The complete adjusting process requires lot of patience because the presence of your hand and the tool will slightly change the capacitance of the trimmer.
First have a FM radio near the circuit, set your FM receiver for a clear, blank space (no reception). Apply power to the circuit, then, with a non-conductive tool, start adjusting the trimmer capacitor until you find the right point, the clearest reception.
Second time try to place radio far away from the circuit and re-adjust trimmer capacitor.
L1 is 6 turns of 0.5 -1mm solid wire (air-wound) 8 mm diameter coil. You may use wire reclaimed from an old transformer. If you can't find wire to recycle need to buy enamel covered wire as in the specialized shops selling "magnet wire" (also search for shops which specialize in rewinding electric motors). The coil are wound in a single layer using a drill bit as a winding form. Use a 8 mm diameter bolt and wrap the wire in the threads.
Parts list:C1 = 22nF up to 100nF
C2 = 100nF up to 470nF
C3 = 1nF up to 3.3nF
C7 = 22nF up to 470nF
C4 = 8.2pF up to 12pF ceramic type
C5= 27 up to 39 pF ceramic type
C6 = 3-30pF trimmer capacitor (any value minimum 1-5pF, maximum 25-50pF)
R1 = 4.7k -- 6.8k
R2 = 820k- 1.5M
R3 = 10k-15k
R4 = 39k-56K
R5= 390- 680ohms
T1 -- general purpose silicon NPN bipolar transistor
BC109, BC173, BC238
T2- general purpose silicon NPN bipolar transistor
BC107, BC238, 2N2222, 2N2306A general purpose silicon NPN bipolar transistor
BC238 used for amplifier applications was used.
However, you may substitute the BC238 with a 2N2222 or a 2N3906, these are also general purpose transistors
Testing the FM transmitter:
http://www.youtube.com/user/LEDchaser#p/u/10/pQepqtqJBJg
