Test Equipment Anonymous (TEA) group therapy thread

[tautech]

1) Rewire the mains transformer as usual to accommodate for the higher line voltage we get these days, so as not to over-stress the device and risk a failure later down the line (pun) because of that, in the long term.

2) Remove the hard wired power cord (that's not original anyway). I hate hard wired power cords, they drive me nuts. Will put a socket instead. It had one originally anyway, according to the service manual.

Especially when they have been wired incorrectly with the neutral fused. 

[Vince]

No worries ! There is no Neutral or Live to be concerned about over here : you just can't rely on the wiring of the power sockets in the walls, that would be foolish. I understand it's different in some countries like the USA where they like to enforce the wiring more than we care to do over here, and plugs are even "keyed", you can insert the plug only one way. No such plug over here.

If you have to bet your life on Neutral / Live being on a particular colour wire at the end of a power cable, then you might as well play russian roulette, it's stupid... It's like looking at a RIFA up close, hoping it does not explode in your face, because "it's a SAFETY cap, it's designed NOT to fail " right... right ?!   

[Vince]

Oh forgot : seller was super cool : I noted he had a few old databooks on a shelf... he said hey, take them if you want !

So I got some old paper... I just love old databooks.

When the internet collapses and we can't download datasheet in a couple clicks... I won't be totally clueless about at least some components !   

I have 5 books. Motorola, TI and RCA.

Motorola is actually a 3 volume book :
- Volume 1 : " EIA registered type numbers. 1N5000 and 2N5000 "
- Volume 2 : " EIA registered type numbers. 1N5000 and 2N5000 and 3N.... and 4N.... "
- Volume 3 : " Motorola Non-Registered Type Numbers ".

Texas Instruments : " The Power Semiconductor Databook for design engineers "

RCA : " Power devices : power transistors, TRIACs, SCR's. ".

[tautech]

The TI & RCA copies make me jealous. Good scores ! 

[Neomys Sapiens]

The third volume of the Motorola Databook should have all those MPSA- and related types!

[EggertEnjoyer123]

After comparing the HP 8566 schematics against the HP 86290, I think I finally found why my phase noise sucked.
The HP 8566 schematic has two capacitors and a resistor in the YTO circuit, and it was labeled "Coil Damping Network". My 86290 does not have that. I just bodged in the same values as found in the HP 8566, and my phase noise is significantly better now. I'm still able to measure the phase noise with the spectrum analyzer, which is not great, but we're getting there...

You can also figure out what the bandwidth of the PLL is that I'm using. The "flat area" on the noise spectrum seems to be around 50-60 kHz wide, which is the loop bandwidth I'm using.
 

[Robert763]

No worries ! There is no Neutral or Live to be concerned about over here : you just can't rely on the wiring of the power sockets in the walls, that would be foolish. I understand it's different in some countries like the USA where they like to enforce the wiring more than we care to do over here, and plugs are even "keyed", you can insert the plug only one way. No such plug over here.

If you have to bet your life on Neutral / Live being on a particular colour wire at the end of a power cable, then you might as well play russian roulette, it's stupid... It's like looking at a RIFA up close, hoping it does not explode in your face, because "it's a SAFETY cap, it's designed NOT to fail " right... right ?!   

There are very few countries now that do not requiew polarised mains connectors. Even North America has made the change, even two pin plugs. There are exaceptions for some items to have non-polarised plugs (double insulated, sealed). but the outlet is polarised. Even if the plug is non polarised if the cable is colour coded then the live  & neutral connections inside the equipment  should follow the conventions.
This particular error is probably rooted in the odd North American convention of using black for the live (line) conductor.
While the crossed connection is only an additional hazard in conjunction with another fault or during servicing there is no reason not to wire it correctly. Which I'm sure you will do when you fit the inlet connector.

Robert.
 

[TERRA Operative]

Japan is another country that does not have polarised plugs, even though the sockets are polarised. Go figure.....

[m k]

Define mains connector.

Here fixed wall connections have pretty much always been polarized.
Same with Schuko plug, when you wire one inside is named connections.
Then when you use them both are symmetric and everybody knows that electricity goes through both wires.

I'd say that blind fate is much more dangerous.
But most dangerous is still, despite the system, that one DIY guru who knows just enough to be dangerous to self and others.

Few years ago a plumber was electrocuted to death.
He used wall powered and metal cased tools from toilet light chassis socket that had live wire zeroed to PE.
Inhabitant had survived with luck and using only double protected Europlug devices.

[Vince]

No worries ! There is no Neutral or Live to be concerned about over here : you just can't rely on the wiring of the power sockets in the walls, that would be foolish. I understand it's different in some countries like the USA where they like to enforce the wiring more than we care to do over here, and plugs are even "keyed", you can insert the plug only one way. No such plug over here.

If you have to bet your life on Neutral / Live being on a particular colour wire at the end of a power cable, then you might as well play russian roulette, it's stupid... It's like looking at a RIFA up close, hoping it does not explode in your face, because "it's a SAFETY cap, it's designed NOT to fail " right... right ?!   

There are very few countries now that do not requiew polarised mains connectors. Even North America has made the change, even two pin plugs. There are exaceptions for some items to have non-polarised plugs (double insulated, sealed). but the outlet is polarised. Even if the plug is non polarised if the cable is colour coded then the live  & neutral connections inside the equipment  should follow the conventions.
This particular error is probably rooted in the odd North American convention of using black for the live (line) conductor.
While the crossed connection is only an additional hazard in conjunction with another fault or during servicing there is no reason not to wire it correctly. Which I'm sure you will do when you fit the inlet connector.

Robert.

OK Robert, I will make a note somewhere... to wire the brown/live wire to the fuse/switch...

Maybe then, it would be an idea to use a 3 prong socket even on TE that don't have one originally (just not actually connecting the earth wire inside the TE), this way the wall side plug of the cable can only be inserted the correct way around in the wall socket, unlike 2 prong plugs that can go both ways ?!
Well, all the ancient TE I restore has a metallic cabinet anyway, so they are earthed most of the time... except all of the Metrix gear that is 100% metal cabinet but never has an earthed cable... 

[Vince]

The TI & RCA copies make me jealous. Good scores ! 

OK, after a good night of sleep...I have now spent an hour looking more closely at these books.

The TI one is indeed excellent. As the title on hte cover suggests, it's not a dumb/dry databook with datasheet and only that, from the first page to the last (like the Motorola 3 volumes do, for example).
No, the TI book has several interesting chapers at the beginning, and also a couple at the end, that aim at making this book a practical guide, to help engineers quickly find what they need.
There is a little glossary of the many terms used in the datasheets, to explain what they actually mean, rahter than merely saying what the acronym means. There is a cross reference index that give you old part numbers and with what more modern part you might replace them with.
There actual pictures of the of all the packages types. There are  detailed information and drawings about the mounting H/W required for every package type.
There are quick/easy selection guides to give you an overview of what parts you could use depending on the type of application you need.
There are details about the various manufacturing processes TI uses, there respective advantages and disadvantages.
etc....

AND, it covers both Germanium and Silicion parts, so it's gold mine to  help me restore my vintage Tek this and that.

The RCA one is similar, though not as complete as the TI one. It's also made of cheap / crap quality paper.. thick pages that feel like sand paper and are heavily yellowed. The TI and Motorola in comparison, despite being just as old, 50 years or so, look brand new : thin, smooth to the touch, sparkling white sheets.
BUT... the RCA book has one huge, massive quality : there is cross index that maps RCA cryptic part  number, to standard part numbers !
This alone make this book absolutely priceless, for every time I searched for an RCA part number on-line for some components I slavaged.. I could never, never.. NEVER find information on it, never mind a datasheet ! So to the bin the parts always went as a consequence !

Now, I won't bin them immediately... I will first look them up in this book see if I may find them...

The third volume of the Motorola Databook should have all those MPSA- and related types!

The Motorola books alos cover lots of Germanium stuff so again veru useful for my old TE restorations.
third volume indeed covers the MPSA prefixes, but not very much at all, only 11 parts, 30 pages or so, our of almost 1,500 pages !
There are many, many different 'Mxxxx' prefixes in this book.
so I guess 'M' just stands for 'Motorola' (surprise surprise), and the following letters are used to describe what kind of part it is.
They don't give a glossary of what prefix means what, mind you, that would be too kind and thoughtful of Motorola... but flicking through the page one can figure out for himself. Sometimes, just sometimes, there is some logic in the letters they used.

First, transistors were all Germanium, and prefix was just 'MP'.
Then Silicon appeared and they prefixed these with 'MPS'... 'S' like "silicon" I guess, so that's easy enough to remember.
Then later it looks like  they introduced a new manufacturing process which the called "Annular".
So added they called these MPS-A ... 'A' like annular I guess.
So there you go, what MPSA means, and the history behind it, how cool are old books eh ?! 

So overall all these books are actually super cool and extremely useful to help me with my vintage TE, I am so glad I picked them up !

[Robert763]

It isn't possible to give fixed guidance on replacing mains leads on old equipment. Particularly regarding adding an earth conductor. It depends on the original design.
Generally though any old equipment with exposed metal parts should have a 3 core lead and 3 pin plug with the chassis grounded.

[Vince]

Oh one thing I found interesting while reading these old data books...  about the way they referred to Thyristors and TRIACs.

It appears that they considered "Thryristors" as a broad category which encompassed TRIACs actually !

Yes. What we call "TRIACs" today, they sometimes called TRIACs as well, but also sometimes "Reverse-conducting Thyristors" ! Yes, no kidding.

And what we call "Thyristors" today, they either called them "SCR" as we know, but also "Reverse-blocking Thryristors".

Actually they called SCR and TRIACs "triode" jobbies, because they also made " bi-directional DIODE Thyristors " !
I guess that one is what we would call a DIAC  today or that I also saw called SIDAC I think, in an old SIDEC catalogue.

Oh it's so much fun reading these old books, feels like I have my own personal time machine at home !!!  Let me dig out my slide rules and punch cards 

[tautech]

Before power TRIACs existed 2 parallel but reversed Thyristors were often used and early power TRIACs were known as Alternistors.
Have come across all these when repairing old welders, stick and MIG.

Before solid state welders (SMPS) came into common use electronic power control negated the need for sliding choke control of current and helped reduce weight and portability. A 180A stick welder we had was the first I could lift with one hand, RE schematic attached.

[m k]

It isn't possible to give fixed guidance on replacing mains leads on old equipment. Particularly regarding adding an earth conductor. It depends on the original design.
Generally though any old equipment with exposed metal parts should have a 3 core lead and 3 pin plug with the chassis grounded.

One good example category is old turntables.
Mine is Kenwood and like the name indicates its base is wood, but it still has an AC motor, I guess.

[m k]

I thought I'll put that sophisticated HV power project forward anyway, but it's actually quite difficult.
Some components are not here, like HV capacitors, but surely that is a nuance, maybe not.

Farnell has received LR8 regulators, so it is a first try.
Targeting 450V stuff, 10-20uF is enough, but even that category is very thin.
All but Wurth made ones are from USA and 25€ is added per shipment.

Local dealer don't have LR8s but many capacitors they have, though their motor capacitors are quite highly priced, for Labor MIM replacements are those.
Somehow I don't feel comfortable with these new elcos and that up to 250V thyratron + L + 2xCRC PSU, new ones are too miniature.

RS seems to have a good capacitor selection also.
(CHEMI-CON, Nichicon, Rubycon, Panasonic)
And they also have received some LR8 regulators.
Their total P&P is under 20€, seems to be it then.
They also have some bigger film capacitors that are not motor grade and so much cheaper.
But package size, that is not very supportive, usually many.

And then what,
I forgot that DMM2 power cable again.
Farnell doesn't have it anymore, but maybe RS has.
Now the one in use is from old coffee distiller and it's a bit too stiff.

[factory]

The cable I used for the Advance DMM2 was 2183Y three core 0.5mm² mains cable, grey is out of stock at Farnell, but they have other colours in small amounts, or I could send you some from the roll I have.

David

[m k]

Their web service must have had a hiccup when I last checked.
The whole multicore section was empty, I thought they are pulling the plug.
I think some other easy searches were also empty.
Now it's normal again.

[Ice-Tea]

No, Ice-tea, you don't get to keep these. You sell them as fast as possible to feed your children. They're looking funy at you again lately.

You keep the jank-ass stuff that is kinda functional and that won't fetch a decent price for some reason.

Go on. Open that eBay account. Hush... No tears, they won't help you anyways...

[TERRA Operative]

Sell equipment to feed the children?

More like sell the children to get more equipment...

[Vince]

Today is a good day. Remember I bought this puppy 6 months ago ?

A Rochar DMM, one more Rochar piece of kit in my stable. Only problem is that it's sick and unlike my other Rochar TE, I could not find a manual for it.

Well, there is one now !

Looks like it was uploaded a month ago to this well known (over here anyway) French website, if anyone has one of these instruments as well, here is the link :

https://archives.doctsf.com/documents/feuilleter_document.php?num_doc=115911

It's written in French of course, sorry.

But it's bloody good , 45 freaking pages, and as many Megabytes ! That's quite a lot for such a small and low spec instrument.
Of course it's not as good as a Tek or HP manual but what is ?
By vintage French standard, it is an incredibly good / comprehensive manual.

I now stand a chance of fixing this little guy !! 

[Ice-Tea]

Sell equipment to feed the children?

More like sell the children to get more equipment...

There's no eBay category for that.

I checked.

[TERRA Operative]

Anyone who has any Yokogawa gear, or interest therein, I've just set up a shiny new groups.io for Yokogawa stuff.

https://groups.io/g/Yokogawa-Test-Equipment

Once I figure out payment stuff, I'll upgrade to a plan that allows storage etc to create a bit of a repository of manuals and info etc.



And on that note, I just got myself a Yokogawa 2552 DC Voltage standard, and the add-on 2561 DC Current Unit. Nice... Will match nicely with my Yokogawa 2558 AC Voltage/Current standard. 

[EggertEnjoyer123]

Anyone who has any Yokogawa gear, or interest therein, I've just set up a shiny new groups.io for Yokogawa stuff.

https://groups.io/g/Yokogawa-Test-Equipment

Once I figure out payment stuff, I'll upgrade to a plan that allows storage etc to create a bit of a repository of manuals and info etc.



And on that note, I just got myself a Yokogawa 2552 DC Voltage standard, and the add-on 2561 DC Current Unit. Nice... Will match nicely with my Yokogawa 2558 AC Voltage/Current standard. 

Joined, I have a 8 channel Yokogawa scope that I found in the trash a while back. Nothing wrong with it except for a dead battery.

[m k]

We can't even dive, everything is locked away.

Shops can't give leftovers away either, it's a possible health hazard.