Hello John
Some random jottings follow. After over 220 SOTA activation and becoming a SOTA mountain goat , I can say that it's about pack weight. Mine has been around 28 lb constantly. I play a trade off between weather conditions, how high and how far against radio hobby equipment. 1 pointer in Shropshire would permit a FT857D, LiPo batteries and a lot of wire antenna with less stuff for taking care of me. An 8 pointer in the Lake District or North Wales needs more clothing, drinks and food so there's room for a handheld and 2m dipole. Line of sight from 800m ASL is rather good.
There's no ATV category in SOTA as far as I know. Perhaps the club could ask the management team at SOTA nicely for one? Our clubmates in Cumbria have done 6cm FM ATV on SOTA summits and managed a summit 2 summit. All on 1 pointer summits. Well done there.
You're going to need a barrow, hand cart or mountain bike with panniers for the kind of mass that you're using. An ex-infantry soldier would do. All great until the first stile or tight gate! We wish an activator a safe descent because we know how vulnerable are ankles. I've some horrid injuries from 2009 on Moel y Golfa so know this first hand.

Is 70cm the sweet spot for DATV in terms of amplifier power and mass ? One of those amp kits off Ali Express that have no instructions might do if Jim G7NTG has worked out what to do? One of my 70cm beams is from B&Q - stockists of 25mm electrical plastic conduit, aluminium rod and tube and PVC tube (dipole centre). It splits in two with a sleeve joint. 22mm wastewater pipe fits inside 25mm conduit. About 200 grams too. My 2m and 23cm beams are B and Q too.
When I attempt SOTA DATV I am going with my activation partner Alastair M0TYM who does a good impersonation of a Sherpa. He once carried 2 SLABs up Aran Fawddwy and only found out at the top. We didn’t use the batteries nor the HF radio cos it was bloody awful weather. I fancy trying to activate tv on Cadair Berwyn after many smaller hills practice. Pipe dreams.
Ray M0DHP does SOTA and DATV - separately - on the South Downs so might be a handy collaborator. Butser hill to Chactonbury Ring S2S?
This is a tricky challenge. Well done so far.
73
David M0YDH