Fascinating thread so far! Here are a few comments garnered from years of experience as an outdoor enthusiast and some observations as a professional in the ski and avalanche industry:
Activating using HF on snow is great from a technical perspective. Since HF (especially at lower frequencies) will pretty much pass through snow and ice crystals the main benefit of a deep snowpack is raising your overall antenna height above ground without having to bring a longer pole. It’s also easier to jam the pole (I use a 3.2m avalanche probe) into the snow instead of looking for rocks or other objects to support it. If you’ve got enough snow and time, you can also build a small wind wall out of snow blocks to stay sheltered from some of the elements.
Avalanche, cornice, and poorly bridged crevasses can be major hazards and proper training and guided experience are important in order to mitigate, manage, or avoid them. Environmental concerns like temperature and precipitation are also significant. As it’s been mentioned, keeping your radio and antenna setup simple can reduce the amount of time spent on the summit and keeps your climbing partners happier.
At high altitude
My OEC textbook contains the following definitions for altitude bands:
Low altitude: elevations less than 5,000 feet (1,500m)
Intermediate altitude: elevations between 5,000 feet and 8,000 feet (1,500m to 2,400m)
High altitude: elevations between 8,000 feet and 12,000 feet (2,400m to 3,500m)
Very high altitude: elevations between 12,000 feet to 18,000 feet (3,500m to 5,500m)
Extreme altitude: elevations above 18,000 feet (5,500m)
Physiological response to altitude can be affected by genetic makeup, underlying medical conditions, and general health, but the deadliest forms of altitude sickness typically occur at or above the high altitude band. Ascending quickly will exacerbate symptoms and there is significant variance in how quickly people will acclimatize to different elevations.
Acute Mountain Sickness (AMS) is the mildest form of altitude sickness and feels like a bad hangover; symptoms include dry cough, difficulty breathing during heavy activity, headache, nausea/vomiting, dizziness, low urine output, and malaise. AMS rarely kicks in below 6,500 feet (2,000m) and is found more commonly above 8,000 feet (2,400m). The symptoms generally go away after 3-4 days and are typically not life threatening on their own. This is also about how long it takes most people to adjust to the change in altitude.
High Altitude Pulmonary Edema (HAPE) is what happens when fluid builds up in the lungs when an individuals blood pressure rises as a result of several altitude related factors. Trouble breathing while at rest (especially while sleeping) and persistent cough are early stage symptoms, and pink frothy sputum and hypoxia are late stage symptoms. HAPE occurs in approximately 1 in 10,000 of intermediate altitude skiers and needs to be addressed quickly. Descending to lower elevations and seeking medical attention are the best options for HAPE.
High Altitude Cerebral Edema (HACE) is the most severe form of altitude sickness and can develop into a potentially deadly condition where the brain swells inside the cranium, resulting in intra-cranial pressure and possibly brain damage or even death. It progresses from headache and nausea to ataxia (uncoordinated muscle movements) before advanced symptoms appear such as altered mental status, fatigue, drowsiness, difficulty speaking, paralysis, and coma. Hallucinations and psychotic behavior are also commonly observed. HACE is generally preceded by AMS symptoms and progression can take from 12 hours to 3 days. It is commonly encountered at elevations above 9,600 feet (3,000m.) Immediate medical attention is required to treat HACE.
Other altitude related problems include high altitude bronchitis (persistent dry cough resulting from exposure to cold, dry air, above 14,000 feet,) high altitude retinal hemorrhage (rupture of blood vessels in the back of the eye,) solar keratitis (blindness as a result of increased UV exposure,) chillblains (blue or red swollen skin resembling frostbite or nip,) and peripheral edema (swelling of the face, hands, or feet as a result of fluid leaking into surrounding tissues.) These conditions generally do not leave lasting effects, though if concerned you should consult a medical professional.
On summits with no trees or other means of stringing up antennas
This has been covered pretty well in the thread. I usually try to find a rock to lash the pole to and use a pole short enough that the arms of the dipole support it, or use short guy wires lashed to other rocks. On smooth granite summits I’ve used climbing protection (nuts and cams) to anchor guy ropes and antenna wire into cracks. If you’re really out of space then you can always (safely) throw the wire over a cliff and hope for the best. I’ve yet to try it, but sitting on the pole with it horizontally over an edge and the wire dangling off the end is an option. Don’t be afraid to get creative!
This is where things get tricky. SSB signals at QRP power generally require quite a bit of power and/or gain from the chaser in order to result in a QSO. Self-spotting helps immensely. Increasing your own power output will require, at the least, a larger battery or a shorter activating window. The FT817 is also my current go-to rig for SOTA SSB, but I find it a bit heavy for what I’m actually getting out of it.
There are a few monoband kits available, though the KN-Q7A has reached EOL recently and it will be a while until a new model is released. The new BitX40 module is probably your best bet at the moment, provided you can homebrew a few simple components. Fortunately there’s a very strong community to help you if you run into trouble. Definitely worth a look. If you’re having a slow time picking up CW then you may want to look into some of the other digital modes that are available.
Finally, being in good shape will help a lot. I’ve found that the better shape I’m in the more energy and mental clarity I have for operating from the summit. It may take a while to feel the effects of regular training, but the benefits are so numerous that there’s really no reason to not do it!
Hope to catch you on the air sometime!