Here’s an odd one for the bell lovers on here, I believe the model number to be 4034-2, with a Simplex 4090-2, with some solid state electronics. I just picked this up on Marketplace, definitely an odd piece, and one I haven’t found any information on. For starters, it appears to mount to the same backbox as the ultra rare Simplex 4037 (may be getting a couple in the coming months, stay tuned). The bell doesn’t seem to be particularly special, but it is run by some solid state electronics, mainly a Sylvania 5823 relay control vacuum tube. I’m guessing that it must do some type of coding for the bell. I haven’t tested it yet, I want to reform the capacitors with a small wattage incandescent lamp to ensure they don’t blow up and fill my basement with capacitor smoke, since it does run directly on 120VAC. My guess is this seems to be more on the time keeping division of Simplex rather than fire alarm, but I thought you’d all enjoy this, and any information on this device is greatly appreciated.
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If I were to guess, this was probably used with those older Simplex synchronous clock systems with the motor-generator unit injecting a ripple on AC mains that would resync the clocks (paraphrasing heavily there).
Maybe this bell uses the same principle, but with a different frequency overlaid over AC mains that would only be injected by the MG at certain hours.
Either way, this is definitely a very curious looking system.
That is quite strange, I’ve never seen a bell with a vacuum tube on the back