Transmitter FM 45W with valve

TECHNICAL CHARACTERISTICS: 

• Tendency of catering: 220V AC
• Frequency of emission at FM: 88~108MHz
• Force of expense: max 45W (without the R3) 

Circuit diagram

Materially: 

• R1 15KW/2W
• R2 1KW/10W
• R3 1KW/10W (for biggest force in the exit you replace with short-circuit).
• C1 50pF trimmer
• C2 30pF trimmer
• C3 22pF/4KV
• C4, c6, c9 10nF/1KV
• C5, c7 1nF/1KV
• C8 100mF+100mF/450V (Double electrolytic)
• C9, c10 10nF
• RFC1, rfc2, rfc3 air Inductors: 15 coils diameter 8mm, from wire 1mm.
• T1 Transformer 220V/6V-1A
• T2 Transformer of configuration with being first 4 or 8W
• T3 Inductor with core ferrite (externally it resembles with small transformer but has a turn only).
• D1 BY127 rectifier
• Lamp 807 SYLV USA or EL34 or equivalent
• ANTENNA Simple dipole L/2. (L= wave length)
• S1 Main switch of catering.
• S2 Switch of catering of rise (him we close after zestacej' the thread).

Most elements you can him find in a old back-white television with lamps.
Regulations: 

• With the C2 we regulate the frequency.
• With the C1 we adapt the resistance of aerial (practically him we regulate so that it is heard our voice in the radio as long as you become cleaner).

Notes: 

• The catering better it does not become at straight line from the network 220V but via transformer 220V/220V of isolation and safety 1A.
• When does not exist the R3, the force of expense is bigger, but respectively is increased also the hum 50Hz, because the simplicity of designing.
• The control (Audio In) can become from a kasseto'fwno or other powerful source. If it is microphone it will be supposed precedes amplifier so that it acquires a force of order of 8W roughly. 

Author: Kyriakos Kontakos
Source http://www.electronics-lab.com/