Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

- H2 cars (like they are shilled in germany strongly) need to go for a safety checkup of their 600 bar gas system every 10k

Hydrogen at 600bar? What could possibly go wrong!

Start by thinking of a puncture/cut in a collision. If that doesn't raise red flags, consider a grease monkey repairing it afterward...

Smaller version of this?

[YurkshireLad]

Also re: petrol vs diesel torque, the way they output torque is quite different. Petrol engines do it at a much higher rev range which means by the time the torque is there, the angular velocity is such that it breaks traction very easily.

That explains my findings about low revs of a diesel engine being just that much more controllable when grip is at a premium and the use of the lowest revs you can get away with.

This video shows the differance of that with a front-wheel drive car, high revs, wheel spins and loses both grip and direction control, the 36ft bus, low revs manages to maintain full control all the time.

I love saltburn! Sadly I haven't been there in years.

[VK5RC]

My chemistry is terrible but I thought the big issues with hydrogen are, its air-fuel explosive ratio is huge (NASA say between 4 and 94%) and leaks out of plain metal (steel) containers. Petrol's explosive air fuel ratio is narrower (1.2 —7 % by volume)
You can pour petrol into a car pretty easily by hand, quite a bit easier than filling with hydrogen.
The only person I knew who handled hydrogen regularly - a meteorologist neighbour - it was some years ago - hated the stuff - the weather balloon filling stations were always 20m away from the building and had serious blast protection structure and personal safety equipment. These are not insurmountable problems but to me they are not trivial.
Maybe larger commercial (district level) hydrogen storage with fuel cells for the electricity grid (? possible at that size) , if pumped hydro not available. It will be interesting to see what technology settles and works.

[duckduck]

fun and games and Murphy hitting me in the crotch  ...
coolant warning light came back on yesterday on that Volvo again. Coolant missing.
all that while I still had to return the trailer ...

my former neighbor gave me his car and I was able to get rid of the trailer. scrawled back to the Mechanik who said that he was refusing further work on the car. he said that he suspected a ruptured head or head gasket. that would coincide with the white fog coming Out of the exhaust.
FML

What a nightmare. When the engine overheated it may have warped the block and/or head. There is goop that you can buy to dump in the radiator that MIGHT patch the leak. It worked for me for several weeks (long enough to buy a replacement car). The goop is a total janky band-aid and, if it even works, the car will be living on borrowed time. Plan on expensive repairs (to do it right) or a replacement vehicle. You have my sympathy.

When ethylene glycol (engine anti-freeze) gets into the combustion chamber or drips on the exhaust it makes a very particular sweet smell. Remember that smell. It is a powerful diagnostic tool to have in your tool box. In very small coolant leaks, you might smell it in the exhaust only right after start-up when there has been time for the coolant to weep into the combustion chamber after the car was last turned off.

EDIT:

And who can forget the always lovely https://en.wikipedia.org/wiki/Hydrogen_embrittlement ?

[med6753]

I see no problem with H2 powered vehicles. 

Well, the Hindenburg was diesel powered, the hydrogen just provided lift.

No shit Dick Tracy. The Obvious is obvious. Try to make a joke and someone has to ruin it. Fucking killjoy. 

And yes, I am aware it was supposed to be filled with Helium but we wouldn't allow the Germans to have it.

[factory]

  some TEA content 



David

[Cerebus]

No shit Dick Tracy. The Obvious is obvious. Try to make a joke and someone has to ruin it. Fucking killjoy. 

We know how much you like to be miserable, if we go around letting you have fun you'll really be unhappy rather than creatively miserable. Now, aren't there some kids you have to chase off your lawn? Go on, you know you want to...

 

[Vince]

some TEA content 


David

I agree with you, so here you go, still hot from the oven.

Packed all my electronic stuff in a million plastic moving boxes 3 years ago now... now starting to unpack and sort and organize everything, at long last.
First box is being processed as we speak :  I am working on a box that from a distance looked like a giant fuzzy blob of unidentified leads cables and probes, among other miscellaneous things.
After some patience pulling the leads one by one... I eventually found myself with mostly a bunch of DMM test leads. Now neatly organized and accessible... just counted them : 20 leads. Luckily I seem to have as many red ones as there are black ones, which is a good start. I can't say that much about my socks out of the drying machine today.

I guess buying 20 old DMM brought me a bit too many used test leads 
Now need to look at them one by one to decide which ones are worthy of actually being used, and which ones are going to the trash. Well, I don't think I will trash them... I will at least cut the ends and keep the wires... supple and stranded thick gauge wires are expensive... would be stupid to scrap them. I can always reuse them to power stuff I am working on.

[BU508A]

What do the Tek-experts here think about this Rohde & Schwarz 7623A scope?
Is it overpriced? Seller is asking EUR 550.- for it plus shipping.



And what is this on the backside?

[Vince]

It's an early '70s 100MHz analog scope !! 550 Euros 

For 100 Euros tops, if you lived nearby and could go pick it up... otherwise keep your money ! 

Scope as such is nice, seems to be alive, has a storage tube and a cool comparator plugin in the first slot/bay, no missing or broken knobs at first glance. With a good cleanup it would be a lovely scope... it does deserve a good home for sure, but NOT at this silly price, guy is smoking funny stuff ! Either that, or the trailing zero in the price tag, was a typo / literal , a slip of the finger...

[Specmaster]

some TEA content 



David

What a nice and neat unit, thats   

[med6753]

What do the Tek-experts here think about this Rohde & Schwarz 7623A scope?
Is it overpriced? Seller is asking EUR 550.- for it plus shipping.



And what is this on the backside?

Over $600 USD? No way. I would estimate higher than Vince though. $250 - $300 USD. Has that somewhat valuable 7A13 plug-in.

What specifically are you asking about on the backside?

[mnementh]

   I got to fondle my 3478A today. *wibble*

Then I had to get to work on the ToD again... 

Sorry... that's a archive photo. I only had time to fondle; nothing more.

mnem
I'm going home to mutter...

[BU508A]

What do the Tek-experts here think about this Rohde & Schwarz 7623A scope?
Is it overpriced? Seller is asking EUR 550.- for it plus shipping.



And what is this on the backside?

Over $600 USD? No way. I would estimate higher than Vince though. $250 - $300 USD. Has that somewhat valuable 7A13 plug-in.

What specifically are you asking about on the backside?

This box with the 3 + 3 BNC connectors. It has a sawtooth output. I assume, it is for some external triggering. What confuses me is: it looks like an add-on module or some kind of afterthought. 

[Brumby]

I got to fondle my 3478A today.

That reminds me ... I really need to replace the battery in mine.

Any recommendations on what to go for ... or for what to avoid?

[Vince]

This box with the 3 + 3 BNC connectors. It has a sawtooth output. I assume, it is for some external triggering. What confuses me is: it looks like an add-on module or some kind of afterthought. 

Well most '70s Tek scopes I have seen have stuff protruding at the back.. saves space. This scope you are looking at here looks 100% stock, perfectly normal. In the 5000 series scopes, also same vintage then, you have a protruding mains transformer and also protruding CRT neck. It's just how Tek did their scopes back then. Again I assume / guess it was to save space, but I don't really know...

[Vince]

Done with the test leads.  I reconstituted all the sets. 10 of them. In the end there were only 2 sets that we too far gone to justify holding on too, so I scrapped them and salvaged the wires, and cleaned them.
So 8 left. That includes one set of pin sharp gold plated probes for SMD stuff, a couple sets of Fluke 2mm, and x3 sets of Metrix 4mm banana leads.

So I have 8 extra sets of test leads now... can't possibly keep them all handy, would take too much space and clutter the space, for too little use; who needs 10 extra sets of leads at all times on their bench, not me anyway...

I guess I will just keep 2 or 3 at hand on the bench, the best quality ones, one 2mm and one 4mm, and store the rest away so that it does not clutter the bench or my close by drawers where I want to store only the stuff that actually gets used often and needs to be at hand, easily.  If I ever need 5 or 6 DMM / sets of leads at the same time for god knows what monstrous project... it's OK to spend a minute to go get them in a slightly more remote drawer/box, 2 meters away... it's an acceptable compromise...

Come to think of it I must have at least 4 or 5 more sets... for, some of my Metrix DMM are NIB and came in their original box (card board or leather pouch or plastic case with accessories...) and I am pretty sure all of these boxes were fitted / came with NIB OEM test leads...

So... lots of test leads ! 

1H30 AM, unboxing and sorting stuff shall continue tomorrow after some sleep... 

[cyclin_al]

mnem

listed under free stuff?  Hmmm.....

The first thing to check is the head gaskets (two in a boxer engine) and coolant pathways.
They engineered the engine to a spec. and then had to go to lightweight 0w20 oil in order not to clog the oil channels in the block.
Always, always, always be sure to warm up the engine before driving.  Then again, it is in Texas, so it probably has been warmed up all its life there 

Nice cars for driveability and fun factor.  Not necessarily the easiest to wrench.  Then again, certain folks look for things to tinker on...

EDIT:  You (dwagon) have actually seen me in one of these cars.

Oops,  Forth Worth is not in Texas.  I have no clue why I thought that... premature seniors moment?

[SilverSolder]

Over the years I've driven loads of cars, buses, coaches, lorries and vans in all kinds of weathers and I can't think of a single time that wheel spin has been of assistance no matter. You are trying to get moving, and in most vehicles when you get wheel spin it will be because there is zero grip. Without traction control being ON, all the drive will be sent to the spinning wheel, therefore no movement. The wheel is just polishing further the surface that is giving no grip.

Agree that wheel spin while stationary buys you nothing other than digging in deeper. Controlled wheel spin while moving can sometimes be a distinct advantage until the tires finally grip. Key word is "controlled". If you just mash the gas you might as well walk.

I have driven tens of thousands of miles a year professionally for over 40 years, in all conditions and have never once been in a situation where I have lost control of the vehicle, developed wheel spin on snow or ice. In my early career as an apprentice working for the National Bus Company, I was sent out a few times to deliver a replacement service bus to various locations, where the regular service driver had managed to become stuck in snow or ice, to allow passengers to get to their destinations in the new bus. I would then have to recover the "stuck" bus and drive it back to the garage in town. I always managed it safely. The trick is to have a very light foot and very gentle inputs into everything, steering etc, pulling away in second gear rather than first as this reduces the torque being applied to the driving wheels. Keep the engine revs low at all times and keep in the highest gear possible. That technique has stood me in great stead ever since, especially while I was doing a stint of lorry driving all over the UK, including driving across the Pennines on the notorious A66 (long before it was dualled), in a Ford D series 7ton box truck, from Penrith to Scotch Corner in the middle of a massive blizzard and managed it none stop while others had become stuck.

Sounds to my like you're trying to make a virtue of never having learned to steer with the right foot.

Seriously... there's a biiiiig difference between driving a large heavy vehicle on paved streets vs driving small passenger vehicles on slick, muddy or slushy terrain. There are times when the best tactic is not to try and plow through, but rather to float across the obstacle.

If you don't learn how to utilize drive wheel spin, you won't last 30 seconds on any dirt oval track, or in most off-road scenarios, be it racing or just donking around in the back 40.

As for traction control... I had just such a problem with the Rav4 first winter we had it; our house had a steep drive, and neighbors would often park directly across the street such that we had to come up at a angle. Problem was, the inboard front wheel would start up the hill, and just as the outboard wheel would start to come up the lip of the apron, it would start to slip on the ice/snow/slush because of the front of the car lifting due to the inboard wheel already being a foot or two up the hill. Now the fekking traction control kills the throttle, making the car roll/slide down the damn drive into the street without my consent; the first time there was a vehicle following close behind me and I almost hit them. 

Several times I tried, and as slow as I could go or as fast as I could hit it without risking sliding past the drive, it didn't matter; the traction control would kill throttle at the worst possible moment.

Stopped fighting it, took out the manual to figure out how to turn the stoopit thing off, and whoop! zipped right up the drive with literally a barely noticeable fraction of a second of spinning at the lip of the apron.

Several times over the next 2 winters I had opportunity (read: I forgot to turn the fucking thing off) to test this theory; every time, turning traction control off returned normal control of the vehicle to me, the driver.

Which is where it belongs.

Cheers,

mnem
 

Yep, totally agree, traction control can on the odd occasion work against you. But seriously, for the best of that 40 years of driving professionally, such gadgets as ABS, Traction etc were not available, even on the range topping cars and buses and lorries, good grief no.

The buses were powered by a Gardener 6 cylinder, long stroke diesel engine of 10.45 litres producing 150HP @ 1700RPM. Not as powerful as many would think, and they tick over @ approx 500 to 600RPM, but the torques available was massive, simply releasing the clutch at idle there was more than enough torque to pull away cleanly. It was a similar story with the Ford D series truck, although its idling speed was much higher. I think diesel engines are preferable in winter conditions because of their increased weight and grip as a result of the weight, but also because of their low down pure grunt.

I think those advantages of the diesel is shared by hybrids (or electrics) in snow -  gobs of low down torque, which is very controllable (no need to rev the engine and finely balance the clutch).

[med6753]

This box with the 3 + 3 BNC connectors. It has a sawtooth output. I assume, it is for some external triggering. What confuses me is: it looks like an add-on module or some kind of afterthought. 

Well most '70s Tek scopes I have seen have stuff protruding at the back.. saves space. This scope you are looking at here looks 100% stock, perfectly normal. In the 5000 series scopes, also same vintage then, you have a protruding mains transformer and also protruding CRT neck. It's just how Tek did their scopes back then. Again I assume / guess it was to save space, but I don't really know...

As Vince stated looks normal to me. I don't have a 7623 nor have I used one but I do have a military 7603 and it has a similar arrangement in the back.
 

[med6753]

No shit Dick Tracy. The Obvious is obvious. Try to make a joke and someone has to ruin it. Fucking killjoy. 

We know how much you like to be miserable, if we go around letting you have fun you'll really be unhappy rather than creatively miserable. Now, aren't there some kids you have to chase off your lawn? Go on, you know you want to...

 

Who's miserable? Not this boy. I'm a happy and content grouchy old bastard. Being anti-social keeps the idiots away and that makes me overjoyed.

The kids can play on the lawn as much as they want. It's not my lawn. It's the landlord's. And he has to mow it and care for it, not me. But right now that would be a little difficult since it's covered in snow and ice. 

[Brumby]

My preferred storage solution for such things - which includes all kinds of cables and plug-packs - is to put each set into a zip-lock bag.  You can then dump all these into any storage container you like and they will never get tangled.  Also far easier and quicker to sort through them - and FAR less likely to get damaged.

Here's a random sample from my unsorted  container.

[SilverSolder]

No shit Dick Tracy. The Obvious is obvious. Try to make a joke and someone has to ruin it. Fucking killjoy. 

We know how much you like to be miserable, if we go around letting you have fun you'll really be unhappy rather than creatively miserable. Now, aren't there some kids you have to chase off your lawn? Go on, you know you want to...

 

Who's miserable? Not this boy. I'm a happy and content grouchy old bastard. Being anti-social keeps the idiots away and that makes me overjoyed.

The kids can play on the lawn as much as they want. It's not my lawn. It's the landlord's. And he has to mow it and care for it, not me. But right now that would be a little difficult since it's covered in snow and ice.

Not many Americans see the beauty of renting, lol! 

[Vince]

listed under free stuff?  Hmmm.....

The first thing to check is the head gaskets (two in a boxer engine) and coolant pathways.
They engineered the engine to a spec. and then had to go to lightweight 0w20 oil in order not to clog the oil channels in the block.
Always, always, always be sure to warm up the engine before driving.  Then again, it is in Texas, so it probably has been warmed up all its life there 

Nice cars for driveability and fun factor.  Not necessarily the easiest to wrench.  Then again, certain folks look for things to tinker on...

Reminds me of this video posted 2 weeks ago at X-mas, from a guy I follow on YT. A car channel were a professional mechanic sometimes fixes cars and gives them for free to people in need / charity.
In that video he fixed.. a Subaru. Once fixed, he had a chat with some Subaru nuts on the Subaru forum, only to realize that this car even once fixed, would still be a ticking time bomb, that would need lots of work all the time, because they are just... horrible cars.  So he thought it would therefore not be a good idea to give such a car to a poor family... so instead he wanted to give it a Subaru nut, who knows these cars, likes their quirks and don't mind putting up with them and fixing them as they need to.... So in this video he tries to surprise one of the guys in the local Subaru forum, and when he says "Hey, this is YOUR Car, here are the keys !! "... the guy keeps a straight face, stays very calm, no excitement or thank you.. he just says.. " HELL NO I DON'T WANT IT !!!!   "     EVEN the Subaru guys don't want that car !     That just cracked me up ! 

[cyclin_al]

Over the years I've driven loads of cars, buses, coaches, lorries and vans in all kinds of weathers and I can't think of a single time that wheel spin has been of assistance no matter. You are trying to get moving, and in most vehicles when you get wheel spin it will be because there is zero grip. Without traction control being ON, all the drive will be sent to the spinning wheel, therefore no movement. The wheel is just polishing further the surface that is giving no grip.

Agree that wheel spin while stationary buys you nothing other than digging in deeper. Controlled wheel spin while moving can sometimes be a distinct advantage until the tires finally grip. Key word is "controlled". If you just mash the gas you might as well walk.

I have driven tens of thousands of miles a year professionally for over 40 years, in all conditions and have never once been in a situation where I have lost control of the vehicle, developed wheel spin on snow or ice. In my early career as an apprentice working for the National Bus Company, I was sent out a few times to deliver a replacement service bus to various locations, where the regular service driver had managed to become stuck in snow or ice, to allow passengers to get to their destinations in the new bus. I would then have to recover the "stuck" bus and drive it back to the garage in town. I always managed it safely. The trick is to have a very light foot and very gentle inputs into everything, steering etc, pulling away in second gear rather than first as this reduces the torque being applied to the driving wheels. Keep the engine revs low at all times and keep in the highest gear possible. That technique has stood me in great stead ever since, especially while I was doing a stint of lorry driving all over the UK, including driving across the Pennines on the notorious A66 (long before it was dualled), in a Ford D series 7ton box truck, from Penrith to Scotch Corner in the middle of a massive blizzard and managed it none stop while others had become stuck.

What you are describing is exactly what a hybrid drivetrain is good at:  finely modulated torque, you can really  the force until just before the wheels begin to spin...   - 

It is a logical deduction from physics: static friction is generally higher than dynamic friction - you don't want the wheels to spin and end up in the dynamic area.

I keep an elastic tow rope in my car, which I use to help people out of trouble in the snow.  The funniest one was pulling a beefy 4WD Jeep out of a snow drift that the overconfident young driver had intentionally tried to plow through.  I got him out, then proceeded to drive though the same drift as I left, just to prove that older men can be just as silly as young'uns, if they try a little! 

Same here.  I have used a Subaru Impreza to pull a Jeep out of a parking spot. 
The Impreza was almost "surfing" on the snow due to limited ground clearance, but very gentle consistent tension was enough to help the Jeep get rolling.
I was the young and cocky one back then.  Once clear, the lady driving the Jeep asked if she should stay until I got clear of the snowbank blocking the parking lot; I declined... whew I did make it out on my own!

I have had opportunity to drive on ice tracks with my old truck.  I even did a course on said track that was meant for certain authorities to brush up their winter driving skills.
When rolling along, a precise blip of the throttle while turning could rotate the truck with an incredibly small turning radius.  The result was the ability to keep the truck on the driving line along the track edge with some snow, and avoid the ice sheet in the centre of the track...

I have lost vehicle control three times.  The first was sheer lack of experience as a novice.  The other times were intentional in controlled conditions and were experiments in what it was like to greatly overshoot the limits.