09-06-2014, 12:26 AM
Mike;
Another "Curtain Burner" replacement that won't work on DC is the silicon diode one, or the use of a bucking transformer. In fact the capacitive dropper and the silicon diode trick won't work on alternative power line frequencies, if you set it up for a 60 cps power system it will not work on 50 cps, or anything other then 60 cps. Of course there are not any 120 volt 50 cps power grids that I am aware of, and the European systems that are 50 cps are all 240 VAC, but it will cause a problems even if a 240-120 volt dropping transformer is used. This isn't an issue with a proper AC transformer set, most of those were designed to accommodate 40-60 cps or 50-60 cps.
The "Curtain Burner" resistive line cords were a bit of a misnomer anyhow, at least when they were still in good condition. Having a resistive element spread out over 5-6 feet would make it a little warm, not hot like a toaster, and they were reasonably well insulated, with asbestos of course. However they did warn people not to coil the cords up, or to pin them against a wall behind furniture as the heat would build up inside, nor to shorten the cord.
This is one sort of radio that I have never owned, a set with a resistive line cord, all of my early AC/DC sets use either a ballast tube or a candohm riveted to the chassis. Early AC/DC sets are not that common in Canada, prior to 1939-40 they were not allowed to be sold here, so all the ones I have are American imports.
Regards
Arran
Another "Curtain Burner" replacement that won't work on DC is the silicon diode one, or the use of a bucking transformer. In fact the capacitive dropper and the silicon diode trick won't work on alternative power line frequencies, if you set it up for a 60 cps power system it will not work on 50 cps, or anything other then 60 cps. Of course there are not any 120 volt 50 cps power grids that I am aware of, and the European systems that are 50 cps are all 240 VAC, but it will cause a problems even if a 240-120 volt dropping transformer is used. This isn't an issue with a proper AC transformer set, most of those were designed to accommodate 40-60 cps or 50-60 cps.
The "Curtain Burner" resistive line cords were a bit of a misnomer anyhow, at least when they were still in good condition. Having a resistive element spread out over 5-6 feet would make it a little warm, not hot like a toaster, and they were reasonably well insulated, with asbestos of course. However they did warn people not to coil the cords up, or to pin them against a wall behind furniture as the heat would build up inside, nor to shorten the cord.
This is one sort of radio that I have never owned, a set with a resistive line cord, all of my early AC/DC sets use either a ballast tube or a candohm riveted to the chassis. Early AC/DC sets are not that common in Canada, prior to 1939-40 they were not allowed to be sold here, so all the ones I have are American imports.
Regards
Arran
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