Ok, I connected 2 ceramic 10W resistors in series across the wiring to the field coil, one was 600 Ohms the other 500 ohms, resistance total measured 1109 ohms, first I connected a 6 ohm 40 w speaker to the red and black leads from the output transformer, it is playing, although sound was fairly distorted, then I connected a 4 ohm 2-way car speaker at 40 W and sound was a lot better, although distorting at higher volume, after playing for a half hour i checked the temp of the resistors and either resistor was over 80F and there is absolutely no hum!. I am very close here, I'm thinking a 2 ohm 20 W speaker would probably sound the best? thoughts?
Now that I think about it the basket on Philco speakers is fastened to the rear bracket with round headed pins that push out. You would still have to remove the cone but that's fairly simple, some acetone to melt the old cement around the rim, and it will come right off after a 15 minute soaking. Still, even if you don't want to tackle rebuilding the original speaker I would still keep it around in case you want to have a go at rebuilding it, or find someone else to do it, or end up selling the set later.
Regards
Arran
I would definitely keep the speaker Arran, maybe sometime I will try and repair the field coil, but for now I can live with how the radio sounds using the 4 ohm speaker.
thanks all commenters for your help!
