I spent an hour this morning re-arranging a long wire antenna - it's now insulated, is not (now) lying on anything, and I connected the other side to an earth stake instead of a flimsy counterpoise ending on the (admittedly metal) washing line post.
The signals I'm seeing on 80m WSPR now are awesome, even though I am still only up about 4m. G8JNJ/A (I assume it was him) came in at +9, and in the last 10 mins of operation I haven't seen a negative dB
TX seems better too - I'm using my usual 500mW, and DK4XI is hearing me.
I'd better re-fettle the "main" LW at M0DEV, methinks. It's got the good earth, but the route runs through trees, in a zig-zag. There must be points where some RF escapes to earth...