Jeff Geerling silences a Calnex rubidium frequency reference with a Noctua fan swap
Noctua Fan Swap on a Calnex Rb/GPS Frequency Reference
The Delta fan in Geerling's Calnex Rb/GPS frequency reference was unbearable for desk use, so he swapped in a Noctua NF-A4x20 FLX using OmniJoin connectors after snipping the stock cable. Inside he found a SpectraTime GRClok-1500, a stabby pin-fin heatsink, and the rare joy of a device held together entirely by Torx T10 screws. It takes 20-30 minutes to acquire rubidium lock and GNSS sync.
It is quite rare to take apart a device these days and not have to pull out multiple bits from an iFixit toolkit, or have multiple exotic screwdrivers at the ready.
- Scene_Cast2
One issue I've had with swapping fans for Noctuas is the airflow matching. The louder fans aren't louder just because they're lower quality (which they definitely are), but also because (almost always in my experience) they force more air through.
That unit from the article sounds very temperature sensitive. I'd be wary of throwing a precision unit like that out of spec and out of calibration.
FWIW I've noctua-swapped so many things including an oscilloscope.
- rpcope1
I assume Jeff used an industrialPPC variant here, but I kind of wonder if there isn't an EBM Papst or Sanyo Denki part that would have been sufficiently quiet and a better fit. The Noctua parts are usually at least decent, but they're really not the end all for fans.
- bikezen
Funny this is popping up, just ordered a noctua and buck converter to replace the very annoying fan in my rack mounted UPS this morning. The fan is audible through some sliding doors and has been driving me nuts.
- dajonker
I got a ThinkStation P8 thinking it would be a nice workstation, but the fan noise was just unbearable. Not loud (although it could get LOUD), but extremely annoying. A cooling solution created for a rack mount system where the person buying the machine will never hear it. Absolutely unsuitable at home. I was looking into doing a Noctua Fan Swap here as well, but after reading the fan specs, I found out that this would be impossible, or possibly melt the machine. The 60mm fans on the PSU were rated at something like 25 watt _each_ and push more air at way more pressure than the strongest 120mm Noctua fan.
The Mac Studio that replaced it is practically silent and very energy efficient, while not being significantly slower.
- PorciiVorbesc
Anyone know why that heatsink is that weird hedgehog spines design and not the more common regular extruded fin?