Secondary intermediate standard circuit. Has been adjusted in the 465KHz. Circuit at all levels have Ic test port. The whole machine contains 7 triodes, so it is called a 7-tube radio. Among them, the triode V1 is the frequency conversion tube, the V2 and V3 are the middle discharge tubes, the V4 is the detection tube, the V5 is the low frequency preamplifier tube, and the V6 and V7 are the low frequency power amplifier tubes. and high quality Frequency Range: 525-1605KHz Output Power: 100MW Power Supply: 3V ( battery) (Not included) Circuit introduction: the main properties of the 108-2 7 transistor radio frequency range: 525~1605KHZ Speaker: . 57mm diameter, 8 ohm Different batches may have different appearance, which does not affect use. Fine workmanship. Easy to assemble. Long service life. Colour:multicolor Material:PCB+electronic components+plastic Package Contents: 4 set x Radio Electronic DIY Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.