11-03-2014, 10:06 AM
This morning, I removed the power transformer and performed a limited autopsy (limited in that I did not open up the windings).
[Image: http://www.philcoradio.com/images/phorum...e00020.jpg]
It doesn't look bad in the photo, does it? The only tell-tale signs of burning are some of the wires exiting the windings, and the charred appearance on the inside of the bell on the left. But the smell of roasted transformer is very strong.
Note the handwriting on the winding:
[Image: http://www.philcoradio.com/images/phorum...e00021.jpg]
'Tis a shame to lose this transformer, but if this radio was indeed a preproduction sample (and it gives many indications that it is), someone took it home and used it to death.
Arran, I really appreciate the effort you made to find suitable Edcor replacements. There is only one problem - the mounting width of the holes on either side of the bell is 2-1/2 inches. The original transformer only has 2-1/8" on either side of the bell, and as you will see in the photo below, there isn't much room to go much more than this.
[Image: http://www.philcoradio.com/images/phorum...e00022.jpg]
In addition, whether I purchase Edcor or Hammond, another hole will have to be drilled where the melted wax from the transformer formed a round indentation on the chassis - both new transformers have wires protruding from both bells while the original had all wires coming out one end only (hence, only one large hole in the chassis).
Arran, you've just about convinced me to rewire the rectifier socket, use a new transformer with a 5V winding, and use a 5Y3GT in place of the 6X5. But there is still the issue of the mounting holes. The Hammond 270DX has a footprint of 2" across the bell x 1.938" between bells. Now, there's the 270EX, more current capacity, with a footprint of 2" x 2.688".
270DX - 550 VCT @ 104 mA; 5V @ 2A; 6.3V @ 3A
270EX - 550 VCT @ 144 mA; 5V @ 3A: 6.3V @ 4A
Both exceed the 42-720's requirements (570 VCT @ 70 mA; 6.3V @ 2.5A) and are both small enough to fit. As you notice in the photo just above, there are holes drilled already to allow for up to a 2.75" mounting length (between bells).
The 270DX is $59.07 at Mouser; the 270EX is $64.76.
So I need to raise a little $$. Anyone need some Philco coils rewound?
I'll place an ad in the For Sale or Trade section since ads are not allowed here.
[Image: http://www.philcoradio.com/images/phorum...e00020.jpg]
It doesn't look bad in the photo, does it? The only tell-tale signs of burning are some of the wires exiting the windings, and the charred appearance on the inside of the bell on the left. But the smell of roasted transformer is very strong.
Note the handwriting on the winding:
[Image: http://www.philcoradio.com/images/phorum...e00021.jpg]
'Tis a shame to lose this transformer, but if this radio was indeed a preproduction sample (and it gives many indications that it is), someone took it home and used it to death.
Arran, I really appreciate the effort you made to find suitable Edcor replacements. There is only one problem - the mounting width of the holes on either side of the bell is 2-1/2 inches. The original transformer only has 2-1/8" on either side of the bell, and as you will see in the photo below, there isn't much room to go much more than this.
[Image: http://www.philcoradio.com/images/phorum...e00022.jpg]
In addition, whether I purchase Edcor or Hammond, another hole will have to be drilled where the melted wax from the transformer formed a round indentation on the chassis - both new transformers have wires protruding from both bells while the original had all wires coming out one end only (hence, only one large hole in the chassis).
Arran, you've just about convinced me to rewire the rectifier socket, use a new transformer with a 5V winding, and use a 5Y3GT in place of the 6X5. But there is still the issue of the mounting holes. The Hammond 270DX has a footprint of 2" across the bell x 1.938" between bells. Now, there's the 270EX, more current capacity, with a footprint of 2" x 2.688".
270DX - 550 VCT @ 104 mA; 5V @ 2A; 6.3V @ 3A
270EX - 550 VCT @ 144 mA; 5V @ 3A: 6.3V @ 4A
Both exceed the 42-720's requirements (570 VCT @ 70 mA; 6.3V @ 2.5A) and are both small enough to fit. As you notice in the photo just above, there are holes drilled already to allow for up to a 2.75" mounting length (between bells).
The 270DX is $59.07 at Mouser; the 270EX is $64.76.
So I need to raise a little $$. Anyone need some Philco coils rewound?
I'll place an ad in the For Sale or Trade section since ads are not allowed here.
--
Ron Ramirez
Ferdinand IN
