DIY EDT-2902 Multiband Radio Kit Electronic Production Training Kit

Package list:http://files.banggood.com/2017/11/LIST.xlsxCircuit diagram:http://files.banggood.com/2017/11/circuit-diagram.jpgDebugging:1) FM band debugging:Put the assembled circuit board into the test stand. Turn the switch to ON, turn the band selectorto FM, D1 LED light.The first step: adjust the receive frequency range, adjust the quadruple variable capacitor to the lowestend, the test standdisplay FM frequency, use a tool to adjust the L103 oscillation coil to make the figure shows about 69MHZ, then adjustquadruple variable capacitorto frequency display the most high-end, use the tool to adjust the variable capacitor to makethe display frequency at 108.5MHZ or so, repeatedly adjusted to make the FM frequencyinrange 69-108.5MHZ.The second step: adjust the sensitivity, adjust the variable capacitor to about 80MHZ,received a radio and adjust the L102 coil to makethe speaker output maximum sound, then adjust the quadruple variable capacitor to about 106MHZ,received a radio stationand adjust the quadruple variable capacitor Trim frequency selection circuit capacitortomakethe speaker output maximum, repeated the above adjustments to achieve the best sensitivity effect.2) Debugging the mid-wave band:The first step: adjust the receiving frequency range, switch the band selector switch to MWposition, D2 LED light. Adjust the quadruple variable capacitor to the lowest end, and thetest standshows the frequency of the middle wave. Use a tool to adjust the T101 oscillation to make it