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Разместил: feri  Просмотров этой страницы: 4041 |
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Описание файла
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Schematic expertise gave impression of a circuit constructed with simulated block but never completely
measured, neither totally checked !
- Input filter designed under 50 Ohms not matched to NE602 input (Zin 1500 Ohms).
- Output filter designed under 50 Ohms not matched to NE602 output (Zin 1500 Ohms).
- FM band notch C19 // L11 not efficient ! calculated resonant frequency 100H (low Q ferrite inductor) with
25 pF is about 3.2 MHz ! May be a calculation mistake, inductor should be 100 nH !
- Local oscillator (HCMOS) and NE602 LO input are not 50 Ohms !
- Poor supply decoupling from USB !
- L10 at 1 mH is more capacitive than inductive from 106 to 136 MHz ! It should be 1 H !
- C1 and C12 are too low value and limits frequencies under 20 MHz as high pass filter ! better with 1 nF.
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| Файл загружен: 23 Фев 2012 16:16, посл. исправление: 23 Фев 2012 16:19 |
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