You can get to know how to isolate signals of rc helicopter models. This will ensure top antenna and transformers functionality. The first valve acts as a preamp, while the second amplified RF. CV through capacitor sets the output frequency at which the transmitter emits. The only component that must be manufactured by us is the coil L. Consists of 100 turns of wire AWG28 with one taken in the middle of the winding (50 + 50 laps) on a hollow plastic tube of 1 inch in diameter. Once the coil fluxes, it should be sprayed with paint or other setting that allows the coils. To fix the chassis can be mounted with a small L metal. The variable capacitor is a common tandem tuning of a body. Power supply The rc helicopter power supply, is formed around a transformer medium rare. It consists of a primary 200 V (voltage or the place where the equipment used) and two separate sides. One of them must have an output voltage of 6.3 V, needed to feed the lamp filaments. The other side should be 300 V with midpoint (150 + 150 V), which is used for high operating voltage of the valves. Remember that all capacitors should have a voltage twice the work. So if the transformer delivers 300 V 8¼F capacitors should be 600 V. If you put the system in a cabinet remember spending time in the design of ventilation. The light output can be replaced by: 6L6, 6AQ5, 6V6, among others. But always keep in mind that the pin out is different, which will have to consult the manual (if they still exist). The FM rc helicopter transmitter module whose description is given below, is the starting point for creating a small personal station unassuming, but able to bear comparison from the point of view of the transmission quality with other larger stations. Characteristics and functional analysis According to the choice of supply voltage (9 to 12 V) can have a power between a few hundred mille watts to 3 watts, between 88 and 108 MHz of measurements is found that emission powers order listed, with a suitably chosen antenna is in good condition can cover an entire population of small size. Normally it is required to excite the issuer through a mixing console that allows creating the desired sound effects, which are also expected to be the direct connection of a microphone. You can expect the quality of B.F. reach a level close to Hi-Fi, but if you have problems with background noise level too, the 741 could be replaced by other low-noise operational rc helicopter amplifiers.