Figuring out how the plosive keys work on the Bell labs / AT&T Voder and reproducing the key

I have been trying to figure how the plosive keys work on the Voder. I have already figured out some of the stuff with the key.

I have a diagram from a Patent , that shows how the plosive key works but I don't exactly know for sure if its 100% correct. I am also guessing things could have been changed between the actual key circuitry and the circuit diagram in the patent, but though it also seems that patent for the Key was applied for and granted after the Voder came out?

What I need help with :

- I need assistance on figuring out the filters for the pop in the beginning before the actual plosive sound? I tried using audacity to figure it out haven't been successful yet. In the plosive circuit diagram it seems the pops are generated by a 2 separate filters connected to the unvoiced/ voiced sound sources based on if the plosive is unvoiced or voiced. Also it seems like each filter are really 2 RLC bandpass filters combined in parallel? Obviously those might be not the real circuits used to generate the pop just representative of the circuits used.

- Theres a 3rd RLC bandpass filter on that plosive key diagram that seems connected to the output of the 10 keys and filters on the voder, which is labeled resonance controls , that I haven't figured out yet. and the patent doesn't really explain what it does. The explanation of what the plosive key is doing doesn't explain what it is doing either. I am guessing it could be representative of something. I am guessing the resonance controls could be the 10 keys and that filter is maybe representative of 1 of the 10 bandpass filters ? But though I have always thought the resonance controls meant both the keys and the filters in that circuit.

- How the plosive key can switch between the K and G plosive just by how fast you press it down?

- Figuring out how to duplicate the key using modern switches and modern electronics. I was thinking of maybe using one shot timers to set the timing of each step ?

I have an explanation of how the key works, basically the key has multiple contacts and when you press down on it, it goes through the contacts as you press down the key.

How to make K sound using the K/G plosive ley to say the word "Key" :

Hold down wrist bar , press the K/G plosive key , and the 6th key on the voder at the same time.

steps of the plosive key when the above is done :

1 ) removal of voiced energy from resonance controls and all filters

2 ) discharge capacitor in resonance circuit to make the pop sound shown at A

3) interval of silence

4 ) connect filter 6 to unvoiced source to produce noise shown at B

5) When key reaches bottom reconnect voiced source , so you can press the keys to make the "e" sound shown at C

If the K/G plosive key is pressed in 1/2 or 1/3 the time (faster?) , the key will produce the G plosive instead of the K plosive.

Timing for the K sound :


information about the G plosive:
- It seems like the timing is backwards from the K plosive. as you seen above the timing is a 6 millisecond pop , 40 millisecond of silence , and 31 millisecond of white noise through the 6th filter, for the K plosive. Using audacity and finding where it says a G I found out , the timing is 31 milliseconds in the beginning, the silence, 6 milliseconds at the end. I am not sure though if the pop and the actual plosive sound is backwards , whenever the G is produced.

Plosive key circuit diagram :

actual photo of plosive keys :
if you look closely at the actual plosive key, it has the same amount of contacts on the key as the above circuit diagram , which is how it was figured out this circuit diagram in the patent is some version of this plosive key.

real plosive keys.JPG