en:selectivity
Unterschiede
Hier werden die Unterschiede zwischen zwei Versionen angezeigt.
en:selectivity [2021/04/17 17:27] – angelegt mb | en:selectivity [2021/05/28 11:23] (aktuell) – mb | ||
---|---|---|---|
Zeile 14: | Zeile 14: | ||
A second important parameter is the filter skirt; with cheaper filters with wide filter skirts, the interference cannot be cut off as effectively as with high-quality filters with steep skirts. | A second important parameter is the filter skirt; with cheaper filters with wide filter skirts, the interference cannot be cut off as effectively as with high-quality filters with steep skirts. | ||
- | It is also important to choose the optimum bandwidth according to the reception mode: [[IF]] | + | It is also important to choose the optimum bandwidth according to the reception mode: [[IF filters]] with a width of 4 - 6 kHz are useful for AM reception of broadcasting stations, 1.8 - 3 kHz for [[SSB]] reception, and narrow-band filters with a width of 250 - 500 Hz are used for [[CW]] reception. |
**LC filters** are inexpensive to produce, but they only have a high quality or steep skirts at low [[intermediate frequency|intermediate frequencies]]. **Ceramic filters** are also inexpensive. More expensive are **crystal filters** with steep skirts and the best results are achieved with **mechanical filters**. | **LC filters** are inexpensive to produce, but they only have a high quality or steep skirts at low [[intermediate frequency|intermediate frequencies]]. **Ceramic filters** are also inexpensive. More expensive are **crystal filters** with steep skirts and the best results are achieved with **mechanical filters**. | ||
In some receivers, a continuously variable bandwidth (BWC) has been realised; with modern DSP technology (digital signal processing), | In some receivers, a continuously variable bandwidth (BWC) has been realised; with modern DSP technology (digital signal processing), |
en/selectivity.1618673266.txt.gz · Zuletzt geändert: 2021/04/17 17:27 von mb