Decades ago, a dear friend of mine celebrated a birthday party in their "student home" which was a rather old, facework building with little ground area but spanning vertically over three floors. Just like me, he loved anciend "steam" radios and had quite a collection. To be able to play the same music on all the floors, he asked me to make a small FM transmitter for him that should be powerful enough to provide a good signal to the radios on all the floors, to connect to his "central" hifi system. Finally, while the party was going on, all the people living in his village could tune in to his music...
Anyway, the design is proven to be working with a fairly good audio quality. It may be of slightly old-fashioned concept with the transistors in common-base circuit but it's simple and easy to build. I attached a screenshot of the schematic, and if you like, I can share the (single-layer) PCB layout as well.
Cheers,
Thomas
P.S. I used the Sanyo varactors and oscillator transistor simply because I "inherited" an almost unlimited supply of those. Other, similar components will work just as well.