Test Equipment Anonymous (TEA) group therapy thread

[tautech]

All of them 

All 65 ? 

That's not like you. 

[Specmaster]

TDS210 lives! A cap on the secondary side had gone funky. I replaced all of the secondary side ones, from stock fortunately, and it powered up straight away. Also the display is bright again now. Think that cap was loading the bugger down.

Watch cap diameters if you have to do this. I was lucky I had some narrow ones in. I think I bought them to recap this but didn't bother in the end 

Edit: also DS1054Z arriving tomorrow but typically I forgot I had a hospital appointment so will have to go and fetch it from the local TNT depot on friday probably 

So which one will you keep ? 

That is an easy one to answer tautech, initially I expect it will be both of them but possibly further down the line once his projects are built and running and something else becomes a priority, I daresay the Rigol will go because it will yield the biggest return and after all, the TDS210 is not a bad bit of kit at all, especially if the expansion module is sourced and fitted to enable the FFT function. 

[tggzzz]

Just one post regarding calculators.

With a term like 1 + 2 * 3 why do the RPN people naturally do
  2 ENTER 3 * 1 +
obeying the multiplication before addition rule?

They don't. They were taught to 1 enter 2 enter 3 * +

For example the HP35 manual includes...


Of course there are amateurs that neither RTFM nor learn how to use their tools, and that is especially prevalent with softies; FFI see https://thedailywtf.com

[tautech]

TDS210 lives! A cap on the secondary side had gone funky. I replaced all of the secondary side ones, from stock fortunately, and it powered up straight away. Also the display is bright again now. Think that cap was loading the bugger down.

Watch cap diameters if you have to do this. I was lucky I had some narrow ones in. I think I bought them to recap this but didn't bother in the end 

Edit: also DS1054Z arriving tomorrow but typically I forgot I had a hospital appointment so will have to go and fetch it from the local TNT depot on friday probably 

So which one will you keep ? 

That is an easy one to answer tautech, initially I expect it will be both of them but possibly further down the line once his projects are built and running and something else becomes a priority, I daresay the Rigol will go because it will yield the biggest return and after all, the TDS210 is not a bad bit of kit at all, especially if the expansion module is sourced and fitted to enable the FFT function. 

Yeah but only 3 left in the repair queue now which would free enough funds to buy some quite good.

[bitseeker]

This morning, I found this, along with a stack of other test equipment, in a shed about five miles south of here:



I bought the differential amp, a HP6236B, a box full of tektronix 50 ohm BNC terminations, attenuators, calibration fixtures, N type adapters, and RG174 pigtails,



along with a bag on JANX 2N1485 NOS transistors for 240USD.  Apparently it is part of a ex-tek engineer hoard; I am waiting for photos of the other bins.  The DM1855A was last calibrated in 2015, and other than the ding and busted button, appears to be in good working order.

This is how it starts, isn't it? 

More like how it continues. I think you've already gone past the "start" phase.

[tggzzz]

Why should I misuse my brain to rearrange a formula so that it can be processed inward out ?! For a more complex formula, its a lot safer to enter it as it is with the brackets and compute it in a straightforward way. The task of denesting brackets can be done by the computer, why should humans do it ? 

GUI limitations are the main driver, followed by code size. If there are no such GUI limitations, then it makes sense to use a computer.

Famously the Sinclair Scientific does all of its keyboard operations, arithmetic, display driving, and transcendental operations in a program memory that contained only 320 instructions.

[bitseeker]

Just one post regarding calculators.

With a term like 1 + 2 * 3 why do the RPN people naturally do
  2 ENTER 3 * 1 +
obeying the multiplication before addition rule?

They don't. They were taught to 1 enter 2 enter 3 * +

For example the HP35 manual includes...


Of course there are amateurs that neither RTFM nor learn how to use their tools, and that is especially prevalent with softies; FFI see https://thedailywtf.com

Yep, that's what the stack is there for. Of course, in this example, it ends up being one extra keystroke that way, but reducing key presses isn't always the priority.

[med6753]

TDS210 lives! A cap on the secondary side had gone funky. I replaced all of the secondary side ones, from stock fortunately, and it powered up straight away. Also the display is bright again now. Think that cap was loading the bugger down.

Watch cap diameters if you have to do this. I was lucky I had some narrow ones in. I think I bought them to recap this but didn't bother in the end 

Edit: also DS1054Z arriving tomorrow but typically I forgot I had a hospital appointment so will have to go and fetch it from the local TNT depot on friday probably 

Ahem.  See, even the precise and superior old iron needs maintenance and put it off at your own peril. 

[bitseeker]

Yeah, we need periodic maintenance, too...put it off at your own peril.

[tggzzz]

The task of denesting brackets can be done by the computer, why should humans do it ?

Was this method of entry perhaps invented when calculator chips were less powerful than today?  I.e. it might take less memory / less instructions to do the job if there is a "human preprocessor" there...

See some of the details in http://files.righto.com/calculator/sinclair_scientific_simulator.html and be surprised

[bitseeker]

Interesting. Takes a bit of work to get tan(45°) and the result is a bit off (9.9990E-01) due to "manual" radians conversion and limited resolution, but pretty amazing feat.

[bd139]

All of them 

All 65 ? 

That's not like you. 

Well lets say that I have the moral high ground now so if I want scopes up to the ceiling, I'm damn well having them

TDS210 lives! A cap on the secondary side had gone funky. I replaced all of the secondary side ones, from stock fortunately, and it powered up straight away. Also the display is bright again now. Think that cap was loading the bugger down.

Watch cap diameters if you have to do this. I was lucky I had some narrow ones in. I think I bought them to recap this but didn't bother in the end 

Edit: also DS1054Z arriving tomorrow but typically I forgot I had a hospital appointment so will have to go and fetch it from the local TNT depot on friday probably 

Ahem.  See, even the precise and superior old iron needs maintenance and put it off at your own peril. 

Yes. However there's also the opposite end of the spectrum which is "if it ain't broke, don't fix it". A compromise sits somewhere between

Of course there are amateurs that neither RTFM nor learn how to use their tools, and that is especially prevalent with softies; FFI see https://thedailywtf.com

That is true.

However in the example you used, refer to later manuals, particularly the HP 35s one, they recommend that you work from the inner parenthesis outwards. This is advantageous when you find early on where the painful bits of the expression are. Like transfer functions:



Now to commit a sin. The calculator I use most is probably Excel 

[bitseeker]

Now to commit a sin. The calculator I use most is probably Excel 

Me too. (And it's got its own issues!)

[Neomys Sapiens]

@0culus:
Fun aside, about the threads again:
I do not have a specimen of the smaller threaded end now. So if it is this one that fits the probe, try to identify it. It might even be a widely available UNC thread and then we would only have to find a fitting set screw, maybe modify the tip and drill a hole or cut a notch for soldering to it.
Of the larger thread, I have some left. I'll look at them myself.

[tggzzz]

Interesting. Takes a bit of work to get tan(45°) and the result is a bit off (9.9990E-01) due to "manual" radians conversion and limited resolution, but pretty amazing feat.

That's a good result for the Sinclair Scientfic. Sinclair, the master of over optimistic adverts, never claimed it was more accurate than slide rules.

But it was remarkable: <10% of the price of other scientific calculators, and affordable by schoolkids.

[tggzzz]

Now to commit a sin. The calculator I use most is probably Excel 

It isn't a sin. For many jobs it is the appropriate tool.

Having multiple tools in your toolbox plus knowing when to use/avoid each is a characteristic of an educated engineer. CF people that have hammers and denounce screwdrivers as the work of the devil.

[mnementh]

Only Reed-Prince screwdrivers. Those effing things ARE the tools of the Devil.

mnem
And the screws they fit.

[0culus]

@0culus:
Fun aside, about the threads again:
I do not have a specimen of the smaller threaded end now. So if it is this one that fits the probe, try to identify it. It might even be a widely available UNC thread and then we would only have to find a fitting set screw, maybe modify the tip and drill a hole or cut a notch for soldering to it.
Of the larger thread, I have some left. I'll look at them myself.

I'll let you know. The probe is buried in a bin right now, probably next week before I have time to dig it out again.

[tautech]

Ero-Shan's got a magic eye watching us, now.

Sorting through a box of old tubes and stumbled on one I have.
Anyone want it for a project ?

Ordinarily i'd be tempted to say "ME!" but i'm too busy working on my novel or working myself half to death for profit.

Magic eyes are so cool, but I had to resist as well. Too much in the queue! *sigh*

Just for neo, an RCA 6U5 plus base and ~300mm leads

-snip-

Pulled from a then very old valve receiver.....decades ago.
Glass envelope slightly loose in base.
Filament checks OK @ 5.7 ohms

Consider me tempted. No really, i've given everyone else a chance and i got a project in mind (that may or may not take 6 months to get around to).

Parcel on the way and reply PM sent.

GGl'ed your address, wow what a nice quiet bit of MO. 

[neo]

Parcel on the way and reply PM sent.

GGl'ed your address, wow what a nice quiet bit of MO. 

Not sure if you are being sardonic or not. Regardless the Ozarks are their own special kind of heaven.

[beanflying]

Parcel on the way and reply PM sent.

GGl'ed your address, wow what a nice quiet bit of MO. 

Not sure if you are being sardonic or not. Regardless the Ozarks are their own special kind of heaven.

@Tautech watch 'Winters Bone' or rewatch 'Deliverance'

Seriously nice countryside however IRL 

[tautech]

Parcel on the way and reply PM sent.

GGl'ed your address, wow what a nice quiet bit of MO. 

Not sure if you are being sardonic or not. Regardless the Ozarks are their own special kind of heaven.

Only just a little envious as I like the rural lifestyle and all the outdoor pursuits it offers.
Once we were quite rural and no one traveled to work off their properties but alas the town now grows closer each decade. 

[med6753]

All of them 

All 65 ? 

That's not like you. 

Well lets say that I have the moral high ground now so if I want scopes up to the ceiling, I'm damn well having them

I think I'm already there, 8 foot ceilings here. 

Working:

Tek 2465
Tek 2465 DMS
Tek 2430
Tek 465B/DM44
Tek 475A
Tek 7603N
B&K 2120

Parts mules:

Tek 465/DM44
Tek 2430

 

Oops...almost forgot the Siglent SDS 1052DL DSO (working)

[bd139]

It’s the floor I worry about when collecting equipment. I was sitting round a friend’s maisonette years ago and the TV disappeared through the floor 

Where I currently live, the downstairs floor is solid concrete. Joy to 1950’s ex local authority housing. Nuclear bomb and scope proof.

Hmm perhaps I should get a 7704 and matching trolley 

[neo]

Parcel on the way and reply PM sent.

GGl'ed your address, wow what a nice quiet bit of MO. 

Not sure if you are being sardonic or not. Regardless the Ozarks are their own special kind of heaven.

Only just a little envious as I like the rural lifestyle and all the outdoor pursuits it offers.
Once we were quite rural and no one traveled to work off their properties but alas the town now grows closer each decade. 

Yeah, it can be nice. Not too outdoorsy, sadly perhaps, but i sure do love the scenery in spring.

It’s the floor I worry about when collecting equipment. I was sitting round a friend’s maisonette years ago and the TV disappeared through the floor 

Where I currently live, the downstairs floor is solid concrete. Joy to 1950’s ex local authority housing. Nuclear bomb and scope proof.

Hmm perhaps I should get a 7704 and matching trolley 

DO IT!  Neo approves.