Test Equipment Anonymous (TEA) group therapy thread

[bd139]

Trivia time: what wallpaper should I use on my phone?

Constraint: 320 high, 240 wide. Yes, it is a phone, not a computer with a phone as an afterthought.

Solid colour

[Andrew_Debbie]

We got shoved into the deep end of UK light bulbs when we moved here from the US.

Rented a house where the previous tennant took all the light bulbs with them.    Quickly discovered the fixtures in the house used 5 different sizes.    Oh and lamp shades.  Taking the shades with you when you move is a thing.


Pretty much everything invented after 1750 is done differently here.   I had to learn how to fix a toilet,  how to repair a door latch and dance the magic dance required to make a combi boiler heat a cold house.    . And who's idea was it to put  Wires under floorboards instead of in the walls?

[tggzzz]

Trivia time: what wallpaper should I use on my phone?

Constraint: 320 high, 240 wide. Yes, it is a phone, not a computer with a phone as an afterthought.

Solid colour

Which colour e.g. white (good for a torch) or blanched almond (my tty background), or....? Don't suggest puce or any of the 16 Windows colours.

[bd139]

Trivia time: what wallpaper should I use on my phone?

Constraint: 320 high, 240 wide. Yes, it is a phone, not a computer with a phone as an afterthought.

Solid colour

Which colour e.g. white (good for a torch) or blanched almond (my tty background), or....? Don't suggest puce or any of the 16 Windows colours.

Opposite to the text colour usually

[med6753]

We got shoved into the deep end of UK light bulbs when we moved here from the US.

Rented a house where the previous tennant took all the light bulbs with them.    Quickly discovered the fixtures in the house used 5 different sizes.    Oh and lamp shades.  Taking the shades with you when you move is a thing.


Pretty much everything invented after 1750 is done differently here.   I had to learn how to fix a toilet,  how to repair a door latch and dance the magic dance required to make a combi boiler heat a cold house.    . And who's idea was it to put  Wires under floorboards instead of in the walls?

And then some places in the UK allow ring circuits. Absolutely asinine and IMHO dangerous. Yes, we have some dumb things here like non-polarized outlets and plugs but at least the wiring in the walls can withstand full rated current.     

[Andrew_Debbie]

I'm not sure which surprised me more.  Finding these in the house, or that the hardware store in the village had a good stock of fuse wire.

[McBryce]

Trivia time: what wallpaper should I use on my phone?

Constraint: 320 high, 240 wide. Yes, it is a phone, not a computer with a phone as an afterthought.

Was a hard choice, Tant or RIFA?

McBryce.

[bd139]

I'm not sure which surprised me more.  Finding these in the house, or that the hardware store in the village had a good stock of fuse wire.

My mothers house had them in it. Horrible things.

But at the same time increasingly rare.

[Andrew_Debbie]

And then some places in the UK allow ring circuits. Absolutely asinine and IMHO dangerous. Yes, we have some dumb things here like non-polarized outlets and plugs but at least the wiring in the walls can withstand full rated current.   

The house we are in now  was rewired about 10 years ago.   At least it has proper grounding and  RCD (ground fault) protection.     The sockets are on a ring circuits.    I did some checks and everything appears to be ok.

I'm not too worred about it since the plugs all have fuses. 

[tautech]

I'm not sure which surprised me more.  Finding these in the house, or that the hardware store in the village had a good stock of fuse wire.

My mothers house had them in it. Horrible things.

But at the same time increasingly rare.

Really, them ^ modern. 
Most of the circuits fuses in my place are porcelain.

[Specmaster]

All old style incandescent fittings have issues, bayonet as well. 
Heat is the killer where the metal holder bonding to the fitting can let go so it won't even hold a bulb or the plunger pin springs weaken with repeated heat cycling over the years resulting in insufficient contact pressure which you could liken to trying to power a bulb via a miniscule spark gap. 
Result = bulbs that don't last long vs bulbs in good bayonet fittings that seemingly last for years and years.

You missed out what I consider to be the real main problem with bayonet holders is where the spring load contact pins embed themselves into the solder pads on the end of the lamp over a period of time. This often brings a shockingly dangerous failure mode IMO which people can easily fall foul of when trying to change the lamp. The glass detaches itself from the base and then, more often than not, breaks, possibly injuring the lamp changer and also leaving potentially live filament stamens exposed ready to shock anybody foolish enough not to switch at the circuit breaker first when changing the lamp. I have also seen many times when the glass envelope, complete with the filament stamens, separate from the brass lamp cap, leaving the cap in the holder, wedged in by the embedded pins with two short wires exposed from the solder pads, waiting for someone's finger to slip inside the brass cap Removing a cap where that has happened can be rather tricky to say the least, especially as is the case with my Mothers-in Laws chandeliers 

This happens when the lamp is too powerful for the rating of the lamp-holder, and is as likely to happen with a screw as a bayonet in my experience. I would also like to point out that on a BC the metal body is either earthed or more often not connected to anything at all, electrically speaking, whereas the ES body is live, and if the person that terminated it screwed up it's going to be the phase/line as well (neutral is considered to be a live conductor as well as the phase/line).

Nope, I don't think that a 60W candle lamp is excessive for a lamp holder to handle without the pins sinking into the solder, I even replaced the lamps with 40W candles with the same results after a few years of use. This is a very common failure mode, especially when the lamp hangs down, as all the heat is then concentrated in the base of the lamp, directly beneath the solder pads.

[Brumby]

Trivia time: what wallpaper should I use on my phone?

Constraint: 320 high, 240 wide. Yes, it is a phone, not a computer with a phone as an afterthought.

Diode symbol - black on white.

If anybody asks what it is, just say it's your favourite group: One direction.





I'll leave quietly....

[Specmaster]

This happens when the lamp is too powerful for the rating of the lamp-holder, and is as likely to happen with a screw as a bayonet in my experience. I would also like to point out that on a BC the metal body is either earthed or more often not connected to anything at all, electrically speaking, whereas the ES body is live, and if the person that terminated it screwed up it's going to be the phase/line as well (neutral is considered to be a live conductor as well as the phase/line).

I think it is dangerous and severely sub-optimal to ever assume anything except "2 live conductors" (and hopefully ground) for single-phase mains. In an Edison threaded socket, which is the dominant one here, both sides thread and bottom pole are always assumed to be live.

Of course, in three-phase supplies, where shit needs to be right for real, this is not the case. 

Our continental mains plugs, being unpolarized, certainly help instill the notion.

They OTOH create musician voodoo, where there's an optimum orientation of the mains plug of ones guitar amp, an idea that is on par with the concept that a 2m audio-phool mains cable at the end of 200m Al and Cu with PVC  insulation and wire-nuts will make things sound better.

This correct about assuming that there are 2 live contacts at the lamp holder, hence why Crabtree introduced their DP switched safety lamp holder but that only works with BC type lamps, not as AVGresponding correctly pointed with ES type of lamps and so the metal cap could be connected to the live. 

[mnementh]

    I recently picked up an interesting Tek plug in unit, a Type O op amp plug in. It can do a lot of different things; highly recommend taking a peek at the Applications section of the manual for more. Of course there is an array of test fixtures for it (that plug into the banana jacks) that I'll have to find now. 

And of course the fact it was Type O has nothing to do with it... 

mnem
So... is that "Type O" as in "Made for Oculus", or "Type O" as in "Universal Donor"...?

[Specmaster]

We got shoved into the deep end of UK light bulbs when we moved here from the US.

Rented a house where the previous tennant took all the light bulbs with them.    Quickly discovered the fixtures in the house used 5 different sizes.    Oh and lamp shades.  Taking the shades with you when you move is a thing.


Pretty much everything invented after 1750 is done differently here.   I had to learn how to fix a toilet,  how to repair a door latch and dance the magic dance required to make a combi boiler heat a cold house.    . And who's idea was it to put  Wires under floorboards instead of in the walls?

Putting the wires in the floor makes perfect sense, people put cabinets, shelves, mirrors, pictures, TV sets, speakers and god what else on the walls, all are fixed with screws or nails, all of which could easily penetrate directly into live cables with nasty outcomes. Wires in the floor have to be a certain depth for safety and also when was the last time you either nailed or screwed anything to the floor, think about, and you'll see that it makes sense.

[mnementh]

It's also worth noting that in some countries, the US for example, the "neutral" may be another phase, where higher currents are needed eg for a tumble dryer.[/color][/size][/b]

Not quite. Residential wiring in the US is single phase. The pole transformer is fed with one HV primary. The secondary of the pole transformer is center tapped grounded. On each side of the center tap is 120V measured to the center tap. Measure across the 2 hots and it's 240V. It is sometimes called "split phase" because the hots are 180 degrees out from each other. But in reality it's single phase.

Devices requiring 240V typically will have 2 hots with ground but no neutral. But some 240V devices have 120V circuits so they require 2 hots, a neutral, and a ground. And as always the neutral and ground are NEVER bonded together at the device. Only at the breaker box.       

Actually, separate dedicated ground (4-wire plug/socket and internal wiring to the panel) have been required on 220V appliance outlets for any new construction for 20 years or more now in the US. Not sure aboot the drop to the panel from the pole, but probably.

mnem
 

[mnementh]

Trivia time: what wallpaper should I use on my phone?

Constraint: 320 high, 240 wide. Yes, it is a phone, not a computer with a phone as an afterthought.

Diode symbol - black on white.   If anybody asks what it is, just say it's your favourite group: One direction.

I'll leave quietly....

Summing Amplifier...

mnem

[Robert763]

We got shoved into the deep end of UK light bulbs when we moved here from the US.

Rented a house where the previous tennant took all the light bulbs with them.    Quickly discovered the fixtures in the house used 5 different sizes.    Oh and lamp shades.  Taking the shades with you when you move is a thing.


Pretty much everything invented after 1750 is done differently here.   I had to learn how to fix a toilet,  how to repair a door latch and dance the magic dance required to make a combi boiler heat a cold house.    . And who's idea was it to put  Wires under floorboards instead of in the walls?

And then some places in the UK allow ring circuits. Absolutely asinine and IMHO dangerous. Yes, we have some dumb things here like non-polarized outlets and plugs but at least the wiring in the walls can withstand full rated current.   

And what is wrong or dangerous with ring circuits?
Until the latest wiring regulations they were the norm. Now we are allowing spur circuits. The cynic in me says it's to give the equipment manufacturers and electricians more work. 

[mnementh]

What could POSSIBLY go wrong...?   

mnem
 

[bd139]

Fire? 

[Cerebus]

We got shoved into the deep end of UK light bulbs when we moved here from the US.

Rented a house where the previous tennant took all the light bulbs with them.    Quickly discovered the fixtures in the house used 5 different sizes.    Oh and lamp shades.  Taking the shades with you when you move is a thing.


Pretty much everything invented after 1750 is done differently here.   I had to learn how to fix a toilet,  how to repair a door latch and dance the magic dance required to make a combi boiler heat a cold house.    . And who's idea was it to put  Wires under floorboards instead of in the walls?

Putting the wires in the floor makes perfect sense, people put cabinets, shelves, mirrors, pictures, TV sets, speakers and god what else on the walls, all are fixed with screws or nails, all of which could easily penetrate directly into live cables with nasty outcomes. Wires in the floor have to be a certain depth for safety and also when was the last time you either nailed or screwed anything to the floor, think about, and you'll see that it makes sense.

Also remember that the walls in most UK buildings have been here a long time and are made out of substantial things like brick and concrete, even the internal walls in many cases, whereas the US they make even the exterior walls out of ticky-tac*  and it's not unusual for a US residential dwelling to have a short design life, sometime as short as 30 years. It's only relatively modern UK housing where all the interior walls are hollow.

The terraced house I'm in was built in the 19th Century and the internal walls are brick. It predates electricity and indoor plumbing (as is attested by the presence of a, now disused, outside toilet) as do probably most of the houses in the bit of East London that I'm in. The median age of a US residential dwelling according to the US NAHB was 37 years in 2015, 31 years in 2005. In the UK that's more like 70 years (about 50% of UK housing stock is WWII built or later).

Having chased out a few brick walls for cabling in my time I know very well why we don't put the bulk of the wiring there if we can help it.

* 'siding' for exterior walls is only used in the UK for things like industrial units, sheds and barns, and the average Briton would be horrified to be asked to live in something made out of it.

[mnementh]

Fire? 

Why did that sound so hopeful...? 

* Are you really that bored...? *

mnem
*currently moving all that to the side bench so I can work on more important things... like rebuilding my lightsaber...*

[tggzzz]

Wires in the floor have to be a certain depth for safety

In my parent's 1840 house, that depth is the thickness of the floorboard Yes, it does need rewiring, for muiltiple reasons.

In their previous house some (abandoned) wires were encased in a wood E profile, and others used a lead sheath as the earth.

[tggzzz]

Also remember that the walls in most UK buildings have been here a long time and are made out of substantial things like brick and concrete, even the internal walls in many cases,

My parents house is made from brick and rubble, 3ft thick at the bottom, about a foot thick at the top.

The terraced house I'm in was built in the 19th Century and the internal walls are brick. It predates electricity and indoor plumbing (as is attested by the presence of a, now disused, outside toilet) as do probably most of the houses in the bit of East London that I'm in.

My father removed the servants' outside toilet. 30 years later I discovered that might have been illegal, for reasons I'm not going to discuss here

[med6753]

Found the problem with the Type 547 vertical amplifier and gotta load the parts cannon.

This 320 ohm 5 watt resistor on the left is toast. Mouser has 310 ohm 5 watt but also 10 ohm 5 watt. So I got that covered.



See schematic. It's R1118 in upper right corner. Q1109 is an update on later S/N's and doesn't appear in mine. Q1114 and Q1134 are matched pair final vertical amplifier and they are toast. Luckily an Ebay seller in Arizona has them as a matched pair for $20 USD plus $4 USD shipping. I've bought from that seller before and he's top notch.     I'm going to pull and test the balance of the transistors to the right of the delay line. 



So this on hold until I get replacement parts.