Re: help detune fm radio(88-108mhz) into vhf fm(108 - 175m
One option is to add preamplifier/mixer, based on a dual-gate MOSFET, and a VCO ..
Depending on the frequency range of the VCO, you will be able to receive almost "anything" you like ..
Here are examples of pre-amplifier(BF990) and VCO(BB149): https://hem.passagen.se/communication/mxtest.html