10 MHz VFO
A high-stability variable-frequency oscillator (VFO) designed for operation in the 10-MHz range requires careful consideration of its components and power supply. The oscillator's performance is heavily influenced by the stability of the voltage supplied; fluctuations can lead to frequency drift, which is detrimental in applications requiring precise frequency control.
To achieve the desired stability, it is advisable to implement a voltage regulator that can maintain a constant output despite variations in input voltage or load conditions. This ensures that the oscillator operates within its specified parameters, providing reliable frequency output.
In the gate circuit of the oscillator, the choice of capacitors plays a significant role in determining the overall stability of the circuit. Silver mica capacitors are recommended due to their low dielectric loss, high stability, and excellent temperature characteristics. These capacitors are less prone to aging and have a minimal change in capacitance over time, making them ideal for high-frequency applications.
The oscillator circuit may utilize a field-effect transistor (FET) for its active component, as FETs are known for their high input impedance and low noise characteristics, which contribute to the overall performance of the oscillator. Proper biasing of the FET is essential to ensure linear operation and to avoid distortion of the output signal.
In summary, the design of a high-stability variable-frequency oscillator operating in the 10-MHz range requires a stable power supply and carefully selected components, particularly silver mica capacitors in the gate circuit, to achieve optimal performance and reliability.Values shown for high-stability variable-frequency oscillator give operation in 10-MHz range. Stable supply voltage is essential. Use silver mica capacitors in gate circuit for maximum stability. -E. M. Noll, FET Principles Experiments, and Projects, " Howard W. Sams, Indianapolis, IN, 2nd Ed. , 1975, p 193-194. 🔗 External reference
Related Circuits
A 183.6 MHz SAW filter is utilized in a CDMA application. The S-parameter of the SAW filter is employed to simulate the interaction with the mixer. An example is provided using the SAWTEK 855893 SAW filter. This application note...
This 200 MHz JFET cascode circuit exhibits low cross-modulation, significant signal handling capability, no need for neutralization, and automatic gain control (AGC) managed by adjusting the bias of the upper cascode JFET. A specific requirement for this circuit is...
The RF2104 830MHz amplifier circuit operates as illustrated in the figure. A radio frequency (RF) signal enters through a 5-foot input, passes through a preamplifier, and is then amplified by an amplifier stage at the 12-pin output. The circuit...
TR1 (BC547) is an inverted Hartley oscillator which based upon an inductor fabricated on the PCB. This makes it megga-stable, and setable anywhere in the VHF FM band (76MHz to 119MHz) and the BB105 varicap makes it voltage tuneable...
This circuit transmits a continuous audio tone on the FM broadcast band (88-108 MHz), which can be utilized for remote control or security applications. The circuit draws approximately 30 mA from a 6-9 volt battery and has a reception...
The circuit is constituted by the RF2324 1880MHz internal amplifier collector bias application. A radio frequency (RF) signal enters through input pin 3 and is processed by a preamplifier. The final stage power amplifier output is amplified by 7...