Why did Australia mostly avoid live-chassis radios and TVs?
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Location: Canberra, ACT
Member since 24 April 2012
Member #: 1136
Postcount: 168
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Ever had a live chassis computer? Just prior to the dreaded Y2K the govt agency where I worked received a batch of servers from a three-letter computer company that came with Chinese made power cords. These had the appropriate certification sticker attached but had obviously never been tested. The active and earth leads had been transposed at the IEC plug end. By shear luck this 'modification' was discovered before anybody was zapped.
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Location: Albury, NSW
Member since 1 May 2016
Member #: 1919
Postcount: 2048
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Never heard of one! But my friend Ian Robertson on here would be interested in hearing about it I'm sure!
He will find the post . I'm only a beginner with electronics.
Pete
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6805
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The active and earth leads had been transposed at the IEC plug end.
Good grief! A moulded product too. Presumably part of a large batch of such cables.
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Location: Belrose, NSW
Member since 31 December 2015
Member #: 1844
Postcount: 2527
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Yes we've seen moulded cables of various types with wiring errors.
If you've seen where and how they make them in the Philippines for example you wouldn't be surprised.....
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Location: Belrose, NSW
Member since 31 December 2015
Member #: 1844
Postcount: 2527
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The later Philips colour chassis (KT3 / KL9) were quite simple too as levels of IC integration increased. Just a single PCB that hinged down for really easy access. But they were live chassis, or at least the later ones were.
The big problem with the PCB-on-the-bottom design was that the board would accumulate dust which would soak up water. You'd always have to hit them with the compressed air.
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Location: Silver City WI, US
Member since 10 May 2013
Member #: 1340
Postcount: 977
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QUOTE: "GE Compactrons... if it lights up and moves people will watch it!"
The prize for the "Volkswagen Beetle" of televisions would have to go to the highly profitable General Electric 'PortaColour':
Bare bones simplicity: no power transformer, no chassis, no chroma-Osc/APC, no DC-luminance....fewer tubes than some B&W TVs!
Truly lightweight, not much heavier than a bowling ball, a remarkable achievement for the mid-1960s when "portable" TVs were heavy!
For safety, all GE had to do was use a polarised power plug/cord + AC interlock + small warning label on cover (as per their Legal Dept.)
To save more costs, they make their own picture tube with in-line guns to circumvent RCA patents and use NTSC decoding in the German version to avoid PAL ("Pay Another Licence")
After a long successful production run until 1978, GE does something even more clever: they, soon thereafter, exit the television business! But this would require finding someone foolish enough to buy it - (for a large sum of money.) Who would be the "Greater Fool"? Answer: Thomson-CFS/French government! (see 'Greater fool theory')
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Location: Oradell, US
Member since 2 April 2010
Member #: 643
Postcount: 833
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I've heard that Argentina uses the same pattern and size plugs Australia uses, but the hot and neutrals are swapped. Maybe those Chinese cords were meant for Argentina? In any event, equipment should be designed to expect that the neutral and hot might be swapped by mistake by some underqualified handyman installing receptacles.
As for hot chassis radios, they were super common in the USA. And most all repair shops had isolation transformers on their workbenches. Later on, such radios had interlock power cords, remove the back and the power cord disconnects. And the control knobs were all plastic, and often not removable off the cabinet if the radio chassis was still inside. The radio was a self contained module, safe as long as you didn't modify it.
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6805
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the hot and neutrals are swapped. Maybe those Chinese cords were meant for Argentina?
In the reported case, the active and earth leads were swapped. That's criminal negligence in my book.
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Location: Wangaratta, VIC
Member since 21 February 2009
Member #: 438
Postcount: 5474
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Australia has a "Tag and Test" System that has spread it's tentacle's from industry into various other area's. This required originally, checking of cables & portable mains tools such as drills.
The horror story at the local Men's Shed, putting the politics aside, has meant that a "No Tag" no use policy has had to be implemented.
The problem stems, like St Vinnies and similar, from stuff being donated "In Good Faith". Often translated to "By giving you / dumping you with this crap: We avoid dumping fees". This spiteful greed, in many cases has penalised, those in need, as these charities will not handle electrical goods as it often costs more (if they have to pay someone) to ensure that the stuff is safe, than its worth, so useable stuff ends up as scrap.
As I have mentioned, and as for Wa2ise comment, several cables were found to have inverted wiring, There were those with the usual gap between plugs & sockets and the sheath (that's always been illegal) some had dodgy plugs & sockets, others had been cooked, plus a couple with cuts into the core wires and also into the sheath of the core wire.
There were of course a couple with open circuits: The plain scary when its got a three wire plug & socket & a two wire recycled Vacuum cleaner cable. In that test run a Lathe that should have been grounded, had an open ground wire.
Welders can also be treacherous. A transformer, stick welder shorted to its grounded metal body, secondary side. That fused its supply cable earth wire. As the RCD (GFCI in US) only senses earth leakage primary side & secondary provides isolation: RCD WILL NOT TRIP.
That also applies to any transformer where the secondary isolates from the mains. This fault can fuse the earth wiring all the way back to the fuse box & likely further.
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Location: Oradell, US
Member since 2 April 2010
Member #: 643
Postcount: 833
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QUOTE: In the reported case, the active and earth leads were swapped.
Ow! how'd I miss that, my brain must have done an "autocorrect" between my eyes and my mind....
The equipment wouldn't power up being fed a ground where the active should be, and with the neutral in its proper place.
Though the user would get lit up....
I once miswired a power plug like this once. But I figured it out when the load didn't power up. I didn't get lit up as I was wearing sneakers and I didn't touch any grounds.
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Location: Toongabbie, NSW
Member since 19 November 2015
Member #: 1828
Postcount: 1336
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I had a lesson very early on in life and that is why I have a master core balance + EL 10ma breaker into my workshop.
BEFORE I put the breaker in, I set up a guitar amplifier on the bench plugged it in and steadying the amp chassis with one hand reached up and touched the audio test panel.
I woke up sometime later laying on the floor on my back where I had been thrown off the seat.
The good news is I did wake up.
The amplifier simply had the ACTIVE and the EARTH swapped and I got the lot across the chest.
THEN I put the breaker in and ALWAYS test the earth continuity of ANYTHING with a 3 pin cord BEFORE I power it up EVEN if I have just made it!
I regularly check the safety breaker by a resistor load test from active to earth at any power point, the safety has always worked so the Heinman must have been a good well made 1960's model. I also have those cheap 30ma EL units as part of the power point sprinkled around and on extension leads going outside.
The master safety may have a habit of hopping out on some loads, but that's better than being dead.
Fred.
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Location: Albury, NSW
Member since 1 May 2016
Member #: 1919
Postcount: 2048
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Fred
Very lucky your still here Fred!
The only shock I have ever had was years ago and it was before I had any knowledge of electronics and now I still only have some knowledge, but it was a TV and it was unplugged and not knowing any better at the time that crt or caps hold power I pulled a damage HT plug out the back of the crt on a 1962 Kriesler and it bit me!, nothing major . Good wake up call!
These days I have a basic understanding and know more than years ago and I do the old pocket trick
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6805
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ALWAYS test the earth continuity of ANYTHING with a 3 pin cord BEFORE I power it up
Same here, both before and after repairs.
As for serious shocks, I got the worst belt of my life at age 16 from a hot radio chassis in the physics lab after school when the science teacher said to a few of us interested in electronics "Let's check out these old radios I was given". We powered on up and the reception was poor so I thought "a better earth is needed". I grabbed the lab bench gas tap with one hand and touched the chassis with the knuckles of the other hand. I have never forgotten that experience (neither I suspect has the science teacher). It made me very respectful of mains power ever since.
Hot chassis: isolation transformer is a must.
On a related matter, I always down tools if someone starts talking to me. I was taught that by my grandfather who was motor mechanic.
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Location: Latham, ACT
Member since 21 February 2015
Member #: 1705
Postcount: 2195
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Gotta agree I always down tools when my wife starts nagging me when I'm working on a radio lol.
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Location: Albury, NSW
Member since 1 May 2016
Member #: 1919
Postcount: 2048
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My original trade was a mechanic! Years ago! I dont work on cars anymore! But where I did work as a teen and for many years was at Engineering work shop. It was their family business and they were wonderful people but extremely eccentric! As the years went on my bosses mum lost the plot and could not be left alone so she would spend the whole day dragging a chair around the work shop and sitting right next to me as I worked! She would sit there with her dogs and Roll cigarettes all day ! Drinking bucket loads of Tea !
She was English and mad as Hatter and had a major problem with the Brandy! Although she was a woman we called her Barry.
It made it near impossible to work as she would constantly ask questions, like ,,, where is her son? Or she would ask me how my dog is and how my mums is and then she would asked about all the pets by name!!!!!
She was a wonderful Soul and I was very fond of her and she was like family to me ,but boy it made it hard to work, but fun place to work.
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