Impedance matching for loop antenna A VLF

Hello everyone

Can anyone please help me designing a balun/transformer to match a receiver loop impedance of 4ohms to a value of 50ohms (coaxial cable). I have designed a multi-turn antenna. It is working in the range of 3-30khz.

Please help.

well, what IS its impedance? If it just looks like a slightly inductive short circuit, it will be hard to match to. Try driving it with a current source.