I am free, it is better to be a 1W power FM broadcast transmitter to talk about the production of the transmitter, the buga, the release is said to have hundreds of Follow Me Radio, huh, is it Really? But wait for him, who knows what is going to the Monkey? Far water can't save your thirst, it is better to work with yourself now. This FM transmitter is made special, one without engraving board, two no circuit diagrams can not be used, three if not weld the wrong one, how can I reach more than 600MW? How, how is it?
Tony said nonsense, you can see the picture below today (the principle did not speak, is it going to point in place?)
Be
Be
Power element foot
Be
instruction:
1: The oscillation level uses the "colpitts" oscillating circuit, don't look at it is LC oscillation, but this LC is non-one LC, but it can not be mixed with other FM circuits, and the hand moves or hits the situation. Yes, there is no thing. The oscillation is completed by a 2SC1907, Coila and the top 10PF above the left, together determine the basic frequency of the circuit. The audio modulation is completed by the varactor diode, and can be added to the aircraft by a 47-270K resistor, linear will be better. "Colpitts" oscillation circuit is stable, and it is necessary to attribute it to the 33PF in the figure, which opens the critical LC part and other circuits to "isolate". 2: Adam C2053 buffer SEF C1970 amplifier, 1W C1970 is exporting the impedance of about 50 Euro, huh, the impedance matching circuit is saved. The following Coilc and capacitors are "pass band filters", which is unable to make you trouble. 3: How is the board PCB? Are you seen the square in the center? It actually scars a small piece of block with a double-sided PCB board, and the main board is welded. When it is fixed, the other side is soldered, and there is not much part, and is it? 4: The parameters of all parts don't make mistakes. I will use it. I will use it. The small ceramic capacitor should use the high-frequency red dot, the green other, the parameters are not accurate, the welding is nothing wrong with it. It can be powered. Ten million, remember to give the antenna terminal before the power is applied to the antenna, and if it is not C1970, it will be burned! There is a power meter or any other instrument to adjust the best, no, find a small light gun to 1.25V75MA low-voltage small current, the wire of the +--pole 10 cm left and right is rounded from the rounded transmit terminal. The debugging is relatively simple, direct power, the total current should be within 300mA, the bulb is also bright, basic OK, all circuits need to be adjusted only Coilb and C, adjust the target, and light bulbs.
This circuit is reliable and easy to succeed that its circuit has basically determined the general parameters of the equipment - even if the inductive inductance B and C are required, the circuit is not adjusted after the circuit is installed. The difference in radio frequency, adjustment and non-adjustment is also output outward is the size of the power and clutter.
In addition, the antenna rack should be connected with a cable when the circuit is high.
It seems to be all right? Finally, I don't interfere with the normal listening of others. The frequency is preferably adjusted outside of 88--108MHz. After all, 1W fm power cannot be small (generally small and medium-sized city FM radio station's spare mobile emergency station is about 10W), otherwise If the government will quickly find you trouble.
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