Test Equipment Anonymous (TEA) group therapy thread

[tautech]

Just remember the limits for forum images/attachments:
maximum individual image size 1000KB,
maximum total size per post 2000KB

I usually downsize images to lower-quality jpegs so I can fit several in.
 

The problem with sending photos as attachments is that in order to meet the file size requirements, quality has to suffer and sometimes, that quality matters so that there is no real alternative to using hosting sites then.

Yes, I agree that if the site closes or changes their policies that the links may not anymore but I see no suitable alternative because the bandwidth and huge storage problems that would accompany attachments of high quality would no doubt be cost prohibitive for the forum to sustain. 

Yes, that is exactly the problem. I want a picture of my tube tester in all its beauty not a tiny thumbnail. Of course compromises must be made, or do they? I've went back through all of my hamfest pictures and replaced the links with imgur and uploaded a lower res back up. Best of both worlds,  .

Do you have trouble or don't know how to embed thumbnails into a post ?
You just need the URL of the uploaded thumbnail between the img tags of the Insert Image icon.

Can give crash course if needed but it's best to study how others do it so just Quote a post and study the syntax.
Have that one as a side tab so you can see how it's going while building your own post.

[mnementh]

I don't see a benefit to  doing that when what he wants is local copies small enough for the very constraining 2MB/post limit purely as a courtesy in case of catastrophe, while still linking to large, high-res images on a 3rd-party site.

I've run into similar headaches myself... like the photo sequence from my 3D Printer posts. I realize that Dave, Inc are just trying to keep the usual space-wastery by the FB Dingle crowd from causing eevBlog to get slammed with massive hosting/bandwidth surcharges, but it IS A bit of a PITA.


mnem
*Back to the salt mines*

[tautech]

I don't see a benefit to  doing that when what he wants is local copies small enough for the very constraining 2MB/post limit purely as a courtesy in case of catastrophe, while still linking to large, high-res images on a 3rd-party site.

I've run into similar headaches myself... like the photo sequence from my 3D Printer posts. I realize that Dave, Inc are just trying to keep the usual space-wastery by the FB Dingle crowd from causing eevBlog to get slammed with massive hosting/bandwidth surcharges, but it IS A bit of a PITA.


mnem
*Back to the salt mines*

It is a PITA sure but that's all we have so we just live with it unfortunately.
Hires, who hasn't got a Tb drive in their PC ?
Keep your hires pics there and post appropriate res pics here.
In an Op I started a couple weeks back and uploaded 15 images as thumbnails for a single post and didn't hit the 2M limit. Sure it's a little bit of work but nowhere near as much as typing and proof reading the 1000 words in it, and multiple times. Along with the pics it was some hours work but what else would you do when it's pissing with rain outside ?
250 Kb/pic is plenty of detail and if you need greater detail down load and enlarge in a image tool.
That's 8 pics/post, who needs more ?
Make a further post. 

[Cerebus]

You mean these?


mnem

No. School buses are almost non-existent in the UK (there are a handful of rural schools that run one, but it really is a handful). Back in the day I either walked to school, cycled or caught an omnibus. Nowadays apparently children aren't safe unless they are driven to the school's gates, ideally in a vehicle no smaller than a BMW X5 with no more than two occupants including the driver who, it seems, ought to have no more than a rudimentary grasp of the rules of the road.

We've just done the weekly run to the supermarket. During the summer at around the time we went it has consistently taken perhaps 15 minutes driving, during term time it will take nearer 30.

Tooling around the Arc de Triomphe is safer than negotiating the roads around a British School in late afternoon.

A Frenchman demonstrating the only safe way to negotiate the Arc de Triomphe:

[iainwhite]

That's 8 pics/post, who needs more ?
Make a further post. 

I agree!   I find the forum attachment system fine for most posts - plus the post is kept to minimal screen "real estate" with the use of thumbnails, but you can easily click on an image and expand it to the full page width if you want to look closer.

[Cerebus]

Yes I’m wondering what I should do. I’m on the fence as to whether I should keep it original and museum piece or make it 100% safe and use it as a lab instrument. A working VTVM is actually pretty damn useful as both my Brymen and Keysight meters are pretty RF sensitive and jump all over the place. Not so with a VTVM. But that means either heavily modifying it to make it floating or keeping it grounded. If it’s grounded you can measure non ground referenced circuits which is a pain however.

Hmm.

I'm having a similar dilemma with that Variac I picked up last week. I can either keep the vintage case and just make it electrically safe in the most basic form, or I can stick the actual Variac in a new case with RCD, a circuit breaker on the secondary and metering to make a properly safe, abuse proof, more convenient to use instrument.

[tautech]

That's 8 pics/post, who needs more ?
Make a further post. 

I agree!   I find the forum attachment system fine for most posts - plus the post is kept to minimal screen "real estate" with the use of thumbnails, but you can easily click on an image and expand it to the full page width if you want to look closer.

The screen real estate thing is subjective, if you want to embed pics within text then you must edit after posting with the pic's URL but that's little different to having pics hosted somewhere else. Upload them here as thumbnails and they're never lost into some digital black hole.

[neo]

Do you have trouble or don't know how to embed thumbnails into a post ?
You just need the URL of the uploaded thumbnail between the img tags of the Insert Image icon.

Can give crash course if needed but it's best to study how others do it so just Quote a post and study the syntax.
Have that one as a side tab so you can see how it's going while building your own post.

To tell you the truth i struggle with most technology post 1990  But lets run a comparison
Photo via imgur, all i had to do was upload and link

Same thing via eevblog, had to post with it as an attachment then modify message to include it


I see no problem with imgur so long as i provide a backup on eevblog.

[tautech]

Do you have trouble or don't know how to embed thumbnails into a post ?
You just need the URL of the uploaded thumbnail between the img tags of the Insert Image icon.

Can give crash course if needed but it's best to study how others do it so just Quote a post and study the syntax.
Have that one as a side tab so you can see how it's going while building your own post.

To tell you the truth i struggle with most technology post 1990  But lets run a comparison
Photo via imgur, all i had to do was upload and link
(pics)
I see no problem with imgur so long as i provide a backup on eevblog.

Nice comparison and tube tester. 
Have a look at mnem's pic sizing tricks using width= x .......I guess it's pixels. 

[bd139]

Tooling around the Arc de Triomphe is safer than negotiating the roads around a British School in late afternoon.

Yes the massive hole in the side of my old Fiat backs this up. Literally appeared while I was outside the school by some fucktard who can barely operate the death machine that a minimal test let them get in charge of.

Yes I’m wondering what I should do. I’m on the fence as to whether I should keep it original and museum piece or make it 100% safe and use it as a lab instrument. A working VTVM is actually pretty damn useful as both my Brymen and Keysight meters are pretty RF sensitive and jump all over the place. Not so with a VTVM. But that means either heavily modifying it to make it floating or keeping it grounded. If it’s grounded you can measure non ground referenced circuits which is a pain however.

Hmm.

I'm having a similar dilemma with that Variac I picked up last week. I can either keep the vintage case and just make it electrically safe in the most basic form, or I can stick the actual Variac in a new case with RCD, a circuit breaker on the secondary and metering to make a properly safe, abuse proof, more convenient to use instrument.

Some motivation to do it safely... My own variac, now departed thank fuck, was given to me by an SK. It was basically a 1:1 isolation transformer of unknown power handling and a 8kva open frame variac attached and a standard wall box with two sockets as the output. The whole thing was wired with installation cable that the builder had lying around (it was covered in paint) and all lightly screwed to a bit of kitchen worktop about two inches thick. The inlet was the biggest crime of all. There was a single socket (!) on the input side and you had to use a plug to plug lead (dangerous as hell). Whole thing weighed around 25kg and was a two man lift. If you tried to life it yourself you'd get chipboard splinters or it risked breaking in half. I put wheels on the bottom of it but the chipboard was too damp and they basically collapsed. Gave it away in the end as it was too large, heavy and dangerous.

However, some equipment, despite the danger, has a larger cool factor if you leave it as the safety standards of the time demanded.

[Brumby]

No. School buses are almost non-existent in the UK (there are a handful of rural schools that run one, but it really is a handful). Back in the day I either walked to school, cycled or caught an omnibus. Nowadays apparently children aren't safe unless they are driven to the school's gates, ideally in a vehicle no smaller than a BMW X5 with no more than two occupants including the driver who, it seems, ought to have no more than a rudimentary grasp of the rules of the road.

It's the same in Australia.

It's a classic move for drivers of BMW vehicles to not know where their indicator stalk is located or that they get scared of the ticking sound if they happen to knock them.  Those who might just happen to turn one on can do so 1 metre, 3 metres or (if you're lucky) 5 metres from the intersection instead of the 30 metres stipulated in the law - but you will also get those that will initiate the indicator as they are in the turn.

The drop off and pick up zones around schools are a nightmare whenever frequented by parents in cars.

You don't need a calendar to know when school holidays are in force.  Travel at certain times will have you commenting (even if to yourself) about how good the traffic is flowing ... and then you realise "Ah!  School holidays.".

[Specmaster]

Don't forget that when you fit that 3 core cable to earth the VTVM, that it uses the chassis as a common connection in 12 incidents that you'll need to address, also of course in its current configuration that one side of the AC probes is also connected to chassis so its possible for the entire case to be live. As part of that addressing the chassis problem I also did away with the 1.5 cell and used a 6v to 1.5v dc to dc converter so there is no chance of forgetting the battery and risk it leaking in the future.

I'm just about to order up high voltage 4mm banana sockets that will also accept shrouded plugs to fit in mine and horror of horrors, I had forgotten to replace my Selenium rectifier (diode)  so ordering suitable diode as well.

Yes I’m wondering what I should do. I’m on the fence as to whether I should keep it original and museum piece or make it 100% safe and use it as a lab instrument. A working VTVM is actually pretty damn useful as both my Brymen and Keysight meters are pretty RF sensitive and jump all over the place. Not so with a VTVM. But that means either heavily modifying it to make it floating or keeping it grounded. If it’s grounded you can measure non ground referenced circuits which is a pain however.

Hmm.

Not really a pain, just find all the ground points, disconnect them and then link em altogether. build a small circuit to stick 4 diodes and smoothing cap on and a Dc to DC convertor on to replace the battery, swap out the banana sockets, heave the jack socket into the parts bin and replace it with a power LED, job done. You'll have a meter that isn't RF sensitive, wont load up the  circuit under test either and also you'll be preserving a piece of "griefkit" for years to come.

[bd139]

I've just run through use cases and it's too dangerous to go measuring line voltage with this sort of kit and everything else I do is ground referenced or floating (battery powered) so I think I'm going to actually tie the chassis to ground so that common and ground are one and the same. It's easy to undo and doesn't compromise the instrument as well. DC+/- measurements are fine, AC large/small signal measurements are fine as any reference voltage in circuit is ok to load the cap up against, ohms I only use for resistors and not continuity.

Also it takes the least amount of effort 

Going to keep the incandescent lamp. I like the warmth from them. The Tek 465 I have was made before LEDs were on the market which is cool too

Edit: Trying to work out what to do with battery situation as well. If you remove it then the thing has to source up to 160mA in short conditions max which is a bit too much on top of the heater winding. Typical alkaline AA these days has got as much whack as an old C cell so I might make a "tub" out of a film canister that you can put an AA in so if it does leak it just keeps it in the film canister and run the electrodes out to the existing contacts. Leak proof then!

[Specmaster]

I've just run through use cases and it's too dangerous to go measuring line voltage with this sort of kit and everything else I do is ground referenced or floating (battery powered) so I think I'm going to actually tie the chassis to ground so that common and ground are one and the same. It's easy to undo and doesn't compromise the instrument as well. DC+/- measurements are fine, AC large/small signal measurements are fine as any reference voltage in circuit is ok to load the cap up against, ohms I only use for resistors and not continuity.

Also it takes the least amount of effort 

Going to keep the incandescent lamp. I like the warmth from them. The Tek 465 I have was made before LEDs were on the market which is cool too

Take a look at the schematic and you'll see that the "Common" input jack is directly grounded to chassis, not to bad I hear you say as long as its the neutral of any AC that is plugged into it, reverse connection somewhere else along the supply chain and that neutral becomes the live and then your dumping that straight to house ground 

I've modded mine already and it can be used directly onto 240v no worries.

[bd139]

Yeah I've been through the schematic here. The plan is simply to bond the chassis to earth with a crimp and screw with lock nut etc.

Thus if you do connect AC to it, live to probe and neutral to common:

1. If you've got PME that works and neutral and ground are the same then it'll indicate the line voltage.
2. If you've got PME that doesn't work and neutral and ground are raised it'll indicate how fucked you are.
3. If you've not got PME it'll blow the fuse in the source and/or trip the breaker.

If you connect it the wrong way round it'll just blow the source fuse or breaker.

Figured that was the safest outcome which didn't require your home made changes to be (a) leakage immune and (b) done properly and (c) least likely to kill the next person who ends up with it.

[Specmaster]

It's not hard to do, but I've seen circuit breakers that failed to open the circuit [emoji44] that would leave the person holding the probes exposed to a high energy fault [emoji17]

Edit. As a well qualified electrical engineer (not contractor) it will be perfectly safe once I finish with it and thoroughly tested for any signs of leakage on all possible settings and combinations, thats a given. I used to have to look after a very high profile multi millionaire and Lord, who was very prominent in business and House of Lords, UK country residence in Berkshire and physically cut plugs of things that I considered to be dangerous 

[tggzzz]

We've just done the weekly run to the supermarket. During the summer at around the time we went it has consistently taken perhaps 15 minutes driving, during term time it will take nearer 30.

I've used such an observation to demonstrate to a planning inspector that adding extra houses in my village would dramatically increase the journey time into the nearest town.

Basic technique:

• assume a queue with Poisson arrival times and a constant service time (i.e. an M/D/1 queue)
• the delay (=journey time) is a non-linear function of the applied load, i.e. adding 10% more load can double or triple or worse the delay
• to find where you are on that curve, you need to measure the holiday/school delays, and estimate the extra load due to the school traffic
• you can estimate the holiday load by counting cars
• you can estimate the extra school traffic from the size of the village and the number of school-age children
• and you then plug the numbers into the standard equations

It worked well enough to help delay the houses for 15 years

Tooling around the Arc de Triomphe is safer than negotiating the roads around a British School in late afternoon.

Try driving in Sicily. There a numerical majority of cars have serious bodywork damage, up to and including completely missing front wings so you can look down on the suspension and top of the tyre.

They have a good attitude: they don't mind what you do so long as they can understand and predict what you are doing. Hence there is no problem driving along the pavement, or cars at a two-lane intersection lining up three abreast in each direction, or straddling the white median line. But they get annoyed at people that weave in and out, sometimes straddling the white line, sometimes not.

[bd139]

It's not hard to do, but I've seen circuit breakers that failed to open the circuit [emoji44] that would leave the person holding the probes exposed to a high energy fault [emoji17]

That can happen if you have a bad PME installation or bought shitty MCBs. Got decent quality Siemens kit here, no PME and installation checked out properly.

[bd139]

Try driving in Sicily. There a numerical majority of cars have serious bodywork damage, up to and including completely missing front wings so you can look down on the suspension and top of the tyre.

My old landlord was hospitalised trying to cross the road in Rome. Got hit by no less than three cars, none of whom stopped. Poor woman was in a cage on her leg for months then on crutches for about a year. Italians are craaaazy drivers.

[Specmaster]

It's not hard to do, but I've seen circuit breakers that failed to open the circuit [emoji44] that would leave the person holding the probes exposed to a high energy fault [emoji17]

That can happen if you have a bad PME installation or bought shitty MCBs. Got decent quality Siemens kit here, no PME and installation checked out properly.

What about whoever gets it after you?

[bd139]

If the device is safe and the installation kills them then that's their problem.

If the device is not safe, things are less clear.

[bd139]

Ok just spent an hour on that tek 7603 and did the entire check out procedure. Both verticals are spot on. The horizontal was good apart from x10 mag. I spent a few minutes pulling adjusting and reinserting the plugin and it’s spot on now. I can get a frequency measurement down to 2% easily now on main, delayed and zoomed timebases. 

Just need to swap that knob out and clean it and it’s done. Still working on logistics there.

[mnementh]

In Other News...

Wife and kids are gone to their first day back at school; summer is officially over. Home alone with nothing but my thoughts and Paul Simon on the boom box...

mnem

Another week to go here before the roads congest from 3:15PM to 4:30PM weekdays with idiots who were too cheap to buy the 'optional extra' indicator lights for their scarily large SUVs.

You mean these?

mnem

No. School buses are almost non-existent in the UK (there are a handful of rural schools that run one, but it really is a handful). Back in the day I either walked to school, cycled or caught an omnibus. Nowadays apparently children aren't safe unless they are driven to the school's gates, ideally in a vehicle no smaller than a BMW X5 with no more than two occupants including the driver who, it seems, ought to have no more than a rudimentary grasp of the rules of the road.

We've just done the weekly run to the supermarket. During the summer at around the time we went it has consistently taken perhaps 15 minutes driving, during term time it will take nearer 30.

Tooling around the Arc de Triomphe is safer than negotiating the roads around a British School in late afternoon.

A Frenchman demonstrating the only safe way to negotiate the Arc de Triomphe:

I was actually referring to the 'optional extra' indicator lights part of your comment, and indirectly suggesting that perhaps soccer moms in SUVs should be reclassified as school buses. 

That said; you guys have no idea from SUVs. An X5 is a effing shoe box over here; soccer moms over here drive Suburbans and Escalades: 5.7 meters and 3 tons at ~16MPG. We have fuckwits who drive 1-ton, 4-door extended cab pickups with 8-foot duallie bed that are 7 meters long, then install aftermarket front & rear bumpers made from well-casing to add almost another meter. 

And YES, they drive that 10MPG douchemobile as personal transportation, or if they DO work with it, it's one day a month.    About 6 in 10 vehicles driven as daily transport in Texas are "light trucks" of some sort, and about 1 in 10 are one of those behemoths. 

And THAT is what we're sending our kids halfway around the world to die in a desert for. 

I don't see a benefit to doing that when what he wants is local copies small enough for the very constraining 2MB/post limit purely as a courtesy in case of catastrophe, while still linking to large, high-res images on a 3rd-party site.

I've run into similar headaches myself... like the photo sequence from my 3D Printer posts. I realize that Dave, Inc are just trying to keep the usual space-wastery by the FB Dingle crowd from causing eevBlog to get slammed with massive hosting/bandwidth surcharges, but it IS A bit of a PITA.

mnem
*Back to the salt mines*

It is a PITA sure but that's all we have so we just live with it unfortunately.
Hires, who hasn't got a Tb drive in their PC ?
Keep your hires pics there and post appropriate res pics here.
In an Op I started a couple weeks back and uploaded 15 images as thumbnails for a single post and didn't hit the 2M limit. Sure it's a little bit of work but nowhere near as much as typing and proof reading the 1000 words in it, and multiple times. Along with the pics it was some hours work but what else would you do when it's pissing with rain outside ?
250 Kb/pic is plenty of detail and if you need greater detail down load and enlarge in a image tool.
That's 8 pics/post, who needs more ?
Make a further post. 

Yeahhh... NO.

2MB is ridiculously tiny; even for a single image in many cases. No 2 ways around it. Low-res is being kind.

Not going to get into an argument over filetypes vs compression methods, etc, but shit, even Yapoop allows 25MB of attachments/eMail, and they're well-known cheap-asses when it comes to storage.

Yes I’m wondering what I should do. I’m on the fence as to whether I should keep it original and museum piece or make it 100% safe and use it as a lab instrument. A working VTVM is actually pretty damn useful as both my Brymen and Keysight meters are pretty RF sensitive and jump all over the place. Not so with a VTVM. But that means either heavily modifying it to make it floating or keeping it grounded. If it’s grounded you can measure non ground referenced circuits which is a pain however.

Hmm.

I know y'all are probably going to want to tar & feather me for suggesting it... but why not upgrade the mains wiring with 2+GND and a GFCI plug? Does that work differently over there as it does here? 

mnem
America eats its young.

[bd139]

Roughly similar set up I understand but you guys have spurs instead of rings. My bench is on a GFCI (RCD as we call them over here) so that’s already covered.

2MB images are tiny. Seriously. All the ones I upload to imgur start at 6M. The NEFs my DSLR kicks out are 40M a go

[Specmaster]

@bd139, That's good news on the 7603, so its just a knob swap thats required, now? You really struck gold with that for sure