Decoder
The circuit I started with was the one made by sprut. It works fine with the classic receiver using only SAW filters, but it wouldn't work with mine.
Why? Because the shape of the pulses changes when they exit a narrow-band filter. I had to change the thresholding.
My changes include adding one RLC filter (2MHz) and a faster dynamic thresholding. The modification is easy to accomplish even on existing decoders. Don't worry, it works fine!
It will work with classic receivers, too, provided they can drive 75ohm output!
Why? Because the shape of the pulses changes when they exit a narrow-band filter. I had to change the thresholding.
My changes include adding one RLC filter (2MHz) and a faster dynamic thresholding. The modification is easy to accomplish even on existing decoders. Don't worry, it works fine!
It will work with classic receivers, too, provided they can drive 75ohm output!
This is what a strong signal looks like after going through a narrow-band RF filter (analogue signal is yellow; detected signal is green). You see why I had to change the thresholding! (otherwise the output would have been just one long pulse!)
