Hey Matthew, > We use an older model of > https://www.microsemi.com/product-directory/enterprise-network-time-servers/4117-syncserver-s600 > with rubidium oscillator. Not cheap, but hardened and extremely accurate.
Out of interest why rubidium? For short term stability oscillator choice isn't much of a matter for free running even rubidium will be off good +-1us per day or +-30us per week. I've always wondered what niche rubidium covers that isn't handled by much cheaper crystal ovens or actually precise oscillators. -- ++ytti