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25 CPS wrote: ↑Sat Aug 03, 2024 6:36 pm
That's it exactly, frustrating, wasteful and silly, just as you said. Unfortunately, when I saw the row of Audio Precisions on the shelf suddenly disappear, I suspected what happened but it was the conversation about investigating this one problem a couple of weeks later that confirmed it.
Big companies can be incredibly bureaucratic and wasteful, apart from the occasional nutter serving as a manager. One place I worked at had staff auctions for equipment that was being disposed of. They were popular, but they were abandoned because there were complaints from people on other sites that it wasn't fair, and it was hard for the accounting system to accept the payments. Eventually the surplus equipment had to be sent to their recycling centre in France, presumably to end up on the French used TE market, or taken home by people in the know.
The other curious thing common to large organisations, was that the department budget had to be all spent and not doing that was a black mark against the manager. A couple of times I was involved in ordering equipment which we had a need for, but what we ordered was totally over the top for our requirements, just to use up the equipment budget.
tggzzz wrote: ↑Sat Aug 03, 2024 4:28 pm
These are nothing without the calibration certificate, since they are calibrators themselves. Not sure where you would go to get this calibrated; probably NPL or PTB in Germany. PTB have been known to turn up at Makerfaires and allow you to connect your stuff to their equipment. I took a voltage source and measured it with an HP3458 that they had calibrated the day before Not sure they would allow you to do a full calibration of this though, even if I could carry it there
Mine is the kind of thing that only very serious metrology labs would have, the best available until Josephson Junctions came along. 4.5 digit calibrators are mere toys by comparison.
I have a sinking feeling that you are slipping into volt nuttery. Fight it or it will end in ruin.
That horse bolted when I became able to use an example of the best voltage standard (until the 70s) as a thermometer.
The (zener) voltage source I took to Hannover to be measured is much more stable, but the Weston Standard Cell has <10% of the noise.
Zenith wrote: ↑Sat Aug 03, 2024 8:45 pm
Big companies can be incredibly bureaucratic and wasteful, apart from the occasional nutter serving as a manager. One place I worked at had staff auctions for equipment that was being disposed of. They were popular, but they were abandoned because there were complaints from people on other sites that it wasn't fair, and it was hard for the accounting system to accept the payments. Eventually the surplus equipment had to be sent to their recycling centre in France, presumably to end up on the French used TE market, or taken home by people in the know.
The other curious thing common to large organisations, was that the department budget had to be all spent and not doing that was a black mark against the manager. A couple of times I was involved in ordering equipment which we had a need for, but what we ordered was totally over the top for our requirements, just to use up the equipment budget.
They did a departmental garage sale, once. It took place on one of my days off and I had a prior commitment so I couldn't go but it was well reviewed from everything I heard so I don't know why it was never repeated.
Using up the budget is the same thing where I work and there's a standing joke about how many times new office chairs can be bought to use up a budget before the end of the fiscal year.
And yet you were considering a 35kg Fluke calibrator. Still only £108
Very lazily and for a much lower price - a fiver - if it was local.
They say that one doesn't work.
Take your chances on a desoldering rape opportunity?...
I have a 3-piece Datron calibrator that I really ought to get to work. Trouble is that not only is there no service manual, there is no operators manual - and it really needs that.
Piece 1 is a 1kV PSU and controller, not working.
Piece 2 is a KVD, full of ~200 matched VH202C foil resistors. Equivalent new price is ~£30 each There's a chain of them for the voltage divider, plus a chain of them to guard the voltage divider. No expense spared!
Piece 3 is a "calibration bridge / lead compensator". Not much concept of what that is nor how to twiddle the 9 pots. (More VHP102s inside )
Pieces 1 and 3 are connected with a spiders web of PTFE leads between uninsulated 4mm binding posts. Interconnections look understandable, but that's unproven.
Pieces 2 and 3 ought to be interconnected, but aren't, and I doubt I'll ever figure out how.
Fault is that the PSU comes on and works a bit, but locks up when attempting to turn on the output.
Shouldn't it have a 4904 attached in order to work?
Very lazily and for a much lower price - a fiver - if it was local.
They say that one doesn't work.
Take your chances on a desoldering rape opportunity?...
I have a 3-piece Datron calibrator that I really ought to get to work. Trouble is that not only is there no service manual, there is no operators manual - and it really needs that.
Piece 1 is a 1kV PSU and controller, not working.
Piece 2 is a KVD, full of ~200 matched VH202C foil resistors. Equivalent new price is ~£30 each There's a chain of them for the voltage divider, plus a chain of them to guard the voltage divider. No expense spared!
Piece 3 is a "calibration bridge / lead compensator". Not much concept of what that is nor how to twiddle the 9 pots. (More VHP102s inside )
Pieces 1 and 3 are connected with a spiders web of PTFE leads between uninsulated 4mm binding posts. Interconnections look understandable, but that's unproven.
Pieces 2 and 3 ought to be interconnected, but aren't, and I doubt I'll ever figure out how.
Fault is that the PSU comes on and works a bit, but locks up when attempting to turn on the output.
Shouldn't it have a 4904 attached in order to work?
The only information I've spotted about a 4904 is an illegible picture I believe it is a 10V reference voltage, and I presume any reference voltage could be used (even 9V, with loss of accuracy )
tggzzz wrote: ↑Mon Aug 05, 2024 11:37 am
The only information I've spotted about a 4904 is an illegible picture I believe it is a 10V reference voltage, and I presume any reference voltage could be used (even 9V, with loss of accuracy )
Indeed, but it might throw an error or lock up if it doesn't see a reference voltage, or one within a specific range
Resurrecting a classic with a twist over the last couple of days.
Back in 2018 I designed a simple little circuit which bounced a ball around a scope screen. This worked nicely. But it wasn't hard enough.
So by the magic of LTspice, we now have a fully discrete version. Granted it's just the opamps are replaced by transistors but it appears to work. I haven't decided if I can be arsed to build it or not yet
Since it uses BJTs and not MOSFETs, the models are sufficiently good that it would probably work - provided all leads are kept short, and possibly with 47ohm resistors in series with the base of any transistor that thinks it might be an emitter follower :)I
Spice MOSFET models are notoriously crap in some operating regions. To get a better match with reality, better macromodels is contain up to 14(!) components.
bd139 wrote: ↑Tue Aug 06, 2024 9:35 pm
We shall see. I expect at least 3 surprise oscillators instead of amplifiers. The circuit will be mulled and carefully tuned over the next few days.
The biggest problem is I don't actually have enough 2n3904's to build it at the moment.
If you'd made it mostly from PNP's instead I could have sent you as many 2N4236's as you wanted!
bd139 wrote: ↑Tue Aug 06, 2024 9:35 pm
We shall see. I expect at least 3 surprise oscillators instead of amplifiers. The circuit will be mulled and carefully tuned over the next few days.
The biggest problem is I don't actually have enough 2n3904's to build it at the moment.
If you'd made it mostly from PNP's instead I could have sent you as many 2N4236's as you wanted!
I'm sure bd is capable of turning the schematic upside down
bd139 wrote: ↑Tue Aug 06, 2024 9:35 pm
We shall see. I expect at least 3 surprise oscillators instead of amplifiers. The circuit will be mulled and carefully tuned over the next few days.
The biggest problem is I don't actually have enough 2n3904's to build it at the moment.
If you'd made it mostly from PNP's instead I could have sent you as many 2N4236's as you wanted!
I'm sure bd is capable of turning the schematic upside down
Based on the availability of large quantities of 2N2907A's for not much money and the relative expense of 2N2222A's this might not be a bad financial decision
Special. Indeed. Here's an alternate link in case the paywall decides you've already used too many free articles this month even if you've never gone on the Toronto Star website before:
25 CPS wrote: ↑Sun Aug 11, 2024 12:46 pm
Do you want to lose your lunch? The Toronto Star publishes a good number of eyerollers but I almost spat my coffee when I saw this headline.
Rod McQueen: ‘Call me Carly’: The moment I knew Hewlett-Packard’s CEO was special
Special. Indeed. Here's an alternate link in case the paywall decides you've already used too many free articles this month even if you've never gone on the Toronto Star website before:
Thanks for providing one of the best "depth perception" examples I've seen!
An example of the clarity of her speaking: when I saw her, people in the audience had to ask what she meant. The words may have meant something to MBAs, but they didn't to engineers.
A more important example: everybody understood and could be guided by the HPWay. Replacing it with the fatuous Way of the Garage was simply a dog marking it's territory. So I suppose it is her legacy
As for the possibility that men didn't like working for a woman, I'll point out that two of the four parts of HP were run by well-designed women. Then there was princess Carly.
Well they're not wrong. She did exactly what she was paid to do: gut the company and turn it into a shite pushing outfit to maximise short term shareholder gains. Perfect CEO according to the sycophant MBA hordes of gremlins.
These people will be judges harshly when it comes down to serious matters.
25 CPS wrote: ↑Sun Aug 11, 2024 12:46 pm
Do you want to lose your lunch? The Toronto Star publishes a good number of eyerollers but I almost spat my coffee when I saw this headline.
Rod McQueen: ‘Call me Carly’: The moment I knew Hewlett-Packard’s CEO was special
Special. Indeed. Here's an alternate link in case the paywall decides you've already used too many free articles this month even if you've never gone on the Toronto Star website before:
Seriously, though... We've all heard the story of how she tried to schmooze Bill Hewlett (by then an invalid in a wheelchair) at a introductory luncheon, who then looked her right in the eye and told his nurse to "Get me the hell out of here!"; I really don't think there's a much more telling account anywhere.
This article, written just around the time I had first gotten involved with HP as a field ASP, paints a much more convoluted story... but still, pretty evident she was all hat and no cattle even then.
Buying a Gulfstream executive jet with all the costs associated with it, and flitting about in it, when the share price was diving and people were being laid off, said much about her.
25 CPS wrote: ↑Sun Aug 11, 2024 12:46 pm
Do you want to lose your lunch? The Toronto Star publishes a good number of eyerollers but I almost spat my coffee when I saw this headline.
Rod McQueen: ‘Call me Carly’: The moment I knew Hewlett-Packard’s CEO was special
Special. Indeed. Here's an alternate link in case the paywall decides you've already used too many free articles this month even if you've never gone on the Toronto Star website before:
mnementh wrote: ↑Sun Aug 11, 2024 8:12 pm
Seriously, though... We've all heard the story of how she tried to schmooze Bill Hewlett (by then an invalid in a wheelchair) at a introductory luncheon, who then looked her right in the eye and told his nurse to "Get me the hell out of here!"; I really don't think there's a much more telling account anywhere.
It wasn't quite as simple as that...
From a plausible source, "Bill & Dave: How Hewlett and Packard Built the World's Greatest Company" by Michael Shawn Malone
Not sure they would allow you to do a full calibration of this though, even if I could carry it there 
