UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Radio (domestic)

Notices

Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only.

Reply
 
Thread Tools
Old 19th May 2022, 9:25 am   #21
David Simpson
Nonode
 
Join Date: Mar 2008
Location: Aberdeen, UK.
Posts: 2,620
Default Re: AC/ DC radios live chassis.

This subject keeps raising its problematic head from time to time. Each time my response has been much the same.
Into the 3rd decade of the 21st century, electrical safety is paramount. So folk saying that because they worked on 2 wire, unfused, un-determined chassis potential, Radios & TV's, back in the day - so there is no real harm nowadays, gives the wrong message to aspiring younger entrants into the vintage radio fraternity. So, repairing/restoring vintage AC/DC sets with a view to having them working off the mains within a household - 3 wire modern correctly colour-coded flex and the chassis fully earthed so that it passes a PAT Test. Or - fed from a decent modern DC Bench Power Supply. Or - fed from an isolation T/F within a safe workshop & placed on a shelf high enough for "little Johnny" or any child or careless adult not to be able to poke or prod.
Yep, be proud of your lovely(e.g.) bakelite DAC90 & all the hours you spent restoring it - but hey - just admire it sitting on a high shelf somewhere. Doing one up & then flogging it on eBay for the over-priced megabucks you require, with just a "traditional" two-wire supply - - that's greed overcoming safe practices.

Regards, David
David Simpson is offline   Reply With Quote
Old 19th May 2022, 9:49 am   #22
lesmw0sec
Octode
 
Join Date: Jul 2009
Location: Carmel, Llannerchymedd, Anglesey, UK.
Posts: 1,217
Default Re: AC/ DC radios live chassis.

Given that the human body has not changed much for centuries, I'd claim that electrical safety was always paramount. I'd also claim that being aware of how things work and the pitfalls of short-cuts are probably more important than available technology or regulations. Experience and education is the life-saver.
lesmw0sec is offline   Reply With Quote
Old 19th May 2022, 12:35 pm   #23
John10b
Nonode
 
Join Date: Nov 2016
Location: Aberaeron, Ceredigion, Wales, UK.
Posts: 2,191
Default Re: AC/ DC radios live chassis.

My workshop experience was very similar to Sideband, and I did learn a lot about electrical safety, the hard way after seeing the senior bench engineer getting a belt from a live chassis, it was very alarming at the time one I will never forget.
From that day on I never did like sets without a mains transformer.
John
John10b is offline   Reply With Quote
Old 19th May 2022, 1:07 pm   #24
Sideband
Dekatron
 
Sideband's Avatar
 
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 6,749
Default Re: AC/ DC radios live chassis.

Quote:
Originally Posted by David Simpson View Post
This subject keeps raising its problematic head from time to time. Each time my response has been much the same.
Into the 3rd decade of the 21st century, electrical safety is paramount. So folk saying that because they worked on 2 wire, unfused, un-determined chassis potential, Radios & TV's, back in the day - so there is no real harm nowadays, gives the wrong message to aspiring younger entrants into the vintage radio fraternity. So, repairing/restoring vintage AC/DC sets with a view to having them working off the mains within a household - 3 wire modern correctly colour-coded flex and the chassis fully earthed so that it passes a PAT Test. Or - fed from a decent modern DC Bench Power Supply. Or - fed from an isolation T/F within a safe workshop & placed on a shelf high enough for "little Johnny" or any child or careless adult not to be able to poke or prod.
Yep, be proud of your lovely(e.g.) bakelite DAC90 & all the hours you spent restoring it - but hey - just admire it sitting on a high shelf somewhere. Doing one up & then flogging it on eBay for the over-priced megabucks you require, with just a "traditional" two-wire supply - - that's greed overcoming safe practices.

Regards, David
Yep agree with that. However I have no intention of flogging any of my AC/DC sets on eBay or anywhere else for that matter. Strictly for fellow collectors who know any potential risks when my time comes......!

Basically what I was saying was that with care, they are no more unsafe than any other set. Right up into the 80's, most TV's had a live or half-mains chassis (in my opinion, half-mains was more dangerous than AC/DC technology since it didn't matter what way round the mains plug was connected....).
__________________
On Spike Milligan's headstone......I told you I was ill...
Sideband is offline   Reply With Quote
Old 19th May 2022, 1:40 pm   #25
David Simpson
Nonode
 
Join Date: Mar 2008
Location: Aberdeen, UK.
Posts: 2,620
Default Re: AC/ DC radios live chassis.

Yep, many respondents to this thread are thoroughly qualified engineers, technicians, etc. I'm not criticizing their professionalism in any way. But there is a significant number of VRR&R members who don't have such qualifications, or don't display any on their profiles. Some folk, in my experience, are absolutely clueless.
However, to encourage new entrants(much younger than 3 score years & ten, hopefully) to the VR fraternity, us "old uns" should endeavour to try & set jolly high safety standards. Or go the extra mile & offer to hands-on mentor new folk from near their locality.

Regards, David
David Simpson is offline   Reply With Quote
Old 19th May 2022, 6:42 pm   #26
broadgage
Octode
 
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 1,980
Default Re: AC/ DC radios live chassis.

Whilst both the human body and electricity are unchanged, public attitudes to risk have now changed a lot.

AC/DC live chassis radio and TV sets though in general use for decades, are at least a bit risky by the stricter standards expected today.

Before USING such a set I would strongly advise making certain that the neutral goes to the chassis, and that final connection is via polarised plug and socket. I would also advise that such a set be turned off at the socket outlet when not in use.

Before WORKING ON such a set I would strongly advise use of an isolating transformer, or at least an RCD. If a set being worked on is to be left unattended, then I suggest either locking it up, or removing the mains plug.

The fact that such precautions were not normally taken decades ago is of little relevance in today's more safety conscious world.
broadgage is offline   Reply With Quote
Old 19th May 2022, 7:22 pm   #27
akuram1
Pentode
 
Join Date: Sep 2009
Location: Dundee, UK.
Posts: 144
Default Re: AC/ DC radios live chassis.

Of course everything about safety is totally correct but remember in the 50’s and 60’s it was just normal we had to service these sets in many strange places as best we could.
They were safe if great care was always the no1 priority. One hand in your pocket was good advice.
akuram1 is online now   Reply With Quote
Old 20th May 2022, 9:41 am   #28
David Simpson
Nonode
 
Join Date: Mar 2008
Location: Aberdeen, UK.
Posts: 2,620
Default Re: AC/ DC radios live chassis.

akuram1 has hit the nail on the head in saying that safety is the no1 priority.
Dundee eh ? I have fond memories(late 70's) of extreme safety training at Hydro-Electric's Carolina Port Training Centre. Was put up in a B&B on the Broughty Ferry Road a stone's throw away. Then electrical inspection training ten years later at the new training centre up on the by-pass. Still used the same B&B, though.

Regards, David
David Simpson is offline   Reply With Quote
Old 20th May 2022, 10:09 am   #29
tin0gauge
Tetrode
 
tin0gauge's Avatar
 
Join Date: Oct 2013
Location: Guildford, Surrey, UK.
Posts: 81
Default Re: AC/ DC radios live chassis.

Thank you gentlemen for your extensive advise and education.
tin0gauge is offline   Reply With Quote
Old 20th May 2022, 11:09 am   #30
eddie_ce
Hexode
 
eddie_ce's Avatar
 
Join Date: Aug 2010
Location: nr. Hannover, Germany
Posts: 362
Default Re: AC/ DC radios live chassis.

What is the consensus on the following.

A 3 core cable with the Earth (green/yellow) conductor NOT connected to the chassis, but only to a small neon with a high value (270-330k) resistor connected to one side, the other side of the resistor connected to the chassis of the set. If the chassis were live, the neon would light as a warning. The earth leakage current caused by this would be minimal and not cause any RCD to trip.

This is a system I have used on several occasions but must stress for my personal use only. This is perhaps more relevant here on the continent where we do not have the luxury of polarised plugs
__________________
Eddie
BVWS Member.
Friend of the BVWTM
eddie_ce is offline   Reply With Quote
Old 20th May 2022, 11:19 am   #31
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 8,745
Default Re: AC/ DC radios live chassis.

Times and attitudes to safety have changed.
AC/DC radios in particular should never be sold to members of the general public. They are simply unaware of the possible implications when small radios are used in earthy situations such as kitchens.
I would never have given my late mother an AC/DC radio to use anywhere in the house.
There was an appalling lack of chassis isolation with many of these radios. Chassis fixing bolts just covered with tape, grub screws protruding, aged and ill fitting backs with particular reference to the DAC90 horror.
No problem with vintage radio enthusiasts but even here there can be a huge lack of knowledge.
Just use an isolating transformer to remove the live chassis aspect and don't sell them to the general public under any circumstances.
If there was a tragic accident the seller would almost certainly be blamed for selling the radio knowing it had possible dangers. It's of no use getting them to sign bits of paper saying they accept the liability but I would put that in the same league as selling someone a live hand grenade and giving them an information sheet telling them not to pull the pin.
One fatal accident and all electrical appliances will be crushed by order! John.
Heatercathodeshort is offline   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 5:05 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.