3 ms·

Yeah, they are dangerous, but their safety can be improved: add polarized cord (probably have to move the power switch to the hot side for this) and replace the

Yeah, they are dangerous, but their safety can be improved: add polarized cord (probably have to move the power switch to the hot side for this) and replace the chassis ground capacitor. Table top FM radios and TVs also tend to be hot chassis.. (that mains transformer is just too expensive). Even today you can find capacitor dropper powered devices which are hot. AA5s are nice in that you can almost always get them to work for cheap. I mean if you have an older radio with a bad mains transformer, it's probably not worth fixing. Another advantage: they will work on 120V DC. I don't think low end hot chassis radios were popular in Europe, they all seem to have a transformer. Maybe 220V is just too dangerous... (but you can certainly have a primary to secondary fault in a transformer..)

Aloha 4y ago
240 was too high, and most of the non-110v sets use a transformer. In reality, the case is meant to isolate the set, so the thing is only relevant when performing service work, and honestly, I just measure voltage between chassis and earth and make sure there is zero volts of potential.
- gumboza 4y ago
  That’s ok until you accidentally find you have an earth fault.
  - Aloha 4y ago
    Well, in most cases I'm sitting on a chair isolated from earth, several feet in the air (wearing rubber soled shoes), so long as my test equipment shows 0v of potential to the chassis, its pretty safe. It could be that the earth bond has failed, but provided I have both pieces of gear sharing an earth, its all good.
    - gumboza 4y ago
      Famous last words. Leave that scope probe ground clipped on something and every earth is floating live on your bench. Source: ex EE.
      - Aloha 4y ago
        And at 110v, thats a risk I'm willing to take. I wanna note, I worked as an FSE for a telecom, I've been 'bit' more than once by 130v, and by 160v B+ in shit, the sparks from crossed neutral are fine. Anyone who is deeply concerned can buy an isolation transformer.
        gumboza 4y ago
        110v can fuck you up. Don’t take your own advice please. At least no one else should. Isolation transformer will only stop you getting killed one of three ways. Worth backing my experience up as well. Ex EE covering RF and power in defence sector. There is no room for arrogance or assumptions in dealing with safety.
        Aloha 4y ago
        How would you work on these things?
        gumboza 4y ago
        I wouldn’t. Simple.
gumboza 4y ago
Polarised cord only works if your house sockets are wired correctly which is not necessarily the case and your earth bond might not be as good as you think it is. Always assume that the lowest competence is applied when it comes to safety evaluation. At this point I wouldn’t run one of these things at all. If you drop dead you have no idea if some relative is going to plug it in and kill themselves with it. They were designed to a cost target when safety wasn’t a business concern. Steal the tubes and variable caps out and dispose of the rest. At best, stick it in a museum, preferably of dangerous things that should never be plugged in. There’s plenty of tube kit out there you can buy which isn’t even remotely this dangerous.
- RjQoLCOSwiIKfpm 4y ago
  Please do not willy-nilly dispose of beautiful pieces of interior design which likely won't ever be produced again with similar aesthetics. [1] People constantly throwing away cultural heritage without any second thoughts is the reason why we barely have any left from only even more than 100 or 200 years ago - thousands of years of furniture, decoration, etc. are gone. If you don't want them to be dangerous, make them safe. If thats too complex for you, remove the cable and clearly label the backside with "DANGER! [...]" to explain that this shouldn't be used as is, and ideally put a letter inside which explains the technical details. [1] Yes, I know there are things which are newly produced to "look" old. But they only do to people who aren't into that taste. If you are, all of the modern reproductions look like cheap, insufferable garbage.
  - eternityforest 4y ago
    I wonder why faux vintage stuff with modern electronics isn't more realistic and higher quality. It's not like high end woodworking isn't still a thing. At the very least, if the alternative is full disposal, the old ones could be upgraded with modern electronics.
- Jeema101 4y ago
  Okay but assuming there's no exposed metal parts, is one of these radios with a polarized cord really more dangerous than a regular old two pronged lamp with a polarized cord? If you plug that lamp into an outlet with positive and neutral wired wrong you will have mains voltage on the light bulb threads and socket threads instead of ground, and that's gonna be pretty unsafe for anyone changing the bulb. But lamps are so common, we don't even think about them as safety hazards.

Aloha 4y ago

240 was too high, and most of the non-110v sets use a transformer. In reality, the case is meant to isolate the set, so the thing is only relevant when performing service work, and honestly, I just measure voltage between chassis and earth and make sure there is zero volts of potential.

gumboza 4y ago
That’s ok until you accidentally find you have an earth fault.
- Aloha 4y ago
  Well, in most cases I'm sitting on a chair isolated from earth, several feet in the air (wearing rubber soled shoes), so long as my test equipment shows 0v of potential to the chassis, its pretty safe. It could be that the earth bond has failed, but provided I have both pieces of gear sharing an earth, its all good.
  - gumboza 4y ago
    Famous last words. Leave that scope probe ground clipped on something and every earth is floating live on your bench. Source: ex EE.
    - Aloha 4y ago
      And at 110v, thats a risk I'm willing to take. I wanna note, I worked as an FSE for a telecom, I've been 'bit' more than once by 130v, and by 160v B+ in shit, the sparks from crossed neutral are fine. Anyone who is deeply concerned can buy an isolation transformer.
      - gumboza 4y ago
        110v can fuck you up. Don’t take your own advice please. At least no one else should. Isolation transformer will only stop you getting killed one of three ways. Worth backing my experience up as well. Ex EE covering RF and power in defence sector. There is no room for arrogance or assumptions in dealing with safety.
        Aloha 4y ago
        How would you work on these things?
        gumboza 4y ago
        I wouldn’t. Simple.

gumboza 4y ago

Polarised cord only works if your house sockets are wired correctly which is not necessarily the case and your earth bond might not be as good as you think it is. Always assume that the lowest competence is applied when it comes to safety evaluation. At this point I wouldn’t run one of these things at all. If you drop dead you have no idea if some relative is going to plug it in and kill themselves with it. They were designed to a cost target when safety wasn’t a business concern. Steal the tubes and variable caps out and dispose of the rest. At best, stick it in a museum, preferably of dangerous things that should never be plugged in. There’s plenty of tube kit out there you can buy which isn’t even remotely this dangerous.

RjQoLCOSwiIKfpm 4y ago
Please do not willy-nilly dispose of beautiful pieces of interior design which likely won't ever be produced again with similar aesthetics. [1] People constantly throwing away cultural heritage without any second thoughts is the reason why we barely have any left from only even more than 100 or 200 years ago - thousands of years of furniture, decoration, etc. are gone. If you don't want them to be dangerous, make them safe. If thats too complex for you, remove the cable and clearly label the backside with "DANGER! [...]" to explain that this shouldn't be used as is, and ideally put a letter inside which explains the technical details. [1] Yes, I know there are things which are newly produced to "look" old. But they only do to people who aren't into that taste. If you are, all of the modern reproductions look like cheap, insufferable garbage.
- eternityforest 4y ago
  I wonder why faux vintage stuff with modern electronics isn't more realistic and higher quality. It's not like high end woodworking isn't still a thing. At the very least, if the alternative is full disposal, the old ones could be upgraded with modern electronics.
Jeema101 4y ago
Okay but assuming there's no exposed metal parts, is one of these radios with a polarized cord really more dangerous than a regular old two pronged lamp with a polarized cord? If you plug that lamp into an outlet with positive and neutral wired wrong you will have mains voltage on the light bulb threads and socket threads instead of ground, and that's gonna be pretty unsafe for anyone changing the bulb. But lamps are so common, we don't even think about them as safety hazards.