GoKawiilHobbyist replaces stock fan in Calnex rubidium/GPS frequency reference with Noctua NF-A4x20 FLX
A hobbyist running a Calnex Rb/GPS frequency reference in an 'Atomic Clock Tower' setup documented swapping out the unit's noisy stock Delta EFB0412HHD fan for a quieter Noctua NF-A4x20 FLX. The process involved opening the Loctite-secured case, exposing a SpectraTime GRClok-1500 module and heat-spreader cooling assembly, then splicing wires since the original fan's connector didn't match Noctua's cable ends.