Test Equipment Anonymous (TEA) : Discussion and Group Therapy Thread

[Robert]

The other 3400A for sale has a seriously flaking delaminating scale. It honestly looks like water got in it and made the whole thing run. It's still listed for sale too.

The lacquer layer starts to flake. I think storage in even a slightly damp place will cause it, rather than just age. There are a couple of ways of dealing with it. I removed the pealing lacquer very carefully, then replaced the lacquer with the stuff in a can used to fix charcoal drawings. You have to make paper masks so as not to spray the scale mirror. The scale markings under the lacquer are about as permanent as dirt and you have to be careful with them. It has to be done with the scale removed so the spray doesn't get into the movement. You also don't want lacquer flakes getting into the movement. Something of a mission.

Another way would be to make a new scale with a computer, (scan it, or use meter scale software, or maybe scan a good scale), print it making sure it's the correct size, and then go through the fiddly business of gluing it in place.

I'd be tempted by the tatty 3400A - for the right price - which wouldn't be much. The spare parts including screws and feet can be useful, not to mention more valuable parts. Wait two or three weeks, then phone and if they still have it, offer him no more than $10.

These meters should not have a lacquer on the scale. The scales were water transfers that were custom made for each movement in an automated process. One restoration method is to use a dilute waterbased adhesive (Pritt stick dissoved in wate was mentioned but dilute PVA should work). It is applied withe a fine vbrush to the underside of the flake(s) and actually draws the transfer back down onto the surface.

Robert.

[Zenith]

Thanks for that. It explains a lot, including why the scales are sensitive to damp. I haven't thought about water transfers since I used them as a kid on Airfix kits.

Unfortunately, in some cases the dilute glue and brush method won't work, because the surface layer has lifted and disintegrated.

[AVGresponding]

AliX fogger?

https://www.aliexpress.com/item/1005006463663595.html

[25 CPS]

This is the other 3400A that's available locally:

https://www.facebook.com/marketplace/it ... 42ffe0e3f1

They want $150 Canadian for it but claim to be open to offers. Given condition, I wouldn't buy that as a parts mule unless they were willing to accept a very, very serious concession on price for it.

[EC8010]

I paid £70 for my 3400A about seven years ago, which I thought was a little bit steep at the time for a radio rally price. But it is in near-perfect condition and works properly (or at least, it did the last time I came to use it). The specifications (particularly crest factor) are extremely impressive; even before you consider its age.

[Zenith]

It's hard to compare things from country to country, and it depends where you buy; auctions, swapmeets, ebay etc. £80 seems a hopelessly optimistic price for a 3400A in that state.

If you are tempted, offer 'em the price of a couple of beers. They don't look as if they'd bite, but you don't know until you try.

[bd139]

Going through Berlin photos and remembered this one that tickled me.

A painting of people debugging a Robotron 300, an IBM 1401 clone. The socialists knew how to do modern art. None of that abstract bollocks.

IMG_4154.JPG

Side note, new bd140 on the scene so will be here even less than I already am . Suitably weird this one. Wrote some of the GCHQ puzzle book, knows FreeBSD.

[tggzzz]

Going through Berlin photos and remembered this one that tickled me.

A painting of people debugging a Robotron 300, an IBM 1401 clone. The socialists knew how to do modern art. None of that abstract bollocks.


IMG_4154.JPG


Side note, new bd140 on the scene so will be here even less than I already am . Suitably weird this one. Wrote some of the GCHQ puzzle book, knows FreeBSD.

That is a good picture! Having said that, there are a few abstract pictures I like - because I don't think I could do them myself.

Good luck with the complementary polarity

[MED6753]

Going through Berlin photos and remembered this one that tickled me.

A painting of people debugging a Robotron 300, an IBM 1401 clone. The socialists knew how to do modern art. None of that abstract bollocks.

Never did see a 1401 in the flesh. They were built and tested at the Endicott, NY facility. I worked in the Poughkeepsie, NY facility which built and tested S/360 and S/370....as well as all IBM mainframes to this day. But I did see and use it's sidekick 1403 chain printer.

Side note, new bd140 on the scene so will be here even less than I already am . Suitably weird this one. Wrote some of the GCHQ puzzle book, knows FreeBSD.

Yes, our women folk do keep us busy. I was even asked 5 minutes ago what I was doing while typing this.

[bd139]

Going through Berlin photos and remembered this one that tickled me.

A painting of people debugging a Robotron 300, an IBM 1401 clone. The socialists knew how to do modern art. None of that abstract bollocks.

Never did see a 1401 in the flesh. They were built and tested at the Endicott, NY facility. I worked in the Poughkeepsie, NY facility which built and tested S/360 and S/370....as well as all IBM mainframes to this day. But I did see and use it's sidekick 1403 chain printer.

Very cool still. They didn't have any original IBM kit in this museum. They did have a full clone machine though. I am eternally impressed at what they managed to clone if I'm honest. It wasn't trivial!

Robotron 300, the 1401 clone...

IMG_4153.JPG

They did have some DEC kit

IMG_4232.JPG

Actually from a computing perspective one of the best museums I've ever been to. I'll write the whole place up at some point. It was totally unexpectedly good.

Side note, new bd140 on the scene so will be here even less than I already am . Suitably weird this one. Wrote some of the GCHQ puzzle book, knows FreeBSD.

Yes, our women folk do keep us busy. I was even asked 5 minutes ago what I was doing while typing this.

Mine is currently helping a friend get rid of her friend's ex-husband's stuff so I'm good until tomorrow .


Edit: add a couple for tggzzz

IMG_4149.JPG

IMG_4175.JPG

[MED6753]

Mine is currently helping a friend get rid of her friend's ex-husband's stuff so I'm good until tomorrow .

Can I send mine over to help? For some reason she's being a grumpy PITA today.

[MED6753]

That small brownish pile in front of that tall shrub is all that remains of all the snow piles from the January/February snows. In a few days that pile should be gone too. It originally covered that entire area to the lamp post and street sign and up to the curb. And was almost as tall as the shrub. It's been a long Winter and glad it's over.

And yes, that is a Toyota Supra parked in the foreground. Owned by a guy in that far building. I would love to take it for a spin. I've started to get the Civic ready for Spring car shows.

[tggzzz]

Edit: add a couple for tggzzz

Ooh, you tease, you.

I keep trying to buy a Curta, but my offers are rejected.

An Otis King is on farcebook. I said I'd buy it at the asking price, but no response. I believe that is par for the course on farcebook.

[EC8010]

Wow! I've just looked up Curta (having never previously heard of such a thing). Lovely. I can see why you would want one. It's a jewel. Many years ago, I turned down the offer of a Nagra SN for £250 https://www.cryptomuseum.com/covert/rec ... /index.htm. It's a beautiful thing, but £250 was an awful lot of money to me in 1995 and I just couldn't afford it.

[tggzzz]

Wow! I've just looked up Curta (having never previously heard of such a thing). Lovely. I can see why you would want one. It's a jewel. Many years ago, I turned down the offer of a Nagra SN for £250 https://www.cryptomuseum.com/covert/rec ... /index.htm. It's a beautiful thing, but £250 was an awful lot of money to me in 1995 and I just couldn't afford it.

Add in where the inventor was when he invented it, and the amazement grows.

I could afford one if I really wanted it, but somehow thinking and dreaming about geegaws can be as pleasurable as having a geegaw stuffed on a shelf. It is a variant of the old concept that a journey is (and arguably should be) more important than the destination.

P.S. clearly you need to visit TNMoC. It is a short journey from the Dunstable Downs Rally on May 17th

[mansaxel]

I totally forgot to mention that I picked up a Fluke 12 multimeter ... but Fluke tried out a number of other designs like the 12 with a couple of buttons and a switch or the side-switch drawbar meters like the 8060A and others, and I wanted a Fluke 12 to add to my little collection of non-standard form factor Fluke multimeters.

I have the Fluke 10, its little brother. Bought new 32 years ago, and still pristine. It is in my emergency toolkit at work. It always works. It is very dependable, and is still within spec after all those years. I recently topped up my stash of 8060a multimeters, won another one for below 50 USD shipped. In good outer condition, in spec, and with a very good LCD. My intention is to get one to each of the young ones, so they always have a 4 1/2 digit DMM at hand. With the worlds fastest continuity beep!

The Hewlett Packard 3400A ... the dreaded PH-163 power connector that comes up so often.

The PH-163 connector is easily replaced by a Schurter 6160.0001 or similar C6 type inlet; Schurter make a few different ones, googling brought that one up, but there are others from them with various differences. One does have to take a few draws (really not much!) with a round file to the chassis plate of the TE, but since the PH-163 is so obsolete and unobtainium and completely bonkers insecure, I feel this is a life saving action rather than a sacrilege. I'd argue one does best with getting one that mounts to the outside of the chassis; this is in line with how the PH-163 is usually fitted, and it gives the best result. My 211b looked like this, post-conversion:

[mansaxel]

Going through Berlin photos and remembered this one that tickled me.

A painting of people debugging a Robotron 300, an IBM 1401 clone. The socialists knew how to do modern art. None of that abstract bollocks.

Never did see a 1401 in the flesh. They were built and tested at the Endicott, NY facility. I worked in the Poughkeepsie, NY facility which built and tested S/360 and S/370....as well as all IBM mainframes to this day. But I did see and use it's sidekick 1403 chain printer.

The Silicon Valley computer museum has two, most often operational. It is the ones CuriousMarc has posted a pile of videos on; he volunteers at the museum. I have punched a card and had it processed by the one that was running the day I was there. The current scheme is that they are running them Wednesdays and Saturdays, which took some amount of planning to hit, but I managed. If any of you get the chance, I wholeheartedly endorse a visit.

[EC8010]

Add in where the inventor was when he invented it, and the amazement grows.

P.S. clearly you need to visit TNMoC. It is a short journey from the Dunstable Downs Rally on May 17th

Agreed. It shows that advances in any field are driven by individuals who are obsessed and able to ignore the horrifying circumstances in which they work.

Do they have a Curta there? If so, sold.

[tggzzz]

https://www.tnmoc.org/slide-rules-calculators
Cabinet 1, exhibits A and B.

Budget half a day, in the expectation you will want to return. I expect you will remember too many of the exhibits for comfort. It's one of the few places I leave a donation.

Not being able to handle and use a Curta will miss the important tactile and aural aspects of using mechanical calculators, just as using an ASR33 is an essential part of the experience (long hard key travel, delayed impact thump). Certainly the bzzzz and and vibration are an "important" part of using my Original Odhner; too many similar calculators are jammed.

[Zenith]

https://www.tnmoc.org/slide-rules-calculators
Cabinet 1, exhibits A and B.

Budget half a day, in the expectation you will want to return. I expect you will remember too many of the exhibits for comfort. It's one of the few places I leave a donation.

TNMoC is well worth a visit. I feel obliged to visit after Dunstable Downs because it's well done, but gives the impression of being a wing and prayer operation, and so needs support. The staff are very knowledgeable and helpful. I buy a pencil. I may donate a KT66, if I can find it.

Their collection of Sinclair tat is impressive. I always like to see the Harwell Dekatron computer from the early 1950s.

[tggzzz]

TNMoC is well worth a visit. I feel obliged to visit after Dunstable Downs because it's well done, but gives the impression of being a wing and prayer operation, and so needs support. The staff are very knowledgeable and helpful.

Yes, yes, yes, yes, and yes respectively

Compare and contrast each of those points with the adjacent Bletchley Park. I'm not going there again, even though the travel time (from TNMoC) would be 5 minutes at worst!

I suppose the two can be summed up as

• the great and the good [sic] have created a traditional "heritage museum"
• enthusiasts have created and carefully curated a quirky informative interesting experience

[EC8010]

I give in; I will visit TNMoC after the Dunstable Downs rally on 17th May. I'm not sure it will affect me as deeply as it affects tggzzz, but I'll give it a go. And knowledgeable staff is certainly a bonus. I have a somewhat jaundiced view of museums in that stuff goes there to fester and degrade until all relevant knowledge has disappeared. And the same is true of the staff. I have corrected the Science Museum a number of times on their descriptions of BBC kit with no success.

[Zenith]

I have a somewhat jaundiced view of museums in that stuff goes there to fester and degrade until all relevant knowledge has disappeared. And the same is true of the staff. I have corrected the Science Museum a number of times on their descriptions of BBC kit with no success.

Most of the exhibits work and can be seen working. I don't think their Cray works, but they can be forgiven that. tggzzz has often spoken about he was interested in the Elliott computer, and the chap in charge enthusiastically whipped out technical documents to explain things. They give group tours, which I've dropped in on, and the guides are definitely clued up, not just reciting a script, and can answer questions sensibly.

[tggzzz]

I give in; I will visit TNMoC after the Dunstable Downs rally on 17th May. I'm not sure it will affect me as deeply as it affects tggzzz, but I'll give it a go. And knowledgeable staff is certainly a bonus. I have a somewhat jaundiced view of museums in that stuff goes there to fester and degrade until all relevant knowledge has disappeared. And the same is true of the staff. I have corrected the Science Museum a number of times on their descriptions of BBC kit with no success.

Bletchley Park is a prime example of that. Youngsters who haven't even remembered the brochures. But there are worse examples (which have even won awards!): Bristol Mshed is a prime example aimed at the "ohh isn't that pretty, I wonder what it is" and "my auntie had one but she gave it away" brigade. I've moaned to a trustee about it, and he recognised my point.

But how often do you go to a museum, start talking with the person operating/maintaining a machine (Elliott 803)[1] - and have them whip out the blueprint schematics and start discussing them? Doesn't happen every time, but has happened more than once. Peter Onions has built several simulators, including at gate level (i.e. one OC71 plus magnetics )

They still have the world's oldest operating computer (dekatron-based), plus a working replicas of the Colossus and the Turing–Welchman Bombe.

[1] e.g. https://www.tnmoc.org/notes-from-the-mu ... -the-diode

[MED6753]

Going through Berlin photos and remembered this one that tickled me.

A painting of people debugging a Robotron 300, an IBM 1401 clone. The socialists knew how to do modern art. None of that abstract bollocks.

Never did see a 1401 in the flesh. They were built and tested at the Endicott, NY facility. I worked in the Poughkeepsie, NY facility which built and tested S/360 and S/370....as well as all IBM mainframes to this day. But I did see and use it's sidekick 1403 chain printer.

The Silicon Valley computer museum has two, most often operational. It is the ones CuriousMarc has posted a pile of videos on; he volunteers at the museum. I have punched a card and had it processed by the one that was running the day I was there. The current scheme is that they are running them Wednesdays and Saturdays, which took some amount of planning to hit, but I managed. If any of you get the chance, I wholeheartedly endorse a visit.

Spend much time sitting at a keypunch writing up test cases for MECL 10K array boards that were going into an interface tester for the under development 3081. The punched cards were inputted to an IBM 1130 computer. Results printed out on a 1403 chain printer. As I recall the 1130 had a massive 1MEG removable hard drive.