I have recently started rebuilding my first Philco, it's a model 39-116.
I have replaced all the wiring, capacitors,but need a speaker. Anyone have one that works ? Can I replace it with a common 8 ohm speaker? I have the schematic but it doesnt tell me how many ohms or what the resistance is on the transformer that used to be mounted on the top of it.
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Hi "mister"
I think your speaker is a 12 inch unit? It is electrodynamic, with no audio output transformer mounted on it. It has an 860 ohm field coil, and either a 3 or 5 ohm voice coil - a quick look through my stuff does not reveal the exact specs on this speaker's voice coil, maybe Chuck has this info?
It could be replaced with a modern PM speaker, but (1) you would have to add a 850 ohm, around 25 watt, resistor under the chassis; and (2) original-type speakers are not that hard to find; in fact they seem to show up on our favorite online auction site (eBay) quite frequently.
Good luck,
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Ron Ramirez
Ferdinand IN
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1939 Part Catalogue:
Speaker 36-1450
Type "H" 12" electro-dynamic
Voice coil impedance @400 cycles = 5.1 ohms
(this is NOT the D.C. resistance measured with a meter.)
Field coil 860 D.C. ohms
Posts: 13,776
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Thanks for the assist. I have the earlier part catalogs through 1938, then 1941, 1946 and a couple of later ones - the 1941 and 46 catalogs show that speaker as still being available for purchase at that time, but do not give its specifications.
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Ron Ramirez
Ferdinand IN
Thanks for the fast reply guys. I'll be checking Ebay.