Or when I stand within 1 meter of it – than it goes bad when I step away?
Simple explanations you can read on Quora, Reddit, with Chat GPT etc. would go: “When you grab the radio antenna or stand close to it, you are effectively increasing the size of the antenna, which improves the reception. This is because the radio waves are being picked up by a larger surface area, allowing for a stronger signal to be received. When you step away from the radio or stop touching the antenna, you decrease the size of the antenna, which reduces the amount of radio waves that can be picked up, resulting in a weaker signal.”
But we know from experience we know that this is not 100% correct. If it was just increasing surface then every object would help signal receiving, and they don’t. Sometimes even metal objects on which you place your antenna don’t improve its signal as you simply appearing in front of radio.
Explanation probably is in capacitive nature of human body, which then acts like a capacitive battery and amplifies the voltage across the antenna, same as capacitive battery helps in power grids, compensating reactive power and increasing voltage levels.
Explanation to why you don’t even have to touch the antenna to improve radio signal, just come close to radio, is in ground underneath you, probably connecting you with the antenna electrically.
What can also help is raising your antenna as high as possible above the ground. In that way a capacitive impedance between tip of the antenna and the ground will become larger and you’ll get the similar effect. Effect still, again from experience, is not quite the same, as when you hold the antenna. One reason for this could be that human body also acts like a filer, filtering out electromagnetic noise, more precisely absorbing it, because of its dielectric composition.
