Hier werden die Unterschiede zwischen zwei Versionen angezeigt.
en:e-628 [2018/10/31 20:25] mb angelegt |
en:e-628 [2018/10/31 20:26] (aktuell) mb [Technical Principle] |
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If the narrow bandwidths of ± 25 kHz and ± 8 kHz mainly used for [[AM]]-reception are used, the valve V5 ([[de:EF85]]) acts now as 2nd mixer stage and converts the signal with the oscillator signal coming from Osz.2 (9,1 MHz) to generate the second [[IF]] of 1,6 MHz, now the IF filters ZF II² and ZF III³ are in use. On this lower [[intermediate frequency]], filters with better selectivity can constructed more easily. | If the narrow bandwidths of ± 25 kHz and ± 8 kHz mainly used for [[AM]]-reception are used, the valve V5 ([[de:EF85]]) acts now as 2nd mixer stage and converts the signal with the oscillator signal coming from Osz.2 (9,1 MHz) to generate the second [[IF]] of 1,6 MHz, now the IF filters ZF II² and ZF III³ are in use. On this lower [[intermediate frequency]], filters with better selectivity can constructed more easily. | ||
- | For [[AM]] demodulation valve V11 ([[de:EBF80]])is used, this acts also as meter amplifier. For FM demodulation, the signal first has to pass a limiter stage ([[de:6BN6]], Limiter) and will be fed to separate ratio detectors active on the [[IF]] of 10,7 and 1,6 MHz, in both of them, two OA72 semiconductor diodes are used. | + | For [[AM]] demodulation valve V11 ([[de:EBF80]]) is used, this acts also as meter amplifier. For FM demodulation, the signal first has to pass a limiter stage ([[de:6BN6]], Limiter) and will be fed to separate ratio detectors active on the [[IF]] of 10,7 and 1,6 MHz, in both of them, two OA72 semiconductor diodes are used. |
The audio signal is fed to an audio preamplifier stage ([[de:EF86]]) and the audio final stage ([[de:EL91]]) to drive the speaker integrated in the front panel. | The audio signal is fed to an audio preamplifier stage ([[de:EF86]]) and the audio final stage ([[de:EL91]]) to drive the speaker integrated in the front panel. |