09-07-2021, 02:42 PM
The place where one uses safety condensers is at the line power input to the piece of equipment to filter any RF from the line. Here is a link to a good explanation of what safety condensers are, and how they are used:
https://www.allaboutcircuits.com/technic...apacitors/
Here is a section of the schematic diagram of a Philco 38-10.
[Image: https://64.media.tumblr.com/093edcdf2879...8eb4cb.jpg]
Notice the part numbered 47. That is one of the bakelite blocks commonly used in Philco radios to hold condensers and other parts of the circuit. Here you see the two condensers used to filter RF from the line. These are the condensers usually replaced with safety condensers. Since they go between each side of line to the chassis ground, one would use type Y safety condensers in this application, since, should they ever fail, they are designed to fail OPEN, and so, while no longer filtering out RF noise on the line, won't cause a shock hazard by shorting the line to the chassis.
To replace these condensers one needs to remove the bakelite block from the radio, then put it on a little tray to catch the molten tar, and heat it on the oven to about 250 F so that the tar inside it melts. You can then pull out the old paper condensers inside it, and replace them with the modern safety condensers.
https://www.allaboutcircuits.com/technic...apacitors/
Here is a section of the schematic diagram of a Philco 38-10.
[Image: https://64.media.tumblr.com/093edcdf2879...8eb4cb.jpg]
Notice the part numbered 47. That is one of the bakelite blocks commonly used in Philco radios to hold condensers and other parts of the circuit. Here you see the two condensers used to filter RF from the line. These are the condensers usually replaced with safety condensers. Since they go between each side of line to the chassis ground, one would use type Y safety condensers in this application, since, should they ever fail, they are designed to fail OPEN, and so, while no longer filtering out RF noise on the line, won't cause a shock hazard by shorting the line to the chassis.
To replace these condensers one needs to remove the bakelite block from the radio, then put it on a little tray to catch the molten tar, and heat it on the oven to about 250 F so that the tar inside it melts. You can then pull out the old paper condensers inside it, and replace them with the modern safety condensers.
