
After some tests yesterday with Justin G8YTZ (who is pretty much LOS from me at home, although I suspect some rooftops and trees spoil the path) I got my 23cms signal across to him. That showed that both a front-end filter and some pre-amplification would be a help. Today he visited the 'JV site and installed a preamp and filter. The results were spectacular - I was getting the same MER in my shack as via the repeater (26+).
So after peaking up the flat-plate (IRO +10dBD) I then started winding down the power. I got to MER 6 and then measured what I was putting into my cable (70' of LDF4-50 and 13m of Westflex103 up the mast to 10m AGL).
All of 20mW!!
Further tests show I can get in with my Portsdown/Pluto driving a cheap 20dB eBay amp, without overdriving the small amp. That's more like it

Gareth