Missing speaker question

If you find a nice radio with no speaker how do you know what ohm, watt, etc. it needs. If the schematic shows the speaker coil voltage and maybe even the ohms of the voice coil how do you know to replace it with. Trying to find an exact 1920-40's coil speaker is iffy at best. Is there a better way than spending hours, days months searching the internet?

you need to be more specific. What brand of radio and model # or post a picture. Most speakers of that era had either a high resistance voice coil, or a low resistance voice coil and a field coil that was used as a choke in the power supply circuit. You could find a generic replacement from another radio as long as the final audio tube is the same or similar. The field coil is usually over 1000 ohms, and closer to 1500 or 2000 ohms.

The voice coil is usually 3.2 to 8 ohms.

Funny....I guess the the question was like saying "I'm buying a car, what size tires should it have"? I have seen a few lately that said no speaker so it started me thinking how do you go about finding a speaker replacement for a radio whem there is no speaker to look at. So you have to go to the schematic and try to determine what is was from there. Here use this, have this radio with bend speaker I think I can make it work but what if it were missing. All the shematic shows is speaker ohms and voltage across the speaker field. What is the watts and ohms. The best # I can come up with is 8 ohm speaker. Sorry to be so long winded and fague.

http://www.nostalgiaair.org/Resources/323/M0020323.htm

Stewart Warner has a very poor copy of schematics I have read every where for field coils from 600 ohm to 1000 ohms. Not very helpful with your problem but it does seem to be a 5 inch speaker.

Heres a link that goes into finding out how to replace a speaker field coil when one isnt availible by modifying for another type.
http://www.radioremembered.org/edspeaker.htm

yeah I thought the schm was a bit short on info as well. I have seen the article you are referring to here but did not make sence of the voltage drop. Make more sence now now. Thanks and great day. Hope the heat is not bad there. Local weather says 103 here in Memphis today.

Blessings,
B

Another consideration is the output transformer, which is often mounted as a part of the speaker assembly. As long as you're working with the same general style of speaker, that is, transformer and voice coil dynamic, exact characteristics are not extremely critical. Almost any speaker will work with any conventional set. All that may suffer is the maximum output power.

Good info, thanks for the advice.

Blessings,
Ben