That little adapter is called a balun. The two screws were a balanced antenna lead, coax is an unbalanced antenna connection. So it goes from balanced (bal) to unbalanced (un), hence balun.
They’re still used in radio communications, but almost all consumer products use coax/unbalanced connections for their antennas.
I could go into detail about what a balanced/unbalanced antenna is, but it would take more words than I care to type right now. I’ll let anyone who is curious go and Google it.
That little adapter is called a balun. The two screws were a balanced antenna lead, coax is an unbalanced antenna connection. So it goes from balanced (bal) to unbalanced (un), hence balun.
They’re still used in radio communications, but almost all consumer products use coax/unbalanced connections for their antennas.
I could go into detail about what a balanced/unbalanced antenna is, but it would take more words than I care to type right now. I’ll let anyone who is curious go and Google it.