Make a simple small radio station

lorant

Make a simple small radio station [Copy link]

The author once got a six-lamp radio at a friend's house. After disassembling it, he used 6Pl amplifier tubes to assemble it into a small radio station.

See the circuit diagram below: B1, B2, G, R1, R2, C2, C3, C4, and C5 are all disassembled products. Because the power supply filter capacitor in the machine was too large, a color TV filter capacitor was used. L1 uses 22mm enameled wire and winds 100 turns around the magnetic ring of MX-2000. L2 determines the transmitting frequency of the radio station. If the frequency is selected in the medium wave band, L2 can use 35mm enameled wire with 30+50 turns on the medium wave magnetic rod, or use 13mm enameled wire with 90 turns densely wound on a 25mm paper tube. In this way, the transmission frequency will fall between 550-1650kHz. If shortwave band is selected, L2 can be wound with 9 turns of 0.5mm enameled wire on a 16mm paper tube. The frequency of the oscillator formed in this way falls between 6~18MHz. C5 is an air duplex with a capacity of 360pFx2. B1 is the original power transformer. The high voltage part rectifier uses four IN4007 instead. B2 is the original output transformer. C2 and C3 are mica capacitors disassembled from the machine. The withstand voltage of C2 and C3 is preferably greater than 400V. You can also buy cement resistors for R1 and R2 yourself. Because the dissipated power is large, the power is selected as ≧IW. TX is a 1/4 antenna, which can be replaced by a piece of thick wire, whose length is about 1/4 of the emission wavelength. The author chose 3mm, 8m long enameled wire. The entire circuit installation does not require the use of copper-clad boards, just use a piece of bakelite board and drill holes on it. hole, just build a shed and weld it. As long as the components are in good condition, the circuit will start to vibrate after installation. When it starts to vibrate, a light blue electron flow can be seen in G, accompanied by a " " sound. If possible, you can make a simple field strength meter and adjust R2 to maximize the emission field strength. The antenna can be mounted vertically on the wall via an insulator. After connecting the antenna, input an audio signal of about 5W at B2, and move the radio further away from the transmitter. The radio should be able to receive the signal clearly, and the distortion should not be obvious. If the hum is too loud when transmitting,
grounding can solve the problem. According to actual measurements, the transmit power is as high as 4.5W, so the relevant regulations of the National Radio and Television Commission must be followed during the experiment.

任君翱翔

Do you have information or circuit diagrams about AM radio stations?

小丸子

Could you please give me a first look?