S&G 8560 Manipulation Idea using Sound
The idea was to get information from the S&G 8560 via sound. When we engage the actuator we can hear the lever spring vibrate and a brief strike of the fence striking the wheel pack. The fence hitting the wheel pack is at a higher pitch (frequency) than the lever spring. The idea was to build an amplifier with a low pass filter ahead of the amplifying circuit to isolate the fence strike. The hope was to have a clean enough signal to set up triggering on the O-Scope to measure the various values of the fence striking the wheel pack as we manipulate around the dial.
The concept works to a degree. The fence strikes are isolated enough that they were detectable, but the values on the O-scope where slight (I'm using and analogue scope) and hard to distinguish a good variance.
This morning (UTC-6) I took the circuit to our local locksmith and we looked at it on a demo lock he set up, and then we took the circuit to a safe he had in the back that had an 8560 on it. Nothing. Safe wall was too thick. Our local locksmith also has a background in electronics and after a good discussion we concluded that there might be something there, but the device would need to be much more sensitive and be able to produce cleaner signals.
I was not going for the best with this circuit as it was simply meant to see if this was a road worth going down. Our local locksmith mentioned that the 8500 series is much easier to manipulate via "feel", but did not elaborate beyond that. He also mentioned that unless a customer insisted he would use destructive means to enter a safe with an 8500 series lock on it.
I believe at this point I will explore the "Feel" method of manipulation and see if I can figure out anything there, but I do know that there has been enough talk about using an audio device to extract information from the 8500 series that this exercise may prove useful to someone else working on these locks.