Test Equipment Anonymous (TEA) group therapy thread

[dl6lr]

I think this is the final update for the -hp- 4952A:

I was not satisfied with the Gotek mounting and I wanted to replace the three digit LED with an OLED to indicate not only the number of the disc mounted, but the name.
And I found a Gotek disc drive front (for a game computer) with the same form factor as the Sony drive. So I changed it a little bit and printed a front and a bracket, glued it together, inserted the electronics, the OLED and fitted it to the HP.

[factory]

I know, it's kind of pointless designing something using those KM133ID1 driver ICs, but I would like to use the five I bought (cost $20 including P&P in 2020). The seller I got those post Soviet era (1992 made) ICs from is on holiday till 2031 (for obvious reasons), the only miniature versions available now are the older ones in a ceramic package, with a nice conductive back. 



There are several completely incompatible decoder/driver ICs used in old TE including; the 74141, the HP 1820-0092 and the uLogic 996079.

David

Presumably for better heatsinking..?

Maybe, I guess whatever they were intended for wouldn't be as crammed as an adaptor board & wouldn't need traces running underneath.

David

If it's Soviet era stuff it's probably high current/voltage like low efficiency LEDs, number tubes, don't know if they had anything like Panaplex?

As far as I know those smaller package 133ID1 ICs, are supposed to have the same function as the regular DIP 74141 clones, though there is reference in the link below, that some older soviet clones are actually 7441 clones without blanking for BCD 10-15.

http://www.tube-tester.com/sites/nixie/74141-NDT/74141-NDT.htm

The only Panaplex info I can see on there is for western made types, no soviet clones that I can see.

David

[tggzzz]

Yes, I suppose people are more used to 20ms meaning milliseconds, rather than million samples per second, 20ms/s when it's not an engineery scopey person.

It's no problem if you state the spec correctly where for your Tek it's 1GSa/s.
Minus the full stop of course. 

Strictly speaking you should separate the digits from the units with a space, thus 100 MHz.

No, I don't bother!

It does, however infuriate me that "engineers" think time is measured in units of conductance, i.e. Siemens.

[tautech]

Yes, I suppose people are more used to 20ms meaning milliseconds, rather than million samples per second, 20ms/s when it's not an engineery scopey person.

It's no problem if you state the spec correctly where for your Tek it's 1GSa/s.
Minus the full stop of course. 

Strictly speaking you should separate the digits from the units with a space, thus 100 MHz.

No, I don't bother!

I normally always do for frequency despite spellchecks cough it up as an error although all through documentation you see digits and units with and without spacing which is little more than just laziness of the writer.
But I do muck up K and k too often and need get my shit sorted on that.   

[Brumby]

I've never had a problem with K vs k, but I do have to stop and think when an S is involved.  I was more familiar with that value being a mho.

As for the space between value and units - well, that's something I did not know and hadn't thought too much about ... and with comments like this:

Strictly speaking you should separate the digits from the units with a space, thus 100 MHz.

No, I don't bother!

... I think I'll probably keep muddling along as I have.


I do find mHz catches my eye, though - but, as one learns, it is a valid (and necessary) reference when talking about frequency standards.  Though for some reason, I can handle uHz more easily.

[Dundarave]

I’ve figured out that one of the reasons why I regularly check out this thread is directly related to the pleasurable dopamine hit that I get when I’m successfully able to use a special tool, a piece of test or diagnostic gear, or other bit of hardware/software that turns the impossible fix/design/adaptation task into something possible.  Nothing like having the right tool for the job!

Coming from a background, many years ago, of having to “make do” with crude hacks and tools & “test gear” assembled from cobbled together scrap bits and pieces, the idea, for example, of “having a window” into what a circuit is actually doing (instead of guessing) as with a scope, or being able to capture the voltage of a circuit with the magic of a meter capable of a “hold” measurement, still generates that sense of satisfaction that, I think, might be a distinguishing hallmark of a TEA-person.

Even though I am, after all these years, in a position to be able to buy pretty much whatever I need to do any kind of electronic-related task, that thrill of “having the right tool for the job” never seems to ebb.  I love having test gear, tools, and related equipment, even though my fixit/design days are long gone, except for personal stuff.

So tell me, is the whole TEA-complex thing a result of being deprived of expensive (and even not-so-expensive) test gear when we were young lads and lassies, as I speculate? Is there anyone who’s always had access to all the gear they’ve ever wanted or needed and yet still buys old clunkers on EBay for refurbishing?

Or is this TEA thread really a collection of souls that were damaged as a result of technical tool deprivation at a young age, lol?

[tautech]

So tell me, is the whole TEA-complex thing a result of being deprived of expensive (and even not-so-expensive) test gear when we were young lads and lassies, as I speculate?

Certainly as you can now find the classics you wet dreamed about in your youth for just the price of a night on the town. 

Is there anyone who’s always had access to all the gear they’ve ever wanted or needed and yet still buys old clunkers on EBay for refurbishing?

Few as you do get over fixing the old stuff and all their idiosyncrasies once you get access to modern products.

Or is this TEA thread really a collection of souls that were damaged as a result of technical tool deprivation at a young age, lol?

That's where it starts................................

[Brumby]

Pretty much this ^^^

[Squarewave]

So tell me, is the whole TEA-complex thing a result of being deprived of expensive (and even not-so-expensive) test gear when we were young lads and lassies, as I speculate?

I've seen this asked before, or even mentioned as a comment, but I don't think that's the case, certainly not for all and certainly not for me. Some of us had little to no interest in TE for home projects a long time ago, perhaps because we didn't have the home projects or just simply wasn't interested at the time.

Some of what I do at work does sometimes make me think, I don't want to be doing this at home, so I decided to see where else I could expand my interests and uses, then it spiralled as for some projects, I need this, need that, whilst out searching for stuff, other items come up which I already have some kind of version of, but then as time goes on, interests in collecting old TE for restoration becomes an appealing project for some sitting down indoor activity for when the cold weather comes along. It's also useful for self learning if wanting to learn other things I want to look into.

[Peter_O]

For me it is men sitting round a fire in the evening preparing bows and arrows for the next day's hunt. This love to prepare tools is a question of existence and hard wired into our brain for 10.000s of years.

And its maybe a question of mid life crisis: Above brain is hard wired to control us for 50 years max. Then it is thrown into a situation it is not made for: There are another 30 years of open live ahead, but no appropriate config file preloaded. Our brain takes the best config file it has for that situation: 'puberty.conf'. And - bang - the electronics hobby from 40 years ago combines with the bow and arrow thing above and there I go.   

[TERRA Operative]

On the subject of scopes...

Uh oh. I've started thinking to put the Tek TDS794D on the 'to sell' pile....

It's nice having 2GHz bandwidth on tap (bragging rights), but is a bit restrictive with it's 50ohm DC-coupled only inputs, unless I can get my hands on some P6339A probes for not insane prices...
I think my TDS784D will get me by for most things up to 1GHz, which I haven't really needed to push up to yet.

I got the TDS794D for a decent price as it had memory errors but they are fixed now, so selling it at a profit shouldn't be hard, to then fund more test equipment purchases....


Thoughts?

[tggzzz]

It's nice having 2GHz bandwidth on tap (bragging rights), but is a bit restrictive with it's 50ohm DC-coupled only inputs, unless I can get my hands on some P6339A probes for not insane prices...
I think my TDS784D will get me by for most things up to 1GHz, which I haven't really needed to push up to yet.
Thoughts?

At those frequencies conventional probing is pretty impractical; you need to maintain 50ohms in the DUT.

P6339A is a mere 500MHz BW, and is low impedance at those frequencies. 8pF @ 500MHz => 40ohms (useless!)

HP10020A: 1.5GHz, 500/5000/etc ohm (//<1pF). Fleabay prices £50-100. Tek make similar "low impedance" Z0 resistive divider probes. Or make your own!

[Zenith]

So tell me, is the whole TEA-complex thing a result of being deprived of expensive (and even not-so-expensive) test gear when we were young lads and lassies, as I speculate? Is there anyone who’s always had access to all the gear they’ve ever wanted or needed and yet still buys old clunkers on EBay for refurbishing?

Or is this TEA thread really a collection of souls that were damaged as a result of technical tool deprivation at a young age, lol?

In the 60s when amateur electronics was taking off and magazines started to appear, any sort of oscilloscope was an impossible dream for most amateurs. Yes, I believe being able to get things that used to be so far out of reach, is a part of it. Some of the test gear we pick up now for next to nothing, was the price of a luxury car or a modest house when it was first released. I doubt many people had access to all the test gear they wanted or needed from the start.

There's the interesting part of fixing it. I'd rather buy something that didn't work and fix it, than buy something fully functional. Then there's the frustration of something you cannot fix, or will have to wait until the manual turns up, or a suitable scrap one with the missing parts turns up.

There's an aspect of hunting in it. You have to track these things down and track down the spares. There are bragging rights for finding one thrown out, or paying next to nothing for it.

You can compare it with something like collecting clocks, but there are differences. I doubt many clock collectors didn't have a clock as a kid. I doubt there are many pure collectors of TE who can't fix most of it. A lot of clock collectors are collector/restorers who can make new parts and fix a clock themselves. I'd say someone with a small collection (say 20) antique clocks, is more understandable to the world at large than someone with a similar collection of TE

[Robert763]

I really like the format and user interface of the HP 546xx range. As noted it does cover a wide range of capabilities. One key differentiator is the "MegaZoom" capability.  As a quick guide, without remembering loads of model numbers, if it says MegaZoom on the front panel it will do all you want.

[Squarewave]

You can compare it with something like collecting clocks, but there are differences. I doubt many clock collectors didn't have a clock as a kid. I doubt there are many pure collectors of TE who can't fix most of it. A lot of clock collectors are collector/restorers who can make new parts and fix a clock themselves. I'd say someone with a small collection (say 20) antique clocks, is more understandable to the world at large than someone with a similar collection of TE

Clock collecting, there's another one to get into, plenty of second hand clocks for sale.

[McBryce]

You can compare it with something like collecting clocks, but there are differences. I doubt many clock collectors didn't have a clock as a kid. I doubt there are many pure collectors of TE who can't fix most of it. A lot of clock collectors are collector/restorers who can make new parts and fix a clock themselves. I'd say someone with a small collection (say 20) antique clocks, is more understandable to the world at large than someone with a similar collection of TE

Clock collecting, there's another one to get into, plenty of second hand clocks for sale.

Clock collecting / restoration is a whole new level of pain and frustration. It was my fathers hobby (until his failing eyesight and shaky hands forced him to stop). He often bought old clocks to restore only to find out that a cog or some other (non-standard, non-numbered/named) part was missing and made it impossible to fix.

McBryce.

[Squarewave]

Many restorers work around the clock.

[Neper]

Do clocks count as TE?

Don't bother, I'll see myself out.

[Squarewave]

Do clocks count as TE?

Don't bother, I'll see myself out.

Not necessarily, but they can stand the test of time.

[Neomys Sapiens]

Do clocks count as TE?

Don't bother, I'll see myself out.

They can definitely test your patience when disassembled!

[Zoli]

Do clocks count as TE?

Don't bother, I'll see myself out.

IMO, the test equipment definition: is something which has been built/designed to measure/indicate something. Now, applied this to watches/clocks: if just indicates time it isn't really TE; if it is able to measure to measure time properties it does qualify.
Examples: a clock which display time and does alarm only, is NOT TE, even if is DCF77 controlled; a wristwatch, if it has chronometer function is TE, even if it runs from an ordinary resonator.

[McBryce]

As antique clocks aren't particularly accurate, are antique clock restorers non-time-nut time-nuts?

McBryce.

[Zoli]

As antique clocks aren't particularly accurate, are antique clock restorers non-time-nut time-nuts?

McBryce.

They are clock-nuts  Again, context: scope, accuracy, precision, stability, etc. - all the parameters used to characterize a clock is decisive to qualify a clock as test equipment for the given context.

[factory]

Do clocks count as TE?

Don't bother, I'll see myself out.

Absolutely no idea. 





P.S. anyone got one they don't want?

David

[factory]

I’ve figured out that one of the reasons why I regularly check out this thread is directly related to the pleasurable dopamine hit that I get when I’m successfully able to use a special tool, a piece of test or diagnostic gear, or other bit of hardware/software that turns the impossible fix/design/adaptation task into something possible.  Nothing like having the right tool for the job!

Coming from a background, many years ago, of having to “make do” with crude hacks and tools & “test gear” assembled from cobbled together scrap bits and pieces, the idea, for example, of “having a window” into what a circuit is actually doing (instead of guessing) as with a scope, or being able to capture the voltage of a circuit with the magic of a meter capable of a “hold” measurement, still generates that sense of satisfaction that, I think, might be a distinguishing hallmark of a TEA-person.

Even though I am, after all these years, in a position to be able to buy pretty much whatever I need to do any kind of electronic-related task, that thrill of “having the right tool for the job” never seems to ebb.  I love having test gear, tools, and related equipment, even though my fixit/design days are long gone, except for personal stuff.

So tell me, is the whole TEA-complex thing a result of being deprived of expensive (and even not-so-expensive) test gear when we were young lads and lassies, as I speculate? Is there anyone who’s always had access to all the gear they’ve ever wanted or needed and yet still buys old clunkers on EBay for refurbishing?

Or is this TEA thread really a collection of souls that were damaged as a result of technical tool deprivation at a young age, lol?

Neither, never had any interest in test gear when I was young, but I did start collecting old radios, back when I used to listen to Altantic 252 (LW), I didn't know it at the time but I had ended up with a piece of TE, a Windsor (aka Taylor) 65C signal generator, bought at a car boot sale during a family holiday in North Wales, also have a couple of David Derby Mine ohmmeters, one given to me, the other bought at an autojumble somewhere in Scotland (where many of the radios also came from).


 
Eventually started work and again didn't need my own test gear, most people just brought the odd thing into work to attempt to fix, I wasn't that interested in fixing stuff back then, but eventually I started to find I needed TE at home as well to repair old radios, we already had two AVOs and a Megger my Dad had brought home, when the maintenance job got outsourced.

My real addiction started with a HP 5245L counter, then I wanted an oscilloscope, was looking at the Philips 3055 like we had at work, but they were too expensive at the time, ended up buying what I thought was a small scope a HP 175A*, this sat in the kitchen hallway for a few months as I didn't have the power lead for it. Eventually a Racal 836 counter smoke gen (tants  ), a couple of Venner counters, HP 3310A function gen, Taylor 45A valve tester, etc, followed, downhill all the way from there, the TE soon outnumbered my radio collection.

*I bought a HP 3400A which came with a PH163 power lead, this finally allowed me to test the 175A scope, this was a bit of a disappointment as I found the CRT had gone to air  , took me years to find another CRT for it and now have many more old HP scopes, including several 140A & 175A.

In more recent years, management decided they had no interest in electronic repair & closed the lab, they only retained one bench for a couple of products, this has now declined to just one product. I'm glad I have plenty of TE now, because I now prefer repairing stuff, to buying new unrepairable junk.

David