Test Equipment Anonymous (TEA) group therapy thread

[vk6zgo]

I think bd is referring to the bare conductor from the fuse holder, surely it is easy enough to use a small length of normal insulated wire to make that connection.

Ah ok !    Well yeah I guess they could have... but again there much more lethal voltages exposed throughout the scope, so I guess the idea was that if a service tech is stupid enough to touch that wire, he would not survive working on any tube based piece of equipment to begin with. Darwin and all that, I guess ...but yeah, I agree, regardless, using an insulation wire would reduce exposure to AC so why did they not do it .... I don't know ....

Those higher voltages in the sorts of tube equipment we would come across, (leaving out devices like high power tube type radio & TV transmitters, or, perhaps, ham "linears"), are quite poorly regulated, (or looking at it another way, have higher internal resistance), so when you are connected across them, normally cannot provide enough current to really damage you severely.

The ac Mains supply, on the other hand, has superlative regulation, & will happily send you to the "happy hunting grounds"!

[vk6zgo]

Most suspect scope award goes to https://www.ebay.co.uk/itm/313671287713

Giblets... that is crusty...

Have a couple good ones here as well !

https://www.leboncoin.fr/bricolage/2037590332.htm

and

https://www.leboncoin.fr/collection/2035985058.htm


This one is clean but not so sure about value for money ! 

https://www.leboncoin.fr/collection/1845407573.htm

That Unitron looks a lot like an early Telequipment Serviscope.

[0culus]

Trying out the Hallicrafters receiver tonight with a random long wire I found in a pile of radio stuff...turns out it picks up SSB phone on 40 meters just fine when set to CW mode. Pretty nifty little receiver for it's day.

[mansaxel]

Wire colours mean nothing in France, plugs are not polarized. Brown or blue doesn't matter, you can't rely on colours...

but but but the grounded french plug is polarized, no?

No it isn't.

All you know is that neutral is connected to earth.. but you can't rely on colour wire to know which wire is actually neutral or live...
You can't know just by looking at the power outlet, where is the neutral and where is live. If one really cares about it, he can just test for it by himself...

Ah. There is no standard way, but the plug / socket are oriented to always mate in one way, which the Schuko is not.

https://en.wikipedia.org/wiki/CEE_7_standard_AC_plugs_and_sockets#CEE_7/5_socket_and_CEE_7/6_plug_(French;_Type_E)

Guess we need to call it "could but wouldn't" Which is fine by me.

[beanflying]

In 'theory' our Aussie 2 and 3 pin angled mains plugs are polarized but in practice as it only takes one moron in the loop to make it not so assume both active and neutral are hot to earth lest you release the human smoke 



https://www.worldstandards.eu/electricity/plugs-and-sockets/i/

[mansaxel]

In 'theory' our Aussie 2 and 3 pin angled mains plugs are polarized but in practice as it only takes one moron in the loop to make it not so assume both active and neutral are hot to earth lest you release the human smoke 

This. So much this. Better safe than sorry. Assumptions are the mother of the finest fuckups. (although assuming both conductors are live while technically impossible in a Wye 3ph + N net is an assumption I'm OK with.)

[bd139]

LMAO that’s horrible. That’s got to be at least 50A that fuse 

Fun job of the evening. Not. Trying to build 300Hz RBW filter for my SA. This unfortunately requires me to build a half decent crystal filter which means matching a shit ton of crystals by hand then characterising them further later. Frequency binning in progress 

Aren't those crystals already marked with their frequencies then? All of mine are, although I have checked them, but they were all correctly marked already?

Yep. 4.9152 MHz with 30pF loading.

That’s fine for oscillators but not for filters! The motional parameters of the crystals are all slightly different so they can vary in the same fixture by up to 100Hz or so. To get a fairly ripple free narrow filter I need really tight matching between them. Ideally I need to find 8 within 5Hz or so with close Lm and Cm.

This is unfortunately why I’ve got a bag of 200 to go through to select some by hand.

This is also why crystals are a few pence each but crystal filters are £100+ 

Awww... who do you think you're kidding, bd? We can hear you grinning like a fool all the way over here.  You like this shit almost as much as winding toroids... 

mnem
 

Well I fell asleep half way through and nearly fell of my chair. It sucks 

[Vince]

Having non polarised plugs in France just makes things even more dangerous, without other higher voltages present as well, 230 Volts is not a voltage to take lightly, especially with the sheer power of the 230 volt system is capable of delivering.

Yeah especially as they keep increasing voltage over the years, these days it's more like 245/250 !!!  I think they do that to limit losses in the infrastrure as the demand for electricity keeps rising and rising every year.

So you mean in the UK the electrical system is polarized ?!    Lived 3 years there, never even noticed it !

To be honest it's only very recently, 3 years or so, as I started watching youtube "channels", which most are American, that I learned that there was a country in this world that had a polarized system, and it blew my mind. Still does.

Now you are telling in the UK, within Europe well ex, it's polarized as well ?! 

[Vince]

Ah. There is no standard way, but the plug / socket are oriented to always mate in one way, which the Schuko is not.

https://en.wikipedia.org/wiki/CEE_7_standard_AC_plugs_and_sockets#CEE_7/5_socket_and_CEE_7/6_plug_(French;_Type_E)

Guess we need to call it "could but wouldn't" Which is fine by me.

Ah, I see ! So by "polarized" what you really meant was  "can only go one way in the wall socket" ?! 

Well in this case I guess any country in the world has a "polarized" 3 prong plug because well, you gotta put teh third prong SOMEWHERE, and unless you put in the center aligned with the other two, then you end up with a layout that can only go one way...
But that's not polarized... you still have no idea what prong on the wall socket will serve you live or neutral ! And when you stuff a TWO / non-earthed prong in your wall socket... there is nothing/mechanical arrangement to keep you from inserting it which ever way you want, which would defeat right there any polarization even if there was one ! 

I don't think we have had a tremendous amount of death,over the USA say, due to a lack of polarized electrical system.
If really it was that dangerous to not be polarized, you can bet Europe would have enforce a change in the regulations/norms... they freak out simply when farmers want to sell a variety of tomatoes that's not in the official catalog of vegetables, pretending it's a safety hazard !! So I guess a massive issue in the electrical system would rather make them trip, pun intended ! 

[Specmaster]

LMAO that’s horrible. That’s got to be at least 50A that fuse 

Fun job of the evening. Not. Trying to build 300Hz RBW filter for my SA. This unfortunately requires me to build a half decent crystal filter which means matching a shit ton of crystals by hand then characterising them further later. Frequency binning in progress 

Aren't those crystals already marked with their frequencies then? All of mine are, although I have checked them, but they were all correctly marked already?

Yep. 4.9152 MHz with 30pF loading.

That’s fine for oscillators but not for filters! The motional parameters of the crystals are all slightly different so they can vary in the same fixture by up to 100Hz or so. To get a fairly ripple free narrow filter I need really tight matching between them. Ideally I need to find 8 within 5Hz or so with close Lm and Cm.

This is unfortunately why I’ve got a bag of 200 to go through to select some by hand.

This is also why crystals are a few pence each but crystal filters are £100+ 

Awww... who do you think you're kidding, bd? We can hear you grinning like a fool all the way over here.  You like this shit almost as much as winding toroids... 

mnem
 

Well I fell asleep half way through and nearly fell of my chair. It sucks 

Quite often fall asleep in my chair, which has arms so no danger of falling off , unless I fold the arms up. 

[Specmaster]

Having non polarised plugs in France just makes things even more dangerous, without other higher voltages present as well, 230 Volts is not a voltage to take lightly, especially with the sheer power of the 230 volt system is capable of delivering.

Yeah especially as they keep increasing voltage over the years, these days it's more like 245/250 !!!  I think they do that to limit losses in the infrastrure as the demand for electricity keeps rising and rising every year.

So you mean in the UK the electrical system is polarized ?!    Lived 3 years there, never even noticed it !

To be honest it's only very recently, 3 years or so, as I started watching youtube "channels", which most are American, that I learned that there was a country in this world that had a polarized system, and it blew my mind. Still does.

Now you are telling in the UK, within Europe well ex, it's polarized as well ?! 

Yep, the UK and Europe is polarised, the USA is not in most states, if not all of them, but they are also running on 120V and over we use 110V for industrial tools via a 230V centre tapped transformer so any voltage on the secondary side is just 115V above ground which means death is considerably less likely by coming across a live connection.

[Vince]

Yep, the UK and Europe is polarised,

 
 

I am only 43yo... at school I learned electrical stuff, and my dad was an electrician... I have never heard in my entire life that our electrical system was polarized ! 

So you mean " LEGALLY " it is ? There is a norm somewhere that tells you to wire the neutral to a particular terminal on the wall socket ?

I remember asking my dad about it .. I think at best he said there are some "guide lines"... but in practice  electricians just wire them whichever way they want, and you would have to be a FOOL to make ANY assumption as to which is which !!! Why risk your life when it's just so easy to test it if ever one day you actually have to care about it ?
I am not risking my life because "Oh, the norm says neutral must on this hole, so I can stick my finger in it carelessly, nothing will happen, for SURE, how could ANYTHING happen to me.... the NORM says it HAS to be the neutral " !! 

Unless you are competing for a Darwin award, why would you do that...

Anyway, not going to waste B/W over this any longer, but thanks for telling me about it, it's about time I learn about it  ! 
But of course in practice it won't change anything, people don't assume anything and if you ask them which hole in the wall socket is neutral, nobody will be able to tell... and nobody, well the average person I mean, knows even what Neutral or live are ! To them it's just " electricity is dangerous I am not gonna stuff my fingers in the socket or I will get zapped " ! It's common sense and it's all they need to know in practice order to be safe ! So let it continue that way, has worked very well so far !


The ONLY reasonable assumption I am willing to make, it that the guy who wired my house, did go through the trouble of actually making sure he connected the Neutral to earth. Because had he goofed it I guess it would short things out so he would be hard pressed to not notice something was very wrong... but other than that no, it's silly to make any assumption of any kind, unless you really actively are trying to get into trouble, in which case, polarized or not, you will always find a way to find the troubles you are looking for...

[Cubdriver]

Having non polarised plugs in France just makes things even more dangerous, without other higher voltages present as well, 230 Volts is not a voltage to take lightly, especially with the sheer power of the 230 volt system is capable of delivering.

Yeah especially as they keep increasing voltage over the years, these days it's more like 245/250 !!!  I think they do that to limit losses in the infrastrure as the demand for electricity keeps rising and rising every year.

So you mean in the UK the electrical system is polarized ?!    Lived 3 years there, never even noticed it !

To be honest it's only very recently, 3 years or so, as I started watching youtube "channels", which most are American, that I learned that there was a country in this world that had a polarized system, and it blew my mind. Still does.

Now you are telling in the UK, within Europe well ex, it's polarized as well ?! 

Yep, the UK and Europe is polarised, the USA is not in most states, if not all of them, but they are also running on 120V and over we use 110V for industrial tools via a 230V centre tapped transformer so any voltage on the secondary side is just 115V above ground which means death is considerably less likely by coming across a live connection.

The NEC (National Electrical Code) in the USA has required polarized receptacles since the 1960s.

-Pat

[BU508A]

Schuko plug, type "F", non-polarized. Compatible with the French type "E". One can plug it in in two ways.



French type "E". One can plug it in in only one way, similar to UK or Switzerland.

[Vince]

The NEC (National Electrical Code) in the USA has required polarized receptacles since the 1960s.
-Pat

So to sum it up... the entire world is "polarized" .. but only the USA actually mean to take it seriously in practice, as in RELYING on it to be true when they work on stuff or decide where to they can put their fingers...

I guess it's consistent with the usual (modern) USA tradition of protecting people against themselves all the time... with stupid safety warnings on anything and everything...  soon they will put stickers on kitchen knives : " WARNING, LETHAL WEAPON, USE WITH GREAT CARE ! DO NOT EAT ! DO NOT SLIT YOUR WRISTS ! DO NOT THROW AT YOUR KIDS ! " etc....

[Vince]

Schuko plug, type "F", non-polarized. Compatible with the French type "E". One can plug it in in two ways.



French type "E". One can plug it in in only one way, similar to UK or Switzerland.

This "Shyuko" plug you illustrate, is what we have here in France... well have been having for a long time now anyway.
So, it's not polarized you say !

[mansaxel]

Now you are telling in the UK, within Europe well ex, it's polarized as well ?! 

Yep, the UK and Europe is polarised,

The part of Europe that uses the Schuko plug most definitely is not. There is no standard, except that in Germany, they think that if the two holes in the outlet are horizontal, it's nice if it is the same phase and neutral placement in all outlets in an installation (they don't say which!). But since the plug goes in both ways, it's moot once you actually start using the system.



That of the two conductors in the outlet (not counting PE) one is pretty much the same potential as PEN at the entry point, is moot. Because you never know which hole that is.

If you're using three-phase outlets and/or distribution (It's OK to pull 5 wires in conduit and split them to 3 outlets in Sweden, or you can have  a temporary mains system with ruggedised "substations"/boxes that take 16A 3ph in and make 3x16A 1PH) the neutral of course must be in the right place. But that's next level complication.  And the outlet is polarised.

[Specmaster]

Schuko plug, type "F", non-polarized. Compatible with the French type "E". One can plug it in in two ways.



French type "E". One can plug it in in only one way, similar to UK or Switzerland.

This "Shyuko" plug you illustrate, is what we have here in France... well have been having for a long time now anyway.
So, it's not polarized you say !

Well as I see it, if you have the Shyuko plug and the French type E socket then the Shyuko plug will only plug in one way otherwise there is no receptacle to accept the P/E pin which protrudes from the socket, so the plug will only fit in one way round, which is to mind polarised. If on the other hand as others have indicated there no legal requirements for which pin the Hot and Neutral wires are terminated at, then that is a recipe for problems.

Here in the UK there is a correct way of wiring up sockets and it is the wiring regulations that the polarity is supposed to be checked when wiring has been done and we have special test plugs that are plugged into sockets and then the LED's on them will show if it is correctly wired, i.e., Live  to live, Neutral to neutral etc. and this test is supposed to be carried and a test report / certificate issued per installation before allowing anyone else to use the installation.

[Robert763]

LMAO that’s horrible. That’s got to be at least 50A that fuse 

Fun job of the evening. Not. Trying to build 300Hz RBW filter for my SA. This unfortunately requires me to build a half decent crystal filter which means matching a shit ton of crystals by hand then characterising them further later. Frequency binning in progress 

Aren't those crystals already marked with their frequencies then? All of mine are, although I have checked them, but they were all correctly marked already?

Yep. 4.9152 MHz with 30pF loading.

That’s fine for oscillators but not for filters! The motional parameters of the crystals are all slightly different so they can vary in the same fixture by up to 100Hz or so. To get a fairly ripple free narrow filter I need really tight matching between them. Ideally I need to find 8 within 5Hz or so with close Lm and Cm.

This is unfortunately why I’ve got a bag of 200 to go through to select some by hand.

This is also why crystals are a few pence each but crystal filters are £100+ 

I've got a Saunders crystal imedance meter.....
https://prc68.com/I/CrystalImpedanceMeters.html
You could make a trip worthwhile 

[mansaxel]

If on the other hand as others have indicated there no legal requirements for which pin the Hot and Neutral wires are terminated at, then that is a recipe for problems.

Why?

[Robert763]

Ah. There is no standard way, but the plug / socket are oriented to always mate in one way, which the Schuko is not.

https://en.wikipedia.org/wiki/CEE_7_standard_AC_plugs_and_sockets#CEE_7/5_socket_and_CEE_7/6_plug_(French;_Type_E)

Guess we need to call it "could but wouldn't" Which is fine by me.

Ah, I see ! So by "polarized" what you really meant was  "can only go one way in the wall socket" ?! 

Well in this case I guess any country in the world has a "polarized" 3 prong plug because well, you gotta put teh third prong SOMEWHERE, and unless you put in the center aligned with the other two, then you end up with a layout that can only go one way...
But that's not polarized... you still have no idea what prong on the wall socket will serve you live or neutral ! And when you stuff a TWO / non-earthed prong in your wall socket... there is nothing/mechanical arrangement to keep you from inserting it which ever way you want, which would defeat right there any polarization even if there was one ! 

I don't think we have had a tremendous amount of death,over the USA say, due to a lack of polarized electrical system.
If really it was that dangerous to not be polarized, you can bet Europe would have enforce a change in the regulations/norms... they freak out simply when farmers want to sell a variety of tomatoes that's not in the official catalog of vegetables, pretending it's a safety hazard !! So I guess a massive issue in the electrical system would rather make them trip, pun intended ! 

And the winner is Italy
Worst wiring and reversable 3 pin plug

[Vince]

Here in the UK there is a correct way of wiring up sockets and it is the wiring regulations that the polarity is supposed to be checked when wiring has been done and we have special test plugs that are plugged into sockets and then the LED's on them will show if it is correctly wired, i.e., Live  to live, Neutral to neutral etc. and this test is supposed to be carried and a test report / certificate issued per installation before allowing anyone else to use the installation.

Oh OK ! So it's actually enforced in the UK, good to know. That's a nifty little device ! 

However that's only good for new houses, but then once you move in, nobody knows what you do at week-ends... if you mess with your system the next owners of the house won't know... OK let me guess, when you sell a house there is a legal requirement that you get every outlet tested and hand over the report to the potential buyer ? That's cool...

As for France nobody gives a shit of wiring at the outlets. Even on a new house, even though the house is SUPPOSED to be tested/certified before you can move in.... in practice, I was told by my house builder and the electricians I met that worked on my house, that the body in charge of checking all new houses, were understaffed and that in practice they actually checked only about one in 4 houses. For the other 3, they trust the builder's electricians... and just issue the "Tested good" paper without actually even seeing the house. It's just a piece of paper that's all 

Then for USED houses, well nobody gives a shit, no inspection required when you buy one, it's up to the buyer to redo anything he doesn't like, if he feels like it...

I guess it only becomes a problem if people die or the house burns to the ground. Then either the police and/or the insurance companies may want to dig further and blame X or Y for what happened. But other than that...

[Robert763]

Having non polarised plugs in France just makes things even more dangerous, without other higher voltages present as well, 230 Volts is not a voltage to take lightly, especially with the sheer power of the 230 volt system is capable of delivering.

Yeah especially as they keep increasing voltage over the years, these days it's more like 245/250 !!!  I think they do that to limit losses in the infrastrure as the demand for electricity keeps rising and rising every year.

So you mean in the UK the electrical system is polarized ?!    Lived 3 years there, never even noticed it !

To be honest it's only very recently, 3 years or so, as I started watching youtube "channels", which most are American, that I learned that there was a country in this world that had a polarized system, and it blew my mind. Still does.

Now you are telling in the UK, within Europe well ex, it's polarized as well ?! 

Yep, the UK and Europe is polarised, the USA is not in most states, if not all of them, but they are also running on 120V and over we use 110V for industrial tools via a 230V centre tapped transformer so any voltage on the secondary side is just 115V 55V above ground which means death is considerably less likely by coming across a live connection.

FTFY

[Robert763]

The British "13A" plug is probably the safest designs out there. The EU tried to make a common system but had to accepet the lowest standard so non-polarised.
Polarised is obviously safer, but there is a Human Factors issue. Electricians and repair staff in the UK have grown to assume neutral is safe so that increases the chance of an accident if the connection is reversed.
Fortunaaly RCD / RCCD ELCB devices have come along to save us all.

[dl6lr]

Hmm, put a cheeky low (<25%) offer in on an Item I've been watching on ebay for a while. It's lab equipment, not typical TE. The offer was accepted   
I'm going to get a delivery of a 128kg (yes 1/8 of a ton) bit of kit, see below. Most of the weight is lead (Pb not cable). It's obviouly for breaking, I won't even be able to lift it off the pallet
It contains a number of radiation detectors that I intend to flip. Anyone need some 12mm thick lead plate before I weigh it in?
Hopefully it won't contain any radioactive material but 3 similar unit's Ive bought still had test sources in them 

Nice job