Got a great simple converter for my Philco Prewar FM radio. Buy a FM converter from fleabay, converts 76 to 90MHZ to 88 to 108MHZ. Is active and needs a 9V battery and 9V clip for power.
Male has two leads,converter male leads to the two FM radio terminals, and ground lead also used for 9V power.

Female lead I used only inside connector for antenna w/ 4 foot wire. Using both parts of female connector OR longer wire will probaly help. WORKS great, listening to it now. Stronger stations seem to be picked up as multiple harmonics, have not tried longer antenna OR both female leads as antenna.

Moving the small antenna makes a local rock station come in better, you guys need to try this as a plug and play converter. The stations are loud and clear, so it being active helps pull in stations too. I just need to get a small wood box to put converter in.

:banana:

Still working good, will do again for prewar FM!!

I like those adapters. I have one in my old 60s truck going to the original AM. I want to find another one and do about the same as you, make a cabinet for it. Then just run a wire to my radio I am using at the time to bring in FM to the old tube radios.

Very cool. I have several old radios with the old FM range - except it's the 42-49MHz range. I wonder if they have these gadgets for this range.