Here is technical information on your radio:
http://www.nostalgiaair.org/PagesByModel/184/M0006184.pdf
Your transformer needs 4 windings. One primary for 120 volts (all have this).
5 volts @ 2 amps secondary for filament of 5Y3 rectifier tube.
6.3 volts for all other tubes. Current for this winding is determined by tube filaments and lamps. You can look up tubes individually for current. Since this radio has quite a few tubes probably need around 4.5 amps.
A high voltage center tapped secondary is needed. Look for something in the 300-0-300 range around 110 ma. This is higher current than many radios since there are more tubes.
AES, www.tubesandmore.com and others sell transformers. Will part number P-T273CZ fit in your radio? This one has extra margin. P-T272DX is a little smaller but will work. There are others. Larger transformers will operate cooler but may not fit on the chassis.
Norm
:hi guys, i need some info if anyone is able , i got a firestone console radio model 4-A-42 the power trany is fried and i need to know what the voltages are so i can locate a replacement any ideas? thank you very much gary
Mathematically, when you want to find the current required in each circuit, especially the B circuit, you can do so by first working with the filament circuits. Determine the amperages required for them by looking at what tubes are on each winding, and what amperage each tube filament on the particular winding draws. Then take the total amperage for a particular winding and multiply it by its voltage. This will give you the wattage drawn by that winding (which isn't really important when dealing with that winding....all you need to know is the amperage requirement.....but the wattage drawn by that winding and other filament windings will help you later....finding filament wattage drawn is easy, so that is why you start there). Add up the filament wattages, since they are easy to come up with as long as you know what tubes the radio uses. Subtract this wattage from the radio's total wattage. The remaining wattage will be that used by the B circuit, as well as inefficiencies in the power transformer. If you can come close to the original B voltage, or are sure of the original voltage, you can then determine the mA. required from the B winding. Take the voltage and divide it by the winding's wattage, and you will come with the amperage drawn by the winding, and what the winding is required to put forth without overheating. 110 mA, as Norm suggests, though, should be quite fine for this radio. If you have space requirements, and need to cut the transformer down to a certain size, the math can help you get just the transformer you need, and nothing more.....though more is better if you can fit it (amperage wise....not necessarily voltage wise).
Thomas