| Generator GN-38 | |
| Used in EE-8, BD-71/2, RM-29A etc. | |
 This is the remains of an EE-8-A that we learned magneto theory on in A&P school. The GN-38 and MC-131 were mounted at opposite ends of a board. They were wired direct so the bell rang when you cranked the generator. I reassembled the parts and the result is the complete bottom half of the phone. |
GN-38 is a handcrank magneto generator. It is used to create ringer current in field phones. GN-38 (From TM11-330 pg23) Crank Gear Ratio = 1-5 Output Frequency at 1000 rpm of armature (200 rpm of crank) = 16 cycles Output current at above speed: 200 ohm res = 90 milliamps 1000 ohm res = 50 milliamps 10,000 ohm res = 9.5 milliamps Open circuit voltage (approximate = 100 volts) |
| GN-38 type descriptions | |
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Generator GN-38 has three small cobalt steel permanent magnets arranged in two pole faces about an armature. |
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Generator GN-38-A has a rotating magnet with stationary coils. |
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Generator GN-38-B has two stationary magnets and two pole pieces arranged alternately about an armature. |
| GN-38 variations | |
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All 3 have the same gears. |
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GN-38A has a different switch (because of stationary coils.) |
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| GN-38 compared to GN-41 | |
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GN-41 is used in EE-91. GN-41 appears to be a 4 magnet version of a GN-38. GN-41 coil is longer and most likely has more current capability. |
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