This device, when placed in the antenna lead in before your radio, will bleed the static from the antenna discharging it to ground before it has a chance to go through your radio and do real damage. It also tends to make receive quieter by draining static that would ordinarily have to discharge some where sounding like zaps or pops in your receiver. This device should be mounted just behind the radio, with a short patch cord connecting it to the receivers antenna input. Be sure to wire this thing correctly, if it is reversed it will not function correctly and may well degrade performance of your antenna setup.
This device is not a lightning arrestor. It will not withstand a direct strike.
This circuit is simpler than the one above and is small enough to fit inside the radio if so desired. I had tried this setup some years ago but had problems with it. It did have the desired effect of snubbing high voltage surges but it also produced images of local BC stations across the short wave bands. I don't recall the type of diode that I had used, so may be that was the problem. The type of diode specified above reportedly has been used successfully in this application.