04-18-2022, 02:16 PM
Hi,
Try this schematic.
https://philcoradio.com/library/download...20219B.pdf
It is for the late production version of model 630.
Incidentally, what you have is a 630 since it has six tubes. The 640 has seven tubes and four bands, and a larger chassis.
The late production 630 sets have small holes in the RF cans like yours, with screw adjustments inside. Early production 630 sets have large holes in the RF cans for 1/4 inch nut adjustments.
And it isn't a 635 since it has the large terminal board under the chassis, under the 75 tube. 635 sets don't have that.
Regarding the 10 uF cap (67) in parallel with the B-C resistor (70). This was originally part of a three section electrolytic can. Whoever replaced electrolytics in your set may very well have left out the 10 uF, 50 volt electrolytic, which would explain why you don't see one. Trace out the wiring against the schematic in the link above; you may find that the original 10 uF section is still in the circuit.
Try this schematic.
https://philcoradio.com/library/download...20219B.pdf
It is for the late production version of model 630.
Incidentally, what you have is a 630 since it has six tubes. The 640 has seven tubes and four bands, and a larger chassis.
The late production 630 sets have small holes in the RF cans like yours, with screw adjustments inside. Early production 630 sets have large holes in the RF cans for 1/4 inch nut adjustments.
And it isn't a 635 since it has the large terminal board under the chassis, under the 75 tube. 635 sets don't have that.
Regarding the 10 uF cap (67) in parallel with the B-C resistor (70). This was originally part of a three section electrolytic can. Whoever replaced electrolytics in your set may very well have left out the 10 uF, 50 volt electrolytic, which would explain why you don't see one. Trace out the wiring against the schematic in the link above; you may find that the original 10 uF section is still in the circuit.
--
Ron Ramirez
Ferdinand IN
