In attached picture the 2 types of 433MHz receivers I plan to use. Both lack squelch or carrier detect output. And that causes a problem.
If the connected AVR has to respond on every pulse that comes from these receivers, it will be occupied all the time in handling the signal, and rejecting the noisy messages.
To prevent this, I added a filter: this works fine as it blocks all noise with a pulsetime of less than 100 us. Now the AVR still responds on noise, but the good news is that the amount of time spent on this handling is just a few percent of available processing time.
My question to you, fellow freaks, is: what are smarter solutions to solve this problem?