Radio antenna connectors

[TeoChristian]

Hello! I own a Saba 9100 HiFi radio receiver. I saw it allows connecting multiple external antennas. I am trying to build these antennas myself but I don't know what are the connectors which I should use with this receiver. This is a photo of my receiver.

Can someone tell me what connectors should be used there? Thank you very much for help and for any other advice!