The need for 18v seems like an annoyance. In your link they supply it from a battery, but if you want this as a RNG for a computer you aren't going to want a b

The need for 18v seems like an annoyance. In your link they supply it from a battery, but if you want this as a RNG for a computer you aren't going to want a battery... You can use a regulator to supply it but the noise from the regulator will be a critical consideration since the noise from the regulator may be predictable to an outside observer. So that deserves a careful design. This sort of design seems simpler to get right at least electronics wise, https://github.com/waywardgeek/infnoise https://github.com/waywardgeek/infnoise but OTOH the underlying noise process is a lot less clear than a zener, and I would worry that it's picking up external RF.