@ perhof... Thank You, My brains are falling out...
Like every thing Nick Gammon does it is simple direct and doesn't miss a single thing.
I am looking at the information and a couple of 1F 5.5V capacitors I just bought and I am thinking that it might just work...
I need to use a Pro Mini to collect and transmit Temp and RH data every 5 minutes and all I need to finish it now is a half watt 6V solar cell I think I will use one of those 433 MHz OOK 'simple transmitters' with the key line activated and just switch power off and on to the transmitter.
Bob