This afternoon I fired up the 5m long feeder (inner and outer strapped together) running up the pole to the 28MHz halo (used as a top loaded vertical) on 500kHz. Tuning was with a tapped inductor on a ferrite rod and matching using a 3C90 toroid with multiple tapped secondary winding. This works well and the signal reports on WSPR from M0BMU are 18dB stronger than on the earth electrode antenna. Also had reports from GW3UCJ,PA0A, OR7T and M0LMH so far this evening. If I can create a suitable loading coil (4-6mH needed I think) I will try this vertical with the 136kHz QRSS3 beacon as see what the signal is like.