جهاز إرسال اف ام قوي
جهاز إرسال اف ام قوي أعتقد 1000 متر
All resistors are 1/4 watt 5%
R1,R2,R8 = 1K C1 =
R3 = 100K C2,C3 = 10nF, ceramic
R4 = 150K C4,C5,C9
= 4.7uF/63V, electrolytic
R5,R7 = 10K C6,C12,C13,C14 = 1nF, ceramic
220 ohm C7,C8,C11 = 5pF, ceramic
R9 = 10 ohm C10 = 220uF/63V,
P1 = 5K trimpot
Q1,Q2 = 2N3904 L1 = 3.9uH
7001, NTE123AP L2 = 1uH
D1 = 1N4002 L3 = aircoil, 8.5 turns air space
This circuit provides an FM modulated signal
with an output power of around 500mW. The input microphone pre-amp is built
around a couple of 2N3904 transistors (Q1/Q2), and audio gain is limited by the
5k preset trim potentiometer.
The oscillator is a Colpitts stage, frequency
of oscillation governed by the tank circuit made from two 5pF ceramic capacitors
and the L2 inductor.
الدارة الثانية 500 متر
Resistors are 1/4 Watt, 5%
R1 = 10K
R2 = 86K
R4 = 2K2
R5 = 100 ohm
C1,C8 = 2N2
C2 = 4N7, ceramic
C3,C6 = 10pF miniature variable
C4,C9 = 100pF, ceramic
C5 = 1uF, 25V, electrolytic
C7 = 1uF,
Q1 = BC108, NTE123A, NPN transistor
2N2369, 2N2222, NTE123A, NPN transistor
Q1 and Q2 both
reference to a NTE123A replacement type.
With a short antenna the
maximum distance is about 600 feet (200M). But with a proper antenna this
distance can easily
be changed to about 1/2 mile (800M)! Even so, keep in
mind that this simple transmitter is just that; simple!
If you find that the
frequency drift a little, secure the coil with candle wax or a dab of hot-melt
glue. The coil, L1,
is wound on a 10mm body. Use a wooden dowel or similar.
Wind about 4 turn of enameled copper wire
(also called 'magnet wire').
Obviously, remove the body after winding. Scrape the enamel off both ends of the
before attempting to solder.
As for the ceramic capacitors,
try to find and use the socalled 'NP0' types for low noise/temperature drift.
have a black stripe at the top of the cap. They are manufactured by
The variable capacitors, C3 and C6, are just the regular
This type of transmitter works best in a metal enclosure. Just
make sure nothing of your circuit is touching it.
"Gnd." in the
schematic diagram just refers to the negative pole of your battery