21–30 of 71 posts
https://www.radiomuseum.org/r/zenith_h722wh_722_ch_6h066_h_0...
It's brown if anyone is curious.
The old Zenith stuff of this era is nice, because they used almost exclusively disc caps, which means if it doesnt work, all it needs is the power caps (and one more in the tone section usually). What that translates to, is it usually works out of the box.
Definitely read the potential hazards section. Dangerous as hell these things.
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..)
Even with the RC network referenced in the wikipedia article, you're looking at leakage to the chassis of 4.5 to 11.3 mA: https://incompliancemag.com/article/electric-shock-from-radi...
Definitely read the potential hazards section. Dangerous as hell these things.
Definitely read the potential hazards section. Dangerous as hell these things.
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 t…
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.
The hot chassis design is mind-blowingly dangerous by contemporary standards. These things weren't designed to modern creepage distances either. I would worry about creepage to controls on these things. THe article mentions screws potentially being hot as well as other shock hazards finger-accessible through vent hols so no joke be careful to unplug a radio before moving it or otherwise handling it in a way beyond tu…
I'm listening to an AA5 right now, a rather rare Zenith FM only unit - an H722. https://www.radiomuseum.org/r/zenith_h722wh_722_ch_6h066_h_0... It's brown if anyone is curious. The old Zenith stuff of this era is nice, because they used almost exclusively disc caps, which means if it doesnt work, all it needs is the power caps (and one more in the tone section usually). What that translates to, is it usually works ou…
https://www.radiomuseum.org/r/benrus_clock_radio_10b01b15b_1...
With nice Telechron clock..
I'm listening to an AA5 right now, a rather rare Zenith FM only unit - an H722. https://www.radiomuseum.org/r/zenith_h722wh_722_ch_6h066_h_0... It's brown if anyone is curious. The old Zenith stuff of this era is nice, because they used almost exclusively disc caps, which means if it doesnt work, all it needs is the power caps (and one more in the tone section usually). What that translates to, is it usually works ou…
I'm sitting next to one of these: https://www.radiomuseum.org/r/benrus_clock_radio_10b01b15b_1... With nice Telechron clock..
Earlier quoted context omitted.
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 t…
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.
The hot chassis design is mind-blowingly dangerous by contemporary standards. These things weren't designed to modern creepage distances either. I would worry about creepage to controls on these things. THe article mentions screws potentially being hot as well as other shock hazards finger-accessible through vent hols so no joke be careful to unplug a radio before moving it or otherwise handling it in a way beyond tu…