TWO_FREQUENCY_COLPITTS_OSCILLATOR

Published:2009/7/10 2:49:00 Author:May

Using switched crystals, this oscillator is intended for receiver alignment purposes.   (View)

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CODE_PRACTICE_OSCILLATOR_I

Published:2009/7/10 2:49:00 Author:May

Q1, a unijunction transistor, generates a sawtooth of about 1.5 to 2 kHz, depending on C1 and R1. Q2 acts as a speaker driver. A 9-V battery is used, and the keying is done by keying the supply line.   (View)

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FET_PHASE_SHIFT_OSCILLATOR

Published:2009/7/19 22:18:00 Author:Jessie

Frequency of four-mesh phase-shift oscillator can be varied several cycles around 10 cps, using 2.5-meg pot. Attenuation of four-mesh feedback network is 18.36.-L. J. Sevin, Jr., Field-Effect Transistors, McGraw-Hill, N.Y., 1965, p 111.   (View)

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50_to_150_MHz_OSCILLATOR

Published:2009/7/10 2:48:00 Author:May

  (View)

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FEEDBACK_OSCILLATOR

Published:2009/7/19 22:17:00 Author:Jessie

C1 provides positive feedback between amplifier V2 and cathode follower V1, causing oscillation at frequency and amplitude at which loop gain is unity. Twin-T network in negative feed-back loop maintains pure sine wave, free of harmonics. Variable-gain negative-feedback amplifier V3-V4 stabilizes frequency and amplitude at prescribed values.-Oscillator Patent is Granted, Electronics, 31;37, p 108.   (View)

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STABLE_VFO

Published:2009/7/10 2:45:00 Author:May

This VFO circuit covers from 2.13 to 2.58 MHz and is intended for use with an external mixer to heterodyne the signal to desired frequencies. Coil data is shown in the parts list. Two power outputlevels are available-a few hundred mW (0 to + 3 dbm) from Q3. Q4 is a class A amplifier for boosting the power to +22 dbm for driving a high-level mixer. The VFO can be operated on other frequencies, with suitable component charges (see the table).   (View)

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150_to_30_000_kHz_OSCILLATOR

Published:2009/7/10 2:45:00 Author:May

C1 capacitor in series with the crystal may be used to adjust the output frequency of the oscillator. The value can range between 20 pF and 0.01 μF, or it can be a trimmer capacitor. X values are approximate and can vary for most circuits and frequencies; this is also true for resistance values. Adequate power supply decoupling is required; local decoupling capacitors near the oscillator are recommended.   (View)

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CASCADE_TUNNEL_DIODE

Published:2009/7/19 22:16:00 Author:Jessie

Voltage drops across resistors R2 serve as individual voltage sources in series for cascaded diodes that give three times sine-wave output voltage of single relaxation oscillator circuit.-Wen-Hsiung Ko, Designing Tunnel Diode Oscillators, Electronics, 34:6, p 68-72.   (View)

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1_to_4_MHz_CMOS_OSCILLATOR

Published:2009/7/10 2:42:00 Author:May

Notes： 1 1 MΩ＜R1＜5 MΩ2 Select R2 and C2 to prevent spunous frequency．3 ICs are 74C04 or equiwlent   (View)

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FET_VOLTAGE_CONTROLLED_OSCILLATOR

Published:2009/7/19 22:15:00 Author:Jessie

Produces excellent sine-wave output with good linearity over frequency range of 1,500 to 2,500 cps, for control voltage of 0to 7 V d-c. Circuit is resistance-controlled three-section phase-shift oscillator.-R. Selleck, Voltage-Controlled Oscillators, EEE, 13:3, p 47.   (View)

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PHASOR_SOUND_GENERATOR

Published:2009/7/10 2:42:00 Author:May

The 4011B astable is gated by S1 to produce 4-ms pulses at 70－ms intervals. Each pulse charges C2 via D2 producing a high tone that decays slowly as C2 discharges through R5.The process repeats for each pulse   (View)

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FEEDBACK_LOOP_STABILIZES_A_F_OSCILLATOR_AMPLIFIER

Published:2009/7/19 22:14:00 Author:Jessie

Wien bridge determines frequency of oscillator, which is combined with amplifier stages to give single oscillator stage having suffident output power to drive load directly. Thermistor R2 and resistor R3 provide negative feedback path around amplifier and oscillator, to make oscillator gain and frequency independent of load variations.-R. G. Fulks, Novel Feedback loop Stabilizes Audio Oscillator, Electronics, 36:5, p 42-43.   (View)

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lO_to_80_MHz_OSCILLATOR

Published:2009/7/10 2:41:00 Author:May

Notes:1. Y1 is AT cut, fundamental, or overtone crystal.2. Tune L1 and C2 to operating frequency.   (View)

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QUADRATURE_OUTPUTS_OSCILLATOR

Published:2009/7/10 2:39:00 Author:May

The XR-567 functions as a precision oscillator with two separate square-wave outputs at pins 5 and 8, that are at nearly quadrature phase with each othen. Because of the internal biasing arrangement, the actual phase shift between the two outputs is typically 80%.   (View)

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HIGH_CURRENT_OSCILLATOR

Published:2009/7/10 2:38:00 Author:May

The oscillator output of the XR-567 can be amplified using the output amplifier and high-current logic output available at pin 8. In this manner, the circuit can switch 100-mA load currents without sacrificing oscillator stability. The oscillator frequency can be modulated over ±6% in frequency by applying a control voltage of pin 2.   (View)

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20_MC_POWER_OSCILLATOR

Published:2009/7/19 22:12:00 Author:Jessie

Colpitts-type common-base circuit gives power output of 500 mw to 50-ohm load, while dissipating 750 mw. –Texas Instruments Inc., “Solid-State Communications,” McGraw-Hill, N. Y., 1966, p 300.   (View)

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10_to_150_KHz_OSCILLATOR

Published:2009/7/10 2:38:00 Author:May

Note：Y1 is H , NT , E cut   (View)

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10_MC_CRYSTAL

Published:2009/7/19 22:11:00 Author:Jessie

Collector voltage of transistor is kept low and is stabilized by zener diode D1 in microminiature oscillator using crystal in 10-Mc fundamental mode. Voltage-sensitive capacitor D2 and R7 serve for fine frequency adjustmets.-M. Lysobey, Microminiature Crystal Oscillator Using Wafer Modules, Electronics, 35:15, p 60-61.   (View)

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STABLE_SUBCARRIER_OSCILLATOR

Published:2009/7/19 22:11:00 Author:Jessie

Two Colpitts oscillators, designed for 7,350 cps and 12,300 cps, are used with reactance-type frequency modulation. Input stage of each oscilllator is temperature-stabilized by d-c feedback.-D. Enemark, Balloon-Borne Circuits Sort High-Altitude Cosmic Rays, Electronics, 32:35, p 52:,55.   (View)

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330_MHz_CRYSTAL_OSCILLATOR

Published:2009/7/10 2:37:00 Author:May

A μPC 16516G IC operates in the fundamental mode with an experimental crystal at 330 MHz. The 56-to-270 pF capacitor is not critical; about + 1-dBm RF output is available.   (View)

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