This 1:1 balun is built by ham VU2ASH Ashok Joshi from India.
The torroide used is FT 240- 43.
12 bifiller turns each side of 1mm2 PTFE coated wire, each sides. Cross connected at each side for 1:1 balun.
You can use FT 140 -43 torroide for low power up to 250w. Building it is simple, can be seen from windings and connections in photo.
It is balanced winding, top two connections (2 same colour twisted wires forms one connection) go to balance output (to antenna) and bottom two to unbalance pl259 connector (coax feeder to tuner atu or rig)
Pvc water tubing/pipe and end caps are used for enclosure and a small metal bowl to cover the connector / cable from rain.