Inspired by the recent development of HALS - the DIY version of a Near Field Scanner.
This is only an initial rough concept. The aim is to make the device as simple, small and lightweight as possible - DIY friendly.
The machine, as envisioned here, consists of two rotating arms and one vertical rail (a linear rail or V-slot carriages), reducing the weights of the moving parts to a minimum. Microphone (electret or MEMS) is supposed to be placed at the end of a carbon-fibre tube, facing the device under test (DUT), with the tube directly coupled to a small stepper motor.
Basic kinematics (31.03.2026): https://www.desmos.com/calculator/u8iwtcwwta
The proposed geometry allows only a minimal footprint overhang of the machine over the DUT. For example, a scanner with the main rotating arm 350 mm long (320 mm mic arm) allows to measure devices that fit into a cylinder with a 570 mm diameter (W x D = 40 x 40 cm / 28 x 48 cm, etc.). Such a machine can be put on a stool for measurements and be put away when not needed.
