FM demodulators have and always will be desired circuits. Many circuit designs use old and obsolete parts or appear to be too complicated for beginners. This design shows a very simple FM demodulator, a quadrature demodulator to be precise, for a 455 KHz IF using only a handful of parts and an NE602. The NE602 […]
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Search Results for: NE602
How it works: Quadrature detector
Many integrated FM quadrature demodulation circuits, such as the MC3361 or MC3362, have a defined LC tank circuit that creates a specific phase shift of 90 degrees at the center frequency of the demodulator. Let’s take a closer in depth look at how they work. A quadrature demodulator for FM signals consists out of two […]
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Exclusive OR (XOR) gate based phase detector
A phase detector generates a voltage proportional to the difference in phase between two signals. They are used in Phase-Locked-Loop (PLL) designs and PM / FM demodulator circuits. But how do they work? I promised in a previous blog article titled ‘No Tune NE602 / NE612 FM Demodulator’ that I would explain how a quadrature […]
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Sudden Storm (HF receiver in a tuna can)
The Sudden Storm receiver from QRPme is a simple direct conversion receiver. The circuit is nothing new: A NE602 mixer with crystal oscillator for downconversion and a LM386 as audio amplifier. What is new though is the enclosure. The parts for the sudden storm kit are being delivered in a tuna can. But the tuna […]
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