Test Equipment Anonymous (TEA) group therapy thread

[Vince]

Tolérance is -10/+50% ..........

[Vince]

Recapping...

I am on 3.3uF 350V cap. The brand new ones I have, 5 of them, branded " Yaego " (Think I bought them from Reichelt) all measure an ESR of 15 ohms... but the original cap, branded Nichicon, reads only 4 ohms....  am thinking of keeping the old cap ?    .... or at least buy a new one but from a better brand than the Yaego I have. However I have a problem... I checked all 3.3uF/350V caps listed on Farnell website, 10 or so, and none of them have a datasheet that specifies the ESR. They just give tan Phi. Historically, when they specify Phi instead of listing the ESR for every voltage/capacitance combo, it means it's a crappy cheap cap they meant to work only at 60/120Hz to rectify a power supply and that's it.   The types with low ESR, they always specify the ESR for every single value of cap/voltage, at 100kHz or so, not 60Hz....

So I am not too sure what to do with that particular cap. I might leave it in place and just make a note to remember that I didn't replace it. This way if the PSU fails further down the line, I would look at that cap first.

Thoughts ?.....

[factory]

OK had a quick go at the fan motor thign. It's made by Siemen indeed, P/N = 1AD3001-0A

Google does know about it.... it found me two of them on Ebay... used, from old HP gear not Tek, and at 80 and 135 dollars a pop, it's not  for me. 

I've seen similar but not necessarily the same motor in one of my HP 8443A (not used in the older one) and the 8640A & 8640B.

The manual for the HP 8443A gives part no. 3140-0487 1AD20
The NSN lists online give 1AD20 as the Siemens part no. definitely not the same, as I can see the pins are evenly spaced out on the end on the motor.



Not got access to my 8640B manual ATM.

The HP 8640B pdf (prefix 1324A) gives part no. 3140-0490
This is listed as Motor, Elec, Brushless 10VDC 2550 RPM
The NSN lists online give 1AD3001-0A as the Siemens part no. as well as Tek 147-0035-00, as used on lots of Tek scopes, including some (older) 2445/2465.



But a very late HP 8640B pdf (prefix 2520A/Above) gives
(2939A and below) 3160-0453 3100-0453?
(2939A and above) 3160-0497 612
These are both listed as FAN-TBAX 23-CFM 12VDC and are supplied by 12.2VDC nominal according to the circuit diagram.
The NSN lists online give various alternate part numbers, which I can't find any pictures for.

David

[m k]

Demo chips were TMS27C256-1JL.
First bits started flipping after few minutes and majority of bits were flipped in few minutes.
Within few minutes only few stickies were still down, last one flipped after around 7 minutes.
Still blank over night and without extra blanking time.

Still blank after a week.

[m k]

So I am not too sure what to do with that particular cap. I might leave it in place and just make a note to remember that I didn't replace it. This way if the PSU fails further down the line, I would look at that cap first.

Thoughts ?.....

Which one is worse?

[Vince]

So I am not too sure what to do with that particular cap. I might leave it in place and just make a note to remember that I didn't replace it. This way if the PSU fails further down the line, I would look at that cap first.

Thoughts ?.....

Which one is worse?

Is my English that bad ?!  :'(

As I wrote, my new caps measure 15ohms instead of 4 for the old original cap, so the new are much worse than the old. Were it the other way around, Why would I even post about it ? I would have just went for it and replaced that cap...

Now I think of it,  I used htese caps when I recapped my 2467B the other day, and the scope works fine and all voltage rails are good with ripple in spec...  so right there I know that using these lesser brands higher ESR caps, though far from optimal, at the least do'nt cause damage and work well enough for their purpose. Now HOW LONG will it stay that way ? That's an unknown...

That's why I am debating keeping the old, much lower ESR cap in place, or putting a brand new low ESR one but it seems Farnell doesn't have any.

I am trying to check TME to see what they have, but surprise surprise.... their website has now decided to kick me out ! Their website complains that my version of Firefox is too old ?!
Works fine for everything else, what's so special about TME's website ?! 
I just tried with "Chromium", another web browser.... sadly same result. I guess TME don't want my business anymore, shame, sometimes I found them useful.

What the heck. My computer is only 15 years old and I updated the OS / Linux Ubuntu fairly recently, version of April 2016.

I am not upgrading the OS just to fix a one website issue.... not even in your dreams TME...

[factory]

Recapping...

I am on 3.3uF 350V cap. The brand new ones I have, 5 of them, branded " Yaego " (Think I bought them from Reichelt) all measure an ESR of 15 ohms... but the original cap, branded Nichicon, reads only 4 ohms....  am thinking of keep the old cap ?    .... or at least buy a new one but from a better brand. However I have a problem... I checked all such caps from Farnell, 10 or so, and none of them have a datasheet that specifies the ESR. They just give tan Phi. Historically, when they specify Phi instead of listng the ESR for every voltage/capacitance combo, it means it's a crappy cheap cap they meant to work only at 60/120Hz to rectify a power supply and that's it.   The types with low ESR, they specify the ESr for every single value of cap/voltage, at 100kHz or son not 60Hz....

So I am not too sure what to do with that particular cap. I might leave it in place and just make a note to remember that I didn't replace it. This way if the PSU fails further down the line, I would look at that cap first.

Thoughts ?.....

I've compared the four old 3.3uF 350V from my Tek scopes, with some replacements of 3.3uF 400V.

Originals from four scopes, I have two Nippon Chemicon at 3.54uF 6.6Ω, 3.5uF 4.6Ω (leaking from one lead) and two Nichicon 3.73uF 3.3Ω, 3.4uF 3.3Ω.

Replacements are Nichicon UPW series 3.3uF 400V (chosen as the extra would be more useful in higher voltage ratings, for other TE),  I have six left with a 2012 date code.
They measure at 3.02uF, 3.04uf x2, 3uF & 3.08uF all at 3.0Ω and the last is 3.14uF 2.8Ω.


P.S. it looks like the higher voltage UPW caps are a poor seller, Nichicon is discontinuing all rated from 160V to 450V. 

David

[Vince]

OK had a quick go at the fan motor thign. It's made by Siemen indeed, P/N = 1AD3001-0A

Google does know about it.... it found me two of them on Ebay... used, from old HP gear not Tek, and at 80 and 135 dollars a pop, it's not  for me. 

I've seen similar but not necessarily the same motor in one of my HP 8443A (not used in the older one) and the 8640A & 8640B.

The manual for the HP 8443A gives part no. 3140-0487 1AD20
The NSN lists online give 1AD20 as the Siemens part no. definitely not the same, as I can see the pins are evenly spaced out on the end on the motor.

Thanks for taking to research this ! 

Sadly indeed it looks like this motor, though very similar, is not compatible neither mechanically n,or electrically.

I counted 12 pins on the HP motor versus 13 on mine, and the layout of the pins around the circle is different as well.

[factory]

Vince check the third picture again, it's from one of my 8640s, pins are similar to the Tek, haven't got a better picture of that one ATM.
The first two pictures are from a 8443A, definitely wrong as you know, the clamps & fan blades are all separate parts.

David

[m k]

So I am not too sure what to do with that particular cap. I might leave it in place and just make a note to remember that I didn't replace it. This way if the PSU fails further down the line, I would look at that cap first.

Thoughts ?.....

Which one is worse?

Is my English that bad ?!  :'(

As I wrote, my new caps measure 15ohms instead of 4 for the old original cap, so the new are much worse than the old.

Sorry, my bad.

Which situation is worse, the one where old cap fails or the other.

[TERRA Operative]

@Vince
I would be hesitant to use a cap with a higher ESR in a switch mode application. Higher ESR means more internal heat, and with the second tier brand of Yageo, I wouldn't use it... Keep them for a less critical application.
You can always add higher voltages to your search parameters, just make sure it has the same pin pitch, and the physical dimensions aren't to big to fit in the space on the PCB.

Any problem with using Digikey or Mouser? (I can't remember if you mentioned anything before?) They have free shipping over a certain shopping cart value, I've never had a problem with them.

[Vince]

Vince check the third picture again, it's from one of my 8640s, pins are similar to the Tek, haven't got a better picture of that one ATM.
The first two pictures are from a 8443A, definitely wrong as you know, the clamps & fan blades are all separate parts.

David

Oops sorry ! 

Wow same part-number then, that's great.... so how much do you want for it ?! 
The ones on Ebay are out of my league....

[Vince]

@Vince
I would be hesitant to use a cap with a higher ESR in a switch mode application.

I looked at the schematic to try to see if it was seeing  switched / HF voltage or not, but I find the schematic a bit confusing, too complicated for me.... I am not too sure I understand what that particular cap does exactly...

Higher ESR means more internal heat, and with the second tier brand of Yageo, I wouldn't use it... Keep them for a less critical application.
PCB.

Yes, though to be fair and pragmatic, given how little use the scope will get considering its hobby use and it being only one out of many scopes... it could be argued that the cap will die of old age, just sitting, long before it dies of drying out because of its ESR. It kinda mitigates the issue I think....
In any case as I said, I used that cap when I recapped my 2467B, so if really it dies fast.... well I will know about it and report...

You can always add higher voltages to your search parameters

Yes I thought of that shortly before you mentionned it. Indeed 350V is oddball in today's world, whereas 400 and 450V are now extremely common given that they get used all the time in just about every SMPS under the sun. Sadly even when searchin for 400/450 caps, I didn't get taht much more choice, to my dismay, and no low ESR ones. Bummer. I am starting to think somehow the manufacturing of the low ESR one requires some special something that's being hit by the shortage of everything we still suffer from  ?!

Any problem with using Digikey or Mouser? (I can't remember if you mentioned anything before?) They have free shipping over a certain shopping cart value, I've never had a problem with them.

Oh no you triggered me, bad boy ! 

For the 12,845th time.... MouserKey are fantastic, the wides choice and lowest prices, win-win.... IF you live in the US. If not, as you know first hand, you have to  order at least 50 Euros worth of good to get the free shipping and the customs BS be taken care of by them transparently.
So again... same answer as always : I am not wealthy enough to order 50 Euros worth of stuff every time I need a 50 cent cap or this or that.
I don't do enough electroniking either to be able to "pad" the order with other stuff that I might be needing for other projects.

In France /  EU, Farnell is the only major retailer, with a decent choice and decent prices, though much less choice and more expensive than MouserKey. That's why it's my first call always. Then next in line is TME,  but less choice and bit higher prices than Farnell. Then there is Radiospare but not much choice on their consumer-only website, and high prices. I have therefore not ordered anything there for a long time. One day I probably won't even be able to order from Farnell since they don't sell to consumers anymore. They don't take new customers at least. Luckily 20 years ago they still sold to poor souls like me, so they were kind enough to maintain my account. But I am sure one day they will kick me out and I will be in the shit big time.

I've compared the four old 3.3uF 350V from my Tek scopes, with some replacements of 3.3uF 400V.
Originals from four scopes, I have two Nippon Chemicon at 3.54uF 6.6Ω, 3.5uF 4.6Ω (leaking from one lead) and two Nichicon 3.73uF 3.3Ω, 3.4uF 3.3Ω.

Wow ! I am amazed... you kept all the old caps from recapping your 4 24XX ?! 
Thanks for the measurements... 100% in line with what I measured on my own original cap then. It adds up...

Replacements are Nichicon UPW series 3.3uF 400V (chosen as the extra would be more useful in higher voltage ratings, for other TE),  I have six left with a 2012 date code. They measure at 3.02uF, 3.04uf x2, 3uF & 3.08uF all at 3.0Ω and the last is 3.14uF 2.8Ω.
P.S. it looks like the higher voltage UPW caps are a poor seller, Nichicon is discontinuing all rated from 160V to 450V. 

No luck with Farnell and Reichelt. Will try to get a web browser working with TME (in a VM maybe) so I can check there as well.
If I fail to find any seller with OK stuff, would you be willing to part with a couple of your 12 caps ? Should cost me very little if sent in a regular / inconspicuous mail envelope, and no need to bother with customs forms / BS I think.

[TERRA Operative]

Ah yeah, I usually get a Mouserkey cart full every few months, It's a pain to wait...

I can send you small stuff pretty cheaply now Corona is over and postage is returning to normal, so a small box of parts (Think cellphone box to tissue box size or so) sent 'small packet' service is definitely feasable. It won't be the fastest shipping, but it's often surprisingly cheap.

[Vince]

How much would that cost ?
And how much for a 100g or 250g or 500g envelope ?
For small parts an envelope is enough and cheaper than a box I guess.

Glad to hear prices have come down... in a bit we will have to investigate the cost of shipping a BIG box full of old Tek scopes ! 
By slow boat for sure... cheapest option I would guess.
Maybe it would be cheaper, who knows, to send it first to China and then from China to France. Shipping prices to Europe might much cheaper from China rather than direct from Japan ?! Japan being a rich country they probably rip you off. Just a thought...

[Neomys Sapiens]

Oh no you triggered me, bad boy ! 

For the 12,845th time.... MouserKey are fantastic, the wides choice and lowest prices, win-win.... IF you live in the US. If not, as you know first hand, you have to  order at least 50 Euros worth of good to get the free shipping and the customs BS be taken care of by them transparently.
So again... same answer as always : I am not wealthy enough to order 50 Euros worth of stuff every time I need a 50 cent cap or this or that.
I don't do enough electroniking either to be able to "pad" the order with other stuff that I might be needing for other projects.

Just one point: have you tried to order via Mouser Germany? while the 50.-€ minimum order stillholds true, I'm not getting charged with import duties!

[Vince]

That's because the import duties are paid direct by MouserKey for orders from 50 Euros.
There is no "German" or "French" Mouserkey, only websites / fronts. All the goods are stored in the USA so everything has to be imported , Europe or Japan, same deal.

[Neomys Sapiens]

2) While checking my stock of X rated caps, found a brand new RIFA lookalike Kermet cap. It was marked "100nF + 33R ".... I bet that means it comes with a built-in 33 ohms series resistor. So this must be a thing I guess, hence why Tek did. So if they integrated the resistor inside the cap, it's hard to argue that it could be a fusible... that would force you to replace the entire cap rather than just the resistor inside.

Those ready-made R/C combinations are in common use for contact protection, contactor coil snubbers and alleviation of RFI/EMI problems. They are often listed under 'filters' rather than caps or resistors. While a drop of solder and shrink tube yields the same result (provided a suitable cap and resistor are at hand), I consider them useful and like to have an assortment of them on hand.

[Vince]

OK OK....

They were of course listed in the X cap section of whatever website I ordered from, Farnell or TME.

Which means..... that I failed to notice they had this built-in resistor... which means... that I must be more careful from now on when I order X/Y caps ! 

Now that I am aware of it hopefully my brain will keep that in mind...

[m k]

I looked at the schematic to try to see if it was seeing  switched / HF voltage or not, but I find the schematic a bit confusing, too complicated for me.... I am not too sure I understand what that particular cap does exactly...

Same here, so less educated guess.

First line voltage selector is dimming rectified input, if 230V is selected, odd, sort of.
Then T1020 is choking and so is left of T1050 by loading C1050, right of T1050 are secondaries.
But upper side of T1050 is also source for Q1050 that is pushing center of T1060 up and Q1060/1070 are pulling its sides down to REF.

T1050 load is not symmetric, maybe windings neither, so if something is left in lower left part when phase goes down and kickback is more than threshold of CR1050 it start providing T1060 and then *1072 and *1071 parts.
How's that?

[EggertEnjoyer123]

I have an annoying problem.
I obtained an oscilloscope for free. (It was at the Vintage Computer Festival and it was left on a "free" table, so I have no chance of getting ahold of the person who gave it to me).

The problem is that someone mismatched the plugins and mainframe. I have a 182A mainframe, but a 1830A/1840A timebase and amplifier. A 183A mainframe is required for these plugins. (Someone out there probably has a 183A with 1805A and is happy because the newer HP mainframes are backwards compatible). When the scope is turned on, no sweeping occurs because the 182A is missing a +35V rail that the 1830A/40A relies on, among other things (like the fact that the 182A has a lower bandwidth CRT)

I would probably have to find someone with the correct mainframe and convince them to do a swap. Seems annoying. I guess I could hand it off to someone who collects HP scopes who has the correct models. Also I already have 5 other scopes

[BU508A]

@TERRA Operative

May I ask you for a favour?

Dalibor Farny from .cz has designed the so-called H-Tube. This tube is an essential part of a project of the Artist Alfredo Jaar.
My understanding is, that this project will coming to the public, beginning at the 22nd of July 2023.
I tried to find some information about this project but I didn't find anything substantial.
With your japanese connections, could you try to find out more?

What I got so far:
the video from Dalibor: https://youtu.be/7FBVD0Uk0HI
https://niewmedia.com/en/news/010640/
https://www.hiroshima-moca.jp/exhibition/alfredo_jaar

Thanks for your help, much appreciated.

[factory]

I have an annoying problem.
I obtained an oscilloscope for free. (It was at the Vintage Computer Festival and it was left on a "free" table, so I have no chance of getting ahold of the person who gave it to me).

The problem is that someone mismatched the plugins and mainframe. I have a 182A mainframe, but a 1830A/1840A timebase and amplifier. A 183A mainframe is required for these plugins. (Someone out there probably has a 183A with 1805A and is happy because the newer HP mainframes are backwards compatible). When the scope is turned on, no sweeping occurs because the 182A is missing a +35V rail that the 1830A/40A relies on, among other things (like the fact that the 182A has a lower bandwidth CRT)

I would probably have to find someone with the correct mainframe and convince them to do a swap. Seems annoying. I guess I could hand it off to someone who collects HP scopes who has the correct models. Also I already have 5 other scopes

Guessing either the 183A/B/C/D mainframe failed or they wanted to use the larger screen 182A, either way those 1830A/40A are not usable in the 182A.
The 183 series mainframe has switches at the back of the plug-in compartment, these select between the high & regular low bandwidth plug-ins, to match the impedance, the Jan 1970 HP journal covers the 183A/B scope in lots more detail.



With any of these 18x series mainframes in unknown condition, it's recommended to make sure the PSU voltages are correct before inserting the plug-ins. I read somewhere that good working plug-ins can get damaged by a defective mainframe PSU. 

Also you should be able to test the CRT without the plug-ins, using the external sweep input, set the display switch to "EXT" and use the ext input BNC, you should be able to get a line on the CRT, the manual describes this procedure too.

The 182A is the early version of the 182C/T, the CRT in the 182A has external graticule illumination, the later 182C/T has it built into the CRT, making that one longer as a result and impossible to service if the filament blows, well apart from replacing the CRT.

The 100MHz 1805A plug-in is one I don't have, most of these scopes seemed to have the 50MHz, you should have an easier time finding one in the US, along with a 183 series, if you want one of course. 

I don't recommend the SA plug-ins for these, they are horrible, the switches are the nasty ones that fall to bits, along with being a PITA to service, apparently they drift badly when in working order too.
I'm not the only one on here to hate the 18x series SA plug-ins, the older 140/1 series SA is much better.

David

[TERRA Operative]

@TERRA Operative

May I ask you for a favour?

Dalibor Farny from .cz has designed the so-called H-Tube. This tube is an essential part of a project of the Artist Alfredo Jaar.
My understanding is, that this project will coming to the public, beginning at the 22nd of July 2023.
I tried to find some information about this project but I didn't find anything substantial.
With your japanese connections, could you try to find out more?

What I got so far:
the video from Dalibor: https://youtu.be/7FBVD0Uk0HI
https://niewmedia.com/en/news/010640/
https://www.hiroshima-moca.jp/exhibition/alfredo_jaar

Thanks for your help, much appreciated.

Interesting. Hiroshima is quite a way away from me, but I'll see what I can dig up.

[Robert763]

Did some TE fettling this weekend. I'm doing something with a battery at work (can't say what) and need a simulator. That menas at least a two quadrant (source / sink) PSU. Work don't have anything suitable so I went to my store and dug out a old HP 467A amplifier /  PSU. This older (1965 design) bit of TE looks simple but is a DC to 1MHz (Flat to 1MHz, 3dB down at about 7.5MHz into 50R) amplfier and 4 quadrant -20V to + 20V at 0.5A power supply. A single control covers the whole voltage range, no +Ve / -Ve switching. Quite a bit of performance. I've had this for years and never used it. Can't remember where I got it but it had an Atomic Weapons Research Establishment sticker on it. Has isolated BNCs on the rear for input and output rather than usual 4mm binding posts on the front. It's also looking a bit tatty. However powered it up and it's fully working. Ripple and regulation are well within specification at full output a 0 to 100% load change made a <10mV change in output.
So a tidy up and fitting of binding posts was in order. I think it came out quite well. Binding posts are from a scrapped digital telephone test set that was for an obsolete system. No useful TE was harmed.