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Very High Altitude SOTA

Hey SOTA friends!

Last year, I had two high-altitude activations - one failed and one successful.

The first was Mount Shasta (W6/CN-001 - 4317m). I brought a borrowed FT-817 and a VHF/UHF Arrow Yagi. This summit requires elements of actual mountaineering. For various reasons, I didn’t make any contacts. I had a couple of non-ham climbing partners waiting not-so-patiently for me to finish before I even got started, and VHF was jammed with contest traffic. I didn’t do HF since I didn’t have my own HF equipment at the time. I’m absolutely certain that, had I not been rushed, and had been more familiar with the equipment, and had been able to think, this might not have been a failed activation.

The second was Mount Whitney (W6/SN-001 - 4418m). This was a way more fair-weather activation, with a trail all the way to the top. I did it trail-running style so I could get the entire 22 mile (35.4km) trip done in a day. As such, I brought an HT and a half-wave telescoping antenna for VHF. I easily made 4-5 contacts during the 30-45 minutes I was on the summit.

One thing both of these had in common, is that I had trouble intelligently operating – a combination of the thin air and exertion. I know that the more I get myself familiar with portable operating in general, the easier these high-altitude summits will become. Making it so I don’t have to do much thinking while I’m up there will go a long way toward having a successful activation.

Here’s what I’d like to gather information on – does anyone have tips/advice for doing activations:

  • On snow
  • At high altitude
  • On summits with no trees or other means of stringing up antennas
  • Lightweight SSB

I’m looking for tips on preparing, equipment, setup, support, operating – anything.

I have an FT-817, SotaBeams linked dipole (40/20m), autotuner, end-fed random wire antenna, and a 7m telescoping squid pole.

I’m planning on learning CW this year, but it’s not yet an option. I know things can get quite lightweight with CW and I might even be able to operate HF on trail runs once I learn CW. But for now, I’ll work with what I’ve got.


Hi Rex,

This is a very interesting topic.

Although I have not yet activated as high as you have these are some of the things I have noticed that affected my operating skills when working at fairly high altitude or in cold temps.

  • If possible go with ham friends. Your non-ham friends will not be patient for you to set-up your gear and then suffer in the elements while you are trying to make contacts. When you stand in the cold doing nothing it is not fun, especially if you are not operating. This will put pressure on you and the way you operate.

  • Give yourself plenty of time to operate (setting-up, operating, packing), not just to reach the summit. This will let you operate stress-free and test multiple bands.

  • Make sure you are warm and comfortable even when sitting idle in very cold temps. Hypothermia is a very real risk especially when you are not exerting yourself. There are different levels of hypothermia from mild to severe but the colder you get the less efficient and lucid you will be at operating. If you’re cold you may end-up with what my friend F4EGG and myself refer to as the “SOTA brain freeze” when you’re having troubles remembering the other OM’s call sign or even your own.

  • Try to stay zen. I remember one of my activations where the top of the hike was technical and downright dangerous. While operating I had a hard time focusing on the QSOs as in the back of my mind I kept wondering how I was going to get off the mountain without falling off a cliff. So obviously, having the proper equipement on technical routes is paramount. If you have protection in exposed spots you will have better peace of mind, you will be more relaxed and you will operate better.

  • Less oxygen? I am not sure about that one but I do tend to notice that the higher I go the less efficient at setting-up and operating I am even if temperatures are not an issue. So it could definitly be a factor.

  • It looks like you are a very fit person (35km in one day with xx meters of vert!) but as always the less tired you are when you reach the summit the better at operating you will be. So saving on weight is always very important. It looks like you have a very good set-up already with a FT-817 and a dipole. Today on one of the SOTA threads I saw one of those MTR mountain toppers. It looks like a huuuge weight saving vs a FT-817. I may have to break the piggy bank on one of those.

  • Whether activating on snow or at high altitude with no trees, wind is always the predominant factor for me. It is very rare to be at high altitude and have little wind. So stringing a dipole with a pole and stopping them from falling in the wind can be difficult, I find that in this kind of conditions a small tripod and a vertical (does not have to be huge) is always the jack of all trades in any conditions. Not necessary as light as just a dipole but you will be less stressed when operating wondering if your antenna is going to fly off into the wind. Try to find a tripod that is not too heavy and invest in a strong head that can bear the load that the wind may put on the antenna.

  • If you need to anchor in the snow some of your equipment and the ground is not pure ice, you can use plastic bags filled with snow with your guy lines. It will be lighter than some of those heavy metal spikes for the snow. Dig a small hole, put the plastic bag filled with snow in it with tension on the guy line. Cover up the hole and stomp on it. The ground will freeze back and harden in no time, leaving you with a solid anchor.

  • Some set-ups are better for summer operations than winter. Solar is one example. Trying to stop you foldable panel from flying off in winter is not that easy…

  • Gear that is easy to operate with gloves on will put less stress on you.

  • Calibrate your gear for your type of operation. No need to take a huge battery if you plan on only a few QSOs. But bear in mind that low temperatures greatly impact the operating time. So testing and experience will be key. LiFePo4 types of batteries are lightweight and stable with a great power/weight ratio.

  • If you have 3G/4G and can send a spot from where you are then people will know where to look for you and it will be a huge help. If you operate in CW you can also use RBN to get spotted. You could also use satellite beacons that send emails to your friends with your QRG and other details (SPOT locator for example).

  • Putting your plans on SOTA watch for your upcoming summit will help as well. If you have APRS or DPRS tracks so that people know when you have reached the summit it will be helpful as well. If you can also contact your friends via VHF to ask them to spot you, it will be very helpful.

Well, this is what comes to mind so far. I have had a failed activation last year (0 QSO) in Japan with a non-ham friend while backcountry skiing. Most of my failure comes down to not enough time to operate from the summit. Bad planning on my part. I will try again this winter.

Well done on the 4k+m activations!



As a bonus, here is my friend Thierry (F4EGG) with a mild case of SOTA brain freeze. Although it was summer and only 3,000m and the sun had just come out, it was bitterly cold and I think Thierry had a mild case of hypothermia. At one stage he has to pause to remember his own call sign :slight_smile: . I always tease him about that one!

By the way, in that vid you can see a small tripod with a ATAS 25 vertical. Can be set-up pretty much anywhere.



All very good info! Thanks for the thoughtful and thorough response. Definitely makes sense.


Hello Rex,
I would like to add a couple of hints from my experience of activating in the Canadian Rockies in winter. The way I operate is to choose one band before I leave, post an alert, and on the peak I choose one frequency and stick to that, planning on having chasers come to me. This simplifies equipment and operating procedure. The wire harness for my dipole has no links to tangle, it is made of 26AWG teflon-coated stranded wire, so it unravels easily. Not changing frequency means the radio can be set-up and operated with gloves on. I modeled my inverted V (EZNEC) on 20m with a 20’ pole and found it was not very directional at all, so I just erect the wires up and down-wind. It’s easier and provides extra support to the whole antenna.

Speaking of erecting the pole, I found a great hint in the ARRL antenna compendium. I use a guy-ring at 2/3 the height of the pole (a good position to reduce the twisting moment on the pole from the wind), then three guy-lines that are 1.25 x the height of the guy ring will need anchors placed the length of the guy-line apart. This makes setting up the pole very easy as there is no adjustment on anchor placement or length of guy lines needed. I have a one-page crib sheet on how I do this if you are interested.

For equipment I use an FT817 with a 25 watt amplifier. and importantly I monitor the drive power (2.5w) using the 817 “pwr” meter setting. The peaks of my voice should just drive the meter to its maximum value. I find a lot of people using my 817 have quiet voices or hold the mike a long way away from their mouths, and so send unnecessarily weak signals.

Finally, this method of operating relies on getting spots posted on SOTAwatch. I use Droidspot on my phone, with a stylus so I operate it with gloves on. If I think cell coverage will not be present, I make sure I have a friend standing by to hear me and post a spot, although I have to say that I the N.American chasers are brilliant at finding me, and are the most polite and efficient operators. I am often able to work between 20 to 30 contacts in 10 to 15 minutes and the whole activation, including set-up and tear-down can be done in 20 to 25 minutes.



Hi Rex!
I think that Sota activity on high mountain and in poor wx condition is like a round of chess boxing! HI!
If the ascent, wind, cold or your YL prevent you, the activation will be much hard!
In order to pick me up, about 30 minutes before reaching the top I eat a good dose of soluble carbohydrate: in this way I won’t accuse low blood sugar and I recovery energy.
I have everything in order in the rucksack so the assembly is easy and fast.
About battery and its working temperature, I noticed that not only Pb battery but also LiPo battery has problem with the low temp, put them near the body could be a solution.
I use a LiPo 11.4 V nominal 3cell 5500mAh.
Another problem when I fixed a wire of end fed random wire to the telescopic pole I noticed is that the electrical tape freezes and crumbles at low temp.
In a rucksack I also have scotch tape which resists at low temp.
For the VHF activation I rather use a stilo RH-771 in orizontal mode…altitude really gives an hand!

73 de IW2OBX Roberto

1 Like

This is a really interesting (to me) thread and contains a lot of wisdom. My only contribution is to add that it is not necessary to be at great elevation to suffer the majority of the problems (and their solutions) expressed here - other than Oxygen shortage of course.

I did an activation recently at a height of only 670m but it had been a real challenge to get there - steep climb and rough ground (and unfit!!). When I sat down on the summit for lunch I realised I couldn’t even remember how to erect my antenna (not where, but how!). Cue to get down fast - I was knackered.

Thanks for all the advice, it is very relevant to all SOTA activations

Hi Rex

At high altitude - I imagine i’m preaching to the choir but take ample water and clothing to match the peak conditions. Remember the real destination is home and not the peak. Be safe as its better to fail and try again.

On summits with no trees - jam mast between rocks and pile stones around mast. Guy if necessary (I frequently don’t if I think mast will stay put for 20+ minutes) with lightweight MSR (or equivalent) tent guying line/pegs and connect to mast 10-12 ft from base. Use hiking poles to keep other end of end fed 3 ft above ground. Works for me.

Lightweight SSB - if you aren’t super attached to the 817 then consider the Elecraft KX2. With an internal battery and tuner I suspect its less bulky than the 817 and its 10 watts versus 817’s 5 watts. The end fed is pretty much the lightest antenna you can get. I use a carbon fibre fishing pole which probably is lighter than your squid pole but they are fragile and typically break at the skinny end.

I haven’t had an issue with SSB only activations doing almost 100 over last 18 months with KX3/KX2 operating at 10 watts. I think CW is a lifestyle choice, do it if you feel compelled but SSB works just fine and I have had many contacts from West Coast out over five to eight thousand miles including some in last two months.

Have fun and feel free to contact me off line.

W6 Association Manager



This topic is very relevant here in Colorado, where we have thousands of high summits, and more 4000M+ SOTA summits than you would imagine. Activators in relatively good condition can climb many of our peaks, especially in good weather, so we learn to deal with altitude in various ways. I agree with most of the points others have stated here. I offer these ideas:

  1. Avoid setting up in the wind if at all possible. Wind is your enemy in several ways. On many summits there is shelter from wind - but you may have to climb down below the top, while staying within the SOTA activation zone. I have activated many summits where I set up my gear 10M to 15M below the summit because of high wind. The wind can be so strong on top that I cannot stand safely - but often I find a “dead spot” only 10M below the summit, in the lee, or downwind side, of the mountain. The only effect I see on HF, when operating below the summit, is that contacts with stations behind the summit are weaker. Even so, with good solar conditions, I have made contacts with EU DX stations when operating 15M or more below a summit blocking the direction to EU. On HF signal blockage is not as much as with VHF/UHF.

  2. You will make more contacts and have a better activation out of the wind, than you will trying to deal with the chaos and hypothermia. It’s also nice to be in the sun, and sometimes it’s a tough call where to be.

  3. Practice routines. Develop gear and techniques that work reliably. Stick with what works, and improve what you do. There’s no substitute for experience. Learn from problems and think of better ways to accomplish what you want to do.

  4. Reduce the weight you carry. The higher you go, your capacity to carry radio gear decreases due to the altitude, less oxygen (less metabolism), longer hikes, increased fatigue, colder temperatures, and the necessity to carry more insulation and other equipment required for the climb.

  5. It’s practical to do totally fun HF activations with only a few pounds of radio-related gear - including the antenna, pole, radio gear, everything. It is possible to go below 2 pounds total and be at the top of the game!

  6. You do not need a 7M pole - try 5M. I use 6M or less.

  7. I often guy my pole at high altitude, where there are no trees. I use 2 or 3 light dacron cords tied above a large rubber band about 2M up the pole. I tie the lines to rocks - rocks can be moved to make adjustments. Run the wire along the wind if winds are high.

  8. You do not need a heavy radio or battery. Lighter gear is available now.

  9. Solar power is cool, but it offers no benefit for high altitude. Lithium technology can deliver all the power you need. 6 to 7 ounces of Li Ion battery will run an MTR or similar for many hours of activating. Some leading activators use batteries of only 1 or 2 ounces.

  10. Use an end-fed antenna set up as an inverted-L on a pole. 33 feet of #24 teflon wire will work several HF bands, using a tuner, counterpoise, etc. There is much to learn about what works best, and what is poor. I often use 52 feet with links and short counterpoise, even above 4000M - and I like 40, 30, 20, 17M!

  11. Don’t carry more than a few feet of coax cable. It adds nothing but weight, and it causes loss.

  12. Dipoles are harder to deal with in the wind than a simple inverted L. Dipoles require feedline. Dipoles are more tricky to set up in the rocks. Dipoles don’t work on multiple bands as easily as end-feds. Use dipoles at lower altitude.

  13. You will get more SOTA points for carrying less gear - not more.

  14. Start simple - operate on one band, carry minimal gear, save time, and have fun. Expand with experience.

  15. Don’t be idealistic. SOTA isn’t a contest. Really, it’s about compromise - how to do a good, fun activation without trying to do too much. Don’t try to impress anyone, even yourself, especially early in the journey.

  16. Don’t exceed your own limits. Work within the envelope. You can always push your limits a little as you do more activations and experience gives you advantages. Avoid bad weather and other risk factors.

  17. Plan carefully before your climb. Planning increases your efficiency and may reduce some risks. Learn about where you’re planning to climb, and think about what may affect your activation once you’re on top.

  18. The mountains don’t care. High altitude has no mercy, and it greatly increases your risks. Many have died or been hurt because of adverse situations, bad judgement, mistakes, or accidents.

73 and GL,



Thanks! Good stuff. If I could afford a KX2, I’d definitely get one. But for now it’s the FT-817.

I’ll be in touch! I’m going to be doing Shasta again this year. This time, hopefully with a successful SOTA activation.

Thanks George. Good info!

I’ve been meaning to try out the inverted L. However, I’m trying to envision how I’d set it up. I get that the feedpoint would be near the bottom of the pole, but where does the wire go once it’s reached the top of the pole, if there are no trees, etc. around?

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:

On snow
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!

Lightweight SSB
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!


Finally figured out how to upload an image

This is an inverted L deployment that netted me about 30 contacts across the US a couple of months back. The feed point is near the base of the carbon fiber mast. The other end of the end fed is held 3 ft off the ground by my hiking poles which I had jammed into some sage to provide enough leverage to keep antenna off of ground.

This was a quick deployment, no guy lines, no trees, jammed into rocks and it worked just fine on 20m and 40m.

Hope this helps!!



Quite helpful! Thanks. Sometimes ya just gotta get a visual on things!

Thank you. Yes, I run into mild AMS almost every time. I’m trying to get in better shape, which does seem to postpone the onset of symptoms. If I could afford the time, I’d just spend time at altitude before ascent.

Good tips on the setup. The common theme in the string seems to be “be creative!” I’m definitely going to try and practice a couple of different simple setups before attempting Mt. Shasta again this year.

Any hams out there want to join me on my next Mount Shasta trip in late May/early June? Hehe.


Shasta scares me, but coordinating a Lassen S2S is possibility.

Now that sounds like fun! I’ll let you know what my plans look like once the date gets closer.

Great post Carey (KX0R)! The only thing to add is proper clothing, climbing equipment, etc. That is a subject in itself!

73, Brad

Hi All,

This post probably should be called Very High Altitude SOTA. Anything above 2,400 m and up to 5,500 m is Very High Altitude. High Altitude is generally defined as 1,500 to 2,400 m.

You need very to be fit and preferably acclimatized to climb above 3,000 m otherwise you may suffer from some significant oxygen deprivation effects. Breathlessness and fatigue are normal and acceptable effects but lightheadedness and nausea can make the descent dangerous. Your CW will certainly suffer!.

I think the VHA activators here would be very well aware of this but someone from the coast might not enjoy their activation if they haven’t been above 4,000 m before.

Pilots flying unpressurised aircraft above about 3,750 m are required to have oxygen available.

No VK peaks exceed 2,400 m - those that once were have been ground down over a very long time.


Good point! I wonder if I can rename it…