In article jzuoe.940$KQ2.679@trnddc08, "puns" wrote:

Are those small 300/75 ohm tv baluns. voltage or current type?

Hello, and these broadband 4:1 (impedance ratio) baluns most often are
voltage type using two transformers. At the lower end of the operating
frequency band the balun appears as a 4:1 autotransformer while at higher
frequencies the transformer windings appear as transmission lines (ideally
each line would have a Zo of 150 ohms). FWIW, the broadband operation of
these types of devices were initially described in detail in C.L
Ruthroff's 1959 IRE paper, "Some Broadband RF Transformers." Sincerely,

John Wood (Code 5550) e-mail:
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337