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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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  • 0
    Thanks for all the input. It is much appreciated. Personally I've always used dipoles and loops so no need for earth rods to be a part of my station! 


    Clive I'm a bit ashamed to say I am a qualified electrician!! As I said in my opening post I have never given PME's and radio much thought. In 20 years I've never had anything to do with TT installations.


    The main reason for all the questions is I have volunteered myself to give a talk at radio club on earthing in the shack. In my ignorance I thought it would be straight forward. Obviously it isn't straight forward as David pointed out. I can see on the night I am going to be met with one of my favorite lines  "It's been like that for years and never been a problem". I'll carry on with my questions on here and all being well when the time comes in April I'll be an expert.


    One point that does need getting over is how dangerous a PME can be in fault conditions where a radio shack is in use.


    A few thoughts on a shack that has got an antenna using an earth rod, in a property that is supplied by a PME
    1.  An earth bar is installed in the shack all equipment is bonded to the earth bar and a 10mm2 back to the MET along with a 10mm2 from the earth rod to the MET

    • Bond the piece of equipment that is connected to the earth rod antenna system where it enters the shack with a 10mm2 back to the MET?

    • Supplementary bond with a 4mm2 across all the gear and back to the main earth terminal.

    • Rely on the coax braid to keep at the metal gear at the same potential


    I don't know if it's me making this be more complicated then it is but it certainly appears to me that the more I think about earthing in a radio shack the more complicated it becomes.
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  • 0
    Thanks for all the input. It is much appreciated. Personally I've always used dipoles and loops so no need for earth rods to be a part of my station! 


    Clive I'm a bit ashamed to say I am a qualified electrician!! As I said in my opening post I have never given PME's and radio much thought. In 20 years I've never had anything to do with TT installations.


    The main reason for all the questions is I have volunteered myself to give a talk at radio club on earthing in the shack. In my ignorance I thought it would be straight forward. Obviously it isn't straight forward as David pointed out. I can see on the night I am going to be met with one of my favorite lines  "It's been like that for years and never been a problem". I'll carry on with my questions on here and all being well when the time comes in April I'll be an expert.


    One point that does need getting over is how dangerous a PME can be in fault conditions where a radio shack is in use.


    A few thoughts on a shack that has got an antenna using an earth rod, in a property that is supplied by a PME
    1.  An earth bar is installed in the shack all equipment is bonded to the earth bar and a 10mm2 back to the MET along with a 10mm2 from the earth rod to the MET

    • Bond the piece of equipment that is connected to the earth rod antenna system where it enters the shack with a 10mm2 back to the MET?

    • Supplementary bond with a 4mm2 across all the gear and back to the main earth terminal.

    • Rely on the coax braid to keep at the metal gear at the same potential


    I don't know if it's me making this be more complicated then it is but it certainly appears to me that the more I think about earthing in a radio shack the more complicated it becomes.
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