Lockdown Activities

Summer has arrived in North Wales, which is precisely why the Police have been going around - under dubious authority in many cases - shutting off carparks and other places where people might otherwise lawfully take their exercise, and lawfully keep a good distance from each other.

Pre-emptive strikes by Police to prevent the use of such car parks do not appear to have a basis in law, and have already been criticised in Derbyshire, promoting a withdrawal of warning notices placed on cars and the recording of their numberplates.

But we all accept that there is a need to stay away from each other right now.  That's why I've spent a happy couple of hours yesterday and this morning installing a proper ground screen underneath my delta loop in my own garden.

My faithful delta loop (and 8-ele 2m Yagi, left), looking north.

A vertical delta loop is essentially a pair of phased verticals, each 'element' having a single radial in the form of the base wire.

Although I have extremely good ground under the antenna, there is an easily measurable difference in ground coupling between wet and dry soil.  So the ground, good though it is, can certainly be improved.

Using some cheap leftover SOTABeams antenna wire, I set about installing 16 radials into slots cut into the soil, radiating out from the centre of the antenna, each about 8m long.  Each wire is connected to a central stainless steel bolt, placed on the ground, under the middle of the base wire.  The radials are not connected to the antenna.

Ground screen scars (now vanished).

It's an open question as to what difference such a ground screen will make in practice; I doubt it is realistically possible to distinguish propagation effects from any ground improvement effects.

Looking at the antenna with an analyser doesn't show any evident shift in resonant frequency or SWR (currently 1.05:1) although the ground is quite dry at the moment.  A more obvious difference may appear when the ground is very wet; we'll see.  Luckily, I have reference sweeps to compare with when that occurs.

What I can say is that, a few hours later, my delta was doing very well against the small handful of stations hearing VK3MO at 14MHz in Europe at around 23:00UT:

14MHz reception of VK3MO (4 x 5 ele Yagi array, 5W out).

Daily WSPR challenge not looking too bad, currently number 9 globally: