The FM aerial (that I probably bought at a boot sale) in my loft and always worked fine with my old Aiwa AX7400. That was disposed of on 2006 (should have kept it) in favour of an Onkyo mini system with DAB.
I have always had problems with 'hissy' reception on 92.9MHz from Rowridge (BBC R4) and recently bought a Denon DRA-455 tuner amp and that really struggles to get stereo FM on any frequency from Rowridge.
The aerial is a 3 element yagi but the dipole has two separate arms doubled back in the usual fashion but the ends terminate with plastic stoppers with a one inch gap separating them. There are no obvious electronic components where the coax connects.
After looking at FM dipoles online I notice that they have all? have a dipole that is continuous, so out of interest I cleaned the ends of the my FM dipole with wire wool and joined them together with a few turns of scrap 1mm lighting cable core.
Result !. FM reception in stereo as good as it gets and even R3 now has barely any hiss at normal listening volume.
I wonder how the original manufacturer intended it to work?
Maybe it was intended for 300ohm input (which the Denon does not have) ?. Mystery.