Why do we sometimes get the signal from tapped coils?

[polis323]

why in some cases we receive
the signal(in the FM transmiters)
from a tap of the coil(inductor)
like in the schematic;
why do we conect the
antenna directly to the collector like other circuits;

 

[mostafamuslim]

Re: tapped coils

this is because the impedance of the antenna is 50 or 37(monopole) ohm which is small so that the quality factor of the tank circuit is very small ,,yhe solution to take the o/p from tapped coil and then the impedance of the anteenna will be multipied by the squqreof the turnsratio ie(n1+n2/n1)^2