Thanks Steve. I still have to reconfigure it, but I'm optermistic. There are a couple of by pass 0.1 ceramic disks directly on the 78xx leads, can't see it in the picture of the 2 x version, there are two the same again but on the board of the 1 x version, but a liitle further from the 78xx than I would like. As an after thought and to avoid voltage drops I added on the 1 x version a pair of 1000uf capacitors hoping to minimise voltage drop. By yes I understand what your saying, I'm glad you see what I meant about resistor placement, its put to bed any worry's I had on that issue. I will reconfigure in a while and post results, hoping a 50 watt load is tolerated. Its ok on the 1 x version which was connected for test over 24 hours. 1x version transistor, no load 12.15 volts, loaded to 20 watts 11.80 volts, and loaded to 50 watts 11.56 volts, stable for 24 hours before I diconected. Load was halogeon 12 volt lamps. Regulator temp max was 62°C and transistor was 74°C, current drain at 50 watts was 3.8 Amps. These figures where stable.