The Pixie "micro-power Telegraph transceiver kit instructionsThis is a very small volume of a simple 40 meter band micro-power amplitude telegraph transceiver， 9V square battery or external 7-12V DC power supply. This machine was first popular in foreign countries， after the introduction of domestic enthusiasts， and gave it a Chinese name ---- " Pixie".Visit our Web site， you can see a more detailed explanation. http://bg4ubx.comA brief introduction Key IndicatorsPower supply: 9V-12V (Recommended 9V laminated battery)Antenna: 50 ohm， unbalancedFrequency range: transmitter local oscillator frequency: 7023kHz; receive local oscillator frequency: about 7023-7026KHzHeadphones: low-impedance headphones (recommended SONY， aiwa high sensitivity Walkman headset)Transmit power: 0.8W (using a 9V power supply)， 1.2W (12V power supply)Suppress spurious (harmonic):-20dB Circuit schematic See the last page of the document accompanying drawings， Q1 and surrounding components constituting a typical Colpitts oscillator and keeps oscillating (the oscillation signal leaks around 1mW) when receiving the local oscillator signal is directly coupled through a capacitor to Q2. Emission state (the key is pressed)， Q2 as a class C amplifier， the amplified signal via 0.01uF capacitor coupled to a pi-type low-pass filter， and then sent to the antenna; reception state (key release)， Q1 element around the beat oscillator (BFO)， D2 coupled with high voltage and reduce capacitive pressure is increased with the ends of the DC， the local oscillation frequency can be increased to approximately 0-3KHz 7.023MHz reception signal can be easily carried out bats frequency. Q2 is biased in the non-linear region (think transistor is nothing more than two back-to-back second diode incorrect)， the signal received by the antenna with the BFO signal mixer， mixing the audio signal obtained after the 0.1uF capacitor coupling posed to the LM386 audio power amplifier， the audio signal amplified by the 10uF capacitor across the LM386 5 feet straight evacuation headphones. The key control not only the LM386-off of the power supply is switched D2 varactor bias， so that the capacity of the type of state change.Debugging method The end of welding should check whether there is a short circuit， and if not， with 9V laminated battery connected to the headset， not to take the antenna， under normal circumstances should hear a slight "rustling" sound， connected to the antenna noise increases or you can hear some signal， the whole current of less than 10mA. This receiver should be normal.��High-frequency power meter circuit diagram with 1W 50 ohm dummy load�� And then connected to the high-frequency power meter with a dummy load reference circuit diagram (above)， the "KEY" at both ends of the short-circuited， the headphones should be quick and silent， high-frequency power meter output. Transmit state machine current 40-100mA. The launch 0.5 meters in the next put a shortwave / medium wave radio， check all the receive frequency range， in addition to the carrier frequency and multiplier should not hear the other signal generated by the "shoes". For any other signal (howling)， indicating the presence of high-frequency instabilities. Schedule gives a DC reference voltage of each of the main elements of the transmitting and receiving state.The absence of a simple high-frequency power meter， optional two machines on the hair， such as can normally receive another keying signal， that is， to determine the initial machine properly.Never without a dummy load or antenna to transmit signals directly to avoid damage to the circuit! Shell selection and installationBeautiful metal casing not only shoes considerably， and can effectively shield near interference. Optional shell a lot， for example， metal cans， aluminum boxes， medical elongated aluminum case. To pay attention in the choice of the box open as convenient as possible， because the battery run out need to be