Best to use the one from the library on this site, then when you refer to part 30 we know which part you are referring to. Of course any radio not a Philco you would have to provide a schematic or link to a schematic.
These tubes are local tubes and the base is kind of a shield. The center post of the tube socket should be wired to chassis ground for the shield to work. If you look at the second XXL in the schematic, you can see a dashed line just inside the tube, it is connected to ground. That's the center post. You will see components connected to the center post because it is a convenient ground terminal.
So you can see how Important it is to identify parts with the schematic, especially when you have multiple parts of the same value. When removing a part, connect a jumper wire with gator clips to each terminal so you have a reference where the new one goes.
"So you can see how Important it is to identify parts with the schematic, especially when you have multiple parts of the same value. When removing a part, connect a jumper wire with gator clips to each terminal so you have a reference where the new one goes."
Thanks Rod,
I definitely only replace one part at a time, that alone has been enough of a headache with this chassis.
I am back tracking on my resistors as the one that burned based on the old one's resistance was correct but another resistor that connects to the tube wasn't correct. I swapped them initially based on the schematic and a resistor chart. I am double checking with my pictures; there's only 14 so I'd rather be safe than sorry.
I believe I'm making progress, resistors have been rechecked and corrected, removed that ugly blue capacitor and more wiring. Powered it up, pilot lights are working, and the humming sound is still there but very faint compared to when I started. Now to the speaker and the Antenna.
Well guys I am stuck, frustrated and about ready to give up. For starters all I'm getting from the speaker is a humming sound no stations coming in.
Issues encountering now is resistor 42 has burned again but only after I reinstalled the blue capacitor removed yesterday. I reinstalled the blue capacitor because a new one installed in it's place popped today.
My problems seem to be around area 40 and 41 on the schematic. Capacitor 40 looks like a double 400volt, unless I'm missing itI don't see the blue capacitor on the schematic. My original picture shows #40 cap, blue cap and #41 resistor connected.
Earlier it was mentioned that cap 40 could be rebuilt. Can it not just be replaced with 2 450 caps? Today while testing the 2nd 450 cap which connects to resistor 42 and the speaker wire it eventually popped.
I've attached a before photo showing the #40 cap and the blue cap. Can someone let me know if the blue cap is seen on the schematic.
From what I see is the blue cap was added by someone after the radio was sold presumably to replace cap 40A. I can't tell if the original 40A had been removed from the circuit. In any case, you should remove original 40A and the blue cap and connect a 4.7mfd cap with the negative lead to ground.
I am assuming the black electrolytic cap in the last Pic is cap 40 and the center terminal of the strip is ground. Therefore, it appears cap 40 is connected backwards with it's positive lead connected to ground. When you do this you get the result you experienced, pop!! The 2.2k resistor should be connected between the positive leads of caps 40A and 40 as the schematic shows.
Whenever a new cap is connected across a defective one the result is a bigger defective cap.
Take your time and carefully remove the old caps from the circuit then connect the new caps in the correct polarity. Test the 2.2k resistor, it may be okay. If the resistor gets hot then there's a problem with one of the circuits that is connected to cap 40.
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