I need some advice/guidance. I want to set up a 4-antenna array with some Yagis mounted on a 25' quick deploy mast from M2, run a short distance to a 300w amp and then into a Yaesu FT-991A. This is all on 70cm. Hopefully we can set up the mast and antenna outside and run coax thru an open window. This is going to be a quick set up, temporary operation and then tear down. I don't know if we will have much grounding resources, but likely could find a earth grounded pipe to clamp on to. The ground will likely be frozen and covered with snow when we set up. Lighting is not really a concern in our environment. The main concern is RF grounding. I understand a Yagi is a balanced antenna, but can there still be issues from not having good RF ground? I just don't know if we will encounter common mode current or any other RF interference from it. Does anyone have any good practical ideas on ways to protect or help minimize problems from RF grounding issues particular to a setup like this?