Free electronic circuit design and schematic diagram
This amplifier circuit combines the LT1010 and a fast discrete stage with an LT1008 based dc stabilizing loop. A differential stage which is single-ends into the LT1010 is formed by Q1 and Q2. An output of 1 V pk-pk into a typical 75-Ω video load is delivered by the circuit. With gain = 2, the gain is considered flat up […]
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This is an AM radio power amplifier circuit. What is different with other general amplifier is that this circuit has a low-pass filter (passive type), built using R1C1 to limit the input-output frequency response. Additionally, a ferroxcube K5-001-001/3B with 3 turns of wire is used as ferrite bead at output filter. All components should be spaced very close to the […]
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This is an active antenna circuit with gain. This circuit is used to bost the signal. This circuit is made from a few transistors and other components. This circuit can provide RF gain of about12 to 18 dB. This circuit uses Q2 as a voltage amplifier. the RF signal direct-coupled from Q1’s Source terminal to the base of Q2. The […]
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The circuit of off-air monitor for SSB transmitter can be built by using combination of detector product with the crystal oscillator. This circuit is used for testing the audio at one point within band. The quality of audio will still constant, if loading and tuning of SSB transmitter are same over rest of band. The LC circuit will resonated to […]
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Combination 8 channel multiplexer and amplifier (IC1) is the heart of the remote multiplexer box in the single coax video system. The MUX baseband video output is coupled by C11 to the coax and the video is decoupled by L1 from dc power arriving on the same line. All circuitry in the multiplexer box is supplied by this power (about […]
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For RF (radio frequency) transmitter experiment, watt meter is useful for optimizing the transmitter circuit. A simple RF watt meter circuit is shown in the schematic diagram below. Because circuit is not frequency sensitive, calibration is accurate on all HF bands. The sensitivity is affected by meter movement, number of turns in primary coil, and resistive voltage driver. Pots can […]
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When operating from 12.5 V auto battery, single TRW PT5757 transistor provides 10 W output. L1 is 4 tums No. 20 enamel and L2 is 10 tums No.20. Both, L1 and L2 has 3/32inch inner diameter. T1 is 4:1 transmission-line transformer made from 3-inch length of twisted-pair No. 20 enamel. This circuit can be used to amplify small transmitter (1W), […]
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