Test Equipment Anonymous (TEA) group therapy thread

[bd139]

...So I’ve got to find the screw now which is on the inside of the tube shield and reinstall it in case it falls out somewhere and shorts something. That possibly means removing the tube 

Ah well I wanted a project. Nice to be back in the trenches!

Mmmhmmm... have you tried *gulp* shaking it out...?   
mnem
Hold onto your butts...

Can't tell you how many times I dropped a screw into the bowels of a 400 series and I had to resort to shaking, turning, and lots of cursing until it finally dropped onto the bench. 

The transistors for the Type 547 showed up but too late in the day. Tomorrow's activity. 

So that's how you got that hernia 

[factory]

...So I’ve got to find the screw now which is on the inside of the tube shield and reinstall it in case it falls out somewhere and shorts something. That possibly means removing the tube 

Ah well I wanted a project. Nice to be back in the trenches!

Mmmhmmm... have you tried *gulp* shaking it out...?   
mnem
Hold onto your butts...

I had a similar thought, to turn it upside down to hear it rattling about, if it's still in there.

My hp 180A has few missing screws for the CRT shield too, but it doesn't seem loose and as the holes don't line up I wondered if they were ever fitted, or if it a was a problem with the early production run. 


David

That’s “interesting”. HP clearly designed that on a Friday afternoon 

See page 32 of Chapter 2, Volume 1, of the history of the hp South Queensferry site here;
https://btcloud.bt.com/web/app/share/view/TLXV3jnGgh#/share/8e9f6503e9344e78993f6396197db66a
Was linked from the hpmemoryproject website here; https://www.hpmemoryproject.org/timeline/hugh_walker/hugh_walker_memoir.htm

They sent another Friday afternoon 180A series to Canada. 

“I visited HP Canada in Montreal and saw some really poor workmanship on a 180A
Oscilloscope and an X-Y Recorder that had just been unpacked from their Queensferry boxes.
There were dry-joints, solder blobs, scratches, out of specification performance, and I was
left saying, ‘I don’t see how it could possibly happen.’ How does it happen? Do we blame
the operator, the test man, the inspector, the Q.A. man, the manager? Everyone is involved,
but in HP, as you know, we rely upon people doing high quality work without dozens of
inspectors checking every stage. I want you all to think about this and to remember that in a
more and more competitive world, the customer will only buy the best. The best must be
HP.”

The history also gives clues as to why the 3734A counter is more common than the 3735A counter, well that was because the 3735A was developed from the earlier model, hence why few 3735A's have been seen on ePay.

David

[Neomys Sapiens]

Quick update.

Tek 475. Spoke to the seller who's response was basically "you're probably holding it wrong"  . So I thought fuck it and cracked it open and went through the usual diagnostic steps. Had a look and the horizontal deflection plate wire was resting on the chassis, probably from a knock. Have bent it away and it works now. Total fix time < 5 mins. Still got it  . The power supply looks a bit noisy so will need a recap by the looks. I will of course measure that first!

Good news is it's a VERY late one. Date coded 1982 and they were discontinued in 1983.

Solartron 7150 plus. I'm going for the original part from RS (£29). Job done properly. As for shrouded jacks, no I'm going to leave them. This is going to be used for low voltage electronics work with mostly pomona clip leads so I don't need mains protection. If I'm going to do anything mains the Fluke 87 or 25 will come out.

You have still the option to install those safety-to-standard 4mm adaptors which lock in place with the miniature allen screw. I got one matching set (including brown and green) for my 7151, where I install them onto the jacks if necessary.

[med6753]

All assembled and tested. The only remaining issues appear to be that the beam finder switch is a bit dirty which I don't care about and the disintegrated knob (366-1280-00) at the top right, which I'm also not that bothered about as it's only the B trigger control.



Currently burning in for an hour before bed. Hopefully the god of tants will not smite me 

I'm certain I have a replacement knob if you want. Let me know. 

[bd139]

I'm certain I have a replacement knob if you want. Let me know. 

I'll give it a few days to make sure it doesn't turn into a tantalum inferno first and then I may take you up on that offer  . Thanks 

[tautech]

I'm certain I have a replacement knob if you want. Let me know. 

I'll give it a few days to make sure it doesn't turn into a tantalum inferno first and then I may take you up on that offer  . Thanks 

No preventative tant eviction planned ?

[med6753]

I'm certain I have a replacement knob if you want. Let me know. 

I'll give it a few days to make sure it doesn't turn into a tantalum inferno first and then I may take you up on that offer  . Thanks 

It's actually 2 knobs. The little slope knob and the larger level knob. Pretty sure I have both. They may be 485 style which look slightly different but will fit. 

[Specmaster]

Hmm, just checking the tracking on my package of incoming goodies, the Yodel tracking site claims that the package is at my local depot but expected delivery date is Saturday, that does sound right to me 

[med6753]

I'm certain I have a replacement knob if you want. Let me know. 

I'll give it a few days to make sure it doesn't turn into a tantalum inferno first and then I may take you up on that offer  . Thanks 

No preventative tant eviction planned ?

I've had lots of tant fails in the 465 and 456B. When I got the 475A I replaced a few of the high value tants and left the rest. I have yet to have a failure. When it comes to those damn tants it's a total crap shoot. 

[bd139]

I'm only fixing problems that I have in front of me these days (other than RIFAs and Schaffners). I don't have the energy to strip it and do the lot any more. Plus time is finite and that gets in the way of actually using it for a project.

The 7150 plus is getting a new mains filter and the other caps in it checked and new display LEDs and that's it for that as an example.

[bd139]

Hmm, just checking the tracking on my package of incoming goodies, the Yodel tracking site claims that the package is at my local depot but expected delivery date is Saturday, that does sound right to me 

If it's Yodel they've got to open it, nick the contents then leave the box in the corner for 2 days so Saturday is about right 

I went mental in the last few weeks. I'm still waiting here for:

1. one large bag of 2n3053's.
2. 2x 2n5924's from Langrex for the TOPS 1.
3. Agilent E3630A
4. HP 5381A

Lots of fun ahead 

[mansaxel]

Lots of fun ahead 

I just got a paper mailing telling me that I've got two packages waiting, one of which is a pair of shoes, expected, and the other is a package from Germany that I don't remember what it is....  All I know is that it's "signature and ID required" -- it won't do with the usual Postnord procedure where I enter the tracking code in the app, and then can ID myself using one of the larger e-ID apps we have here, in the app, which then makes the app create a QR code that indicates to the post office that I've been identified when they scan it.

[bd139]

See page 32 of Chapter 2, Volume 1, of the history of the hp South Queensferry site here;
https://btcloud.bt.com/web/app/share/view/TLXV3jnGgh#/share/8e9f6503e9344e78993f6396197db66a
Was linked from the hpmemoryproject website here; https://www.hpmemoryproject.org/timeline/hugh_walker/hugh_walker_memoir.htm

They sent another Friday afternoon 180A series to Canada. 

“I visited HP Canada in Montreal and saw some really poor workmanship on a 180A
Oscilloscope and an X-Y Recorder that had just been unpacked from their Queensferry boxes.
There were dry-joints, solder blobs, scratches, out of specification performance, and I was
left saying, ‘I don’t see how it could possibly happen.’ How does it happen? Do we blame
the operator, the test man, the inspector, the Q.A. man, the manager? Everyone is involved,
but in HP, as you know, we rely upon people doing high quality work without dozens of
inspectors checking every stage. I want you all to think about this and to remember that in a
more and more competitive world, the customer will only buy the best. The best must be
HP.”

The history also gives clues as to why the 3734A counter is more common than the 3735A counter, well that was because the 3735A was developed from the earlier model, hence why few 3735A's have been seen on ePay.

David

That's pretty funny actually.

I think the worst one I've seen was from Tektronix. It was a 453 where they had actually forgotten to solder the wire on the back of the CH1 out and it was just floating around inside the chassis 

[Specmaster]

Hmm, just checking the tracking on my package of incoming goodies, the Yodel tracking site claims that the package is at my local depot but expected delivery date is Saturday, that does sound right to me 

If it's Yodel they've got to open it, nick the contents then leave the box in the corner for 2 days so Saturday is about right 

I went mental in the last few weeks. I'm still waiting here for:

1. one large bag of 2n3053's.
2. 2x 2n5924's from Langrex for the TOPS 1.
3. Agilent E3630A
4. HP 5381A

Lots of fun ahead 

You have been spending some money there for sure, lots of fun to come then.

[tautech]

I'm certain I have a replacement knob if you want. Let me know. 

I'll give it a few days to make sure it doesn't turn into a tantalum inferno first and then I may take you up on that offer  . Thanks 

No preventative tant eviction planned ?

I've had lots of tant fails in the 465 and 456B. When I got the 475A I replaced a few of the high value tants and left the rest. I have yet to have a failure. When it comes to those damn tants it's a total crap shoot. 

Wasn't suggesting shotgunning all but instead the ones that are known to fail like any 15V rated ones on 12V rails as was common for Tek to do back in the day. 

[mnementh]

Back at proper computer now. Some horrible things to scare you. mnem vomiting earlier will persist

Quick test to see if the caps would do the job. Dodgy prototype soldering        (SNIP) Currently burning in for an hour before bed. Hopefully the god of tants will not smite me 

Oh yeah...? Well take THIS!!!



mnem
There's a RIFA hiding somewhere... just waiting.

[bd139]

Fucking sicko 

[mansaxel]

I think the worst one I've seen was from Tektronix. It was a 453 where they had actually forgotten to solder the wire on the back of the CH1 out and it was just floating around inside the chassis 

My 428b did contain some interesting things; one of the primary leads into the transformer was squeezed against the chassis. Probably worked at the production line test, but rather soon must have become a fuse-blower.

[mnementh]

Fucking sicko 

Thanks for noticing.

mnem
It is hard work; but I have a lot of Karma to burn off.

[Cerebus]

...So I’ve got to find the screw now which is on the inside of the tube shield and reinstall it in case it falls out somewhere and shorts something. That possibly means removing the tube 

Ah well I wanted a project. Nice to be back in the trenches!

Mmmhmmm... have you tried *gulp* shaking it out...?   
mnem
Hold onto your butts...

Can't tell you how many times I dropped a screw into the bowels of a 400 series and I had to resort to shaking, turning, and lots of cursing until it finally dropped onto the bench. 

The transistors for the Type 547 showed up but too late in the day. Tomorrow's activity. 

So that's how you got that hernia 

I have this vision of Mike doing the Tom & Jerry/Wile-E-Coyote thing where Mike's overbalancing backwards at the top of the stairs, holding a Tek overhead, running and the stair carpet is scooting out from under his feet. He teeters, but only until the last of the stair carpet runner is gone, then physics takes over. Or at least, it takes over until it takes the scope a ridiculously long time before it finally catches up with him, prompting tweeting birds flying around an instant tall lump on the head.

[vk6zgo]

...So I’ve got to find the screw now which is on the inside of the tube shield and reinstall it in case it falls out somewhere and shorts something. That possibly means removing the tube 

Ah well I wanted a project. Nice to be back in the trenches!

Mmmhmmm... have you tried *gulp* shaking it out...?   
mnem
Hold onto your butts...

Can't tell you how many times I dropped a screw into the bowels of a 400 series and I had to resort to shaking, turning, and lots of cursing until it finally dropped onto the bench. 

The transistors for the Type 547 showed up but too late in the day. Tomorrow's activity.

Marconi will do the dropping for you!
Years ago, at work, we had a sideband analyser which, at odd intervals, would blow a HT (around 400v) fuse.
This device was of a "clever" construction, being made up of three hinged units that, when mounted on a rack, folded in like a roadmap, making it very compact design for a tube design.

To chase faults, you obviously folded it out, & every time this was done, & the fuse replaced it was"no fault found".
Eventually, we hung an AVO meter on the 10 amps range in place of the fuse, folded it up & turned it on.
Luck was with us, the fault appeared, the needle swung well up the scale, & we could see a wirewound resistor glowing red.
Investigating, we found the resistor mounted across two terminals of a tag strip, with about a 2BA nut sitting just under one terminal.

With the unit unfolded, there was just enough clearance that it didn't short on the terminal, but folding it up distorted things just enough to either almost do so, or to do so immediately, depending on luck.

Even if you were lucky & "jagged" the non- shorted condition, over time, the assembly could distort enough that it would give you a random short circuit!

The nut was removed, nor without difficulty, using a pair of long nosed pliers, & all was well.

[med6753]

[0culus]

...So I’ve got to find the screw now which is on the inside of the tube shield and reinstall it in case it falls out somewhere and shorts something. That possibly means removing the tube 

Ah well I wanted a project. Nice to be back in the trenches!

Mmmhmmm... have you tried *gulp* shaking it out...?   
mnem
Hold onto your butts...

Can't tell you how many times I dropped a screw into the bowels of a 400 series and I had to resort to shaking, turning, and lots of cursing until it finally dropped onto the bench. 

The transistors for the Type 547 showed up but too late in the day. Tomorrow's activity.

This may or may not have happened greater than or equal to twice on my ongoing 454 repair...which I have back on the bench again. Still trying to track down why in the %#@! the A sweep has too little gain.  So I'm going through everything again, checking signal test points and voltages. Can't find any faults! 

[cyclin_al]

As a first step we could try to stop dumping 1.300.000.000 metric tons of food every year.

100% agree with that, thats where the APP I use helps, "To Good To Go" it only works on both Android and IOS phones and or tablets, download it from the App store today and start helping to save both the planet and your pocket by rescuing food that shops near to you would otherwise be throwing in the dustbin because of its sell by date is close.

I often use it to get bags of baked items from Gregg's the bakers, Costa Coffee, Pizza shops and country Bakers, but there are green grocers, supermarkets, cafés  etc on the app. It all depends on your location at the time, go on, try it out, what have you got to lose?

Thanks Spec!

That was quite an interesting read, and it is a practical thing that anyone can give a try to make some improvement.
I have never heard of this app before, so not sure how effective it would be here at the moment.  I suspect it needs a certain level of up-take (aka critical mass) for it to start providing benefit.  Of course, it has to start somewhere ... will likely do an install to try it out tomorrow.

[AVGresponding]

Who wanted a LCD 'scope?
www.ebay.co.uk/itm/203537268248?

Dang... 100 quid...? Even I would buy that just to see what makes it tick...

mnem
 

Bugger, has that been pulled? or was it ending tonight & I just missed it?
The redesigned ePay bidding page doesn't give a start date anymore. 

David

Ended on schedule no bids.
Looks OK to me seller is a house clearence type
Watch for relist.

Duty done, bid entered