To an extent Ofcom's hand is being forced by exposure legislation drafted by others, that has affected  those of use who work with high power RF and high voltages for a living for several years now. Attempts to kick this into the long grass are running out of steam.

(the basic restrictions identified in Tables 4 and 5 of the 1998 ICNIRP Guidelines. At work we have had the Control of EM fields legislation since 2016)


In terms of the average Ham station, all that is required is a half side of A4 sums that will show that for a full legal limit amateur station (well unless you have the extra power  licence variation for moonbounce experiments or huge dishes or something..  and to be honest then you really should know where you are firing your kilowatts) that the public exposure limits are safely met unless your victims come within a few metres of the antenna metalwork. 


If your antennas are in a private garden, and not running so close to the boundary as to expose the neighbours, that is about  it, and in terms of lower power, if you have a transmitter of 10 watts or less (most hand held) then there is no issue even in a crowd, you'd have to stick the antenna into someone to hurt them more seriously  than a spot burn, which even so is only just about possible with exposed metal on the Tx output.

Relating the primary limits in watts per square metre, or the derived ones in volts per metre or amps per metre may be unfamiliar, but once done a few times, should not be to hard for someone who can install their own antennas and knows how they work.


There is a rather simplified  spreadsheet (by ofcom) that over estimates the safe distances in most cases see here   It does not work as is under Linux but can be made to.


Note that we can still carry on as before putting ourselves and other enthusiasts in the line of fire as we see fit so long as at field days etc we put up some barrier rope, or put the antennas a few metres up and out of casual reach of gen public .

Licensees, installers and users are not required to comply with the ICNIRP general public limits if only the licensee owner, installer or user of radio equipment may be exposed <snip> For example, an amateur radio licensee does not need to comply <with the licence> condition in respect of their own exposure to EMC

(here)


In rather slow time (reply may take a few days if hard  sums are needed at legally binding accuracy.. )  I am quite happy to advise any fellow ham in distress  about this, but I suspect most will have very little to worry about,  other than having to think about where the field maxima actually are  is a bit unfamiliar.


Mike


73 de G7VZY

To an extent Ofcom's hand is being forced by exposure legislation drafted by others, that has affected  those of use who work with high power RF and high voltages for a living for several years now. Attempts to kick this into the long grass are running out of steam.

(the basic restrictions identified in Tables 4 and 5 of the 1998 ICNIRP Guidelines. At work we have had the Control of EM fields legislation since 2016)


In terms of the average Ham station, all that is required is a half side of A4 sums that will show that for a full legal limit amateur station (well unless you have the extra power  licence variation for moonbounce experiments or huge dishes or something..  and to be honest then you really should know where you are firing your kilowatts) that the public exposure limits are safely met unless your victims come within a few metres of the antenna metalwork. 


If your antennas are in a private garden, and not running so close to the boundary as to expose the neighbours, that is about  it, and in terms of lower power, if you have a transmitter of 10 watts or less (most hand held) then there is no issue even in a crowd, you'd have to stick the antenna into someone to hurt them more seriously  than a spot burn, which even so is only just about possible with exposed metal on the Tx output.

Relating the primary limits in watts per square metre, or the derived ones in volts per metre or amps per metre may be unfamiliar, but once done a few times, should not be to hard for someone who can install their own antennas and knows how they work.


There is a rather simplified  spreadsheet (by ofcom) that over estimates the safe distances in most cases see here   It does not work as is under Linux but can be made to.


Note that we can still carry on as before putting ourselves and other enthusiasts in the line of fire as we see fit so long as at field days etc we put up some barrier rope, or put the antennas a few metres up and out of casual reach of gen public .

Licensees, installers and users are not required to comply with the ICNIRP general public limits if only the licensee owner, installer or user of radio equipment may be exposed <snip> For example, an amateur radio licensee does not need to comply <with the licence> condition in respect of their own exposure to EMC

(here)


In rather slow time (reply may take a few days if hard  sums are needed at legally binding accuracy.. )  I am quite happy to advise any fellow ham in distress  about this, but I suspect most will have very little to worry about,  other than having to think about where the field maxima actually are  is a bit unfamiliar.


Mike


73 de G7VZY