03-25-2010, 09:08 AM
I'm here but don't have a lot of time, busy with college.
Anyway...welcome! The 41-788 is a desirable radio and should be a really good performer once restored. I have one of those and its near twin, the 42-788.
One of the 5 uF caps (13A) is in the set's front end; it connects to a line going to the screen grid of the RF amp tube 7C7E.
The other 5 uF cap (13B) is in the audio circuit, connected to the junction of resistors (74), (78), (79) and (87).
The only other electrolytic I see is (88), and it should be a single section electrolytic. Maybe yours has been replaced with a dual or triple section twist-lock, and only one terminal was used?
These 1941 Tropic models were perhaps the first Philcos to use twist-lock electrolytics, which became more common after WWII.
Do you have the schematic/service information for this radio? If not, you need to contact Chuck Schwark and get yourself a really good quality copy.
http://www.philcorepairbench.com/schematics.htm
As for the field coil, you can sub an 800 ohm resistor, and increase the value of the filters somewhat. Like increasing (88) from 16 to 22 or 33 uF. I think 47 uF will be sufficient for (13C) even with a resistor in place of the original field. Use a resistor rated at 25 watts minimum. This resistor will run hot!
Anyway...welcome! The 41-788 is a desirable radio and should be a really good performer once restored. I have one of those and its near twin, the 42-788.
One of the 5 uF caps (13A) is in the set's front end; it connects to a line going to the screen grid of the RF amp tube 7C7E.
The other 5 uF cap (13B) is in the audio circuit, connected to the junction of resistors (74), (78), (79) and (87).
The only other electrolytic I see is (88), and it should be a single section electrolytic. Maybe yours has been replaced with a dual or triple section twist-lock, and only one terminal was used?
These 1941 Tropic models were perhaps the first Philcos to use twist-lock electrolytics, which became more common after WWII.
Do you have the schematic/service information for this radio? If not, you need to contact Chuck Schwark and get yourself a really good quality copy.
http://www.philcorepairbench.com/schematics.htm
As for the field coil, you can sub an 800 ohm resistor, and increase the value of the filters somewhat. Like increasing (88) from 16 to 22 or 33 uF. I think 47 uF will be sufficient for (13C) even with a resistor in place of the original field. Use a resistor rated at 25 watts minimum. This resistor will run hot!
--
Ron Ramirez
Ferdinand IN
