Playing with Filters: Unterschied zwischen den Versionen
Dl8rds (Diskussion | Beiträge) (Die Seite wurde neu angelegt: „== Scope == Well, the title of this page is "Playing with Filters". This is meant literally. So I just wanted to play around a little with my HAMEG HMS-3010 a…“) |
Dl8rds (Diskussion | Beiträge) (→Creating the filter) |
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The background was an idea to construct a bandpass for the frequency range mainly between 1090 MHz (ADS-B) and about 1300 MHz (23 cm band). I wanted to suppress the lower signals quite effectively, and thus maybe create a filter for GPS experiments at 1575 MHz. | The background was an idea to construct a bandpass for the frequency range mainly between 1090 MHz (ADS-B) and about 1300 MHz (23 cm band). I wanted to suppress the lower signals quite effectively, and thus maybe create a filter for GPS experiments at 1575 MHz. | ||
| − | == | + | == Filter Theory == |
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| + | Generally, a bandpass consists of a high pass and a low pass that play together. | ||
[[image:2019-01-19-bandpass1.jpg|400px]] | [[image:2019-01-19-bandpass1.jpg|400px]] | ||
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| + | In order to optimise it a little, i decided to use potentiometers, and since I did not have a 150 kOhm type, I used a fixed value 100 kOhm plus a 50 kOhm poti in series. | ||
[[image:2019-01-19-bandpass2.jpg|400px]] | [[image:2019-01-19-bandpass2.jpg|400px]] | ||
Version vom 20. Januar 2019, 00:01 Uhr
Inhaltsverzeichnis
1 Scope
Well, the title of this page is "Playing with Filters". This is meant literally. So I just wanted to play around a little with my HAMEG HMS-3010 and see how I could build a bandpass and how to understand the steepness of the flanks.
The background was an idea to construct a bandpass for the frequency range mainly between 1090 MHz (ADS-B) and about 1300 MHz (23 cm band). I wanted to suppress the lower signals quite effectively, and thus maybe create a filter for GPS experiments at 1575 MHz.
2 Filter Theory
Generally, a bandpass consists of a high pass and a low pass that play together.
In order to optimise it a little, i decided to use potentiometers, and since I did not have a 150 kOhm type, I used a fixed value 100 kOhm plus a 50 kOhm poti in series.
3 Measuring the filter
4 Measurement setup
