I want to replace the old speaker with the field coil with a permanent magnet type on a Philco transitone. How can I do this. I am a novice.

If the original speaker is still there and is electrically still good, and if the radio is a fairly nice one, I STRONGLY recommend reconing the original speaker. I do not at all recommend replacing it. This destroys the originality and appearance of the radio in a big way. Those without asthetic taste may disagree. If the speaker is reconed and the original voice coil is still in good shape, try to see if they can't re-use it if an exact impedance match cannot be found. Be firm about your repair. Some speaker repair places will play games with you and do a poor job simply because they feel that old equipment such as this is not capable of good results. Because of this they do not care whether your speaker performs perfectly electrically or not. "Those old crappy radios always sound bad....noone will notice."

If the radio is not an important one and functionality is the key concern, and/or if the speaker has a rather large fault--field coil blown, then replace it with a permanent magnet speaker. Often these radios used 3.2 ohm speakers, though this was not always true by any means. Many different speaker resistances were used. If you are going to reuse the original output transformer, purchase a 4 ohm speaker. If you do not know what the original speaker's voice coil impedance is, and you have no way of finding out, purchase both a 4 and an 8 ohm speaker if money allows. They should be good quality speakers that will fit physically within the radio and that will have free movement of the cone--not stiff in any way, though rubber surrounds are not necessary. They may be used with large speakers. High frequency response is not a big issue. It should be good and clear, but anything above about 8 kilocycles is unnecessary. If the field coil is still good, you may remove it from the speaker and leave it lying in an inconspicuous place (you must retain the iron that surrounds the coil as it has a choking affect in the power supply, so you will have to cut/break the frame away from this iron...you may simply remove the coil and use it without the iron...hum may be more present....try it both ways.). You may also leave the whole speaker within the radio, but with small radios this takes up space. You could mount a small modern speaker within the old speaker (design a cardboard baffle so area around edge of small speaker is covered--for acoustic reasons), but this sacrifices tonal quality in a huge way. If the field coil no longer operates, replace it with a 10 or 15 watt wire wound resistor of similar resistance.

If you must replace the output transformer, www.tubesandmore.com sells universal type transformers with multiple primary and secondary impedances. With these, a speaker of 4 or 8 ohms may be used, and so you have more flexibility when purchasing a speaker. Use the highest primary impedance that gives good power. Higher impedances yield more bass but less power. Lower impedances yield more power but less bass, and can overload the output tube. If the output transformer is all that was wrong with your original speaker to begin with, then there is no need to replace the whole speaker. Replace the transformer.

Thomas