12-12-2016, 08:47 PM
And so let us begin work on the RF unit.
I have said many times over the years the following: It is my opinion that David Grimes, the person responsible for the design of this...thing...should have been sentenced to servicing Philco radios with his lousy Unit Construction, 18 hours a day, 7 days a week, for the rest of his life.
But anyway...
The only way I have found to properly service these is to taken them apart. It is the best way to access the paper capacitors which are often hidden between band switch wafers.
Once the RF unit is out of the radio, you begin by removing the metal sides. Each side is held in place by three bolts. One side will have two copper braids soldered to it. Unsolder these where they are soldered onto the side, then remove both sides.
Then you must carefully unsolder two wires from the bottom side of the antenna and RF sections of the tuning condenser. Don't worry, you can get to them from the side. You will also have to unsolder one end of two of the paper capacitors from the frame of the tuning condenser.
Once that is done, remove one bolt and the antenna section comes right out:
[Image: http://www.philcoradio.com/images/phorum/37640_048.jpg]
Now I can (sort of) get to the hidden capacitor. While I'm in here, I also replace the connecting wires. Once finished, this is how it looks:
[Image: http://www.philcoradio.com/images/phorum/37640_049.jpg]
Next, I remove the RF section. This time, I not only have to remove one bolt, but I also have to unsolder the grounded end of another paper capacitor, the other end of which connects into the oscillator circuit. I also have to unsolder the wire from pin 3 of the 6K7G RF tube before I can finally pull the RF section out of the unit.
As with the antenna section, I replaced paper caps (two in this case) as well as the connecting wires.
And here is where things stand now:
[Image: http://www.philcoradio.com/images/phorum/37640_050.jpg]
I still have to do some work in the oscillator section. This is best done while the antenna and RF sections are out of the unit. There is also another aluminum can electrolytic that needs to be restuffed.
Interestingly enough, out of all the RF units I have rebuilt over the years, I cannot recall a single instance in which this electrolytic capacitor can was not still filled with its boric acid solution. I am sure this electrolytic was not put under as much of a strain as were the two main filters. Nevertheless, this can will still be rebuilt.
I have said many times over the years the following: It is my opinion that David Grimes, the person responsible for the design of this...thing...should have been sentenced to servicing Philco radios with his lousy Unit Construction, 18 hours a day, 7 days a week, for the rest of his life.
But anyway...
The only way I have found to properly service these is to taken them apart. It is the best way to access the paper capacitors which are often hidden between band switch wafers.
Once the RF unit is out of the radio, you begin by removing the metal sides. Each side is held in place by three bolts. One side will have two copper braids soldered to it. Unsolder these where they are soldered onto the side, then remove both sides.
Then you must carefully unsolder two wires from the bottom side of the antenna and RF sections of the tuning condenser. Don't worry, you can get to them from the side. You will also have to unsolder one end of two of the paper capacitors from the frame of the tuning condenser.
Once that is done, remove one bolt and the antenna section comes right out:
[Image: http://www.philcoradio.com/images/phorum/37640_048.jpg]
Now I can (sort of) get to the hidden capacitor. While I'm in here, I also replace the connecting wires. Once finished, this is how it looks:
[Image: http://www.philcoradio.com/images/phorum/37640_049.jpg]
Next, I remove the RF section. This time, I not only have to remove one bolt, but I also have to unsolder the grounded end of another paper capacitor, the other end of which connects into the oscillator circuit. I also have to unsolder the wire from pin 3 of the 6K7G RF tube before I can finally pull the RF section out of the unit.
As with the antenna section, I replaced paper caps (two in this case) as well as the connecting wires.
And here is where things stand now:
[Image: http://www.philcoradio.com/images/phorum/37640_050.jpg]
I still have to do some work in the oscillator section. This is best done while the antenna and RF sections are out of the unit. There is also another aluminum can electrolytic that needs to be restuffed.
Interestingly enough, out of all the RF units I have rebuilt over the years, I cannot recall a single instance in which this electrolytic capacitor can was not still filled with its boric acid solution. I am sure this electrolytic was not put under as much of a strain as were the two main filters. Nevertheless, this can will still be rebuilt.
--
Ron Ramirez
Ferdinand IN
