Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

Riddle me this:
What might this strange layout, that looks like it has some things too many and others not enough, be?
Hint: Not all holes will be plated and there will be a ground plane below.
Ultra bonus points: (WIN AS MUCH WASHING MACHINES AS YOU CAN CATCH!)
What crazy construction revelation befell me?

Is it a distributed amplifier?

Indeed it is 
Many thanks to Med, who pointed out these were used on the Tek scopes - I got sucked down that rabbit hole immediately...

K... so what's the deal with only 2 SMAs? O/A design looks more like a single in/out. 

NM... light just dawned. Distributed amplifier, not distribution amplifier. 

mnem

[ch_scr]

Riddle me this:
What might this strange layout, that looks like it has some things too many and others not enough, be?
Hint: Not all holes will be plated and there will be a ground plane below.
Ultra bonus points: (WIN AS MUCH WASHING MACHINES AS YOU CAN CATCH!)
What crazy construction revelation befell me?

Is it a distributed amplifier?

Indeed it is 
Many thanks to Med, who pointed out these were used on the Tek scopes - I got sucked down that rabbit hole immediately...

K... so what's the deal with only 2 SMAs? O/A design looks more like a single in/out. 

mnem

I am not sure I understood the question, one is the input and one is the output of the amplifier? The input transmission line is terminated on the right (but capacitievly decoupled, to preserve gate voltage).
The output transmission line is terminated on the left, and is decoupled to ground - the drain bias will be injected "through" the termination resistors.
Edit: Yeah, it's quite an unusual thing. Elegant and low efficience, just the right thing to tinker on

[mnementh]

...
And I saw some other power on my way back home:

I don't know what the total output there was but Canadian Pacific was well into the eighth notch and moving it.

Two engines only? That's a short one(~100wagons), unless you have mid-and-end-engines, when you go can up to 200 wagons. Depending on the current engine notch, you will wait between 3(notch8/100wagons) to 25(notch4/200 wagons) minutes to pass; below notch 4 you turn around, in the same way when you see three or more active engines to pull...

While most RR's have embraced "distributed power" you can't always rely on what's in the lead pull to determine the length of the train. I still see CSX pulls with 4 or 5 loco's up front but only about 100 cars in tow. It could be they are simply moving loco assets from one yard to another.

Our new place is right in the middle of a major air, sea and rail logistics hub area; every time we go to the storage unit we wind up waiting for at least one train.  It appears that 2 ea end-to-end is the most common config by far, but that may be due to them jockeying cars around.   

The logistics of a region like this, coordinating intermodal traffic from trains at the docks just South of us with loading/unloading of both aircraft and semis and working around rush hour traffic, must be a complete brainfuck.

I used to imagine (before we had crazy high-density distributed-compute datamining server plantations) that if there ever is a spontaneous development of AI, it would be in such a network... 

mnem
*fulminating at the mind again*

[Specmaster]

...
And I saw some other power on my way back home:



I don't know what the total output there was but Canadian Pacific was well into the eighth notch and moving it.

Two engines only? That's a short one(~100wagons), unless you have mid-and-end-engines, when you go can up to 200 wagons. Depending on the current engine notch, you will wait between 3(notch8/100wagons) to 25(notch4/200 wagons) minutes to pass; below notch 4 you turn around, in the same way when you see three or more active engines to pull...

While most RR's have embraced "distributed power" you can't always rely on what's in the lead pull to determine the length of the train. I still see CSX pulls with 4 or 5 loco's up front but only about 100 cars in tow. It could be they are simply moving loco assets from one yard to another.

Our new place is right in the middle of a major air and rail logistics hub area; every time we go to the storage unit we wind up waiting for at least one train.  It appears that 2 ea end-to-end is the most common config by far, but that may be due to them jockeying cars around.

The logistics of a region like this, coordinating with loading of both aircraft and semis and working around rush hour traffic, must be a complete brainfuck.

I used to imagine (before we had crazy high-density distributed-compute datamining server plantations) that if there ever is a spontaneous development of AI, it would be in such a network... 

mnem
*fulminating at the mind again*

I think I have seen some YT vids where they sometimes put a locomotive in the middle as well, or did I imagine that?

[ch_scr]

...
And I saw some other power on my way back home:



I don't know what the total output there was but Canadian Pacific was well into the eighth notch and moving it.

Two engines only? That's a short one(~100wagons), unless you have mid-and-end-engines, when you go can up to 200 wagons. Depending on the current engine notch, you will wait between 3(notch8/100wagons) to 25(notch4/200 wagons) minutes to pass; below notch 4 you turn around, in the same way when you see three or more active engines to pull...

While most RR's have embraced "distributed power" you can't always rely on what's in the lead pull to determine the length of the train. I still see CSX pulls with 4 or 5 loco's up front but only about 100 cars in tow. It could be they are simply moving loco assets from one yard to another.

Our new place is right in the middle of a major air and rail logistics hub area; every time we go to the storage unit we wind up waiting for at least one train.  It appears that 2 ea end-to-end is the most common config by far, but that may be due to them jockeying cars around.

The logistics of a region like this, coordinating with loading of both aircraft and semis and working around rush hour traffic, must be a complete brainfuck.

I used to imagine (before we had crazy high-density distributed-compute datamining server plantations) that if there ever is a spontaneous development of AI, it would be in such a network... 

mnem
*fulminating at the mind again*

I think I have seen some YT vids where they sometimes put a locomotive in the middle as well, or did I imagine that?

Mandatory train video:

[mnementh]

Dang... those rails so wiggly,  looks like ringing in a flyback XFMR! 

mnem
you know you like it wiggly.

[Specmaster]

I've seen that video before, that is an accident just waiting to happen. Look at the rails flexing up and down as the train passes over them. It has to be worthwhile sending a crew out to repair the track, as it must take simply ages for the train to complete any journey at that slow speed.

[mnementh]

Our new place is right in the middle of a major air, sea and rail logistics hub area; every time we go to the storage unit we wind up waiting for at least one train.  It appears that 2 ea end-to-end is the most common config by far, but that may be due to them jockeying cars around.   

The logistics of a region like this, coordinating intermodal traffic from trains at the docks just South of us with loading/unloading of both aircraft and semis and working around rush hour traffic, must be a complete brainfuck.

I used to imagine (before we had crazy high-density distributed-compute datamining server plantations) that if there ever is a spontaneous development of AI, it would be in such a network... 

I think I have seen some YT vids where they sometimes put a locomotive in the middle as well, or did I imagine that?

Oh, yeah, for sure. At the old place, I saw 3-2-2 config on a long one with lots of double-stacked container cars.

Took a while, but my son and I had a interesting conversation aboot the graffiti, why the artists do it and how there are social scientists studying the "artistic DNA" of various creators and how their work influences others all over the world.

The proliferation of certain types of memes follows a very viral pattern, but interestingly, there seems to be "antibodies" in the pattern as well; created by the response from certain regions and their artists.


mnem
Also, it was fun just "feeling the powahhh" as the engine clusters rumbled past.

[mnementh]

I've seen that video before, that is an accident just waiting to happen. Look at the rails flexing up and down as the train passes over them. It has to be worthwhile sending a crew out to repair the track, as it must take simply ages for the train to complete any journey at that slow speed.

Rails flexing is a perfectly normal part of any railway; if they didn't flex they would break. Remember, every engine going past is somewhere in the neighborhood of a quarter to half a million pounds. 

I suspect there's a lot of pros and cons to consider. Leveling/rebuilding any stretch of rail is a large expensive undertaking, during which time the railway is down. If the particular route is relatively low frequency of deliveries but ones that have to go through without fail, I can see holding off on major rework until absolutely necessary.

Just as a rando layman with a very passing interest in railroading I can see that there is a huge can of worms in such a decision-making process.

It's not all aboot maximizing profit without spending on the infrastructure.

mnem
*hoooooooooooonk...*

[med6753]

I think I have seen some YT vids where they sometimes put a locomotive in the middle as well, or did I imagine that?

Yes, it's a very common practice now. And it could be more than one loco. As well as a loco or more at the back. Rail lines have discovered that there are efficiency gains to distributing the power throughout the train as well as less stress on the car couplers.

[Specmaster]

I've seen that video before, that is an accident just waiting to happen. Look at the rails flexing up and down as the train passes over them. It has to be worthwhile sending a crew out to repair the track, as it must take simply ages for the train to complete any journey at that slow speed.

Rails flexing is a perfectly normal part of any railway; if they didn't flex they would break. Remember, every engine going past is somewhere in the neighborhood of a quarter to half a million pounds. 

I suspect there's a lot of pros and cons to consider. Leveling/rebuilding any stretch of rail is a large expensive undertaking, during which time the railway is down. If the particular route is relatively low frequency of deliveries but ones that have to go through without fail, I can see holding off on major rework until absolutely necessary.

Just as a rando layman with a very passing interest in railroading I can see that there is a huge can of worms in such a decision-making process.

It's not all aboot maximizing profit without spending on the infrastructure.

mnem
*hoooooooooooonk...*

A few years back to make ends meet I also worked weekends on the railways doing track-laying and repairs while the tracks on either side of us were still running normal services and I can honestly say that tracks never ever had any flex visible. Yes, there are expansion joints where one rail ends and the next begins, but never was there any visible up and down flexing or sidewise flexing. At the time I was doing this, the sleepers and rails were positioned manually and then along came a special machine called a tamper that lifted rails where required and then packed the ballast under and around the sleepers to lock them into position. Surely if we Brits have technology to do this then you must have as well and these days, the whole process is almost fully automated and fast to do.

Sometimes I have just seen the tamper machine trundle down the tracks between running trains and just repack the ballast firmly, so it is isn't that costly to do, either way it is always going to be massively less expensive than having to deal with the aftermath of derailment, especially if there are personal injuries or fatalities involved surely 

[mnementh]

   

Urrrggghhh...

Trying my hand at some really contorted design work; a 3DP adapter to put my Kobalt packs on a Makita SawzAll I bought at the thrift a while back.

Am I doing the smart, easy thing, and making it by slapping an existing adapter from ThingiVerse onto a simple block that I can screw into place?

Of course not.

I'm starting all over from scratch, and making it so the new adapter nests inside the existing slides of the Makita, because my calipers say it will fit with at least 2mm of meat on all dimensions to hold it together.

mnem
you may all now point and jeer at the cwazy ol' dwagon...

[SeanB]

Problem with railways is that track is a separate entity from freight, which is separate from traction, and passenger is also separated into local commuter and long distance. Thus you have 5 divisions in any region, and they all are want to run the bare minimum of service quality. Track is worst off, it has an entire network to maintain, off the charges it levies on the other entities, so it is very loath to actually spend money till there is a derailment, as the staff in it are not really enough to actually maintain the lines properly, let alone build out new. Accountants cut the staff to the bone to make a profit, and the unions do not allow any cut in benefits, so staff costs are expensive, take a lot of training and in service training, and work very regulated hours.

Track maintenance is one of two things, lots of cheapish labour, spades, rail irons, pickaxes, large hammers and a few rail cars. Or an automated massively expensive machine, with a dozen or more skilled operators, running along slowly, with at least 10 rail cars bringing in precast sleepers, lengths of rail that will be automatically welded into position, relaid, retamped and then the maintenance vehicle travels over the new track section to the next. first one is easy to implement, but takes a shed load of time to work on a length, second is faster, can run around 20km per day for simple maintenance, but you need to run it 24/7/365 to warrant the near billion dollar outlay for the complete arrangement and the staff training and pay. Something like a 3 year apprentice program just for the practical side for the both of them, though the grunt labour does not need much training, other than tell to follow the others, and use the shovel like the guy next to you does, or get clobbered over the head by him when you slack off.

[mnementh]

A few years back to make ends meet I also worked weekends on the railways doing track-laying and repairs while the tracks on either side of us were still running normal services and I can honestly say that tracks never ever had any flex visible. Yes, there are expansion joints where one rail ends and the next begins, but never was there any visible up and down flexing or sidewise flexing. At the time I was doing this, the sleepers and rails were positioned manually and then along came a special machine called a tamper that lifted rails where required and then packed the ballast under and around the sleepers to lock them into position. Surely if we Brits have technology to do this then you must have as well and these days, the whole process is almost fully automated and fast to do.

Sometimes I have just seen the tamper machine trundle down the tracks between running trains and just repack the ballast firmly, so it is isn't that costly to do, either way it is always going to be massively less expensive than having to deal with the aftermath of derailment, especially if there are personal injuries or fatalities involved surely 

https://youtu.be/USAvjTlYVIM

Yeah, I've seen similar vids on how they maintain the tracks too, but it looked to me like that section of track needs a lot more than simple maintenance to be straight & flat again...? 

Honestly... thinking back over the years, I've noticed some flex in the tracks as trains go over from time to time, going back to when I was an idiot kid hanging around the yards in Pittsburgh, squishing pennies and running away from security, and later all throughout my life... I just assumed it had to be normal, given the incredible mass of what was moving over them. But I've always been weird in that I look for and notice such things without even thinking aboot it. 

You guys who really know rail... is that real "excessive neglect" in that vid or pretty much normal?   https://youtu.be/9X2A2f6E5DI

EDIT: Scoped out the vid on yoobToob; looks like definitely on the "actual neglect" side. Fellow talks like a proper rail junkie:

PREX 1603 leading PREX 3054 blasts down the former Wabash Railroad's 5th District!  LOL! actually I condensed 6 minutes of the train crawling down the track!  This is only the third time I've gotten a pair on one of their trains so I was pleased to see them.  The line was most recently the Maumee and Western Railroad (MAW) before being purchased by Pioneer RailCorp.  Maintenance was deferred for decades on this stretch of track.  Pioneer has done a great job rehabbing the worst parts but some pockets like this still exist. To use this video in a commercial player or in broadcasts, please email licensing@storyful.com

If you enjoyed this video please visit this playlist: https://m.youtube.com/playlist?list=PLfStbLtVgQN4bSxkbjaGj3gA6Sg7C1l4D    browse through the 50 plus videos of made along this railroad!

mnem
*scribble-scribble... notate-design-notate... clicky-clicky-clickety-clicky...*   

[Neper]

The video linked above has been made with a very strong telephoto lens, making everything look a whole lot more dramatic than it already is.

For some realy rotten tracks...



These rails in Dungeness, on the English south coast, were formerly used by local fishers to transport their catch across the beach.

[Specmaster]

That video has been made with a very strong telephoto lens, making everything look a whole lot more dramatic than it already is.

If you're talking about the shot with the train in the distance and wobbly track stretched out in front, then yes I agree, however the point I was making is where the train runs over the road and the camera focuses on the track joint close to the road where the 2 rails can be seen lifting and flexing, that is nothing to do with the compression effect of a telephoto lens.

[AVGresponding]

Ok mnem, that buck regulator has been running continuously at 1600mA @5V for a week now and shows no sign of quitting. The output voltage and input current have remained stable in the face of ambient temperatures ranging from 14 to 27 Celsius.

Do I have your permission to end the experiment now? I need the Pyrex bowl back, for cooking, apart from anything else.   

[Zucca]

Ok mnem, that buck regulator has been running continuously at 1600mA @5V for a week now and shows no sign of quitting. The output voltage and input current have remained stable in the face of ambient temperatures ranging from 14 to 27 Celsius.

Do I have your permission to end the experiment now? I need the Pyrex bowl back, for cooking, apart from anything else.   

I also have that terrible DCDC in my 3DP since 1 year and no problem... I think it depends... if you got the good one and not the clone you are okay.

[med6753]

I've seen that video before, that is an accident just waiting to happen. Look at the rails flexing up and down as the train passes over them. It has to be worthwhile sending a crew out to repair the track, as it must take simply ages for the train to complete any journey at that slow speed.

Rails flexing is a perfectly normal part of any railway; if they didn't flex they would break. Remember, every engine going past is somewhere in the neighborhood of a quarter to half a million pounds. 

I suspect there's a lot of pros and cons to consider. Leveling/rebuilding any stretch of rail is a large expensive undertaking, during which time the railway is down. If the particular route is relatively low frequency of deliveries but ones that have to go through without fail, I can see holding off on major rework until absolutely necessary.

Just as a rando layman with a very passing interest in railroading I can see that there is a huge can of worms in such a decision-making process.

It's not all aboot maximizing profit without spending on the infrastructure.

mnem
*hoooooooooooonk...*

A few years back to make ends meet I also worked weekends on the railways doing track-laying and repairs while the tracks on either side of us were still running normal services and I can honestly say that tracks never ever had any flex visible. Yes, there are expansion joints where one rail ends and the next begins, but never was there any visible up and down flexing or sidewise flexing. At the time I was doing this, the sleepers and rails were positioned manually and then along came a special machine called a tamper that lifted rails where required and then packed the ballast under and around the sleepers to lock them into position. Surely if we Brits have technology to do this then you must have as well and these days, the whole process is almost fully automated and fast to do.

Sometimes I have just seen the tamper machine trundle down the tracks between running trains and just repack the ballast firmly, so it is isn't that costly to do, either way it is always going to be massively less expensive than having to deal with the aftermath of derailment, especially if there are personal injuries or fatalities involved surely 

All the Class A railroads here (CSX, Norfolk Southern, BNSF, Union Pacific, etc. CN and Canadian Pacific in Canada) have the same automated track laying equipment as you do in the UK. Those railroads over the past 20 years or so have made great strives in upgrading their infrastructure. Freight, especially containerized cargo, is very profitable. And those roads don't handle passenger traffic which is very unprofitable. That's handled by Amtrak and they use the same rails as owned by the above mentioned roads.

You have obviously never watched a heavy freight up close go by at speed. Even with the best of laid ribbon (welded) rail there is some downward flex. And I'll bet that's built in. You are dealing with very heavy nearly 5000hp each loco's plus 100 to 200 cars behind it. Passenger trains on the other hand are much lighter and I would not expect to see any downward flex.     

[tggzzz]

The video linked above has been made with a very strong telephoto lens, making everything look a whole lot more dramatic than it already is.

For some realy rotten tracks...



These rails in Dungeness, on the English south coast, were formerly used by local fishers to transport their catch across the beach.

I've always assumed those were "offcuts" from the adjacent remarkable Romney Hythe and Dymchurch Railway

[med6753]

Meh......go "Big Boy" or go home. 

[mnementh]

Ok mnem, that buck regulator has been running continuously at 1600mA @5V for a week now and shows no sign of quitting. The output voltage and input current have remained stable in the face of ambient temperatures ranging from 14 to 27 Celsius.

Do I have your permission to end the experiment now? I need the Pyrex bowl back, for cooking, apart from anything else.   

   NO!!!   

Seriously tho... as long as you don't know that it isn't one of the ones that likes to fail Vin-Vout short, I'd def fuse/crowbar the output on that bitch, just for sanity's sake. Oh, and thanks for being such a good sport aboot it.

mnem
 

[mnementh]

Meh......go "Big Boy" or go home.     

Izzat the "million-pound locomotive" I remember seein' in the news a while back after the renovation?

mnem
Pretty sure traction ain't never a problem widdat summitch.

[mansaxel]

Meh......go "Big Boy" or go home. 

The Big Boy is an impressive machine, but even more impressive is the dedication of UP to keep it running, and actually run some revenue with it now and then.

The Railway Museum here have our "equivalent",  the Type R ore locomotive, which had a rather short career due to the Ore Railway where they were used (Luleå-Kiruna-Narvik in the far north of Sweden and Norway) being electrified in 1915 (it still is the same voltage and frequency).



It is in running order, and is being used for excursions now and then.

It was replaced with very large electrics, like the DM3:

[mansaxel]

Izzat the "million-pound locomotive" I remember seein' in the news a while back after the renovation?

Yup.