12 Watt FM transmitter

FM transmitters are discussed in this article is a modification of a series of FM Transmitters on the market (type S-083 from Saturn). S-083 series power only produces less than 1 Watt. With a little modification, simplification and addition of a booster will get the final power 12 Watt. S-083 series consists of 3 parts, yaknik the oscillator, the first level Buffer (Buffer 1) and second-level buffer (buffer 2), see in Figure 4 (Components marked with * are part of the modified)

Once tested, S-083 oscillator results are quite satisfactory, in addition to stable oscillator generates a strong signal. Therefore the oscillator is used without modification. The transistors in the first buffer (Buffer 1) the original use of C2053, C930 replaced by transistors, type at a price much cheaper and readily available in the market. For this purpose the value of R6 was changed to 10K, to provide an appropriate bias for the transistor C930.

SWR Meter & Power Meter

On transmission lines that do not match other than the incident wave is also reflected waveflows. Waves coming from the source to the load direction (from transmitter to antenna)while the reflected wave from the opposite direction (from the antenna to the transmitter).To measure the power of the waves is required Power Meter. Usually on the Power Meterhas two scales, one for power to come and another for the reflected power, the reflectedpower scale to be smaller than the scale of the incident power.

Meter SWR (Standing Wave Ratio Meter - gauges comparative standing waves) are used to measure the ratio of the incident wave and reflected wave. In other words SWR Meter used to measure how match a source with the load. The working principle is based Power Meter SWR Meter. If there is only one measurement of the SWR Power Meter can be calculated from the incident power (Pf) and reflected power (Pr) with the following formula: