There's a big difference between radiation resistance and input impedance, they are not the same things at all. Careful with them.
The typical input impedance of any antenna can be manipulated to some degree by how the antenna is constructed and mounted. In general, a 1/4 wave has an input of something between 20 and 40 ohms, a 1/2 wave between 60 and 80 ohms. But that varies to a large degree according to the relationship between that antenna's 'elements'/'halves'. Either can be adjusted in shape to get you very close to a 50 ohm input, that's quite common.
- 'Doc
(And just because most of the antennas I deal with are connected to transmitters, I tend to favor 50 ohm cable. Most of those antennas are also resonant on the frequency(s) of use, which is nice, but not absolutely necessary for just receiving.)