Test conditions was set up using Baofeng UV-5RC Plus with stock antenna inside my flat.
Keying up at 1 watt was not sufficient enough to open HG, releasing the key there was no response. 5 watts appeared to be enough to open the repeater, upon releasing the key the repeater appeared to be open, however there was no one else listening to give me a report on how well the repeater was actually hearing me or even if it was at 5 watts so I may give it another go, for fairness I will use the same radio with the same antenna with the same power output.
Another nearby repeater is GB3CD but I am not within range of it at my home QTH as far as I know (was unable to hear it before they switched it over to Yaesu System Fusion, not tried since but suspect I still cannot hear it), though it doesn't matter if CD is out of range as it is on Echolink like GB3IR so can do one of two things, connect IR to CD or connect to CD through my phone or computer(s)
I'll post more on this as time permits
73 de M6RSQ