04-29-2007, 01:47 PM
Thae bakelite block cap is 0.3 mF. It was used to "tune" the filter choke (96) at 120 Hz. - the AC ripple freq., due to the less efficient filter caps of that day.
It's not really needed and if it's not the exact value, it wouldn't be effective, since the inductance value of the choke has drifted with time anyway.
The fact that the two main filter caps, parts 98 and 91, being replaced will more than make up for any effectiveness of that 0.3 mF. cap may have added.
Those 8 mF. filters should be 10 mF. with today's modern cap values and this will counteract any need for that "choke tune" cap.
Chuck
It's not really needed and if it's not the exact value, it wouldn't be effective, since the inductance value of the choke has drifted with time anyway.
The fact that the two main filter caps, parts 98 and 91, being replaced will more than make up for any effectiveness of that 0.3 mF. cap may have added.
Those 8 mF. filters should be 10 mF. with today's modern cap values and this will counteract any need for that "choke tune" cap.
Chuck
Chuck Schwark,
The Philco Repair Bench
[Image: http://www.philcorepairbench.com/images/philog3tiny.gif]
http://www.philcorepairbench.com
