Understanding Secondary Frequency Standards

A secondary frequency standard is a device that helps keep time accurately by referencing a more precise source. It's a crucial component in modern electronics and communication systems.

These standards are based on the vibrations of atoms or molecules, which are incredibly stable and consistent. In fact, the cesium atom is used in some of the most accurate secondary frequency standards.

The key benefit of a secondary frequency standard is its ability to provide a stable and consistent frequency reference, even in the presence of external noise or interference. This is essential for applications where precise timing is critical.

Secondary frequency standards are often used in conjunction with primary frequency standards, which are the most precise sources of time and frequency.

Suggestion: Moderate Frequency and Used in Remote Controls

A secondary frequency standard is a type of frequency standard that's based on carefully designed crystal oscillators. These oscillators can maintain a constant frequency for long periods without needing to be readjusted, to within a few parts in a million.

Crystal oscillators used for secondary standards can be designed to operate at frequencies outside the optimum range of 50-100 kHz, and can even tolerate less precise temperature control.

To give you an idea of just how stable these secondary frequency standards can be, consider that they can maintain a constant frequency for long periods without needing to be readjusted.

Some examples of secondary frequency standards include those used in Loran-C transmitters and broadcasting stations, which derive their frequency from an atomic clock.

Here are some examples of secondary frequency standards:

Secondary frequency standards are used in various applications, including calibrating oscillators and frequency meters. They provide accurate measurement purposes.

The Model 100B provides four standard frequencies for accurate measurement purposes, including calibrating oscillators and frequency meters. These frequencies are available through a selector switch or individually from binding posts.

The output wave shape is sinusoidal, allowing easy recognition of high fractional Lissajous patterns. This makes it possible to make exact measurements of frequencies 1% or 2% apart in the audio spectrum.

The Model 100B's temperature-controlled crystal maintains the frequency within ±0.001% from minus 10 degrees Centigrade to plus 50 degrees Centigrade. This ensures accurate measurements over a wide temperature range.

The Model 100B's output system is designed to isolate each frequency, allowing the use of long lengths of low-capacity shielded cable to distribute the standard frequencies in the laboratory or test department.

The output voltage of the Model 100B is at least 5 volts on all frequencies, and the internal impedance is approximately 200 ohms. This allows for satisfactory wave shape with a load impedance as low as 1000 ohms.

The Model 100B can be adjusted to a primary standard such as National Bureau of Standards Station WWV. The frequency can be set to within ±0.01% over a room temperature variation of ±33 degrees Centigrade.

Here are some key characteristics of secondary frequency standards:

These characteristics make secondary frequency standards a valuable tool in various applications, including calibration and measurement.