500-meter FM FM transmitter production

500-meter FM FM transmitter make this paper a low power FM transmitter, the use of a special launch control, modulation depth, does not produce amplitude modulation, distortion, sent from far, stable. Circuit is simple system can work as long as the correct welding, circuit shown in Figure 1. Figure 1 circuit

500-meter FM FM transmitter production

This article describes a low power FM transmitter, the use of a special launch control, modulation depth, does not produce amplitude modulation, distortion, sent from far, stable. Circuit is simple system can work as long as the correct welding, circuit shown in Figure 1.

Figure 1 circuit, by a special launch tube T2 and its peripheral parts composed of a frequency range of 88 ~ 108MHz high frequency oscillator, electret microphones pick up audio signals were first amplified by T1, the low frequency signal amplified again modulated high-frequency carrier. If the microphone off in a very M, the input is the output inspection scope can transmit music signal very well.
Be noted that RF-specific management T2, the model is FF501, using the standard T0-92 package (the same as 9000 transistors), shape and pin arrangement shown in Figure 2, the ICM is 45mA, fT greater than 1 .3 GHz, VCEO to 13V. Exclusive possession of the advantage is consistency, and RF output power is larger, the circuit is easy to adjust, FF501 fully able to work at higher frequencies, the reader may try to launch tube for launching other experimental high-frequency circuits. Circuit L2 enameled with ∮ 1.0mm drill bit on the ∮ 5.1mm 5 turns around the stretched womb to 0.8cm, C3 ~ C8 high-frequency ceramic capacitors are available, the antenna rod is best to use 1.2 m and vertically mounted. Then we must stand a good antenna power. Circuit operating current of about 25 ± 5mA. Such as the launch is not 88 ~ 108MHz frequency range, can be properly adjusted the length of resonant coil L2.
Alignment circuit is completed, FM radio with FM section for receiving, and effective transmission radius of 500m.

Our other product:

15W FM Transmitter with antenna	Economical Complete FM Radio Station	3KW Rack FM Radio Transmitter
5KW Analog TV Transmitter	Circularly Polarized FM Antenna	Four Slot Sew TV Antenna