There are over 50 summits in Colorado with an elevation of 14,000 feet or higher. These are commonly called fourteeners (or 14ers) and get a lot of attention from outdoor enthusiasts. Some folks have climbed all of them, which quickly leads to the question of What Is A Fourteener? This question is really about what is a distinct fourteener versus when is a summit just a subpeak of another fourteener. The Colorado Mountain Club list of 14ers shows 54 peaks, while other lists include a few more summits. Doing a search on Lists Of John reveals there are 74 locations in the state that exceed 14,000 feet. What constitutes “the correct list of 14ers” is often debated in the climbing community but I won’t try to sort that out here. I’ll use the Colorado Mountain Club list of 54 summits for this posting.

Summits On The Air (SOTA)

Obviously, if these are the 54 highest summits in Colorado, they are all going to be SOTA summits, right? Not so fast, Sir Edmund. The SOTA program generally requires summits to have 150 meters (492 feet) of prominence, a measure of the elevation of a summit relative to the surrounding terrain. From peaklist.org:

Prominence is the elevation of a summit relative to the highest point to which one must descend before reascending to a higher summit. 

There are exceptions in the SOTA program that allow for summits of 100-meter prominence, but this does not apply to Colorado. Paul/VK5PAS has a webpage that explains prominence as applied to SOTA.

In recent history, the folks that set up the SOTA Associations have done a great job of sorting through what is a valid summit. In the US, there are excellent databases of geographic information that make this possible. Which is to say that in a particular SOTA Association, a consistent method is applied for determining “what is a summit”? This is all documented for Colorado in the W0C SOTA ARM here: https://sotastore.blob.core.windows.net/arms/ARM-W0C-3_3.pdf

Lincoln, Bross, Democrat, and Cameron

Now, back to the Colorado 14ers. There is a popular trek that allows a climber to summit four 14ers in one day, without extreme effort. The trail starts at Kite Lake, heads up to Mount Democrat (14155 ft), then over to Mount Cameron (14222 feet), and on to Mount Lincoln (14293 feet). The return trip passes over Mount Bross (14178 feet) and back down to Kite Lake. (There have been access issues in recent years concerning private property on this loop, so be sure to check that out and respect any closures).

If we check out the official list of SOTA summits, we will find Mount Democrat (W0C/SR-059) and Mount Lincoln (W0C/FR-001) listed but not Mount Cameron and Mount Bross. Per Lists of John, Cameron and Bross have prominences of 152 and 315 feet. The col between Lincoln and Cameron, does not drop down enough to provide Cameron with sufficient prominence. Same with the col between Cameron and Bross. Mount Lincoln has the highest elevation of those three summits and wins the honor of being listed as a SOTA summit. Note that Democrat, with the lowest elevation of the four summits, does qualify for the SOTA list due to its 770 feet of prominence. (There is a big enough dip between Democrat and Cameron.)

Now back to the list of 54 Colorado Fourteeners: Mount Cameron is not on the list but it often shows up on other 14er lists. Mount Bross is shown on the list of 54 but is not a SOTA summit. There are seven other Colorado 14ers that don’t qualify for SOTA: Crestone Needle, El Diente Peak, Tabeguache Peak, Sunlight Peak, Ellingwood Point, Little Bear Peak, and North Maroon Peak.

You don’t need to become an expert on calculating prominence to do SOTA activations. Really, the key thing is to check the SOTA list and make sure your intended summit is on the list before you hit the trail.

73 Bob K0NR

The post Why is a 14,000 Foot Summit Not Valid for SOTA? appeared first on The KØNR Radio Site.

Rito Alto Peak is an easy 13er about 15 miles west of Westcliffe, CO in the Sangre De Cristo mountain range. This summit caught my attention because it was near Hermit Pass, one of the highest passes in Colorado at 13047 feet. We’ve been taking the Jeep up the highest roads in Colorado, and Hermit Pass was on The List. Looking around on the map, I noticed that Rito Alto Peak was an unactivated 10-point SOTA summit right next to the pass. Not only that, the summit is in the San Juan National Forest (K-4404), enabling a POTA activation as well. So how could we not do a trip up there?

Rito Alto Peak (W0C/SC-004) and Hermit Pass are about 15 miles straight west of Westcliffe, CO. To get there, take CR 160 (Hermit Road) west and then turn south onto FS 160. The turn-off is easy to spot and begins the 4WD portion of the trip. The 4WD road is not particularly difficult from a technical point of view, but the road is very rocky for most of the 9 miles. Every once in a while, the road has a smoother section, only to be followed by lots of rocks. I call these roads “moderate but annoying.” Any real 4WD vehicle should be able to handle this. We drove our stock Jeep Wrangler and it did fine. This is not a road for Suburu-class SUVs.

At the end of the 9 miles of bouncing up the road, we parked at Hermit Pass and started the climb there. (It took us about 2 hours to drive this road.) Of course, you can always hike some or all of the road. Useful climbing info can be found here on 14ers.com. Hermit Peak, to the south of the pass, is NOT a SOTA summit. However, further south is Eureka Mountain (W0C/SC-007), which could also be hiked from Hermit Pass.

The figure above shows the track of our climbing route. There is no trail and there is plenty of talus to step over and around. The route is not critical but we tended to stay on top of the ridge line, sometimes deviating to find a better path. The distance was 0.7 miles one way with an elevation gain of 700 feet. So not too difficult, except for climbing over rocks. Trekking poles are highly recommended.

On the summit, we set up our normal 2m FM station: the Yaesu FT-90 transceiver with 3-element 2m Yagi antenna, and started calling on 146.52 MHz. Joyce made the first contact so she has the honor of doing the first SOTA activation from this summit. You Go Girl!

I was a bit worried about getting enough contacts to qualify for SOTA points but that turned out to not be a problem. We heard strong signals from the Buena Vista area (W0BV, KD0MRC) and Florrisant (K0MGL). We also made some Summit-to-Summit QSOs (S2S): WV0X (St Charles Peak, W0C/SC-031), W0ADV (Snowmass Mountain, W0C/WE-003), and W0CP (McQuaid Butte, W0C/SP-109). We also worked K0EEP, K9RZK, W9RIK, and W9NDR. Our Best DX for the day was 104 miles, with W0ADV on Snowmass. Thanks for all of the 2m FM QSOs!

As shown in the photos, the weather was excellent. We took our time on the mountain and never saw signs of thunderstorms. The climb down was easy and we returned to the Jeep. Then it was 9 more miles bouncing down the road and on to Westcliffe for a late lunch. What a great day for SOTA + POTA + Jeep trip.

73 Bob K0NR

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While planning for the 2022 Colorado 14er Event, I decided to focus on making some long-distance contacts on 1.2 GHz (23 cm). Last year, Dave/W0ADV and I worked summit-to-summit (S2S) at a distance of  244 km (152.6 miles), which is my best result so far. See my previous post here…

Using 1.2 GHz in the Colorado 14er Event

For this year’s event, I wanted to beat that distance so I checked in with the usual SOTA activators that use the 23 cm band, wondering if any of them would be on summits that would support such an effort. I was thinking in terms of another S2S contact using portable FM handheld radios. I identified a few summits in the San Juan mountains that might work, from Pikes Peak or Mount Evans. Also, northern New Mexico has some potential summits, but I did not find anyone interested in activating them.

Knowing that Lauren/N0LD has done quite a bit of VHF/UHF operating from Pikes, I figured he would have some insight concerning summits that are workable from Pikes. We connected via telephone and discussed some options. In that conversation, he suggested I reach out to two hams that have serious 23 cm stations in Kansas: N0LL and N0OY. This shifted my thinking away from S2S contacts to working a UHF station out on the plains. (Kansas has a noticeable lack of SOTA summits.) Pikes Peak (W0C/FR-004) is well-suited to this approach, being easy to access with a road to the top and an excellent radio horizon to the east. I sent an email to Larry/N0LL and Pete/N0OY to see if they were available. Larry replied that his 23 cm gear was currently off the air but Pete said that he was available to give it a try.

The distance from Pikes Peak (W0C/FR-004) to N0OY is almost 400 miles, so the FM handheld radio approach was probably not going to work. My ICOM IC-9700 was the way to go, with 10 watts of RF power to a Yagi antenna. Pete used an ICOM IC-705 to drive a transverter that supplies 50 watts of RF to an 8-foot dish antenna at 45 feet. I chuckled when I heard this because the IC-705 is a popular SOTA rig…just not usually found on 23 cm.

Joyce/K0JJW and I made it to the summit a bit early and immediately set up for the 23 cm attempt. Normally, we operate on the west side of the summit, away from the visitors center and most of the tourists. For 23 cm, I wanted the best shot possible to the east, so we walked over to the boardwalk on the north side of the summit. It sticks out enough to give an excellent view due east.

Once I was set up, I sent a text message to Pete asking him to start transmitting my direction on 1296.1 MHz. We had agreed to start with CW, our most efficient mode, and perhaps later try SSB. He started with a series of CW dashes and I could easily pick up his signal. Joyce pointed the antenna for me, finding the best direction to peak the signal. Pete’s signal was not terribly strong, but solid copy, only a few dB above my noise floor. Because he was running more power than me (about 7 dB), I was concerned that he would not be able to hear me. I called him using CW and initially, he did not respond. We kept trying and my signal came up a bit at his end and we were able to complete the contact. Conditions were marginal enough that we did not try SSB. (Sorry, Joyce missed out on this one…she doesn’t work CW.)

SOTA Requirements

Although we drove to the summit of Pikes Peak, we made sure we were SOTA compliant. Our normal approach on a drive-up summit is to load up our backpacks with a portable station and hike some distance away from our vehicle. My IC-9700 is not exactly a compact transceiver but it is portable enough to transport some distance and it can be powered using a small Bioenno battery. I’ve carried this size radio (often an FT-991) on other SOTA activations, hiking a mile or two with it. It certainly adds weight to my pack, but it is manageable. The antenna was a Comet CYA-1216E, about 5 feet long, with 16 elements and a specified gain of 16.6 dBi.

So this is my new personal best for 23 cm SOTA:628 km, 392 miles. My thanks go to Pete/N0OY for getting on the air and giving this a try. His station was doing more than half the work with this radio contact. I’ve done SOTA QSOs like this with other weak-signal VHF/UHF operators. They may not be active SOTA chasers but they like the challenge of completing a difficult contact. I really appreciate them getting on the air with me. It’s all part of having fun messing around with radios.

This raises the question of what’s next?
Maybe I can get N0OY to move his station another 50 km to the east for another attempt. Probably not.

Stay tuned.

73 Bob K0NR

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This year, the Colorado 14er Event had the normal two-day (Saturday and Sunday) schedule plus two bonus days (Friday and Monday) for four activation days. Of course, Joyce/K0JJW and I decided to activate all four days using VHF/UHF frequencies. Frankly, we have not been doing that much hiking this year, so we were careful to lay out a plan that would work for us over four days.

Kaufman Ridge (W0C/SP-081)

On Friday, we hiked up Kaufman Ridge, which is a relatively easy summit near our cabin. I had an online meeting in the morning that caused us to get a late start this day, but we did chase some activators in the morning. On the summit, we worked a number of stations on VHF/UHF using the IC-705 transceiver. It was clear that most of the activators left their summit before noon, as is the usual practice for the 14ers and high peaks.

Normally, we focus our SOTA fun on VHF/UHF but this time I brought along an end-fed halfwave antenna for 20m and made a few 20m SSB contacts, including one with Elliot/K6EL on Mount Davidson (W6/NC-423). That’s right, a rare HF SOTA activation by K0NR. Joyce and I also turned in a log for Parks On The Air (POTA), which was San Isabel National Forest (K-4407).

Pikes Peak (W0C/FR-004)

On Saturday, I wanted to focus on making some 1.2 GHz (23 cm) contacts so we chose Pikes Peak as a good platform for that. Pikes is always fun because of its easy access (yes, we drove up) and its high location towering over eastern Colorado. We had Jon/KM4PEH and his wife join us on the summit, taking turns using the VHF/UHF bands. I made 42 QSOs on the various bands but my 23 cm contact with N0OY was the most exciting. I worked him in Salina KS on 1296.1 MHz using CW for a distance of 627km (392 mi). This is my new personal best for SOTA on that band.

Saturday was a good day for Summit-to-Summit (S2S) radio contacts, as I picked up 13 of them, all on VHF/UHF in Colorado. Joyce and I both worked Dave/W0ADV on Capitol Peak (W0C/SR-060) using 1.2 GHz FM. Capitol is a challenging climb, as shown in Dave’s video here.

Pikes Peak is in the Pike National Forest (K-4404), so we submitted our logs for POTA.

Mount Antero (W0C/SR-003)

On Sunday, we got up early and drove the Jeep up Mt Antero Road, parking at about 13,600 feet in elevation. This cuts a large chunk of the distance and elevation off the ascent to 14,268 feet. Besides, who wants to hike on a 4WD road anyway? It is still a decent climb over the rocky trail to get to the top.

This was my fourth SOTA activation of Antero, including its first activation back in 2011. (Actually, I’ve activated this many more times during the Colorado 14er Event, which predates SOTA in Colorado.) The activity was down a bit from Saturday and we were much further away from the large population centers, which is a factor on VHF/UHF. Still, we both made 17 QSOs, including five S2S contacts. We submitted our logs to POTA for San Isabel National Forest (K-4407).

Wander Ridge (W0C/SP-042)

On Monday, we activated one of our favorite summits near Cottonwood Pass, SP-042. Usually, I would refer to this as an Unnamed Summit (12,792), which is the name the SOTA database shows. Dave/W0ADV pointed out this summit does have a name: Wander Ridge, so I’ve adopted it for this special peak. The USGS approved that name in 2017 but it has not yet made it into the SOTA database.

From an outdoor hiking perspective, this was the best summit of the weekend. The hike starts at Cottonwood Pass and follows the Continental Divide Trail south toward the summit. Then, a short off-trail hike takes you to the summit. The weather and views were excellent!

The activity was a bit light but we both made 10 contacts, enough to qualify for a POTA activation (in addition to SOTA). This summit is right on the border of San Isabel NF and Gunnison NF, and we chose to activate it from the San Isabel side (K-4407). We only had one S2S contact, with Steve/K5SJC on Pikes Peak.

All in all, it was a fantastic weekend with four excellent summit activations. It was wonderful to work our old and new SOTA friends on the VHF/UHF bands. My special thanks go to Pete/N0OY for firing up his mega 23cm station to work me on Pikes Peak.

73 Bob K0NR

The post Four Days of SOTA Fun appeared first on The KØNR Radio Site.

August 5 to 8, 2022
Friday to Monday
www.ham14er.org

Amateur Radio operators from around Colorado will be climbing many of Colorado’s 14,000-foot mountains and Summits On The Air (SOTA) peaks to set up amateur radio stations in an effort to communicate with other radio amateurs across the state and around the world. Join in on the fun during the annual event and see how many of the mountaintop stations you can contact. Be aware that many mountaintop activators will hit the trail early with the goal of being off the summits by noon due to lightning safety concerns.

This event is normally held the first full weekend in August. Following up on the success of the 10-day W0C SOTA event in 2021, in 2022 we will add two bonus days to the Colorado 14er Event. The main two days remain Saturday and Sunday (Aug 6 & 7), while the bonus days are Friday Aug 5 and Monday Aug 8th, for those SOTA enthusiasts that need more than two days of SOTA fun!

The 14er event includes Summits On the Air (SOTA) peaks, which includes over 1800 summits! If you aren’t up to climbing a 14er, there are many other summits to choose from (with a wide range of difficulty). See the W0C SOTA web page at w0c-sota.org.

Important: The recommended 2m FM frequencies have been changed to 146.58, 146.55, and 146.49 MHz, to align with the use of the North America Adventure Frequency for SOTA (146.58). The National Simplex Calling Frequency (146.52) may be used as appropriate. See the operating frequencies page.

See the very cool Colorado 14er Event gear available at https://www.cafepress.com/mtngoatwear

Radio operators who plan to activate a summit should post their intent on the ham14er group via the ham14er groups.io website. Also, be sure to check out the event information at http://www.ham14er.org

For a complete list of suggested HF, VHF, and UHF frequencies see this web page.

And there is more!

On the same weekend, SOTA enthusiasts in Montana, Idaho, Washington, and Oregon will activate summits for the Pacific Northwest Not-Quite-Fourteener (PNW-NQF) event. Also on the same weekend, the Southern California SOTA group will hold their SOCAL SOTAFEST. So there will be plenty of SOTA stations to work that weekend.

Warning: Climbing mountains is inherently a dangerous activity.
Do not attempt this without proper training, equipment and preparation.

Sponsored by The Colorado 14er Event Task Force

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When doing VHF activations for Summits On The Air (SOTA), the radio range is dependent on the height of the summit and the surrounding terrain. The Radio Mobile website from Roger/VE2DBE is a great tool that can be used to estimate the radio range from a particular site. Repeater system owners often use tools like this to predict the coverage of their repeaters. I don’t normally do this type of analysis for SOTA…I just look at a topo map and get a rough idea of how far my signal will go. Then, I decided to spend a little time analyzing a few summits in Colorado to see what I could learn.

Pikes Peak (W0C/FR-004)

Pikes is a 14,115-foot summit that towers over the eastern plains of Colorado, making it an ideal radio site. The Radio Mobile plot shown below shows the solid radio coverage in blue and the fringe area in yellow. I won’t go into how to use Radio Mobile on this post. As you’d expect, you enter the location of the radio site (summit) along with various parameters such as frequency, minimum detectable signal level, transmit power, and antenna gain. I entered some nominal parameters consistent with typical SOTA stations on 146 MHz (2 meters).

Pikes covers about half of the state of Colorado, reaching out to the Kansas state line. To the west, the coverage does not go as far because the radio signals are blocked by other mountain ranges. In particular, the signal tends to drop off at the Sawatch Range, west of Buena Vista. I’ve activated Pikes many times and this plot lines up well with my general experience. The blue area can be worked quite reliably with a decent station on both ends. By “decent” I mean a 20-watt transmitter on the summit with a small Yagi antenna and a 40-watt radio with an omnidirectional antenna at the chaser station. Working stations near the Kansas state line is usually easy on 2m FM. The highest spot in Kansas (Mount Sunflower, not a SOTA summit) can usually be worked without much trouble. However, longer distance contacts are possible, especially using SSB or CW. I’ve written before about the Myth of VHF Line-Of-Sight.

When using VHF for SOTA activations, It is important to consider the potential stations that will be within range and on the air for you to work. Besides being a high summit, Pikes overlooks the major cities in Colorado, from Fort Collins to Pueblo, so finding someone to work on 146.52 MHz is usually easy. It is common to have a pile up of stations calling you.

Colorado has over fifty 14,000-foot mountains and all those are workable from Pikes Peak on 2m FM.

Mt Herman (W0C/FR-063)

Mt Herman is another popular SOTA summit, with an elevation of 9063 feet, not nearly as high as Pikes Peak. This summit also looks out over the eastern plains of Colorado, as shown in the coverage plot below. Although the range is not as good as Pikes, it still covers the major cities, so again it is easy to do a 2m FM activation from Mt Herman. It is more difficult to work stations to the west. I can usually work stations in Woodland Park and Divide from Mt Herman, but reaching Buena Vista is a challenge.

Threemile Mountain (W0C/SP-107)

VHF activations can be much more challenging when the summit is further away from populated areas. Let’s consider Threemile Mountain, which is 10,020 feet in elevation, located about 20 miles south of Hartsel, CO. This summit tends to get blocked to the east by the Front Range and to the west by the Sawatch Range. Even though the summit is higher than Mt Herman, its radio range is not as good.

In particular, it does not cover Denver, Colorado Springs, and Pueblo very well, so the number of available stations to work drops dramatically. There are a number of stations that monitor 146.52 MHz up in the mountains, so if you are patient you can usually make some VHF contacts. This can be a source of frustration for VHF activators, or you can take it on as a challenge.  I have activated Threemile five times and I don’t think I’ve ever worked a Denver station on 2m FM. I have worked some Denver stations from there using 2m SSB, during a VHF contest. Oh, I did manage to work Larry/N0LL in Smith Center, KS on 2m SSB for a distance of 372 miles. See Radio Fun on Threemile Mountain (W0C/SP-107). So you never know what you’re going to get on VHF/UHF.

Conclusions

So what conclusions can we draw from this analysis?

1. Radio Mobile does a good job of predicting typical 2m FM coverage. My experience on these summits aligns well with the Radio Mobile predictions.
2. But much longer distance contacts are still possible. VHF is not limited to line of sight. Radio Mobile is intended to predict reliable radio coverage, not the exceptional radio contact.
3. Be aware of the population density of the coverage area because that is a huge factor for making radio contacts. New VHF activators should start on summits that overlook the major Colorado cities.
4. Improve your VHF activator station. Every additional dB of signal improves your ability to make those weak-signal contacts on the edge of the coverage area.

As always, get off the couch, gather your radio gear, and head for a summit.

73 Bob K0NR

The post VHF Range From SOTA Summits appeared first on The KØNR Radio Site.

Adam/K6ARK recently posted this video of his 2m SOTA activation in California. Adam does a really nice job with his videos and this one is no exception. During this activation, he worked KE9AJ in Arizona at 256 miles. This was an FM QSO, with KE9AJ running 6 watts and K6ARK running over 120 watts.

In the video, he shows the 8-element 2m Yagi antenna, which has a clever folding boom design (homebrew, I assume). You’ll notice that he is carrying quite a bit of gear in his pack, including a 160w amplifier, a Yaesu FT-857, several batteries, the Yagi antenna, and antenna masts. Adam has posted other videos of VHF SOTA activity, so check out his YouTube channel for them.

Note that at 256 miles, this is definitely propagation beyond line of sight. We’ve talked about this before: The Myth of VHF Line-Of-Sight.

This has me thinking about some of my best VHF SOTA activations, which I will list here.

Sneffels to Pikes

In 2012, for the Colorado 14er Event, Joyce/K0JJW and I climbed Mt Sneffels (W0C/UR-001) at 14,150 feet in elevation. I worked Stu/W0STU on Pikes Peak (W0C/FR-004). We both were running 5 watts on 2m FM, with 3-element Arrow II antennas. I had an FT-817, while Stu used an HT. We made the QSO without too much difficulty, at a distance of 160 miles. Stu put together this video that shows the action on both summits.

Capulin Mountain

Capulin Mountain (W5N/SG-009) is out in the middle of nowhere New Mexico, a long distance from populated areas. My goal was to activate it (and get the points) on VHF, but I knew it would be a challenge. I put the word out to the weak-signal VHF community and used my FT-817 (5 watts) and 3-element Yagi to make contacts. My best DX was with Arne/N7KA at 184 miles. I could hear him fine on SSB but he could not copy me, so we switched to CW to complete the QSO. Arne used a 2M12 Yagi antenna with 700 watts of power vs my 5 watts.

This turned out to be a good lesson in what happens when the two stations are imbalanced with respect to RF power. My 5 watts vs his 700 watts is a difference of 21 dB. No wonder I could hear him just fine but he was struggling to copy me. Flipping over to CW narrows the receiver bandwidth, improving the signal-to-noise ratio, and was enough improvement to make the QSO.

Capulin Mountain (W5N/SG-009) VHF SOTA

Mount Scott

Mount Scott (W5O/WI-002) is a drive-up summit (elevation 2464 feet) in the Witchita Mountains of Oklahoma. It sticks up high enough to have a good radio horizon in all directions. We stopped there to do an activation in March 2018, using the Yaesu FT-90 (set for 30 to 50 watts) and the 3-element Yagi antenna.

We easily worked a bunch of stations on 146.52 MHz FM, including K5RTN in Brownfield, TX. Later, I checked the distance to Brownfield and found that it was 245 miles, which is still my best SOTA DX on 2m FM. There was probably some favorable propagation that morning, perhaps some ducting, for this to occur. K5RTN was operating from home and I am not sure about his power and antenna.

Threemile Mountain

During the 2021 January VHF Contest, we decided to activate Threemile Mountain (W0C/SP-107), which is usually accessible, even in the winter months. Because it is in the Pike National Forest (K-4404), I did a combo operation of SOTA, POTA, and VHF contest. At 10,020 feet in elevation, it is not the highest summit in the region but it has a good radio horizon in all directions.

Also, the hike is relatively short, so I packed the Yaesu FT-991 and a 20 Ah battery, which gave me more power (50 watts) on 2m and 70 cm. Not only that, I actually fired it up below 50 MHz and made some HF contacts, using single-band end-fed halfwave antennas.

I was working a few stations in Denver on 2m SSB when I heard Larry/N0LL calling me from Smith Center, KS. Larry is a well-known Big Gun on VHF with excellent antennas. I’ve worked him in past contests on various bands and modes but I was surprised how strong he was coming in at Threemile Mountain. We probably had favorable conditions on 2 meters that day but nothing exotic, to make a 372 mile QSO. I’ve worked longer distances on 2 meters but this is my best DX for SOTA.

Radio Fun on Threemile Mountain (W0C/SP-107)

Power and Antenna

Most ham transceivers have decent receivers, so the choice of radio on the receive side is not that critical. (OK, you can add a preamp in front of the receiver to improve it.) The big difference for making QSOs (or not) on 2 meters is antenna and power level.

Improving your antenna is normally the first step in improving your VHF SOTA station, because it helps on both transmit and receive. Joyce/K0JJW and I almost always use the 3-element handheld Yagi from Arrow Antenna. Arrow does not specify the gain, but various sources have measured it at 6 dBd. We have made many QSOs over the years where the extra 6 dB made the difference. An omnidirectional antenna would have come up short. I’ve been looking for a higher gain antenna to use for SOTA but have not found one that I like. Adam’s 8-element antenna is tempting but longer antennas pretty much require a mast, which adds weight to the pack. One of the benefits of the 3-element Arrow is that it is handheld, so we don’t carry a mast. Of course, having two of us activating together really helps…one person can hold the antenna while the other operates and logs. A handheld antenna with a single operator can be a challenge.

Concerning power level, the Capulin QSO with N7KA illustrates what happens when two stations are imbalanced with respect to RF power. After this experience, I did purchase a small 2m amplifier that boosts the 5 watts from the FT-817 to 35 watts. It is compact and not too much of a DC power hog.  I think we also heard an imbalance with the QSO between K6ARK and KE9AJ. KE9AJ’s signal was a bit noisy at K6ARK while K6ARK’s signal was full quieting 59 at the other end. This is not a surprise with K6ARK at around 120 watts and K6ARK at 6 watts (13 dB difference).

For higher power on 2 meters, you generally need to bring a bigger radio or an amplifier. The popular HT is generally limited to about 5 watts. For 2m FM, we’ve been carrying the Yaesu FT-90, which is a pretty compact radio and can put out 50 watts of RF power (FM only). On the Threemile Mountain activation mentioned above, we took the FT-991, which is not very SOTA friendly, but it also does 50 watts on 2 meters…and all modes.

Battery capacity also comes into play as higher power requires more DC current. The FT-90 manual says it draws 9.5 amps at full 50 watts of power on 2 meters. (We usually run it at lower power but will punch it up to 50 watts when required.) The FT-991 manual says it draws 15 amps when transmitting at full power on 2m or 70cm. My 160 watt 2m (Mirage) amplifier can draw up to 30 amps on transmit. Wowzy, that’s some real current! The point is that as you increase power, you need to look at your battery situation more carefully.

It might sound like I am suggesting that we should maintain a power balance between the two stations. That’s not the case and is often not even practical. When one station is much stronger than the other, it can be used to advantage. The stronger station is easily heard and the weaker station can point the antenna in the right direction to peak up the signal. The weaker station consistently hears the stronger station, so now the challenge becomes to just get a few seconds of successful transmission in the opposite direction. You keep trying until the weaker station manages to get through. Compare this to having two lower power stations trying to make a contact. They may not even hear each other at all because the antennas are not pointed optimally. When they do hear each other, they are both struggling to hear the other station and complete the QSO. This lowers the probability of completing the contact.

So how much power should you run on 2 meters for SOTA? Of course, More Is Better, except for the extra weight in your backpack. The difficulty of the hike comes into play…on shorter hikes, weight does not matter so much. I am finding that 5 watts is on the skimpy side. On the other hand, going much above 50 watts requires larger batteries, so I am thinking the sweet spot is around 30 to 50 watts. If I do happen to work a base station running 1kW, my signal will be 13 dB lower with 50 watts (worst-case scenario). This is just my opinion, your mileage may vary.

Summary

So can we all agree then that VHF signals can go beyond line-of-sight? These examples are basic tropospheric paths and do not include the exotic propagation modes such as meteor scatter, sporadic-e, aurora, EME, etc. I’ve used most of those modes to work longer distances but not during a SOTA activation. Most hams know that SSB and CW are more effective than FM when signals are weak. In fact, FM weak-signal performance is lousy. Still, we see multiple examples of making some long-distance contacts with FM.

73 Bob K0NR

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