Based on recommendations, I ordered a new Antex soldering iron which should arrive later this week. In the meantime I'll try to assemble (find!) my kit for both VLF earth-mode and optical comms field work. I am still getting very tired, so don't expect too much too soon.
The first tests will be very modest to get me back into "the swing of things". Unless my health starts to make a big improvement, I fear I may have to live with some of my symptoms for the foreseeable future, if not for ever. This would be such a pity as there is so much I want to do. Compared with some though, I have been lucky. If at all possible, I really want to beat my disabilities. I hate being so useless. I remember my "old self" full of energy.