DIY 75ohm to 50ohm impedance matching circuit to work at UHF frequencies around 470MHz to 600Mhz
The simplest solution is to accept some signal (power) loss by using a two resistor solution like this:



But a better solution (less signal power loss) would be to use a transformer based impedance adapter. However these are more difficult to make. There are of course also ready-made devices you could use like this one: