No-name video baluns common mode impedance

I purchased a bunch of no-name, no-spec, video baluns on eBay for use with radio antennas at MF and low HF. A pair of these are for transporting 75 ohm coax video signals over twisted pair LAN cable.

Above, the two styles of baluns purchased. Given the label, nondescript as it is, there is quite a possibility that the internals are the same.

Above is a plot of common mode impedance for a sample of both styles. They are near as dammit identical.

They have moderately high common mode impedance to 5MHz, perhaps adequate for some applications to 10MHz.