what are these two fm antenna connectors? How can I join them?
The first one is commonly known by the name &quot;PAL connector&quot;. Also &quot;IEC connector&quot; (which is very vague, IEC has standardized zillions of connectors), or &quot;Belling-Lee&quot;. It has similar properties to the F, but it's push-on rather than threaded. It's the common antenna connector in the parts of the world that used the PAL standard for analog TV, thus the name.
The second one is indeed an F connector. It's the most common connector for 75-ohm household coax in the USA.
If you search for an &quot;F female to PAL male adapter&quot; or even just &quot;F to PAL&quot; you shouldn't have much trouble finding the part you need.