This is a great idea! Three thoughts to contribute:
1) Be careful about installing the tubing in a way that makes you "spin" the SMA connector instead of the SMA nut - to preserve the center pin contact surfaces, try not to rotate or spin the connector and center pin, only twist the nut.
2) I have started using short sections of colored shrink wrap to "tag" the various bit in a kit. Doesn't help the fingers, but easier on the eyes...
3) You didn't mention it, but in your photo it looks like you have a box for all your VNA bits - this is an excellent practice! I have started making "kits" for my various tools - I have used zippered cases ( pencil cases originally from the school supply section), heavy duty Zip lock and occasionally ESD bags (grocery store for zip locks, ESDs "recycled" from past shipments), and the little latch-able food storage bins (rectangular, many sizes, next to the Zip lock bags at my supermarket). I've also started using Plano storage bins (often in the fishing tackle section of Walmart, BassPro, etc...). Then I keep all the bits with the instrument to make a standard measurement. High quality RF components are still expensive, but the inexpensive imports are good enough for standard measurements, and it is sure nice to have everything in a box "ready to go"...
73
