Test Equipment Anonymous (TEA) group therapy thread

[Robert763]

Re: PP auctions

Someone on the UK vintage radio forum commented that some auction companies, can bid on behalf of the seller and that it is in the terms & conditions, well they were right.

From https://www.ppauctions.com/terms-and-conditions
12. The Auctioneers my divide, combine, add to or withdraw lots and make any catalogue alterations without notice or reason; they shall regulate bidding, accept or reject any bid (at their absolute discretion and without justification) and bid on behalf of the Client, where there is a reserve price or at their authorised discretion.

This certainly explains the unsold lots & bidder with no bidding limit. 

David

That's been standard practice for ever. Used to be called bidding against the back wall. It's a means of not revealing a reserve. Typically the non existent bid is higher than the reserve.
There used to be computer auctions in Ringwood and for 3 auctions a huge lot of mixed printer tractor feed units was "sold". At the third sale a number of "regulars" were told to take whatever they wanted for free. I got a large quantity of steel shafting, toothed belts and pulleys and  few stepper motors. The bin got filled with a lot of plastic.

EDIT: After reading other comments, it not an offence if a reserve is set before the auction (need evidence of this but they don't have t reveal it or tht there is a reserve) AND no one bids above the reserve other than the "back wall".
It is illegal for the auctioneer or seller to bid the price up against another bidder above the reserve or if there is no reserve.
Ebay do (or at least did) check for shill bidding including recording ip addresses. I'd previously used a friends computer to access my ebay account and he got a warning from ebay when he bid on one of my items. H thought he was doing the right thing instead of asking me to close the auction andsell it to him off-ebay.....

In more civilised circles that's know as a "chandelier bit", only used as an initial bid to start things moving if buyers are slow to make an opening bid, it's frowned upon and some would call it unethical. I've never encountered anyone using such bids to outbid an actual bidder to reach a reserve. Every physical auction I've been to a reserve has either been declared to exist at the start of the bidding for a particular lot (but not usually the amount of the reserve), or declared to have not been met after the hammer falls if the reserve was not reached.

Wall bids that counter actual bids made by people make the demand price appear higher than it in fact is - that is deceptive, thus a deceit, thus dishonest. If the auctioneer uses wall bids to push the bids up to the reserve it is fraudulent as it inflates the apparent worth of the goods ("other people are still bidding so it must be worth it"). The whole purpose of an auction is to honestly establish the highest price people will pay for goods of uncertain value. The reserve is just the seller's minimum price, for an auctioneer to make it appear that it is a price that someone in the room is willing to actually pay, notwithstanding whether the reserve is realistic or not, is deliberately misleading. An auctioneer caught doing so is in for a discussion with the police about fraud.

All it would take to make an iron clad case is to sell something that had a stupidly high reserve at well over the market price to someone naïve as to the true value, who then finds out that they've been taken for a mug and complains to the police (and for P.C. Plod on the front desk to actually know the law and refer the complainant to someone in CID).

I think you missed the point, the item is not sold so no money paid, no gain no fraud. The only time it is illegal is if there is a single real bidder and the auctioneer does not sell as soon as the reserve is met. No one is making the real bidder bid more.  I agree it's not good practice  but its done. The moral issue is that it could make the unwary bidder think th item is worh more because someone else is bidding - auction fever. Also remember consumer and retail law does not apply to auctions in the UK.

It is indeed very similar to proxy bidding on an item with a reserve on ebay. For example consider an item listed at 99p start and £60 reserve.  If I Bid £10 the bid stays at 99p and reserve not met. If someone else bids £9.99 it goes to me at £10 but still reserve not met. If I then increse my limit to £55 nothing changes, but if I increase to £65 the bid will jump to £60 to me with reserve met even if no one else bids.

[srb1954]

Maths don't bite you & bounce you on your bum!
In Maths you can have concepts like " -160 is lower than -150", but in Electronics, whether we call it a negative or positive voltage just  depends on where you put your reference, the potential difference is still real!
A 12 v car globe doesn't care if you use it on a modern car with negative earth, or a vintage British car with a positive earth----it still lights up!

Perhaps not the best example. Chances of your lights working on a vintage British car are pretty slim regardless. 

[Neomys Sapiens]

The Telco scissors from US suppliers like Jonard and Klein are one of the few kinds of tools where I feel the US tool industry holds an edge (sic!) to European quality and usefulness.  There are a few other items, surprisingly often by Jonard, where they're unique in providing a good or even existing solution. 

They are really useful, especially with that wire notch.
In exchange, we got the Bernstein or Belzer Kronenschere (as shown by BU508). I also have two surgical scissors with TiN surfacing and a very fine serration. Those cut through almost everything.

For sundry things like wrenches, fixed or adjustable, socket sets, screwdrivers, and most basic pliers, US makers are still in the 70s (in a bad way, that is).  The likes of Bahco (before Crap-On^tm bought them to gut them and sell crap branded with the logo) and Facom (also sadly bought for its brand name by a company whose only useful product today is a breaking bar; i.e. Stanley), Knipex, Stahlwille, Elora, Gedore, Wera and Wiha laugh at the products from the US.  And the Japanese tools are no joke either, with Ko-ken and Vessel being two very good examples.

You can add Engineer Tools to the Japanese list. They have a special pliers for the extraction of fnorked screws, which definitely comes handy sometimes.

There are several lesser-kown US manufacturers, which can provide decent tools:
https://xuron.com/
https://www.excelta.com/
https://swanstromtools.com/
https://ullmandevices.com/ - I love their screw starters, because they make some for Hex and torx as well!
https://www.centraltools.com/moody-tools/
https://www.micromark.com - for their micro screw- and nutstarters (they also sell Wiha and other small tools)

https://omegatec.com/ which are distributor for Apex and Zephyr, which I would prefer as US sourced wrenches and socket kits over Crap-On^tm any time, and also have own niche products.
https://vimtools.com I can't judge, as I did not encounter any of their products yet
and of course those peculiar Chapman kits

Also Ideal-tek, Dumont and Sipel from Switzerland as well as Piergiacomi from Italy. Bernstein is a name every one in electronics should know.
And there is a second tier of German manufacturers whose names to know can be useful. Those are Elora, Heynen/Heyco, Wuro, Felo, Orbis, NWS, Artur Martin, Hans Arndt, Witte, Rennsteig and Athlet.

[TERRA Operative]

You can add Engineer Tools to the Japanese list. They have a special pliers for the extraction of fnorked screws, which definitely comes handy sometimes.

I use a bunch of Enginner brand stuff. It's good quality gear, and their Neji-saurus pliers (Screw-saurus pliers) as you mention are great for getting out of a stuck situation.

[Cubdriver]

For the capacitors, I would stay at the PSU and the memory battery etc for now. The main 'acquisition board' on the underside is quite the process to remove and not really needed unless you are a little insane like me.

I'd posit that ALL of us participating in this thread are well past the point of using the modifier 'a little' in regard to our levels of insanity...

-Pat

[Neomys Sapiens]

Speaking of power cables, anyone got one of those Tek power cables that looks like an extension cable they want to sell? (Number 2 in the attached image).
I have a type 284 pulse gen that needs one and I can't find a rewirable plug that will fit without removing the collar around the connection on the back of the unit.

Would THAT be the right one?
Available here:
https://www.ebay.de/itm/165372312902

Tell me if I should move on it.

[Cubdriver]

Speaking of power cables, anyone got one of those Tek power cables that looks like an extension cable they want to sell? (Number 2 in the attached image).
I have a type 284 pulse gen that needs one and I can't find a rewirable plug that will fit without removing the collar around the connection on the back of the unit.

Would THAT be the right one?
Available here:
https://www.ebay.de/itm/165372312902

Tell me if I should move on it.

I don’t think so - the Tek AC mains cables of that type that I’ve seen have a US-type NEMA 5-15 receptacle (like the ones I posted earlier - two vertical slots for line and neutral blades, and a mouse hole looking third opening for the ground pin), but in the Tek connectors it's centered in a cylindrical housing.  That looks like all three are round holes, and the connector housing is square rather than cylindrical.  Perhaps it’s some sort of calculator or adding machine cord?

-Pat

[TERRA Operative]

Nah, that loos even older I think.
The one I need has a narrow cylindrical NEMA 5-15R socket on the cable where it attaches to the unit.

[Cubdriver]

I remembered that I have a Tek rack unit with sine and square wave generators that has those in it, and was able to dig it out and grab some pics of the business end of the cord.  (Fingers crossed that this works - doing this from an iPad)





-Pat

[Cubdriver]

And one more for good measure:

[TERRA Operative]

Wanna sell it?

[Cubdriver]

Wanna sell it?

LOL - if I had more of them I might be inclined, but they make the PH 163s used in the sixties/early seventies era HP stuff look common by comparison.  Can't recall coming across anything other than what's in that rack, and it's on the brittle side as it's gotta be pushing 50 years old.

[med6753]

Like Pat I have just one of those cables and also like Pat's the rubber is starting to crack from age. Sometime in the mid 1960's Tek eliminated these bulkhead plugs and went to fixed line cords on nearly all their equipment. I have an early S/N Type 547 with the recessed bulkhead plug and two later S/N Type 547's with fixed line cords. Tek was very late in implementing IEC such as on the 24XX series. 

[BU508A]

Speaking of power cables, anyone got one of those Tek power cables that looks like an extension cable they want to sell? (Number 2 in the attached image).
I have a type 284 pulse gen that needs one and I can't find a rewirable plug that will fit without removing the collar around the connection on the back of the unit.

NSN number is: 5995-00-011-9327

Looks like they have some in stock:
https://www.asapaviationstock.com/nsn/rfq/tektronix-inc/5995000119327/161-0024-03/

But, if they are going to sell you one of those things, the price will be extremely high.

[tggzzz]

Math being universal and undeniable, it's the most reliable way of eliminating confusing.

Ask people what is "1+2*3"? Include teachers

I ask them back---"Where are the brackets?"

The slightly more clued up ask that, and I reply "no brackets, just the normal laws of arithmetic".

[Vince]

FIREFOX : need to insall an extension to download Pornhub Youtube videos and whatnot, what is the most popular/better one to use these days ??

Firefox lists a bunch of them when I do a search for "video download "...

Immediate goal is to download TerraOperative's video on his 2467B restoration, as it's really good. I would like to save it to my hard drive i my 2467B folder, so that I am 100% sure I have it at hand when I want, even if Terra goes mad and deletes it, or YT fucks up, or my internet connection goes completely kaput.

I can send you the video file directly if you like. Let me know your file size constraints and I'll open the original project file and pump out a new video file, just for Vince! I'll stick it on my google drive or something for you to download.

How nice ! 

Yes Google drive would be convenient I think, since my e-mail is a Gmail one, so I guess I would not have to do anything special to get your file, no new website to subscribe to or something.

Don't have asilly big hard drive, 500GB with 300GB available. A video under 500MB would be plenty enough. On YT it displays on " 1080 HD " it says. Goole says that means 1900+ pixels wide.. that's much larger than my screen resolution (1600). A video at 1200 pixels wide would be pleeeenty good enough...as long as the picture quality is good, then it can be enlarged/zoomed in full screen without noticeable loss of quality...

Thanks again in advance ! 

[Vince]

Double check, but I seem to remember those 1uF 50V capacitors are bi-polar (aka no polarized) types, I ended up buying a bag of 100 of them, as RS/Farnell don't do them individually, decided not to use Mouser as they refused to sell the RAM battery.

David

Freaking hell you're correct !!!   

You saved my scope, thanks !!! 

Well I want to believe that I would have spotted it upin installation of the new cap... I would have looked for the polarity indication on the PCB silkscreen and found none ! 

100 of them wow that's quite a lot ! 

I just had a look on Farnell. They have some and minimum quantity is only 5 not 100, so it's OK.
However they don't have a 50V one, only 35V or 100V. But the 100V one is still in the same package that we need, so that's fine...
But it looks like a crappy cap though, only 2000 Hours lifetime, bottom of the barrel then 

Might be better to cobble together a non-polarized cap using two polarized one in series. Like two 2.2uF ones.
Packages are very small so we can afford to do it, there is enough space on the board to do it.
The advantage would be that using non polarized caps, we get a lot more choice, so we can get better quality caps.

Thanks again for the warning !

[Vince]

Boy,taking the 2467B PSU apart is not as quick and easy as I would have liked, lots of stuff to take apart.

I better hurry and replace the caps ASAP before I forget how to put it all back together ! 

Looked at all the caps and made a list. 36 caps in all, with the RIFA and electrolytics.  12 different caps in all. Gonna have to spend some time on Farnell's site to pull all that out.

I am sure it's gonna be more expensive than Papa Smurf's Mouser BOM, and by a good bit probably...

But that will be tomorrow's job. For now..... 

Thanks for another entertaining day, looking forward to seeing what subject tomorrow will bring... 

Always considered getting one of these 246* scopes but yeah, nah.

Nah, these are not for you. I can't even believe you even remotely considered getting one. For, they have no large LCD display nor USB nor Ethernet, you would be bitching about it within an hour and scrap it, that would be sad !

No, your Siglent are much better, none of that old Tektronix rubbish  ! 

[Vince]

Problem is finding a new LED with the characteristics as the old one ! So that the colour and brightness are identical (enough) to "blend" with the others ! 
I guess back then there were no high brightness LEDs, so I need to get old school technology LEDs, to begin with. But then need one with the same wavelength and brightness / luminosity !
I will look in the part list, maybe there is a manufacturer part number in there, I could look up the datasheet to find specs and try to find something similar....
If not I guess I will have to buy many different makes and models and try them all to see which one gives the most acceptable result, gonna be time consuming ! 

Color is the only thing really to focus on as I've never seen LED's used without a current limiting resistor so with a little experimentation the brightness should be pretty simple to match.

? The old CD players I fixed used a driver IC to drive all the LEDs, with one single pin on the chip to set the driving current for the LEDs. No resistors, and no possibility to control the current in individual LEDs.

However I just looked at the 2467B front panel schematics and I am in luck.... or not. No specialized constant current driver IC but, instead old fashioned daisy chained shift registers and no multiplexing, great, one single LED per register output. BUT many of the LEDs share a common limiting resistor !  Looks like there are 9 groups of LEDs each with their own common resistor.
Looking more closely, there are 49 LEDs and 22 of them have their own resistors. So... they are the minority, shared resistors are the rule 
I guess they are the ones for which the scope is 100% sure that it will never have to light up more than one LED at a time. Say for a trigger source selector switch... you can only select one trigger source at a time of course...

I can't remember which LED I need to replace so I don't know if I will be in luck or not... will need to wait 'til the PSU is recapped and put back in...
ISTR the LED was somewhere in the upper left corner of the front panel, but which one exactly I don't knoooooow......

[Zucca]

Go for the BD139 route, start shitposting about them on Twitter, seems to produce almost instant positive results.

They should realize a bad post here can create more damages than a bad twitter....

[Brumby]

Go for the BD139 route, start shitposting about them on Twitter, seems to produce almost instant positive results.

They should realize a bad post here can create more damages than a bad twitter....

Perhaps ... but Twitter will likely hit a nerve quicker.

[TERRA Operative]

Just figured out how to fix a "250 nv storage too small, more bytes requested than available" error on the TDS600/700 scopes, well in my case anyway.

Turns out it was the 24C02 memory chips on the acquisition board. I swapped them out for ones pulled from a scrap board and no more error! Yay.


But, it now means I need to recalibrate this scope as those chips hold the calibration data.. I'm halfway through setting up an old PC with the required GPIB card, and halfway through getting the calibration equipment functional, so soon this scope will be 100% again.

I'll have to add a bunch to my next Mous-key order so I have them on hand.

[mnementh]

...I can't remember which LED I need to replace so I don't know if I will be in luck or not... will need to wait 'til the PSU is recapped and put back in...
ISTR the LED was somewhere in the upper left corner of the front panel, but which one exactly I don't knoooooow......   

With the panel unplugged should be easy-peasy, as it appears the +5V rail for the LEDs is isolated from that for the ICs. Just test the LEDs directly using the DIODE/JUNCTION TEST function on your meter. Any that don't light up, investigate further. If none of your meters will produce enough Vfd or current to light a LED on that function, then you have a REALLY GOOD excuse to shop for one that does; even if it's just a cheap Aneng AN8xxx. 

mnem

[TERRA Operative]

FIREFOX : need to insall an extension to download Pornhub Youtube videos and whatnot, what is the most popular/better one to use these days ??

Firefox lists a bunch of them when I do a search for "video download "...

Immediate goal is to download TerraOperative's video on his 2467B restoration, as it's really good. I would like to save it to my hard drive i my 2467B folder, so that I am 100% sure I have it at hand when I want, even if Terra goes mad and deletes it, or YT fucks up, or my internet connection goes completely kaput.

I can send you the video file directly if you like. Let me know your file size constraints and I'll open the original project file and pump out a new video file, just for Vince! I'll stick it on my google drive or something for you to download.

How nice ! 

Yes Google drive would be convenient I think, since my e-mail is a Gmail one, so I guess I would not have to do anything special to get your file, no new website to subscribe to or something.

Don't have asilly big hard drive, 500GB with 300GB available. A video under 500MB would be plenty enough. On YT it displays on " 1080 HD " it says. Goole says that means 1900+ pixels wide.. that's much larger than my screen resolution (1600). A video at 1200 pixels wide would be pleeeenty good enough...as long as the picture quality is good, then it can be enlarged/zoomed in full screen without noticeable loss of quality...

Thanks again in advance ! 

Here's the link.
Downsampled to 720P, and roughly 550Mb in size. It's a bit crunched in quality, but it still very watchable.

https://drive.google.com/file/d/1LwmV_ih7aOi_M5ynSWBiwGHWzx0ZMbji/view?usp=sharing

[mnementh]

...Downsampled to 720P, and roughly 550Mb in size. It's a bit crunched in quality, but it still very watchable.

https://drive.google.com/file/d/1LwmV_ih7aOi_M5ynSWBiwGHWzx0ZMbji/view?usp=sharing

Mmmm... nice & quick DL over Googs' fat pipes... ~28 seconds. 

But... yeah... "a bit crunchy" indeed. Personally would rather have the best rez and suck it up on the storage space. That vid is worth it to be able to read part #s, etc.

mnem
*toddles off to sort some SMDs*