27-07-2018, 08:06 AM
Wayne
Download the VK3UM EMR calculator from http://www.vk3um.com/emr%20calculator.html
It gives you physical isolation distances for various bands and your transmitter power.
Don't use a metal mesh (eg chainwire fence) around the bottom else you will get currents induced in the sections and the possibility of introducing transmitted intermodulation products plus affecting the polar pattern. A poly rope/s on stakes (eg star pickets or PVC pipe) spaced out from the vertical is probably enough of a barrier to stop anyone getting close enough to actually touch it, or at least warn them that they shouldn't. That physical separation means that you don't need to raise the antenna base to the 4M level and still be compliant.
If you don't want to have to leave the star pickets/PVC pipes in place when you are inactive, sink a set of suitable diameter pipes into the ground so they are at ground level, or just below, and then place the star pickets & barrier rope into the pipes when you need to. This arrangement would make it easier to mow the grass too....
I think the EMR rules are in place for those times when you are actually transmitting, rather than all the time, so a removable barrier option should still provide compliance. In the event that an ACMA compliance check is undertaken, simply put the barrier poles & rope/s back in place to show that EMR compliance is understood and being observed.
Common sense must prevail.
Doug
Download the VK3UM EMR calculator from http://www.vk3um.com/emr%20calculator.html
It gives you physical isolation distances for various bands and your transmitter power.
Don't use a metal mesh (eg chainwire fence) around the bottom else you will get currents induced in the sections and the possibility of introducing transmitted intermodulation products plus affecting the polar pattern. A poly rope/s on stakes (eg star pickets or PVC pipe) spaced out from the vertical is probably enough of a barrier to stop anyone getting close enough to actually touch it, or at least warn them that they shouldn't. That physical separation means that you don't need to raise the antenna base to the 4M level and still be compliant.
If you don't want to have to leave the star pickets/PVC pipes in place when you are inactive, sink a set of suitable diameter pipes into the ground so they are at ground level, or just below, and then place the star pickets & barrier rope into the pipes when you need to. This arrangement would make it easier to mow the grass too....
I think the EMR rules are in place for those times when you are actually transmitting, rather than all the time, so a removable barrier option should still provide compliance. In the event that an ACMA compliance check is undertaken, simply put the barrier poles & rope/s back in place to show that EMR compliance is understood and being observed.
Common sense must prevail.
Doug
Doug VK4ADC @ QG62LG51
http://www.vk4adc.com
This Forum is only going to be as interesting as the posts it contains.
If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.
http://www.vk4adc.com
This Forum is only going to be as interesting as the posts it contains.
If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.