just one more can't hurt

[Specmaster]

Please stop discussing high end DMM's and in particular 3458a's my nervous twitchy index finger keeps hovering over the buy it now button on several nice examples already 

It's already going to be a lean Christmas Day as most of my presents to myself have arrived and been unwrapped and played with. So just one more can't hurt

Its fine, go ahead and click the buy it now button, it won't be delivered until Christmas now so you can call it a New Year present to yourself. 

[beanflying]

Haven't 'yet' think I know a place that has some ex army headphones to suit too 

Road trip 10km from home.....

[beanflying]

Still plenty in stock. $9.50 a set.

[beanflying]

 

[mnementh]

I bid on a 3458, but gave up at, IIRC, 40% of the final bid price. I really couldn't justify that since I have a working Solartron 7081 (probably reading ~20ppm high).

I also have a 7 decade Julie Research KVD, and an ESI  KVD with a 3 decade switch + 2 decade potentiometer. The 7081 agrees with the 7 decade KVM to <3ppm. Not bad for 60yo and 30yo equipment

That blue display reminds of my VW Passat, that had lovely blue instrument lighting, uncommon on cars I think.

Given the choice w.r.t. a £100 7081, I'd prefer a Panaplex display, e.g. a £14 Datron 1061 or £40 Solartron 7075. Must try and resurrect the latter, but I'm not holding my breath.

Just so you know; I can hear you gritting your teeth all the way over here...





In other news... my $31 phone arrived today; turned out to be quite a nice little unit once I brought it back to life. I found the microUSB port had suffered some severe corrosion; as a result, it discharged below the LV cutoff threshold of the BMS board on the LiPo. I had to open it up and "jump start" the cell with my RC Hobby charger; after which I was able to charge it normally. I removed the old port and "MacGyver-fied" it as seen here so I can work on getting it set up the way I like while I wait for the replacement port to arrive in the mail.

I think ol' Doc Brown woulda been proud.


mnem
I have the powaahh!

[Cubdriver]

The Data Precision 1450 DMM I ordered the other day arrived.  Fortunately it is a very light weight device, as this was the second worst ebay packing job I've yet seen - it was literally in the box held in place with a styrofoam egg carton.   






Luckily it made its journey unscathed.




I plugged it in and after some brief looking over, it appears to be working pretty well on DC, and based on a few spot comparisons of resistors between it and the HP 4262A LCR meter.  I haven't checked it on AC or the current ranges yet, but so far I'm happy with it.  It'll go into the queue to be opened up and properly photographed and tested at some point.

The voltage readout of the Kepco seems to be what's a bit 'off', seeing as the DP 1450, the Fairchild 7000 next to it, and a DP 3500 that's up on the shelf above out of view all agreed with one another within a few millivolts, and the Kepco was around a tenth of a volt high.



-Pat

[bitseeker]

Lots of nice toys!

Can those Panaplex segments with non-glowing cruft be cleaned up with a little overdrive like Nixies?

[bd139]

That packaging 

[beanflying]

Eggs are fragile so egg cartons are good for fragile things 

[Cubdriver]

That packaging 

It's eco-friendly.  He recycled, and didn't waste a lot of packing material!      

Eggs are fragile so egg cartons are good for fragile things 

Yeah, that's it!!!  Of course!   

Thankfully, in this case at least it worked.

-Pat

[HalFET]

If you had it double boxed and there was a layer of egg cartons between the boxes that'd be pretty awesome impact protection.

[bitseeker]

Eggs are fragile so egg cartons are good for fragile things 

Haha, I like it!

[Cubdriver]

If you had it double boxed and there was a layer of egg cartons between the boxes that'd be pretty awesome impact protection.

Yes, that would have worked.  I suppose on the bright side I don't have a bunch of packing peanuts to get rid of.  Luckily it wasn't handled by the American Tourister Gorilla along the way.  Perhaps it was cushioned by the high volume of packages in transit this year, and never had too far to fall.

-Pat

[HalFET]

If you had it double boxed and there was a layer of egg cartons between the boxes that'd be pretty awesome impact protection.

Yes, that would have worked.  I suppose on the bright side I don't have a bunch of packing peanuts to get rid of.  Luckily it wasn't handled by the American Tourister Gorilla along the way.  Perhaps it was cushioned by the high volume of packages in transit this year, and never had too far to fall.

-Pat

Imagine if it would have been stuck underneath a badly packaged R&S ZVE 

[tggzzz]

I bid on a 3458, but gave up at, IIRC, 40% of the final bid price. I really couldn't justify that since I have a working Solartron 7081 (probably reading ~20ppm high).

I also have a 7 decade Julie Research KVD, and an ESI  KVD with a 3 decade switch + 2 decade potentiometer. The 7081 agrees with the 7 decade KVM to <3ppm. Not bad for 60yo and 30yo equipment

That blue display reminds of my VW Passat, that had lovely blue instrument lighting, uncommon on cars I think.

Given the choice w.r.t. a £100 7081, I'd prefer a Panaplex display, e.g. a £14 Datron 1061 or £40 Solartron 7075. Must try and resurrect the latter, but I'm not holding my breath.

Yes the Panaplex displays are crisp and clean and clear but they are also very hard to get replacements if you ever need them, but those prices £14 and £40 are really good albeit they are not functioning meters so maybe not good after all?

The 1061 needed a new optocoupler to prevent "noise" in the least significant digit.
The 7075 was working when I got it Not sure whether to resurrect it or break it for the Panaplex plus input lead with expensive Fischer connector.
The 7081 needed cooking for 24 hours, reseating a connector worryingly hard, tweaking the line frequency PLL's centre frequency, and a battery to keep results when power was off. Plus a few months powered on intermittently

All in all no really bad experiences.

[tggzzz]

Having played with a few: don't underestimate the Solartron 7081. It might be crusty, and it definitely doesn't look up to the job when you compare it to the HP 3458A. BUT here's a lot of variation between units, and they have to be running for quite a while before the beast is truly let out of its cage. But when it does come out you can (if you get lucky with the unit at hand) have an incredibly low noise floor down into the ridiculous where it's competing with the 3458A on some ranges, just don't expect it to be quick in doing so.

Yes

Here's the noise floor with a Weston Cell acting as a thermometer. Major division is 1uV ~=1ppm, minor is 100nV

[beanflying]

So what you are saying is I 'need' to buy a Solartron and a HP 

[bd139]

On the subject of voltnuttery, can someone recommend a stable absolute voltage reference IC that is off the shelf? I have a voltage reference which I am slightly suspicious of its authenticity at the moment and it's drifted 2mV in a year which is shit. This is without delving into (a) China imports or (b) a voltnut thread.

I am looking at the LM399 + LT1001 combo at the moment, burn it in for a couple of months, then brow beat someone I know who works in a cal lab to get a reference reading off it.

Only need something I can check a 4.5 digit DMM against. Not measure a nat's fart from space.

[Specmaster]

Only need something I can check a 4.5 digit DMM against. Not measure a nat's fart from space.

Not measure a nat's fart from space., love it 

[tggzzz]

So what you are saying is I 'need' to buy a Solartron and a HP 

(I'm going to be kind, and try some aversion therapy....)

No, that's only the start, e.g.
https://www.flickr.com/photos/anachrocomputer/albums/72157689996528645 (There's an hp3456 in there if you look carefully)
https://www.flickr.com/photos/anachrocomputer/sets/72157681714762216
N.B. not my photos

But I would swap my working 7081 for a working hp3458.