08-22-2024, 09:08 PM
Hi John,
Looking at your post and the description, it would seem that the cylindrical device is not a transformer, but the filter that I described in my previous post (See the RCA 100A Speaker schematic). Seems to me that the bottom 2 terminals on the cylindrical device in your post are internally connected together. There is likely a choke coil between the 2 top connections and either one or 2 condensers between either or both top connectors and the bottom connectors, in the Pi network that. The square device on the right is the magnetic reed "motor" (That's what they were called) that drives the cone. normal resistance across the 2 terminals on the motor should be between 500 Ohms and 2K Ohms. I would not be surprised if it were open; I have a whole collection of headphones and an AK Model E speaker with open coils.
There are experts here who have rewound headphone and magnetic speaker coils. These are not exactly fun as there are many many turns of very fine wire. Disassemble the motor and carefully remove any insulating paper and look for corrosion. This is where the break will likely be. If the break is near the surface, then it is easily fixable. However, if it is all the way near the core, then if you can't remove the form, you will need to rewind or replace it.
Looking at your post and the description, it would seem that the cylindrical device is not a transformer, but the filter that I described in my previous post (See the RCA 100A Speaker schematic). Seems to me that the bottom 2 terminals on the cylindrical device in your post are internally connected together. There is likely a choke coil between the 2 top connections and either one or 2 condensers between either or both top connectors and the bottom connectors, in the Pi network that. The square device on the right is the magnetic reed "motor" (That's what they were called) that drives the cone. normal resistance across the 2 terminals on the motor should be between 500 Ohms and 2K Ohms. I would not be surprised if it were open; I have a whole collection of headphones and an AK Model E speaker with open coils.
There are experts here who have rewound headphone and magnetic speaker coils. These are not exactly fun as there are many many turns of very fine wire. Disassemble the motor and carefully remove any insulating paper and look for corrosion. This is where the break will likely be. If the break is near the surface, then it is easily fixable. However, if it is all the way near the core, then if you can't remove the form, you will need to rewind or replace it.
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards,
MrFixr55