This paper, we introduce a kind of BA1404 to the core of the small stereo FM transmitter, because a lot of friends he is very keen, I asked it to information, so put it up in the ranks. In fact, in many applications on the BA1404 electronic magazines and newspapers have introduced many, not really anything new, but he was very practical. BA1404 ROHM company in the United States of FM radio transmitter ASIC; its highly integrated; needs fewer external components; work reliably; wide range of supply voltage adaptation, even when the work down to 1.5V, making it suitable for amateur conditions a variety of radio transmitting equipment. Since I have not scanner, you can only drew PROTEL 中 WORD in a typical circuit in its internal painting Functional Block Diagram and Pin Shuomingtuji Taijiajieshao said to Zhege circuit Peihe high sensitivity of the FM radio from 1000 to Da Dao meters, you can go to trial, shown in Figure 1. Internal structure and pin shown in Figure 2. Specifically, the 38KHz crystal cross hard to find, can balance a 57P capacitor circuit can replace the work of between 5,6 feet, three-dimensional effect is not too obvious too! You can make with his own small stereo a radio station it! Note that the artwork used in the power amplifier stage transistor as 2SC8050 2SC8050 We all know about the maximum frequency of 100MHz, where the use is very appropriate because of excessive power consumption and a sharp fever burned in a short time , it is better to use homemade 3DG130C or 3DG12C other China-made cooling cap in the power tube to a better performance, such as the use of Taiwan's production of D40, D50 and other specialized launch tubes would be better if only need to re-adjust the operating point. Note: Due to my negligence not connected to the power amplifier stage should be connected to the upper part of T1 +4.5-6V power supply terminal on the basis of the last circuit to increase the output filter circuit, the circuit further improve the frequency performance is better.