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Earthing and the radio amateur

Stewart Mason
I've recently joined the IET forums. I replied to a  topic regarding amateur radio and PME on the old forum. Unfortunately I cant access the old forum anymore so I thought it would be best to start a new topic.


So. On the bench there is a transceiver with a metal case. Next to the transceiver there is a antenna tuning unit which is connected to a antenna system which is using an earth rod. Am I right in saying there is a chance of a potential difference between the two metal cases of the equipment regardless if it is a TT, TNS or TNCS?


What would be the ideal solution?  Put the shack on it's own TT supply and bond all the radio equipment back to the MET of the TT and if a earth rod is used for the antennas connect that back to the MET also?


If the TT system was not an option what would be best if the supply was a PME and you didn't want to use balanced antennas removing the use of an earth rod? 


To be honest I've never really given PME's and amateur radio much thought which in hindsight was probably a mistake. I do remember when I did my training an earth rod was recommended for the radios.


Apologies for being so random.


Stewart M0SDM
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    Whilst these points might look great on paper, broadly follows BS EN 50310 practice we use for large electronic installations in buildings (e.g. computer rooms and data-centres etc.), and would certainly make things safe (electrically) in the shack, there are a couple of considerations:
    1. The PME broken-neutral danger is moved from the shack to accessible earthed parts of the antenna outdoors (similar to the outside tap requiring a plastic insert if fed with metal pipes connected to PME earthing terminal) - the lower the antenna earth rod resistance, the lower the touch voltage and the smaller the risk.

    • No-one has mentioned surge protection at all yet ... but if the main installation has SPDs, there should be a separate SPD on the feed to the shack ... and perhaps  query whether a separate SPD scheme is provided in the shack itself.

      (Or alternatively, whenever thunderstorms are forecase, simply disconnect and separate the antenna connector from the equipment and earthed / bonded parts in the shack if you want to save cash.)

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  • 0
    Whilst these points might look great on paper, broadly follows BS EN 50310 practice we use for large electronic installations in buildings (e.g. computer rooms and data-centres etc.), and would certainly make things safe (electrically) in the shack, there are a couple of considerations:
    1. The PME broken-neutral danger is moved from the shack to accessible earthed parts of the antenna outdoors (similar to the outside tap requiring a plastic insert if fed with metal pipes connected to PME earthing terminal) - the lower the antenna earth rod resistance, the lower the touch voltage and the smaller the risk.

    • No-one has mentioned surge protection at all yet ... but if the main installation has SPDs, there should be a separate SPD on the feed to the shack ... and perhaps  query whether a separate SPD scheme is provided in the shack itself.

      (Or alternatively, whenever thunderstorms are forecase, simply disconnect and separate the antenna connector from the equipment and earthed / bonded parts in the shack if you want to save cash.)

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