Veronica 1W FM Transmitter


Veronica 1W FM Transmitter

Veronica 1W FM transmitter is an easy to build transmitter. Veronica is also known for frequency stability, clean FM signal and uses no integrated circuit. The Veronica oscillator is actually formed from 2 oscillators which operates somewhere around 50 MHz in anti phase and the 2 signals are combined to form 100MHz FM radio signal. This kind of circuit design is stable and is amplified up to 1W by 2n4427 transistor. Veronica transmitter is equipped with a mini-mixer and so you may forget an external mixer. This consist from T1 transistor which amplifies the microphone signal before it is combined with CD player audio or PC signal. R1 and R2 are potentiometers (variable resistors) used to adjust the audio level. The component between R8 and C21 represents the oscillator which generates radio signal. D1 is a varicap diode (like a variable capacitor or trimmer) controlled by audio signal. C12, C13 and L1 determines the frequency.

Veronica 1W FM Transmitter

Veronica components list



Resistors:

R1+2 10k pot

R3 820k

R4 4.7k

R5-7+19 220r

R8 1.5k

R9 15k

R10+11 1k

R12 33k

R13+14 56r

R15+16 68k

R17 47r

R18 270r

R20 10k

Capacitors

C1, 2, 7, 16, 17, 19,

24, 29 & 31 1n

C3-5 & 8 10u elect.

C6, 18 & 30 220u elect.

C9, 10 & 20 10n

C11 22p*

C12 47p*

C13 22p trimmer

C14 & 15 15p*

C21, C25 & 26 65p trimmer

C22 100p

C23 5.6p

C27 & 28 1.8p

Coils

L1 – 6 coils / 2 turns, 5mm diam si 5mm length

L2 – 3 turns, 7mm diam si 7mm length

L3 – 4 turns, 5mm diam si 7mm length

L4 – 6 turns, 5mm diam si 10mm length

Diode

D1 KV1310

D2+3 1N4148

D4 Standard LED

D5 1N4001

Transistors

T1+5 BC548

T2+3 BF494

T4 2N4427



The transmitter must be mounted in an aluminium carcase connected to ground. The power supply voltage is between 9 and 16V, at 16V the rf output power is 1W and at 12V is 600mW and at 9V is 200mW.

Veronica 1W FM Transmitter

Veronica 1W FM Transmitter

Veronica 1W FM Transmitter

Veronica 1W FM Transmitter


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