Today, 01:02 AM
Bob;
I was thinking the same with that 150 ohm resistor, put a larger value replacement in it's place to compensate for a silicon diode, or pair of silicon diodes. I think that the forward drop is roughly .7 volts on a silicon diode, obviously more with two in series, I was told that the selenium ones had a 4 or 5 volt drop when they were new, not 75 years old, so adding extra resistance following the replacement rectifier is a good plan, even better when the resistor following it is a dodgy sand resistor. By the way sand resistors are wire wound resistors, but that sand coating didn't do very much to protect the wire, or the connections, from corrosion, and the one in my set is looking a little green on one end, even though it read 160 ohms when I tested it.
I misspoke about the paper caps, the small ones were not 200 vdc rated, they were 100 volt caps, I may have a go at restuffing but I don't think I have any .022 uf caps that are small enough to fit in the shells, which are maybe 3/16'' on the inside. I guess that Phillips decided to use 100 volt ones because of the low voltages involved, and because they were smaller to work with, likely cheaper as well. It's kind of a shame as the set is all original inside, right down to the tubes. Has anyone tried painting those yellow poly film caps? I was thinking of trying some cardboard straws for capacitor shells, if I could find some the right colour. They are no good as straws so maybe they should be put to more constructive use.
Regards
Arran
I was thinking the same with that 150 ohm resistor, put a larger value replacement in it's place to compensate for a silicon diode, or pair of silicon diodes. I think that the forward drop is roughly .7 volts on a silicon diode, obviously more with two in series, I was told that the selenium ones had a 4 or 5 volt drop when they were new, not 75 years old, so adding extra resistance following the replacement rectifier is a good plan, even better when the resistor following it is a dodgy sand resistor. By the way sand resistors are wire wound resistors, but that sand coating didn't do very much to protect the wire, or the connections, from corrosion, and the one in my set is looking a little green on one end, even though it read 160 ohms when I tested it.
I misspoke about the paper caps, the small ones were not 200 vdc rated, they were 100 volt caps, I may have a go at restuffing but I don't think I have any .022 uf caps that are small enough to fit in the shells, which are maybe 3/16'' on the inside. I guess that Phillips decided to use 100 volt ones because of the low voltages involved, and because they were smaller to work with, likely cheaper as well. It's kind of a shame as the set is all original inside, right down to the tubes. Has anyone tried painting those yellow poly film caps? I was thinking of trying some cardboard straws for capacitor shells, if I could find some the right colour. They are no good as straws so maybe they should be put to more constructive use.
Regards
Arran