MFJ 1899T antenna tripod mount and balun
ConstructionI started by winding ten turns of RG-174 on the ferrite core.
I then drilled and threaded (M3) three of the mounting holes for the BNC-connector. The remaining hole was not threaded, as I needed a nut on the inside of the box anyway.
The coaxial cable was then soldered to the BNC-connector, and the ferrite core was glued to the inside of the box.
This step includes threading (1/4"-20) the underside of the box for mounting on a tripod, and terminating the cable with a female SMA-connector. I made a neat cable of approx. 5 m length for my Yaesu FT-817ND as well. It is terminated with a BNC- (for the front panel connector) and an SMA-connector.