Reflectors

[South Derry Guy]

Is there such a thing as reflectors which radio stations use to reflect there Fm signal into a a weak area?

[Mike]

Dont you mean deflectors ?

The only way they can boost their signal in a particular area is to install a low power relay transmitter in/near said area

[briank]

Reflectors are used more so in the microwave frequencies as the beams are more tightly focused. They are basically a large 10 X 20 feet or so flat steel panel angled to reflect to the desired target area. There are completely passive and are often located on mountains. Their effectiveness at FM frequencies would be very limited as there would be higher diffusion at lower frequencies. There are examples of this around Ireland (e.g. Sliabh Mish in Kerry) used by the telecom although fiber has taken over and I think they are dismantling many of these. Brian

[engineeringman]

There was one of these near lough derg in Limerick/Clare/Tipp.
The microwave dish was on the ground facing up to the panel. They are refered to as "beam benders"

[DeargDoom]

Then Montgomery Burns used one to block the sun rays hitting Springfield.

[South Derry Guy]

Yeah hopefully Mid 106fm in Mid-Ulster will be getting one of these systems up and running soon!!

[Hissing Sidebands]

The so called tv Reflectors or deflectors are a misnomer - all they really are are TV transmitters connected to TV receivers - whether they demodulate and remodulate the TV signal or just shift the frequency is irrelevant, they are still transmitters if there is any active electronics in them (ie aerial "booster" amplifiers.
Their early incarnations (some still work this way) are just a receiving antenna conected to a couple of didtribution amps, then back to another antenna which is shielded from the receive one by a land mass, a metallic screen, or both, and with a different polarisation. In theory it could be done this way on FM, but due to the greater wavelength, it can be difficult to get the required isolation to stop the whole lot feeding back and going into oscillation, and jamming the whole band!