I've noticed the occasional
I've built my FM modulator/RF mixer/433 MHz oscillator according to plans from The Internet on a breadboard, now it doesn't work.
We can usually refer the author to something existing, pointing out in comments that breadboard will not do at RF. But we fail at actually giving empirical evidence that would be the case. That's not very good engineering practice.
Is there something we can point users to, that shows measurements?