As mentioned before, it looks like my 8m dipole antenna system has an intermittent fault. Recently, I decided to concentrate on 8m TX with ISM restrictions, which means 10mW ERP. WSPR gives me the best chance. I doubt 8m FT8 at 10mW ERP would be enough.
A reminder that, certainly in the UK, possibly elsewhere, under ISM rules 8m beaconing is licence free and open to all. A full T&I 8m TX permit costs £50 annually in the UK. With more countries opening the band for real amateur radio research, I keep my fingers crossed that radio amateurs will eventually be granted restricted access with conditions. I have long said that just 5kHz in the ISM band would do.
For 10mW ERP tests the antenna must be reliable.
The actual antenna and coax are not problems, whereas erection is more of an issue as this requires ladder work. I can probably manage OK as the ladder work is quite low, but I get giddy very easily these days so even a short distance off the ground is harder than it once was.