Burt,
I've attached a photo of the Sk4000. It is a self-contained test device with an N at one end.
Per your request for an all-in-one device, it's still doable in the same manner as the SK4000.
With the availability of 3D printers now, it is easy to create a housing to accomplish what you want.
The advantage of having an Android or iOS device as the brains, means you get to use its computing capabilities for other RF/Tech/Design applications.
73
Larry
