Test Equipment Anonymous (TEA) group therapy thread

[Neper]

As the new signalling system was commissioned a few years earlier, the Siemens signal box computer kept crashing.

Siemens had a bit of a rough time in the 90s with light-rail prototypes that wouldn't brake, self-igniting diesel locos in Norway, disintegrating Combino trams a bit all over the country, and tilting ICE VT high-speed trains that wouldn't tilt.

[mansaxel]

As the new signalling system was commissioned a few years earlier, the Siemens signal box computer kept crashing.

Siemens had a bit of a rough time in the 90s with light-rail prototypes that wouldn't brake, self-igniting diesel locos in Norway, disintegrating Combino trams a bit all over the country, and tilting ICE VT high-speed trains that wouldn't tilt.

Indeed. The particulars in this case was told by a then prospective-brother-in-law who worked in industrial robot commissioning for Siemens.

[med6753]

As a kid I remember NYC Subway cars as having a very distinctive whine of the DC traction motors as they gained speed. They also had wicker seats, ceiling fans, and open windows. With the open windows you were able to see just how tight those tunnels were. Maybe 6 inches clearance on both sides.

Today's subway cars are totally silent. Heavily insulated with A/C and uncomfortable plastic seats. The only real noise you hear is the old "clack track" rail joints. Only certain long sections are welded ribbon rail.   

[Robert763]

Got it home in one piece, and me in one piece. 

Makes my 8573B look lightweight and the 8574A portable 

[Robert763]

There's been a debate on and off in railway museum circles about what kind of experience is needed for the electrical side of things and I've always argued that rail-specific experience isn't necessary.

Competence is required. That's about it. There's an awful lot of current involved, and at times some pretty impressive voltages (low impedance sourced..)  But, it was built using pretty basic stuff, because that worked and could be made to continue working.

Now, there are finer details in the engineering implementation that might be non-obvious to the layman, but to the electric professional reading the technical docs on the loco they're not incomprehensible.

If you compare it with the intricate craftsmanship of running and maintaining a steam engine, not only is the work much less, it is much more manageable in terms of driving and servicing.

https://youtu.be/7ScBfNG0SiU

The one thing that is different with most traction systems is the use of DC. Few industrial control electricians will have experence of high voltage high power DC systems.

[med6753]

There's been a debate on and off in railway museum circles about what kind of experience is needed for the electrical side of things and I've always argued that rail-specific experience isn't necessary.

Competence is required. That's about it. There's an awful lot of current involved, and at times some pretty impressive voltages (low impedance sourced..)  But, it was built using pretty basic stuff, because that worked and could be made to continue working.

Now, there are finer details in the engineering implementation that might be non-obvious to the layman, but to the electric professional reading the technical docs on the loco they're not incomprehensible.

If you compare it with the intricate craftsmanship of running and maintaining a steam engine, not only is the work much less, it is much more manageable in terms of driving and servicing.

https://youtu.be/7ScBfNG0SiU

The one thing that is different with most traction systems is the use of DC. Few industrial control electricians will have experence of high voltage high power DC systems.

You can bet that's just the opposite here. Entire NYC subway system is 600VDC third rail. Metro North RR from Grand Central Station to points north is 600VDC third rail. I believe Amtrak from Jersey side tunnel under Hudson River to Penn Station is also 600VDC third rail.

The diesel locos that come up here to last stop at Poughkeepsie have a shoe on the wheel trucks to pick up the third rail just north of NYC. Once they pick up the third rail the diesel engine is shut down.   

[Robert763]

What's opposite? I said most traction systems are DC.
The difference I was referring to was industrial electricians working mostly with AC motors etc.

[dl6lr]

As the new signalling system was commissioned a few years earlier, the Siemens signal box computer kept crashing.

Siemens had a bit of a rough time in the 90s with light-rail prototypes that wouldn't brake, self-igniting diesel locos in Norway, disintegrating Combino trams a bit all over the country, and tilting ICE VT high-speed trains that wouldn't tilt.

I dunno if it was Siemens that built the new S-Bahn in Hamburg some years ago. But they failed famously.
S-Bahn uses a DC rail on either side of the track. In stations, it is the opposite side of the platform for obvious reasons.
Between stations Altona and Holstenstrasse, there is a long curved track where the train runs from ground level to a raised platform level. As there are some track switches, the side of the DC rail changes quite some times. The new trains stopped between both stations and could not be restarted. So the had to be pulled to the next station...

The first thing they found was a short gap, where no contact was made on either side. The old trains just used their inertia to fill that gap. The second thing they found was, that arcing during switching the contacts confused the trains computerized control system, which then refused to do anything and had to be rebooted, including all safety procedures on  train startup (like brake check, horn check etc.)

[mansaxel]

You can bet that's just the opposite here. Entire NYC subway system is 600VDC third rail. Metro North RR from Grand Central Station to points north is 600VDC third rail. I believe Amtrak from Jersey side tunnel under Hudson River to Penn Station is also 600VDC third rail.

The diesel locos that come up here to last stop at Poughkeepsie have a shoe on the wheel trucks to pick up the third rail just north of NYC. Once they pick up the third rail the diesel engine is shut down.   

Here, the subway ("Tunnelbanan")  is 600 or 750V DC (the last system built, the Blue Line, uses 750V; the earlier ones are 600. I suppose the under-construction extensions to the Blue Line will be 750, but I'm not as certain regarding the Yellow Line that's being built as an appendix off the Green line.) third rail. Trams and light rail are about the same, but catenary wire. Main-line trains are 15KV 15 16²/₃ Hz AC -- the frequency chosen as it's ¹/₃ of 50Hz and more suited to the single-phase electrical motors of the very early 20th century.  Sweden, Norway, Germany, Austria and Switzerland all share this system.

Edit: I can't write right even when I try.

[nfmax]

Currently sorting through a pile of thermocouples, thermistors and other miscellaneous temperature sensors, part of a 'haul' from last year. Checking the (unlabelled) thermocouple types using my dry-block calibrator and a thermos full of crushed ice (ice cubes from the freezer run through the food processor grating blade), against a reference PT100. The great thing about temperature is you can't rush it. A nice relaxing occupation for a holiday!

[mansaxel]

The Middle Boy spent all his Christmas money on a stomp box. I'm rummaging my junkbox so he does not have to ruin himself by buying 6F22 batteries.  It being audio and me being a kludge it's going to be a linear, and due to the contents of my component drawer it's a LT1085 job.  All the junkbox transformers I've encountered so far that have a sensible voltage won't deliver enough amps.  Below is a pic from the first one I tried, a small "9V" device (as usual, idle unloaded secondary voltage was ~15V) salvaged from a freezer control board. Nope, won't cut it. It can deliver ~74mA into 120Ω but that also means that voltage sags to ~7,6V which is not OK. Also his stompbox eats 100mA according to the manual. That's actually really a lot for a fuzz; most ones take around 12mA. I'd really like to avoid buying something, because that is cheating. 

Of course, the 428b is out and working. Clamp metering is sooo convenient.

[mnementh]

...I think Mnementh was probably thinking of the USS Nevada - she was painted red for operation Crossroads and was intended to be the primary target ship, but the aerial drop missed.
From the WIKI page:   Post-war
Nevada, then with her final commanding officer, Cecil C. Adell (28 October 1945 – 1 July 1946),[37] returned to Pearl Harbor after a brief stint of occupation duty in Tokyo Bay. Nevada was surveyed and, at 32⅓ years old, was deemed too old to be kept in the post-war fleet.[5][57] As a result, she was assigned to be a target ship in the first Bikini atomic experiments (Operation Crossroads) of July 1946.[4] The experiment consisted of detonating two atomic bombs to test their effectiveness against ships.[88] Nevada was the bombardier's target for the first test, codenamed 'Able', which used an air-dropped weapon. To help distinguish the target from surrounding vessels, Nevada was painted a reddish-orange. However, even with the high-visibility color scheme, the bomb fell about 1,700 yd (1,600 m) off-target, exploding above the attack transport Gilliam instead.[89] Due in part to the miss, Nevada survived. The ship also remained afloat after the second test—'Baker', a detonation some 90 ft (27 m) below the surface of the water—but was damaged and extremely radioactive from the spray.[57] Nevada was later towed to Pearl Harbor and decommissioned on 29 August 1946.[4]

After she was thoroughly examined, Iowa and two other vessels used Nevada as a practice gunnery target 65 miles southwest of Pearl Harbor on 31 July 1948.[5][72][n] The ships did not sink Nevada, so she was given a coup de grâce with an aerial torpedo hit amidships.[90][5]

   Oh, good lord you're right... definitely some neurons cross-connected on that memory packet...

mnem
"Awwww... DENDRITES!!!"

[Neper]

The second thing they found was, that arcing during switching the contacts confused the trains computerized control system, which then refused to do anything and had to be rebooted, including all safety procedures on  train startup (like brake check, horn check etc.)

In Ghent, Belgium, they're keeping some of their old PCC trams for de-icing the catenary. The new Bombardier and CAF stock can't cope with the transients caused by icing on the contact wire.

https://www.standaard.be/cnt/dmf20190131_04144270

[Martin.M]

gingle bells, gingle bells ..

 

[Neper]

Heathkit SB-610?

[PA0PBZ]

Heathkit SB-610?

The extra crunchy version!

[AVGresponding]

You can bet that's just the opposite here. Entire NYC subway system is 600VDC third rail. Metro North RR from Grand Central Station to points north is 600VDC third rail. I believe Amtrak from Jersey side tunnel under Hudson River to Penn Station is also 600VDC third rail.

The diesel locos that come up here to last stop at Poughkeepsie have a shoe on the wheel trucks to pick up the third rail just north of NYC. Once they pick up the third rail the diesel engine is shut down.   

Here, the subway ("Tunnelbanan")  is 600 or 750V DC (the last system built, the Blue Line, uses 750V; the earlier ones are 600. I suppose the under-construction extensions to the Blue Line will be 750, but I'm not as certain regarding the Yellow Line that's being built as an appendix off the Green line.) third rail. Trams and light rail are about the same, but catenary wire. Main-line trains are 15KV 15²/₃ Hz AC -- the frequency chosen as it's ¹/₃ of 50Hz and more suited to the single-phase electrical motors of the very early 20th century.  Sweden, Norway, Germany, Austria and Switzerland all share this system.

I'm guessing you meant 16²/₃Hz?

[SilverSolder]

The second thing they found was, that arcing during switching the contacts confused the trains computerized control system, which then refused to do anything and had to be rebooted, including all safety procedures on  train startup (like brake check, horn check etc.)

In Ghent, Belgium, they're keeping some of their old PCC trams for de-icing the catenary. The new Bombardier and CAF stock can't cope with the transients caused by icing on the contact wire.

https://www.standaard.be/cnt/dmf20190131_04144270

I keep an old transformer based car battery charger around...   when a battery gets completely flattened, the modern charger refuses to start charging, as the computer gets confused....

Just yesterday, I wast watching some videos of 4x4 off-road driving, where modern vehicles get stuck in the sand because the computers get confused and refuse to apply power to the wheels....

Moral of the story:   when you are designing computer controlled equipment, include some kind of manual override - and don't make it too obscure to find! 

[Neper]

In the olden days, IBM was seen by us Germans as an acronym for Immer Besser Manuell -> always better by hand.

[factory]

Update on the HP 5340A.

Replacement capacitors assembled & fitted.


All low voltages checked & verified as good. I left the Sangamo caps as they tested OK and didn't have crust underneath or that fishy smell, all the failed caps were Sprague, two of which were shorted.


It now has at least two other problems, first one is the display supply (+175V) is low & the displays dim or barely lit at a result. It's below the 135V-ish that the book states most voltmeters will display, as no smoothing cap is used.
The second problem, the displays are mostly stuck on 7s in self check mode, need to fix problem one first.


David

Ooh, I should get back onto fixing mine, I have a nixie version (actually two of them, and a third that was firmly a parts unit that got stripped down).

I just replaced those PSU caps with new Japanese ones of the same form factor, the original ones were so old and dried out that some sounded like they were full of dirt!

I've made reproduction OCXO Option PSU boards ready to populate one when I get to it, as I came across the needed transformer in the parts unit. Still have to source the actual OCXO though.


I'm definitely looking forward to seeing if the 18GHz inputs have been blown or not.... Hopefully I can cobble a fully working unit from the parts I have on hand..
I'd love to get my hands on the upgraded input section that was reportedly much more resilient, but that seems practically unobtanium unless you luck across it somehow.

Guess I sort of had some luck there, as both of mine seem to have been updated with the later front end assemblies, but both arrived in quite a state.
First 5340A from Germany had lots of fasteners missing, a hole where the I/O board had been robbed and loose RF connectors in the front end. After all those issues had been addressed, it only required the switches cleaning to work.

The second 5340A had two shorted PSU can caps, two failed rectifiers and the odd loose/missing fastener.
I couldn't easily obtain replacements screw terminal can caps, those at Mouser were quite expensive & some values were not stocked. Plus I have lots of surplus caps from the components I bought from work.
Still working on the +175V power supply, but since checking everything on the regulator board (all transistors, zeners & passives checked) I'm beginning to suspect the rectifier or transformer winding. I would check voltages against the good 5340A but can't access it until the storage unit reopens tomorrow.


Here is the output of the transformer with red wires disconnected from the rectifier, the book states the winding is 155V (but no mention of whether that is peak-to-peak or RMS).


With the wires reconnected to the rectifier & regulator board removed, I get this on the output of the rectifier, looks odd to me. Note: the rectified supply here is added to the unregulated +15V before going to the +175V regulator board.


Note: the rectified supply above is added to the unregulated +15V before going to the +175V regulator board.


David

[med6753]

What's opposite? I said most traction systems are DC.
The difference I was referring to was industrial electricians working mostly with AC motors etc.

Was referring to the electricians. They would have vast experience working on DC control systems.

[med6753]

You can bet that's just the opposite here. Entire NYC subway system is 600VDC third rail. Metro North RR from Grand Central Station to points north is 600VDC third rail. I believe Amtrak from Jersey side tunnel under Hudson River to Penn Station is also 600VDC third rail.

The diesel locos that come up here to last stop at Poughkeepsie have a shoe on the wheel trucks to pick up the third rail just north of NYC. Once they pick up the third rail the diesel engine is shut down.   

Here, the subway ("Tunnelbanan")  is 600 or 750V DC (the last system built, the Blue Line, uses 750V; the earlier ones are 600. I suppose the under-construction extensions to the Blue Line will be 750, but I'm not as certain regarding the Yellow Line that's being built as an appendix off the Green line.) third rail. Trams and light rail are about the same, but catenary wire. Main-line trains are 15KV 15²/₃ Hz AC -- the frequency chosen as it's ¹/₃ of 50Hz and more suited to the single-phase electrical motors of the very early 20th century.  Sweden, Norway, Germany, Austria and Switzerland all share this system.

On the New Haven branch of Metro North the MU cars are dual powered. Within NYC limits to and from Grand Central third rail 600VDC. Outside of NYC they switch over to overhead catenary. Unsure of the voltage but it is AC and I believe was initially 25Hz but has been converted to 60Hz. 

[Robert763]

Update on the HP 5340A.

Replacement capacitors assembled & fitted.


All low voltages checked & verified as good. I left the Sangamo caps as they tested OK and didn't have crust underneath or that fishy smell, all the failed caps were Sprague, two of which were shorted.


It now has at least two other problems, first one is the display supply (+175V) is low & the displays dim or barely lit at a result. It's below the 135V-ish that the book states most voltmeters will display, as no smoothing cap is used.
The second problem, the displays are mostly stuck on 7s in self check mode, need to fix problem one first.


David

Ooh, I should get back onto fixing mine, I have a nixie version (actually two of them, and a third that was firmly a parts unit that got stripped down).

I just replaced those PSU caps with new Japanese ones of the same form factor, the original ones were so old and dried out that some sounded like they were full of dirt!

I've made reproduction OCXO Option PSU boards ready to populate one when I get to it, as I came across the needed transformer in the parts unit. Still have to source the actual OCXO though.


I'm definitely looking forward to seeing if the 18GHz inputs have been blown or not.... Hopefully I can cobble a fully working unit from the parts I have on hand..
I'd love to get my hands on the upgraded input section that was reportedly much more resilient, but that seems practically unobtanium unless you luck across it somehow.

Guess I sort of had some luck there, as both of mine seem to have been updated with the later front end assemblies, but both arrived in quite a state.
First 5340A from Germany had lots of fasteners missing, a hole where the I/O board had been robbed and loose RF connectors in the front end. After all those issues had been addressed, it only required the switches cleaning to work.

The second 5340A had two shorted PSU can caps, two failed rectifiers and the odd loose/missing fastener.
I couldn't easily obtain replacements screw terminal can caps, those at Mouser were quite expensive & some values were not stocked. Plus I have lots of surplus caps from the components I bought from work.
Still working on the +175V power supply, but since checking everything on the regulator board (all transistors, zeners & passives checked) I'm beginning to suspect the rectifier or transformer winding. I would check voltages against the good 5340A but can't access it until the storage unit reopens tomorrow.


Here is the output of the transformer with red wires disconnected from the rectifier, the book states the winding is 155V (but no mention of whether that is peak-to-peak or RMS).


With the wires reconnected to the rectifier & regulator board removed, I get this on the output of the rectifier, looks odd to me. Note: the rectified supply here is added to the unregulated +15V before going to the +175V regulator board.


Note: the rectified supply above is added to the unregulated +15V before going to the +175V regulator board.


David

Looks OK to me.
As it is smoothed DC + rectified AC  you need to be careful what you use for voltage measurements. What voltmeter is specified in the manual. A modern digital meter or TRMS meter will give different readings to an old avereage reading moving coil.
The AC does look clipped. Check  the input voltage and settings. What do the other windings measure?

[factory]

The second thing they found was, that arcing during switching the contacts confused the trains computerized control system, which then refused to do anything and had to be rebooted, including all safety procedures on  train startup (like brake check, horn check etc.)

In Ghent, Belgium, they're keeping some of their old PCC trams for de-icing the catenary. The new Bombardier and CAF stock can't cope with the transients caused by icing on the contact wire.

https://www.standaard.be/cnt/dmf20190131_04144270

Historically tram systems often kept some trams & used them/converted them into works cars, for stuff such as rail grinding, snow removal etc. Some of which have been restored by museums.
It will be interesting to see how long the modern trams last in Blackpool, compared with the old ones were kept going for decades.

Re: the rebooting Of Siemens trains, the slow train (London Midland CL 350) from Birmingham to Crewe I used once refused to leave Birmingham, until the driver had completely powered down the train and rebooted it. It also had the most uncomfortable seats, would hate to have to go all the way to London using one of those PoS.

David

[AVGresponding]

Update on the HP 5340A.

Replacement capacitors assembled & fitted.


All low voltages checked & verified as good. I left the Sangamo caps as they tested OK and didn't have crust underneath or that fishy smell, all the failed caps were Sprague, two of which were shorted.


It now has at least two other problems, first one is the display supply (+175V) is low & the displays dim or barely lit at a result. It's below the 135V-ish that the book states most voltmeters will display, as no smoothing cap is used.
The second problem, the displays are mostly stuck on 7s in self check mode, need to fix problem one first.


David

Ooh, I should get back onto fixing mine, I have a nixie version (actually two of them, and a third that was firmly a parts unit that got stripped down).

I just replaced those PSU caps with new Japanese ones of the same form factor, the original ones were so old and dried out that some sounded like they were full of dirt!

I've made reproduction OCXO Option PSU boards ready to populate one when I get to it, as I came across the needed transformer in the parts unit. Still have to source the actual OCXO though.


I'm definitely looking forward to seeing if the 18GHz inputs have been blown or not.... Hopefully I can cobble a fully working unit from the parts I have on hand..
I'd love to get my hands on the upgraded input section that was reportedly much more resilient, but that seems practically unobtanium unless you luck across it somehow.

Guess I sort of had some luck there, as both of mine seem to have been updated with the later front end assemblies, but both arrived in quite a state.
First 5340A from Germany had lots of fasteners missing, a hole where the I/O board had been robbed and loose RF connectors in the front end. After all those issues had been addressed, it only required the switches cleaning to work.

The second 5340A had two shorted PSU can caps, two failed rectifiers and the odd loose/missing fastener.
I couldn't easily obtain replacements screw terminal can caps, those at Mouser were quite expensive & some values were not stocked. Plus I have lots of surplus caps from the components I bought from work.
Still working on the +175V power supply, but since checking everything on the regulator board (all transistors, zeners & passives checked) I'm beginning to suspect the rectifier or transformer winding. I would check voltages against the good 5340A but can't access it until the storage unit reopens tomorrow.


Here is the output of the transformer with red wires disconnected from the rectifier, the book states the winding is 155V (but no mention of whether that is peak-to-peak or RMS).


With the wires reconnected to the rectifier & regulator board removed, I get this on the output of the rectifier, looks odd to me. Note: the rectified supply here is added to the unregulated +15V before going to the +175V regulator board.


Note: the rectified supply above is added to the unregulated +15V before going to the +175V regulator board.


David

Weird how they've drawn the two bridges differently.

Have you tried inverting the phase on one of them?

What's opposite? I said most traction systems are DC.
The difference I was referring to was industrial electricians working mostly with AC motors etc.

Was referring to the electricians. They would have vast experience working on DC control systems.

I'd expect the electricians working on DC traction motors to have knowledge and experience of said systems, however the majority of industrial electricians that I know personally, wouldn't have a clue with DC stuff.

It's not something gone into during the college work part of an apprenticeship here, knowledge like that is acquired during on-the-job training, so you only get it if you're in that specific field.