Filter Shanghai engraving machine, engraving machine which features

Mechanical filter is generally used to demand a narrow bandwidth, low loss, high stability of the system equipment. This is due to a mechanical resonator with high Q value, excellent thermal properties and aging characteristics of demand. Iron nickel alloy oscillator Q value reaches 10000-25000, which promised the relative bandwidth is narrow to 0.05% mechanical filter. And not loss is too large, or the pass band too greasy.

Shanghai engraving machine, with high Q value equal important parameters and the temperature coefficient of frequency and mechanical resonance frequency aging. Oscillator frequency offset is typical of normal distribution, and in the 2 x 10-8/0C level, namely when the frequency is 455KH:, change the scope of each with a temperature of 50 DEG C, filter through offset band about 45Hz. Offset but is, reverse, depending on the use of information. Security is very important, because the equipment in the unilateral, frequency offset is greater than 100H: will cause the carrier suppression becomes poor, or audio attenuation. On the problem of aging, the equipment life period, the typical mechanical filter metal resonator stability degree within 50x10.

When the frequency is 455KHz, the passband error can be controlled in less than 25Hz, the structure shape, material mechanical filter used by countries around the world, and the production of technical specification is various, trying to use a table package. All is impossible, so not to copy meter reading data in listing 1.1.