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

[Zenith]

Hey at least they told you. Usually they just send you an empty bag which was supposed to contain them with "2" written on it to make it look like the staff were actually not on their mid afternoon methadone dip.

I've not had the empty bag treatment from CPC. I have learned that it pays to check what they send you carefully, because sometimes it's the wrong item, or the wrong number of them. With orders being sent in several postings, rather than one lot, there's more scope for that.

I received a padded envelope from them today containing five 3 watt resistors, which were part of a larger order, most of which came last week. I suppose odd envelopes like that will be arriving well into next year. The shortages are not a problem of their making and they are dealing with it as best they can.

Something I wanted after reading a refurbishment parts list for a Tek 2465B, was 270K 3W 1% resistors. None of the major suppliers seem to have them.
I bought some from a UK ebay supplier. There are stories on EEVBlog about how these have been disappointing. I checked them with a meter and they do appear to be 1% resistors. I should have checked the manual. It says 5%.

I'm wary about using ebay for components but it can get you out of a hole.

[mnementh]

Well surprise surprise, RAC arrived just over 2 hours from the time I called them, verdict, battery was dead, not holding its charge, the dealer also concurred with that and swapped it out for another new one, the same. The original had 4-year warranty, but they said that the new one only has the remaining 1-year warranty from the initial purchase date. Strange that I would have thought if the maker was proud of their products I'd get a new 4-year one, oh well it is what it is, at least it should last another 3 years at least.

What you're getting is not a manufacturer's warranty... when you pay the extra for a premium-brand battery, you're buying a term life insurance policy on it with that money. Most will have a "100% free replacement period" and the balance is pro-rata. Some are for a flat-rate/fixed-duration full replacement, and the pro-rata period is omitted.

Under any circumstances, that policy is designed around the actuarial tables and failure rate specific to the design of the battery vs use-case (which arcane incantations those bean-counters have down to a fine art) and your particular battery failure just landed outside the meat of the bell curve.

Never fear; your battery failure is a data point which will be applied to the next generation of batteries, such that the bean-counters can ensure there is still plenty of profit for nothing between those bell ends.

mnem
*currently engaged in The Battle of the Front Yard*

[mnementh]

...Something I wanted after reading a refurbishment parts list for a Tek 2465B, was 270K 3W 1% resistors. None of the major suppliers seem to have them.
I bought some from a UK ebay supplier. There are stories on EEVBlog about how these have been disappointing. I checked them with a meter and they do appear to be 1% resistors. I should have checked the manual. It says 5%.

I'm wary about using ebay for components but it can get you out of a hole.

Ehh... I buy there from time to time; it's a crapshoot but overall I've come out way ahead.

As for your resistors; IIRC, those are not usually needed unless you have a particular failure in the prereg section which results in the release of magic smoke. I've never read of them drifting over time absent a DOA failure on the SMPS.

Obvi, you should check them, but I don't believe they're any sort of a PM item.

mnem
*toddles off to make lunch*

[Cubdriver]

That reminds me - with the colder weather coming, I should probably start using the little desulfating charger on my Jeep again. Need to cobble together some sort of connecting pigtail for it, though, as it's a PITA to open and close the hood to unplug/plug it in every time I go somewhere. Might be a good use for a surplus mil-type Amphenol connector that I can put a cover on... (Of course I'll wait till it's much too cold out to actually DO anything, and wind up bitching about it the whole time, but that's par for the course.)

-Pat

[Zenith]

Ehh... I buy there from time to time; it's a crapshoot but overall I've come out way ahead.

As for your resistors; IIRC, those are not usually needed unless you have a particular failure in the prereg section which results in the release of magic smoke. I've never read of them drifting over time absent a DOA failure on the SMPS.

Obvi, you should check them, but I don't believe they're any sort of a PM item.

mnem
*toddles off to make lunch*

The 270K resistor is reckoned to be on the limit of its rating and it's worth changing while you have the board out. It's the board with the NVRAM. There are also surface mount electrolytics on there, which leak and damage the lands and some surface mount components. On this one those caps have leaked.

In the SMPS there's a Rifa capacitor which has split and spattered its guts about. It took a resistor with it. There are a couple of other resistors in the SMPS with cracked casings which are obvious candidates for replacement. The Rifas will all have to be replaced. I'll replace all the electrolytics, apart from two non-polarised ones, which seem hard to find.

The story was the 2465B was used occasionally for years and worked fine. One day it was switched on and there was a cloud of smoke so it was switched off quick. The owner decided to sell it rather than mess with it.

I'm hoping that's not a fiction and that it was OK, apart from the Rifa and resistor giving up the ghost with a cloud of smoke. There were unbroken seals on the scope which was nice to see. It had a 5A mains fuse fitted, which is not a good sign. It suggests that after the cloud of smoke a fuse was blown, and when it was replaced the scope didn't work. The 5A fuse was intact.

I'm also hoping that the NVRAM (dated 1989) with the calibration data is readable. If not I gather it can be something of a mission.

There's too much hope in this for my liking

[bd139]

I have a list of things I like to avoid where possible. Here for clarity:

1. Things people have attempted to fix already that couldn't.
2. Things with floppy drives that are required for them to function.
3. Things with Dallas NVRAM.
4. Things that can't be calibrated without special equipment.
5. Things that require signature analysers.
6. Things with no service manuals.
7. Things with undocumented power supplies even though the rest of the service manual is complete.
8. Really clever designs that weren't actually that clever.
9. Extremely rare things.
10. Things that have already clearly exploded.
11. Fire damaged things
12. Stuff that has been run over by a tank.

I figure a 2465B triggers points 1, 3, 4 and 10 so I would nope outta there

[Zenith]

There's no sign of an attempt to fix it, so 1 doesn't apply.

The Dallas NVRAM "might" be readable after 30 odd years of use. 3 might apply.

If 3 applies 4 will, but I haven't looked into calibration at all.

Having Rifa capacitors go up in smoke is common, even inevitable, for all the 70s/80s/90s gear that used them. Problems with those capacitors hardly count as "clearly exploded". 10 doesn't apply.

[Cerebus]

Same with an upcoming trip to Edinburgh. £166 on the train. 4:40 each way. By car 7h each way and £440.

Is there a sleeper service to Edinburgh, as there is to Glasgow? Last time I priced out Glasgow the sleeper (with a compartment) was a bit more expensive than a normal train ticket. (You pay by the compartment on the sleeper, so you can take an extra person with you "for free".) Much more civilised, and there is a bar onboard.

Nope it's going. Will get a trash bike for local use and use the busses.

Bike? That doesn't sound too bad, albeit risky nowadays if watching my fellow motorists dealing with passing, or indeed even spotting, cyclists is anything to judge by.

Bus? Sharing it with the local unwashed (and I use that term advisedly)? Best avoided.

Mind you, if you're prepared to brave busses then you could really take the bull by the horns and get a National Express overnight (laughingly called 'sleeper') coach to Edinburgh. I happened to have cause to look up the Glasgow->London price the other day and it was as little as £19 one way (I could have actually booked a ticket at that price, it wasn't just a 'from' fare that was actually impossible to book). Bloody cheap if you're prepared to rough it!

[Specmaster]

Mine has the original battery in it. 8 years old now. I don't drive it though.

On that, after a page or so of rampant scribblings and HP 12C prodding (this thing is current favourite toy) and going through service history and invoices on my car I've decided it's time to let it go. The total cost of ownership is too high and utility is too low to consider keeping it. I added the sum of all expenses together, took off the current value and divided it by the number of miles I've done and it comes out at £0.39/mile just for incidental costs of it existing. Add fuel at current costs at £0.15/mile and it's just not worth it. In context I'd have to use it more to reduce the cost but I don't need to.

To put it in perspective I need to go to Stroud in a couple of weeks. 200 mile round trip at .39 .15 + 200 * is £108. The train there is £50.60 and I get to sit on my arse and read a book at the same time. I am aware I'm going to miss radio rallies but eBay is working out far more productive at the moment.

Same with an upcoming trip to Edinburgh. £166 on the train. 4:40 each way. By car 7h each way and £440.

Nope it's going. Will get a trash bike for local use and use the busses.

I think that you should put that HP12C down carefully and step away from it, what are you going to calculate next and come out strongly opposed to, I wonder

I do however get your point when you look at it from a pure economy point of view, but then you need to factor in the extra's like getting to and from the station to begin your journey, and then there is the similar problem at the other end to say nothing of the extra time taken up to actually complete the final part of the journey. The inclement weather and also the severe restrictions on what you take with you, or what you bring back home and also of course the cost of the beginning and ending of the journey, station to station is a relative small part of the whole picture in my view. What about your trips to the depths of the countryside for your treks in the hills etc?

[AVGresponding]

The total cost of ownership is too high and utility is too low to consider keeping it. I added the sum of all expenses together, took off the current value and divided it by the number of miles I've done and it comes out at £0.39/mile just for incidental costs of it existing. Add fuel at current costs at £0.15/mile and it's just not worth it. In context I'd have to use it more to reduce the cost but I don't need to.

To put it in perspective I need to go to Stroud in a couple of weeks. 200 mile round trip at .39 .15 + 200 * is £108. The train there is £50.60 and I get to sit on my arse and read a book at the same time. I am aware I'm going to miss radio rallies but eBay is working out far more productive at the moment.

Same with an upcoming trip to Edinburgh. £166 on the train. 4:40 each way. By car 7h each way and £440.

Nope it's going. Will get a trash bike for local use and use the busses.

I'm surprised at the per-mile costs you arrived at, that seems way more expensive than it should be. Also bear in mind that your incidental costs are not linear; the more miles you do, the lower the per-mile figure is.

It's probably cheaper still to fly to Edinburgh and back, probably via Amsterdam or something equally ridiculous. I certainly wouldn't fancy a 7 hour each way drive.

[Zenith]

I could get by without a car but I wouldn't like to, and as Specmaster points out, there are all sorts of factors that you can't easily put a price on, but which are important.

I live in a village with a three convenience stores. They are very handy and I use them, but they are expensive and with limited choice. The town with a sizeable shopping centre and several supermarkets, is three miles away. I could get there by bus or take a taxi. I could use the Tesco or Asda delivery service for a fiver, but I don't want to mess about like that. Then there are people and places I want to visit, and that would be difficult to impossible without a car.

Sometimes - rarely - it makes sense to take the bus to the station and take the train.

Perhaps if you live in a big city, it makes sense to use public transport and hire a car for the few times a year you want it.

[Specmaster]

<snip>
Perhaps if you live in a big city, it makes sense to use public transport and hire a car for the few times a year you want it.

Add in to that as well that there might well be reasons that could prevent someone from hiring a car, for instance, age. By that I mean, that at my age, I discovered that I am no longer able to hire a van if I needed one. Not sure what the position is if I wanted to hire a car, of course BD is not in my age group so he could hire if needed.

[bd139]

Yeah it doesn’t make sense for everyone. I’m in a uniquely calculated location which makes this a non PITA. If I was somewhere else I’d need a car.

The incidental costs are the total cost of ownership ie depreciation, maintenance, insurance, tax divided by the mileage. Best in mind I’ve had it 5 years and I have done merely 15k in it during that time. That comes out at £0.39 for every mile I’ve driven. If I do a lot more miles that will go down but I just don’t need to do it so I don’t bother. That’s excluding fuel as the price of that is volatile but it’s working out around £0.15 a mile at the moment.

As for public transport I have several busses literally 2 mins outside my door that run all day every day and am 5 minutes walk from a major station. I can be in the city in 30 mins easily.

On bikes, almost road free access to Thames Path.

Not really even about economy. I could afford to crash it tomorrow and just buy another one. It’s more that the benefits just aren’t worth the headspace.

[AVGresponding]

Someone clearly left his diagnostic skills on the bedside table this morning, or maybe the belt he got off the primary side reservoir caps scrambled his brains a bit.

One of the supercaps is obviously domed, and the base of it's heatshrink is split and it's puked up its electrolyte, and when he measured the voltage across it, it was 0.0002, which would make no sense in the application; it should be at, or just below, the shutoff voltage for the silicon it's powering.

Commenter SeanBZA nails it for me.

https://www.youtube.com/watch?v=0rG_dBBxrR0

[Specmaster]

Someone clearly left his diagnostic skills on the bedside table this morning, or maybe the belt he got off the primary side reservoir caps scrambled his brains a bit.

One of the supercaps is obviously domed, and the base of it's heatshrink is split and it's puked up its electrolyte, and when he measured the voltage across it, it was 0.0002, which would make no sense in the application; it should be at, or just below, the shutoff voltage for the silicon it's powering.

Commenter SeanBZA nails it for me.

https://www.youtube.com/watch?v=0rG_dBBxrR0

Maybe his thumb is his brain and was still suffering from that zap

[bitseeker]

That reminds me - with the colder weather coming, I should probably start using the little desulfating charger on my Jeep again. Need to cobble together some sort of connecting pigtail for it, though, as it's a PITA to open and close the hood to unplug/plug it in every time I go somewhere.

I like the Battery Tender Jr. I've been using. I keep the pigtail from the battery tucked under the hood near one of the wipers so it's easy to get to. The last time I changed the battery was 2009.

(Interesting. The thumbs up "smilie" is supported but doesn't appear in the list beside the post edit box. The display limit is more than enough at 50 smilies.)

[mnementh]

Someone clearly left his diagnostic skills on the bedside table this morning, or maybe the belt he got off the primary side reservoir caps scrambled his brains a bit.

One of the supercaps is obviously domed, and the base of it's heatshrink is split and it's puked up its electrolyte, and when he measured the voltage across it, it was 0.0002, which would make no sense in the application; it should be at, or just below, the shutoff voltage for the silicon it's powering.

Commenter SeanBZA nails it for me.

https://www.youtube.com/watch?v=0rG_dBBxrR0

Maybe his thumb is his brain and was still suffering from that zap

All y'alls must've broken his pee-weeny li'l brain wid'jer comments... he took the vid down.

mnem
*toddles off to ded*

[mnementh]

That reminds me - with the colder weather coming, I should probably start using the little desulfating charger on my Jeep again. Need to cobble together some sort of connecting pigtail for it, though, as it's a PITA to open and close the hood to unplug/plug it in every time I go somewhere.

I like the Battery Tender Jr. I've been using. I keep the pigtail from the battery tucked under the hood near one of the wipers so it's easy to get to. The last time I changed the battery was 2009.

(Interesting. The thumbs up "smilie" is supported but doesn't appear in the list beside the post edit box. The display limit is more than enough at 50 smilies.)

Yeah, it appears phucked-upBB supports all the GitHub emojis.

Cheat-sheet is here:

mnem

[bd139]

You mean Unicode ones
?

[Cerebus]

My personal favourite Unicode emoji: which goes well with

[Cubdriver]

Finally managed to snag one of these in decent shape for a painful (but not agonizingly so relative to what people ask for them on our favorite wallet-draining site) price. It looks to be in excellent shape, and I expect it will prove quite handy. I'd only had this search in place for a few years now; people seem to either want stupid $$ for them, or they look like they've been through the war, often with mangled contacts.





-Pat

[MED6753]

Finally managed to snag one of these in decent shape for a painful (but not agonizingly so relative to what people ask for them on our favorite wallet-draining site) price. It looks to be in excellent shape, and I expect it will prove quite handy. I'd only had this search in place for a few years now; people seem to either want stupid $$ for them, or they look like they've been through the war, often with mangled contacts.


-Pat

I'll give you $25 cash for it.

Lucky dog......nice find.

[bd139]

Rare as unicorn farts those.

[Zenith]

Another day, another Jiffy bag from CPC. This one contains 20 1N4149 diodes which cost 48p. There are still a few items outstanding, including one 2.2µF 250V capacitor.

At this rate all their profits from this order will be gobbled up in Jiffy bags and postage.

[bd139]

Another day, another Jiffy bag from CPC. This one contains 20 1N4149 diodes which cost 48p. There are still a few items outstanding, including one 2.2µF 250V capacitor.

At this rate all their profits from this order will be gobbled up in Jiffy bags and postage.

That reminds me of the time I ordered 100x 1N4004's from them as part of an order. The diodes arrived in a separate consignment after being delayed for 2 days. Each diode arrived in a separate small plastic bag. They were cut from tape. This was put inside another bag and obviously because by the time it got to that state it was too big to fit in a jiffy bag, it arrived in a bloody great big box with packing pillows in it.

I received 97 diodes. Three bags were empty.