03-23-2018, 10:20 AM
I recently purchased this model, I now find that the speakers voice coil is seized in that when you gently push down near the middle of speaker it does not move up and down. Rather than paying 100 bucks to have it re-coned (I'm a newbie with speaker matters!) I'd like to replace the speaker with a PM speaker that I have which is similar size. The PM speaker measures 6.3 ohms across the black and red leads.
Now from what I have read for info on the speaker that was original is that it is an H-4 has a field coil dc resistance of 3200 ohms output transformer dc resistance of 800 ohms, voice coil impedance of .7 ohms.
So to get this right all i need to do is connect a 3.2K 10 watt resistor to where the field coil was connected ( female connections at plug)? Then connect my pm speaker to the output of the output transformer?
what about the field choke? would i have to do something with that? Would I need to double the size of electro cap #68 to 12 uf vs 6 uf to cut hum? Please find attached drawn up schematic regarding the above. any help would be appreciated!
Now from what I have read for info on the speaker that was original is that it is an H-4 has a field coil dc resistance of 3200 ohms output transformer dc resistance of 800 ohms, voice coil impedance of .7 ohms.
So to get this right all i need to do is connect a 3.2K 10 watt resistor to where the field coil was connected ( female connections at plug)? Then connect my pm speaker to the output of the output transformer?
what about the field choke? would i have to do something with that? Would I need to double the size of electro cap #68 to 12 uf vs 6 uf to cut hum? Please find attached drawn up schematic regarding the above. any help would be appreciated!
