The problem is that the radio ham, by putting bits of wire and metal outdoors, more often than not has more than one earthing system. Maybe not if if the station is VHF/UHF only and the antennas are all yagi designs looking like an overgrown TV antenna on the roof, as these do not need an RF earth to function, but a station for HF or even more so LF, is not really complete without a decent connection to the  earth beneath the antenna.

So given you have an earthed extraneous part to deal with, the options are somewhat restricted.


As far as lightning is concerned, any outdoor tower or mast, if not planted directly in the ground, should be arranged so that it can flash over  to an electrode if it is more than a few hundred volts off true earth.  A simple spark gap will do. Similar precautions to protect  external feed cables before they go indoors are also advised.

Sealed unit spark gaps with an inert gas filling are available. examples  though the breakdown voltages are a bit low for full legal power operation.

  For a direct strike, like the rest of the installation, such measures will of course be blown to smithereens, but for the far more likely induced few tens of KV from a strike within a km or so, they do greatly increase the chances of the indoor gear surviving, and of not injecting nasty voltages onto the local mains supply.

Gas discharge tubes and spark gaps allow a short to ground to be present only when it is actually needed, being open circuit the rest of the time! Howeverby far the best precaution to protect the house end is to disconnect the radio, from both antenna and mains supply, when not in use, and to short the antennas to ground if their design allows that.

The problem is that the radio ham, by putting bits of wire and metal outdoors, more often than not has more than one earthing system. Maybe not if if the station is VHF/UHF only and the antennas are all yagi designs looking like an overgrown TV antenna on the roof, as these do not need an RF earth to function, but a station for HF or even more so LF, is not really complete without a decent connection to the  earth beneath the antenna.

So given you have an earthed extraneous part to deal with, the options are somewhat restricted.


As far as lightning is concerned, any outdoor tower or mast, if not planted directly in the ground, should be arranged so that it can flash over  to an electrode if it is more than a few hundred volts off true earth.  A simple spark gap will do. Similar precautions to protect  external feed cables before they go indoors are also advised.

Sealed unit spark gaps with an inert gas filling are available. examples  though the breakdown voltages are a bit low for full legal power operation.

  For a direct strike, like the rest of the installation, such measures will of course be blown to smithereens, but for the far more likely induced few tens of KV from a strike within a km or so, they do greatly increase the chances of the indoor gear surviving, and of not injecting nasty voltages onto the local mains supply.

Gas discharge tubes and spark gaps allow a short to ground to be present only when it is actually needed, being open circuit the rest of the time! Howeverby far the best precaution to protect the house end is to disconnect the radio, from both antenna and mains supply, when not in use, and to short the antennas to ground if their design allows that.