Radio from home

My main amateur radio interests lie in frequencies above 50MHz. To regularly make lots of contacts on these frequencies, you need to have a clear view of the horizon and big antennas. I live in a flat in Palmers green in the north part of London (see below) and both of those criteria are shot!

Terrain from home

I cannot have any significant permanent antennas, and the take off in several directions is poor as the montage below shows (generated by G4KLX's excellent UKW tools). The map on the left shows the land profile centered on my QTH, with the higher land represented by brighter white. The middle map shows the horizon angle in degrees from the antenna view. The left map is a 3D profile. I am obviously blocked to the north and west meaning my UK VHF contacts are hard won.

Portable

After looking at lots of maps, I identified a site at Coldblow Farm, in JO01HH as having potential. This has a great take off to the east which is main source of points in VHF contests (see left picture below) but not so good to the west and north west for intra UK QSOs. It is however, electrically quiet and has a good horizon in many directions as seen in the right picture below. This is now my number one site for IARU contests, but I don't use it too often as I have to pay for access.