Test Equipment Anonymous

25 CPS wrote: ↑Mon Aug 07, 2023 9:55 pm

mansaxel wrote: ↑Sun Aug 06, 2023 11:52 am

25 CPS wrote: ↑Fri Aug 04, 2023 2:19 am
I'm beginning to suspect a problem downstream of the internal timebase. This counter takes a 1 MHz reference input so I couldn't directly connect it to my 10 MHz reference distribution but I used a signal generator that is locked to it to generate 1 MHz out and it was still off.

Check the supply crapacitors. I've read about more than one counter that had power rail ripple and added 50 or in your case 60Hz and its overtones to the result. Depending on the timebase trigger frequency the outcome varies, of course.

Thanks for the suggestion. I had been giving some thought to how the miscount is present whether the counter is running off the internal timebase or external 1 MHz because this implies pretty strongly that there's a problem taking place outside of the internal timebase. A noisy power problem would affect the whole machine for sure.

I did get a bit more playing time with this counter and I also wasn't able to adjust out the miscounting by varying the frequency of the external reference off 1 MHz either. I'll check the power supply performance on it next whenever I have another chance to play with it. The other possibility that comes to mind is the division and counting network downstream of the timebase source. It's possible something in there could be damaged; hopefully that's not the case because power supply components are much easier to source than difficult/unobtainable HP parts. The other thing I need to do is see if there's a better scan of the manual out there than the one on the Keysight website where the illustrations did not come through well at all.

I just dug out my 5216A Manual. Attached here are pics of the power supply schematic and the board layout to start with. Let me know what you need specifically, and I'll try to get good pics for you.





-Pat

25 CPS wrote: ↑Tue Aug 08, 2023 3:52 am I've been meaning to put this post together for a while and I just finished off doing some final testing this evening to conclude things.

One of the places I help out is a trolley museum in Baltimore. Sometime between 2019 and late 2021 one side of the interior lights inside of a 1948 Philadelphia streetcar went out and nobody was able to get them working again by swapping bulbs, changing fuses etc...

[SNIP]

...then, when while we were trying to get to the bottom of why it still wasn't working and trying to figure out why we were seeing such strange resistance measurements in places, we discovered this in the compartment under the very rear seat:



Sometime while the streetcar was still in Philadelphia, the resistors used to make up the balance of the voltage divider so the whole thing adds up to 600 V had been replaced by additional lightbulbs wired in series.

[SNIP]

After we got that socket fixed up and the fixture reassembled, we replaced the burnt out bulbs with spares, reassembled everything and tested:

. .

Full interior lighting and both sides of the destination sign lit up for the first time in years. The handful of lights in the middle of the ceiling are all 32 V regular bulbs wired in parallel along with the headlight and energized off the streetcar's low voltage power supply that's backed up by battery. You do not want a self shorting bulb anywhere in that circuit because as soon as it burns out and shorts out, it would be a dead short across the low voltage supply and pop the fuse for the headlight circuit.

[SNIP]

Anyways, that's a good example of some of my portable test equipment kit being used in the field for totally unrelated to work volunteer stuff.

mnem
fuxxored...? fixxored.

DO NOT ATTEMPT THIS AT HOME!

this is me checking the crt HV on my hp 54502a.

picked up my first fluke side button multimeter sunday morning at the berryville va hamfest. it appears to work A-OK.

input impedance is 10Mohm on all ranges so you just put it in series with the homebrew 990Mohm resistor. multiply the reading by 100 and badda bing.......11.47KV.

ps paid 20 bucks for the meter. figured it probably had a leaky dead battery inside and would turn into a project, so was gonna' try bargaining with the nice lady. but the damn thing turned on and worked, so it seemed best to just hand over the sticker price and walk away.

Ooh don't like the stripboard. It can easilly arc across and breakdown. The SRPB bord is't the best insulator either.
A bit of bare GRP board materal and connections with just the resistor leads is better. A acrylic tube with them all in series is even better.

Robert.

Robert wrote: ↑Tue Aug 08, 2023 6:24 pm Ooh don't like the stripboard. It can easilly arc across and breakdown. The SRPB bord is't the best insulator either.
A bit of bare GRP board materal and connections with just the resistor leads is better. A acrylic tube with them all in series is even better.

Robert.

that is a bare perf board. no copper cladding. just holes.

suppose it could still arc. it could then blow up a $20 meter.

meh.

Cubdriver wrote: ↑Tue Aug 08, 2023 4:39 am Nice job of troubleshooting! That one was for sure quite the head scratcher.

-Pat

Yeah; it's fascinating how something so simple (a string of lamps in series, literally every vintage christmas tree festoon!) can be so completely confusing and hard to sort. Well done.

@25 CPS Geez what an overcomplicated system to provide interior lighting on a means of public transport, makes my time looking after 130+ buses chicken feed. I don't understand why they didn't just stick a transformer in and have all lamps at 32V, unless of course the 600v was DC?

Specmaster wrote: ↑Tue Aug 08, 2023 7:34 pm @25 CPS Geez what an overcomplicated system to provide interior lighting on a means of public transport, makes my time looking after 130+ buses chicken feed. I don't understand why they didn't just stick a transformer in and have all lamps at 32V, unless of course the 600v was DC?

Rube Goldberg apparently worked in streetcar lighting design, too. What a crazy, convoluted system.

mnementh wrote: ↑Mon Aug 07, 2023 11:59 pm Well, it's supposed to be a simple matter of him getting the PT he needs in an environment that is safe for him in his condition; it's supposed to be in-patient medical care, not a old-folks home. This is pretty intensive health-care, so I expect no insurance is going to put up with him in such a place for extended timeframe.

But for now things are on hold; he's been complaining of pain in his foot and leg which is bad enough he can't put full weight on the leg. They're doing an MRI on him tonight to see if they can find some actual cause for the pain.

I spent the day seeking out grab rails and no-skid sticky flowers for the shower, then clearing stuff and making room for the hospital bed.

We'll see what happens tomorrow.

Update time:

The MRI showed some squished disc issues in his lower back, but they weren't too detailed in their explanation. As of last night when the boi and I came home, (2200-ish) they hadn't moved him due to bed availability, but supposedly they have admitted dad to the hospital proper, and will be actually working with him to get him to a point where he can either be taken home (able to at least get from bed to a commode) or to a inpatient PT rehab location.

I'm taking your concerns to heart; if the latter happens, I will continue to visit him twice a day as I have done, and I will keep on top of what they're actually doing with him. If he says they aren't actually doing the PT, or if he appears to be drugged and incoherent, I will sign him out immediately.

Think I've done more walking in the last week than the entire month prior; that hospital campus is effing yuuuge... I need to start getting to bed earlier, cuz I am paying for it now. Fortunately I have the kids to crack the whip and keep me moving.

mnem
Thank you all for your concern; it does help this old country boy to know there's someone who GAF.

HEY 25 CPS

just wanted to say i really enjoyed your trolley project.

unfortunately my skinny ass never rode in that car.

from 73 till 78 it did ride on the septa 102 route almost every day to and from work and college.

our red arrow line (sharon hill/media) used different style cars than the city routes.

but still......seeing your pictures gave me flashbacks. and i did not know that there is a trolley museum down in charm city.

THANKS!

ps "charm city" always makes me laugh......but no more than "city of brotherly love"

Afternoon. Couple of photos...
Climbed up half a volcano
Nice waterfall
Even nicer waterfall
Shit hotdog
One for mansaxel ... Swedish gear in use

bd139 wrote: ↑Thu Aug 10, 2023 3:01 pm Nice waterfall

Stand with your feet in the right/wrong place there, and after a while you will be doing the splits.

Even nicer waterfall

Good picture of the railings they've erected for the snowflakes. I see none of the sheeple went along the easy path to take a photo close to the waterfall, viz just above the green arrow to the green spot.

Shit hotdog

Stop whining. At least they took the barcode off each individual potato before mutilating them. There's a reason why the Icelanders used to need to eat Hákarl, and why until after WW2 some of them (esp. near Skaftafell) used horses to harvest subsistence crops from the sea.

Alternatively: if you can afford potatoes in Iceland, your salary is too high. Ditto alcohol.

P.S. despite appearances to the contrary, I would prefer it if a slightly different person returned safely.

nixiefreqq wrote: ↑Wed Aug 09, 2023 11:44 am HEY 25 CPS

just wanted to say i really enjoyed your trolley project.

unfortunately my skinny ass never rode in that car.

from 73 till 78 it did ride on the septa 102 route almost every day to and from work and college.

our red arrow line (sharon hill/media) used different style cars than the city routes.

but still......seeing your pictures gave me flashbacks. and i did not know that there is a trolley museum down in charm city.

THANKS!

ps "charm city" always makes me laugh......but no more than "city of brotherly love"

That looks like the area around 69th Street. Here's a picture I took last November nearby when I was visiting a friend of mine who lives in Upper Darby. Unfortunately the ones in your pictures are now relegated to museums. The Pennsylvania Trolley Museum outside of Pittsburgh has a good collection of Red Arrow cars and they can run them since their line is the same Pennsylvania broad gauge as used in Philadelphia so there's no need to do any work regauging the trucks before they can be used. Baltimore's track gauge is even wider so that Philadelphia car had to be modified before it could be used there. They have cars 14 and 24 from the same order as 12 in your picture and I got to enjoy running 14 when I visited there back in 2003 or 2004.

mansaxel wrote: ↑Tue Aug 08, 2023 7:25 pm

Cubdriver wrote: ↑Tue Aug 08, 2023 4:39 am Nice job of troubleshooting! That one was for sure quite the head scratcher.

-Pat

Yeah; it's fascinating how something so simple (a string of lamps in series, literally every vintage christmas tree festoon!) can be so completely confusing and hard to sort. Well done.

Specmaster wrote: ↑Tue Aug 08, 2023 7:34 pm @25 CPS Geez what an overcomplicated system to provide interior lighting on a means of public transport, makes my time looking after 130+ buses chicken feed. I don't understand why they didn't just stick a transformer in and have all lamps at 32V, unless of course the 600v was DC?

It is 600 V DC which rules out using a transformer to step it down to 32 or 120 or any other normal lighting voltage, so series strings is how this problem was solved and the additional complications to make it as reliable as possible and avoid the "if one goes out, they all go out" problem as much as possible were added over the decades until they reached this level of sophistication. I actually left out another one of the complications this one has since it was actually present and working correctly: each lighting string also has a device in the ground end with a tradename "Fusetron" that drops additional resistance in series with the lights if the current goes up too much. The theory there is if too many bulbs burn out, the remaining ones will be overvolted and draw too much current until it turns into a runaway situation where they fail, short out, stress the remaining lit ones, until they all go out and deliver a short circuit downstream of the lighting fuse. This device attempts to detect a rise in current after several bulbs burn out and short out and adds resistance in line to prevent that runaway situation from taking place. Thankfully everything worked fine with that and it didn't add any more problems to the laundry list of issues in that one lighting circuit.

But yes, for what should be a simple string of light bulbs wired in series, it actually is a fairly complicated setup on these streetcars, and with multiple serious problems in different parts of it, not easy to troubleshoot. I can definitely understand why each of the people at the streetcar museum who tried to fix this by taking a spare bulb and swapping it in different places over the last couple of years didn't get anywhere with it and gave up because there were a lot of issues that had to be fixed to get the whole thing working properly again.

As far as 120 V domestic lighting goes, the compact fluorescent in the porch light died all of a sudden last night.



This marks the end of the end of the compact fluorescent era at my house since this was the last one I had when I put it in the porch. I replaced all of the CFLs in the house years ago and used the pulled ones up in the outdoor lights until they were all gone. The replacement:



That's what I had on hand late last night when the burnout happened, a GE 60 Watt incandescent that was made in Hungary. They used to make these here at a factory off the QEW in Oakville and I drive by what's left of the plant twice a day when I commute to work. The other day someone in a safety vest was doing some kind of survey where the factory building used to be. Part of the office section in the front is still standing but the rest of it was demolished about 15 years ago and torn down to the concrete slab which the guy in the safety vest was walking around on.

I never liked incandescent replacement CFLs or the way they were foisted.

Siemens and Philips had sold those things for years, but they were never popular. They were more efficient, but more expensive. They didn't have a long life in lumieres they were not designed for. They had a warm up time which made them dangerous for stairs and generally irritating. People with epilepsy claimed to have it triggered by them. A lot of people didn't like the quality of the light. Nasty altogether.

They were pushed because of their planet saving credentials. Large stores had their arms twisted not to stock incandescents. CFLs were heavily subsidised for a period as a sweetener. At one time you could buy them in the supermarkets for £0.09 (nine pence) each. There was a loophole where "Rough Use" incandescents were still able to be sold for inspection lights and so on, and they appeared in the pound stores. These had always existed. The filaments weren't run as hot and had extra supports. I stocked up while the going was good, because there are uses for domestic incandescents in lamp limiters or as heaters.

Things changed a lot with practical and affordable LED domestic lights. This is a genuine advance in technology and I have no objections to using them at all.

Ehh, both were subsidized because the they found they could get their oil money from the production side in the electronics and plastic, then charge the same amount per customer while serving more customers less KWH each from the same out-dated infrastructure. While burning coal-raped-into-oil to fuel it.

Now we have the ever-finer granularity of planned failure rate where they promise to save you glumpteen-hunnerd dollars over the next gumpteen years... when in most cases you're lucky to see year 3. Unlike many incandescents which lasted a decade or more in the barn.

mnem
that.

bd139 wrote: ↑Thu Aug 10, 2023 3:01 pmAfternoon. Couple of photos...

I like this one better. Reminds me of Watkins Glen area of NY, where I grew up.

mnem

maybe if you didn't actually spread the shit on your hot-dog...

25 CPS wrote: ↑Thu Aug 10, 2023 3:47 pm

nixiefreqq wrote: ↑Wed Aug 09, 2023 11:44 am HEY 25 CPS

just wanted to say i really enjoyed your trolley project.

unfortunately my skinny ass never rode in that car.

from 73 till 78 it did ride on the septa 102 route almost every day to and from work and college.

That looks like the area around 69th Street. Here's a picture I took last November nearby when I was visiting a friend of mine who lives in Upper Darby. Unfortunately the ones in your pictures are now relegated to museums. The Pennsylvania Trolley Museum outside of Pittsburgh has a good collection of Red Arrow cars and they can run them since their line is the same Pennsylvania broad gauge as used in Philadelphia so there's no need to do any work regauging the trucks before they can be used. Baltimore's track gauge is even wider so that Philadelphia car had to be modified before it could be used there. They have cars 14 and 24 from the same order as 12 in your picture and I got to enjoy running 14 when I visited there back in 2003 or 2004.

your picture looks like the beverly blvd stop looking toward the beverly hills middle school?

graduated from upper darby high just up the road and then worked at a dept store on 69th street during my college years.

those two pictures i posted were found on the web. one is near 69th st and the other is up near the media-sharon hill split (you can see the funeral home in the background). when you rode those old hunks of iron every day you were not a rail fan......we were commuter/victims and developed a deep disdain for anything related to septa.

in fact, i got married once at the magistrates office at barclay square almost right across from where your picture may have been taken. oh man, have not thought about that in decades.......am heading for the bourbon cabinet......need some sweet relief from that memory.


edit forgot to say.......CFL bulbs suck shit thru a dirty sock.

Zenith wrote: ↑Thu Aug 10, 2023 7:28 pm [CFLs] had a warm up time which made them dangerous for stairs and generally irritating. People with epilepsy claimed to have it triggered by them. A lot of people didn't like the quality of the light. Nasty altogether.

I don't disagree, but given that both produce light the same way, why should a LED's phosphor be any better than an Hg discharge lamp's phosphor?

LEDs also had/have the reputation for shifting colour towards yellow over time, possibly because some cheapskate manufacturer used some "MultiComp" epoxy.

CFLs and the traditional florescent tubes are different in the way the phosphor is energised. I have had for about 30 years a couple of CFL floor standing reading lamps which I've had no problems with, but the electronics is quite bulky and in the base of the lamp, not contained in the bulb. They don't have a warm up time. If I didn't like them I wouldn't have bought a second and there were incandescent alternatives. Part of the problem was that people with strong objections to CFLs were cornered into buying them. You can still buy incandescents, but you have to go to some trouble to get them. As I recall you can't pick them up in the supermarket these days.

I haven't noticed any problems with LED lamps changing colour, and I haven't sought out premium brands. After a lot of use, they start to blink and that's a sign that the end is nigh.

I'd rather not buy Multicomp components, but if there's no easy alternative because CPC don't offer one and I don't want to put in another order elsewhere, or there's long waiting time, I will. I regard them as Brand X / poor relation parts. That said I've used a few and they've been perfectly OK.

nixiefreqq wrote: ↑Tue Aug 08, 2023 4:43 pm DO NOT ATTEMPT THIS AT HOME!

I have done similar about >40a ago, when I was a student. Although the meter didn't have 10M input impedance, it had 50k/V, so 60M for the highest 1200V range. I remember I did place a shunt to the meters output as I had not have high enough resistors. I still have the meter (well, the cardboard box has suffered a little):

bd139 wrote: ↑Thu Aug 10, 2023 3:01 pm Shit hotdog

What is the brown sauce? Chokolade or Balsamico?

Zenith wrote: ↑Fri Aug 11, 2023 7:44 am CFLs and the traditional florescent tubes are different in the way the phosphor is energised. I have had for about 30 years a couple of CFL floor standing reading lamps which I've had no problems with, but the electronics is quite bulky and in the base of the lamp, not contained in the bulb. They don't have a warm up time. If I didn't like them I wouldn't have bought a second and there were incandescent alternatives. Part of the problem was that people with strong objections to CFLs were cornered into buying them. You can still buy incandescents, but you have to go to some trouble to get them. As I recall you can't pick them up in the supermarket these days.

I don't disagree, but phosphors work by downconverting a higher energy (i.e. UV) photon to a lower energy visible photon. The difference between LEDs and CFLs is in the way the higher energy photons are created: Hg discharge vs semiconductor band gap.

I haven't noticed any problems with LED lamps changing colour, and I haven't sought out premium brands. After a lot of use, they start to blink and that's a sign that the end is nigh.

CFLs have a much larger surface area than LEDs, so for the same light output the energy density (both light and heat) is higher. I believe that was the source of the reported problems.

I'd rather not buy Multicomp components, but if there's no easy alternative because CPC don't offer one and I don't want to put in another order elsewhere, or there's long waiting time, I will. I regard them as Brand X / poor relation parts. That said I've used a few and they've been perfectly OK.

Just so; so have I. But I remember RS branded 741s that didn't have a normal Vos distribution, but a bimodal distribution with peaks near the Vos limits. And then there was Clive Sinclair; 'nuff said.

No difference in the way phosphors are activated in CFLs compared to traditional fluoresent tubes. There may be differences in phosphor and even gas mix but that is true for both lamp types.
All fluorescents banned in EU and UK from next year....

CFLs run at a much higher frequency than fluorescent strip lights. That may account for some differences and the warm up time. There's quite a lot of electronics squeezed into the base, getting hot and probably cut to the bone in terms of engineering and component quality. Incandescent replacement CFLs appear to be a nearly dead breed these days.

Traditional fluorescent strip lights were very much utilitarian lighting, Great in a garage or shed, but few chose to have them in their living rooms. If people had been forced to use them for that, there would have been resistance.

LEDs for lighting have come a long way in the past few years with improvements in the basic technology and no doubt improved phosphors and other refinements, such as realising what was to be avoided in terms of plastic encapsulation etc. It's been a few years since street lights round here were converted to LED versions. They are a genuine improvement on what went before, especially sodium lamps. They clock up several hours a day, year round, and as far as I can see they don't fail and haven't degraded.

I believe that lighting LEDs produce blue light which is converted by a mixture of phosphors to some more acceptable mixture of wavelengths; anything from a bluish cold white to distinctly yellowish. Fluorescent lights and CFLs also came with a range of shades depending on the phosphors used.