Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

Yep wanted to use the damn thing tonight as well on an actual project.

Current status:

1. Tektronix 475A - timebase problems. Waiting for repair slot.
2. Tektronix 465 - vertical amp problems. Waiting for repair slot.
3. Tektronix TDS210 - power supply problems. Grr.
4. Tektronix 2235 - HT problems. Waiting for repair slot.

Venn diagram:



Thus I need something not Tek, not old and not Kaputt. 

No, you need to fix the Kaputt's and stop worrying about who's calculator is better. 

I reckon it might just be the normal "other" calculators getting their revenge on RPN calculators and their users 

[Specmaster]

@housedad, congratulations on your win, I've entered but I seldom win anything anyway.

[bd139]

RPNers are people of very few words 

Yes

Or maybe no...... as bd showed... accidently when his example used exactly the same number of keystrokes 

Yes that was indeed a cock up on my part  I am awake now 

The majority of performance benefits come from much more complicated things such as the example bitseeker suggested. But the real power is in the ability to store keystrokes as programs and execute them on the fly. For example The AD8307 power meter calibration I have was done using the calculator's linear regression ability. So the power meter calibration values were loaded into the stats registers while I was actually doing the testing. Then a linreg was applied and the m and b values stored in persistent memory. After that it's trivial to write a program which does the conversion from volts to dBm resulting in:

2.015 XEQ P (this returns the power in dBm for the input voltage 2.015)
XEQ W (this turns it into watts in engineering units)

That saves a whoooooole load of work.

One strike and it's out?, if you're going back to a Rigol DS1054Z again  , fix the TDS210 and keep as a backup because it wont be long before the Rigol goes and you can then get back to your "All the scope I need" TDS210. On the other hand, you can enter the great Keysight giveaway and every day there are 4 scopes being given away.

I've been hammering that keysight giveaway as usual. Nothing yet!

The TDS210 is a very very good scope and certainly is all I need. Alas time isn't friendly and money is at the moment so it's about trading some convenience and the ability to proceed on motivational projects here because it's bust. You can't buy a trustworthy scope from ebay and get it next day.

More from Marc and the Apollo Guidance Computer. Some good HP and Tek pr0n too. 

https://youtu.be/uyxQmb2u6Hk

AGC implementation always fascinated me. It pushed through a number of difficult barriers on the enginering front.

[Specmaster]

Yep, I'm hammering on the keysight giveaway site daily but no joy as yet, but who knows.....

[Ero-Shan]

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?
If the AOS people automatically did the same they entered
  2 * 3 + 1 =
and get the same on any calculator.
Aren't here 2 things conflated?

Like with the editors, I'll add nothing further. About time we end this discussion and let everyone use his or her tools of choice.

[Housedad]

@housedad, congratulations on your win, I've entered but I seldom win anything anyway.

Thank you.    I found out that they also have a show each day on YouTube where they announce the winners.  Apparently mine was on the 11th.   the winners are announced at about 7:22 on the vid.

[bd139]

Do you get an email as well?

[Housedad]

Yes, got an email.  Sent in the forms they requested.   

[med6753]

Yes, got an email.  Sent in the forms they requested.

Yep, so Uncle Sam can get his cut. Unfortunately contest winnings are considered income therefore the IRS comes knocking. 

[Housedad]

Yes, got an email.  Sent in the forms they requested.

Yep, so Uncle Sam can get his cut. Unfortunately contest winnings are considered income therefore the IRS comes knocking. 

Yeah, it sucks, but it is still cheaper than buying one. 

[bd139]

Indeed.

About £232 here for duty, 63% of a DS1054Z local price with VAT.

[med6753]

Indeed.

About £232 here for duty, 63% of a DS1054Z local price with VAT.

At least our .gov hasn't gone that nuts with the duty BS but we do have state sales tax of 6.25% on purchases made WITHIN the state or if the company has an office WITHIN the state. But many states now want to find a way to charge it's residents sales tax on internet purchases.
 
NYS wants to do that but they are slick in other ways. We have a state income tax in additional to the Federal. NYS "assumes" you make internet purchases and based upon your income their is a fixed surcharge on your taxes to cover those purchases. And you can't opt out even if you never made internet purchases.   

[0culus]

Man, daylight savings can go pound sand. I haven't slept since the damn time change.   

[bd139]

@med6753: we have 20% sales tax on everything. Then duty on top if it's imported. There's a massive black market here, and some friggery via Amazon though which gets around that. Then again we don't pay for healthcare 

@0culus: They're getting rid of DST changes in Europe. Hope we get that too. Does me in too.

[tautech]

Man, daylight savings can go pound sand. I haven't slept since the damn time change.   

We've still ~3 weeks of summer DLS before clocks go back an hour and it's been a great summer here......unless you need rain for tanks etc.
https://www.timeanddate.com/time/change/new-zealand/auckland

[0culus]

@ bd There are a few states that don't do it (Arizona is the most famous). I don't live in Arizona. 

@tautech the fall change isn't so bad....it's the spring one that blows. 

[med6753]

@med6753: we have 20% sales tax on everything. Then duty on top if it's imported. There's a massive black market here, and some friggery via Amazon though which gets around that. Then again we don't pay for healthcare 

@0culus: They're getting rid of DST changes in Europe. Hope we get that too. Does me in too.

Wow, that really sucks and I guess I can't complain too much. But they call New York State "Land of Taxes" and I swear if they could figure out how to tax you for taking a shit they would. 

[tautech]

@med6753: we have 20% sales tax on everything. Then duty on top if it's imported. There's a massive black market here, and some friggery via Amazon though which gets around that. Then again we don't pay for healthcare 

@0culus: They're getting rid of DST changes in Europe. Hope we get that too. Does me in too.

Wow, that really sucks and I guess I can't complain too much. But they call New York State "Land of Taxes" and I swear if they could figure out how to tax you for taking a shit they would. 

Well in some places they do.....a toilet pan tax !

[grbk]

RPN fight!

Task one ... solve tggzzz's example:

RPN: <2> <ENTER> <3> <*> <+> (5 keystrokes)
modern casio: <1> <+> <2> <*> <3> <=> (6 keystrokes) Note: older pre VPAM ones will get this wrong.

Task two ... solve this for 4 different values: x^2+3

RPN:
<prgrm> <lbl> <c> <2> <pow> <3> <+> <rtn>
<1> <xeq> <c>
<2> <xeq> <c>
<3> <xeq> <c>
<4> <xeq> <c>

Alg:
Fuck off

Casio:
menu this menu that, fuck around, input, read manual, fire up excel and do it there.

You dropped a <1> in your RPN example, so they're both 6 keystrokes

Bzzzt! You also have to <Enter> the <1>. Otherwise, you'd be starting off with 12 on the stack.

Anyway, 1 + 2 * 3 is kinda boring. Stuff like the following is more fun. Life is good with a stack.

  1 + 2 / 3
----------------
7 / 8 + 2 * 3

<2> <ENTER> <3> <*> <1> <+> gives me 7 with 6 keystrokes. No enter required!

Edit: agreed though; this example is simple enough that it doesn't really show the situations where RPN shines.

[Wolfgang]

RPN fight!

Task one ... solve tggzzz's example:

RPN: <2> <ENTER> <3> <*> <+> (5 keystrokes)
modern casio: <1> <+> <2> <*> <3> <=> (6 keystrokes) Note: older pre VPAM ones will get this wrong.

Task two ... solve this for 4 different values: x^2+3

RPN:
<prgrm> <lbl> <c> <2> <pow> <3> <+> <rtn>
<1> <xeq> <c>
<2> <xeq> <c>
<3> <xeq> <c>
<4> <xeq> <c>

Alg:
Fuck off

Casio:
menu this menu that, fuck around, input, read manual, fire up excel and do it there.

You dropped a <1> in your RPN example, so they're both 6 keystrokes

Bzzzt! You also have to <Enter> the <1>. Otherwise, you'd be starting off with 12 on the stack.

Anyway, 1 + 2 * 3 is kinda boring. Stuff like the following is more fun. Life is good with a stack.

  1 + 2 / 3
----------------
7 / 8 + 2 * 3

<2> <ENTER> <3> <*> <1> <+> gives me 7 with 6 keystrokes. No enter required!

Edit: agreed though; this example is simple enough that it doesn't really show the situations where RPN shines.

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 ? 

[med6753]

Holy shitballs! What is this? 



The 2430 I ordered claiming it powered up but had display issues. So I was going to use it as a parts mule and swap over the dead power supply. But there's a problem. There's nothing wrong with this one. Powers up. Passes all self tests. The only display issue I see is a slight defocusing of the readouts upper left and right corners. Adjusting focus and astig have no real affect. But it's hardly noticeable and perfectly acceptable. So my 2430 just became the parts mule. This guy is good to go. $45 USD plus $22 shipping. A freaking steal. It's missing the bail handle probably because it was rack mounted. No problem...case from the parts mule. And both external trig BNC's are bent. I'm sure I can straighten them out. Now all I have to do is figure out how to use it....it's got a weird GUI.



Unlike some of us in here I have NOT given up on the old SUPERIOR iron.         

[bd139]

LOL that's a winner and a half! A lot of the time when I see something "doesn't power up" or something it usually works and is a worn out or loose fuse or something trivial. But that. That's a special one 

....

And a delivery here. Got the 3478A. Extremely well packaged.  Seems pretty clean. No one has futzed around inside it 

Nice and clean inside. Couple of lurking crusty RIFAs which will get the boot tomorrow (I already have some in stock). Will clean it up.



Dink on the corner and a bit of LCD bleed but you can't see this looking straight on. Hopefully this won't progress. If it does that'll be a project!



Quick test says it agrees on the mark with my 87V on all ranges

Edit: looking at the schematic I might leave them as they're only switching snubbers

[SilverSolder]

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...

[Specmaster]

LOL that's a winner and a half! A lot of the time when I see something "doesn't power up" or something it usually works and is a worn out or loose fuse or something trivial. But that. That's a special one 

....

And a delivery here. Got the 3478A. Extremely well packaged.  Seems pretty clean. No one has futzed around inside it 

Nice and clean inside. Couple of lurking crusty RIFAs which will get the boot tomorrow (I already have some in stock). Will clean it up.



Dink on the corner and a bit of LCD bleed but you can't see this looking straight on. Hopefully this won't progress. If it does that'll be a project!



Quick test says it agrees on the mark with my 87V on all ranges

Edit: looking at the schematic I might leave them as they're only switching snubbers

That looks to be a winner all round then, no need for a calibration if it and the 87V agree, highly unlikely that both are out of calibration. Those caps may only be snubbers, but I did replace them as a precaution on mine, right little bastards they are as well being below the switch. The screen bleed would worry me a bit, although it might not be normally visible and it has taken all of this time to reach its current condition so its not likely to be in your possession long enough to worry you. 

[bd139]

Screen bleed is somewhat exaggerated in that picture due to the angle I was taking the photo at (on my lap). If you look at it straight on it's fine.