Posts Tagged ‘vhf/uhf’
I was happy to contribute an article to the recent ARRL Parks On The Air (POTA) book. This piece is based on my Pikes Peak mountain topping article that appeared in the June 2023 issue of QST. This book is a collection of articles about POTA from 14 different authors, each writing about a different aspect of the program. The articles are all easy to read and generally provide a first-hand account of how the author has experienced POTA operating. There is plenty of beginner information and operating tips sprinkled throughout the book. More experienced POTA enthusiasts will probably pick up a few new ideas as well.
The Table of Contents below lists the articles and authors, giving you a good idea of the material covered. The meat of the book is only 118 pages long and it is quite easy to read.
My piece covered the triple activation I did from the summit of Pikes Peak, combining POTA, SOTA, and the June VHF Contest into one mountaintop adventure. For POTA, the park was the Pike National Forest (K-4404). I’ve done this type of combo activation in the past, sometimes just SOTA + POTA or just SOTA + VHF Contest. This time I did all three.
73 Bob K0NR
The FCC will be voting on and will likely approve a Report and Order that eliminates the symbol rate restriction on HF data transmissions, replacing it with a bandwidth limit of 2.8 kHz. See FCC To Vote on Removing Symbol Rate Restrictions. The symbol rate limit of 300-baud is an obsolete way of limiting the signal bandwidth, created back when the data transmissions were predominately Frequency Shift Keying (FSK). It was a simple, practical way to regulate the bandwidth at that time but technology has moved on. The use of digital signal processing and efficient wireless encoding techniques require a better approach to bandwidth regulation.
A practical impact of this change is to allow higher speed protocols such as PACTOR-4 having a bandwidth of 2.4 kHz. I suspect we will see other protocols emerge that squeeze the best data rate out of the 2.8 kHz bandwidth.
Living in a Narrowband World
The FCC proposal implements a 2.8 kHz bandwidth limit on data emissions on the HF bands. Some folks have suggested a narrower bandwidth while others argue that wider bandwidth signals should be allowed. And some even think we should have no bandwidth limit at all.
The problem is that the amateur HF bands are not very wide. For example, the popular 20m band is 14.0 to 14.350 MHz, providing only 350 kHz of spectrum. Common practice on this and the other HF bands is to use modulation types that have bandwidths of 3 kHz or less. (Yeah, AM signals are twice that wide, at 6 KHz, a topic for another day.) Of course, CW and some of the data modes are much narrower than 3 kHz. But the general approach to regulating HF is to allow many narrowband signals on the band. Limiting HF data transmissions to 2.8 kHz bandwidth is consistent with existing practice while still allowing for innovation and experimentation.
VHF/UHF Bandwidth Limits
The FCC also plans to issue a Further Notice of Proposed Rulemaking (FNPR) that:
- Proposes to remove the baud rate limitation in the 2200 meter and 630 meter bands, which the Commission allocated for amateur radio use after it released the Notice of Proposed Rulemaking in 2016.
- Proposes to remove the baud rate limitation in the VHF and UHF bands.
- Seeks comment on the appropriate bandwidth limitation for the 2200 meter band, the 630 meter band, and the VHF/UHF bands.
I won’t comment on the 2200 meter and 630 meter bands. The FCC proposes to remove the symbol rate limit on the VHF and UHF bands and asks what bandwidth limit is appropriate. The current bandwidth limits are 20 kHz for the 6m and 2m bands, 100 kHz for the 1.25m and 70 cm bands, and the FCC seems fine leaving these the same. Authorized emission types are listed in FCC Part 97.305.
With 4 MHz of spectrum, the 2m band is much wider than any of the HF bands. It might be tempting to conclude that there is plenty of room for wideband signals on this band. Many hams think 2 meters is just used for FM simplex and repeaters but a closer look reveals that it supports many diverse modes: weak-signal SSB/CW, meteor scatter, EME, FM simplex, FM repeaters, digital voice modes (D-STAR, DMR, Fusion), satellites, and more. The 20-kHz limit seems appropriate, as it roughly matches the bandwidth of the most common (FM) voice signals on that band. It is not an appropriate band for trying out wider bandwidth signals.
The 6m band should probably keep the same 20-kHz limit. (I don’t think there is a compelling reason to change it.) The 1.25m band already allows 100-kHz bandwidth data signals, which some radio amateurs have used for higher-speed data links (still not what I would call wideband).
The 70 cm band is much bigger (420 MHz to 450 MHz) and could accommodate some wider bandwidth signals. Perhaps the existing 100-kHz limit should be increased? Keep in mind that fast-scan ATV is allowed on this band with a bandwidth of 6 MHz. Maybe we can make some room for a few larger bandwidth data channels, to encourage innovation and experimentation.
The bands above 70 cm have no bandwidth limit other than the signal must stay within the designated ham band. It has been this way for a long time, without causing any issues (that I know of).
The FCC’s proposal makes a lot of sense and it is long overdue. Frankly, it is a bit of an embarrassment that it has taken so long.
Better late than never.
73 Bob K0NR
Lobo Overlook is an excellent summit and tourist spot near Wolf Creek Pass, one of the most scenic passes in Colorado. I’ve been up there for VHF contests and other mountaintop operations and initially thought it might be a SOTA summit. No such luck, as it is superseded by a higher summit nearby (W0C/RG-169). Lobo Overlook is accessed via an easy 3-mile gravel road just off the pass. The road leads to two small loops at the top, one of which is the actual Lobo Overlook while the other goes to an obvious radio site. The trail to RG-169 is best accessed from the radio site, so we parked there. Wolf Creek Pass and Lobo Overlook sit right on the Continental Divide and the Continental Divide Trail (CDT) passes through here just a bit to the west.
This unnamed summit is listed as 11820 in the SOTA database. However, Lists of John (which was used to create the W0C SOTA database) shows this summit as 11831. My topo map seems to agree with 11831, so this might be an error. Of course, such a cool summit near the CDT deserves a name, so Joyce/K0JJW and I decided to call it Lobo Peak, for obvious reasons. (I looked for an existing nearby Lobo Peak and did not find one.)
Near the radio site, we started at the marked trailhead and headed west on Lobo Trail (878), actually going downhill to intersect the CDT about a half mile down the trail. At the trailhead, it was not obvious which summit we were headed to and it might not even be visible at that point. The summit did reveal itself as we headed down the CDT (see first photo above). We followed the CDT to a visible game trail that takes off steeply to the right (lat/lon 37.49765, -106.81515). There are several game trails that split off, heading up towards the saddle to the left of the summit and we stayed on the most established one. We set up our station within the activation zone just below the actual summit, avoiding the rock scrambling to get to the top.
The one-way distance on the trail is 1.2 miles with an up-and-down profile. Lobo Overlook is only slightly lower in elevation from “Lobo Peak”. The trail starts at about 11,770 feet, descending to a low point of 11,500 and back up to 11,800 at the summit. So that produces a net ascent of about 300 feet, maybe more, one way. Of course, you get to repeat this on the way back.
SOTA and POTA Activations
Once in the activation zone, we deployed the IC-705 on 2m FM, driving the 3-element Yagi antenna. We worked Travis/KB9LMJ on 146.52 MHz, who was mobile in Pagosa Springs. Further calling on 2m FM did not yield any contacts, but K0JJW and I did work each other on VHF/UHF. We had anticipated that this might be a tough place to activate on VHF, so we brought along the HF gear and set up an EndFed Halfwave antenna for 20m. Propagation was good and we soon worked 11 stations on 20m SSB.
This summit sits right on the dividing line between the Rio Grande National Forest and the San Juan National Forest, both valid for Parks On The Air (POTA). We opted to operate from the Rio Grande side (K-4405) because that was a new one for both of us.
Continental Divide Trail
I’ve hiked sections of the Continental Divide Trail before, including some pre-SOTA backpack trips with Denny/KB9DPF. It is a great trail because it runs along the backbone of the Rocky Mountains. It is often accessible via roads to high mountain passes. (Another example is Wander Ridge, just off Cottonwood Pass.) Once you hop onto the CDT, you are hiking an established trail that is literally on top of the world.
This is an excellent, easy-to-access summit in the Wolf Creek Pass area. So if you are in the area, this might be one to activate. The road to Lobo Overlook is closed during the winter.
73 Bob K0NR
Argentine Peak (W0C/SR-019) is a high 13er (13,738 ft) in the Sawatch Range of the Rocky Mountains. I had my eye on this summit for a Summits On The Air (SOTA) activation for quite some time now. This summit is a short distance from Argentine Pass, which is the fourth-highest road in Colorado at 13,207 feet. A non-radio goal I have is to drive the Jeep up the twenty highest roads in Colorado, so Argentine Pass is on that list. Not only that, Argentine Peak sits on the Continental Divide, separating the Arapaho National Forest and the White River National Forest, so it can also be activated for Parks On The Air (POTA).
So the plan emerged: Joyce/K0JJW and I would take the Jeep to Argentine Pass and then climb up to Argentine Peak for a SOTA and POTA activation. The road is usually blocked by snow for much of the summer, making it a late summer/early fall adventure. Somehow September slipped away and it is now October, but fortunately, the road is still open. Note that the more common way to hike Argentine Pass is from Silver Dollar Lake trailhead (see KX0R trip report).
The 4WD route starts with FS 248.1 as it leaves Guanella Pass Road, about 3 miles south of Georgetown, CO (see map above). The forest service road takes off at a point where the Guanella Pass Road takes a very sharp bend. You should have a good topo map to guide you on this route as there are quite a few roads in the area. In general, you follow FS 248.1 which has some subvariants such as 248.1B and 248.1K. The exact choice of roads is not critical but, eventually, you need to get on FS 724.1 which sports a few wide and steep switchbacks up to Argentine Pass. The one-way distance is 9 miles and it took us about 1.5 hours to make the drive.
This road and route is considered moderate 4WD and FS 248.1 provides a good taste of that right after you leave the paved road. Many other sections of the road are easy 4WD but there are some challenging spots along the way. This is a real 4WD road, so you’ll need a decent high-clearance 4WD vehicle in the class of a Wrangler, Bronco, 4Runner, etc. We drove a stock Jeep Wrangler and had no trouble. However, at one spot, the wheel placement was very critical, so Joyce spotted me as I drove through it. Not that difficult…unless you screw it up.
As shown below, the climbing route up Argentine Peak (blue line) follows the Continental Divide ridge line as it heads south from Argentine Pass. The road up Argentine Pass ends kind of high in the pass, so at first, we were walking downhill. A faint trail follows the top of the ridge but fades out in many places. Looking at the topo map, I underestimated how much up and down there would be on the ridge but it was not too difficult.
The hike is about 1 mile with 650 feet vertical (one-way). We had fantastic weather in October: sunny, with temperatures in the 40’s F and some light wind (10 to 15 mph). This is one of those top-of-the-world hiking experiences, right along the Continental Divide.
This mountain goat wandered by while we were on the summit.We used our standard 2m/70cm FM station: Yaesu FT-90 running 30 watts to a 3-element Yagi for 2 meters or a 7-element Yagi for 70 cm. We worked stations mostly on 146.52 MHz FM and a few on 446.0 MHz. With downtown Denver about 45 miles away, we easily worked stations in the greater Denver area. We were also successful working stations out to 60 or 70 miles, often with good signal reports in both directions. We both made 20 QSOs using VHF/UHF.
For POTA, we were right on the dividing line between White River NF and Arapaho NF but needed to choose one for our activation. We had previously activated Arapaho, so we chose to operate from White River NF on this trip (K-4410) which is a new park for us.
We had an absolute blast on this activation. I think it was the combination of a Jeep trip, hiking, SOTA, and POTA all wrapped into one adventure that made it so good. As a bonus, we had excellent weather and a visit by the mountain goat!
73 Bob K0NR
To save time, let me get this out of the way:
Yes, I do know that making contacts via FT8 is not as personal and may not be as much fun as running a pileup on SSB or CW. Still, it is Real Ham Radio and enjoyable in a different way.
I’ve used this station on multiple activations now but I have to admit that these have been mostly for POTA. It seems that whenever I get on top of a SOTA summit, I tend to focus on making VHF contacts which consumes the available time and the HF gear remains stashed way in my pack. This is more about my operating habits than anything else. Looking at spots though, there is a lot of FT8 on POTA and not nearly as much on SOTA. The SOTA crowd tends to have a lot of traditional CW enthusiasts and maybe POTA has fewer of them. Also, SOTA operating is usually backpack portable so carrying a compute device for FT8 may be considered an unnecessary hassle. POTA stations are often in or near a vehicle, so station size/weight is less of a concern.
For POTA, I make sure my activation is posted at pota.app, indicating the park number I am activating. When calling CQ, I modify the standard FT8 text to be “CQ POTA” to indicate that I am doing an activation. When my signal is detected by the Reverse Beacon Network (RBN), a spot is created that shows me doing a POTA activation from that park. Pretty cool. If I have an internet connection, I monitor my spots using the Ham Alert app. This provides useful feedback about where my signal is showing up around the world.
But what are the main reasons that FT8 is useful for POTA?
FT8 is popular
In case you haven’t noticed, FT8 has emerged from being just a niche activity to now being very popular on most ham bands. At times this can be a problem with the standard FT8 frequency slice being overloaded with signals. There is a lot of FT8 activity on the bands, for general ham use and SOTA/POTA.
FT8 works well with low power
FT8 and the other WSJT-X modes are designed to work well with weak signals, so they are a great match for low-power operation. Of course, QRP power levels are very common for backpack portable activations, mostly due to the limitations of carrying a reasonable-size battery.
FT8 signals are spotted on RBN
As mentioned earlier, FT8 signals are picked up and spotted by RBN. For better or worse, people have come to rely on spotting for many types of ham radio operating. When on a SOTA or POTA activation, you really want to be spotted as such. For phone activations, I usually do that with a smartphone but that requires some extra effort and a mobile phone connection. FT8 and RBN take care of that for you.
FT8 logging is automated
The various FT8 software applications automatically log the QSO information, which means it is easy and less error-prone. After the activation, I just pull up the ADIF log file, check it for obvious errors, add in the SOTA/POTA info, and submit it to the appropriate websites.
FT8 is campsite friendly
This last one may be a bit subtle but I’ve found FT8 to be campsite friendly. By that, I mean I can get on the air at any time (early, late or at nap time) and not disturb anyone else. (On SSB, I would likely be enthusiastically yelling into the microphone trying to work a pileup.) Besides the audio noise factor, FT8 operation allows for multitasking. I can converse with my fellow campers while still keeping up with the FT8 flow. Alternatively, I can cook dinner, make a fire, or pack my backpack while the FT8 QSOs roll in. This may sound a little bit like cheating but, hey, whatever works.
So clearly, I’ve been having fun with FT8 for POTA. I consider it to be another tool in the toolkit. There are times when I will make good use of it but there will also be times to use other modes.
73 Bob K0NR
This past year, Joyce/\K0JJW and I did quite a few Summits On The Air (SOTA) and Parks On The Air (POTA) activations, often as part of an RV camping trip. During this time, we made some improvements to our portable gear. For SOTA, we primarily use the VHF/UHF bands but we have been sprinkling in a bit more HF activity. For POTA, we often don’t have a Height Above Average Terrain advantage, so we definitely use the HF bands.
Our main goal was to have a backpack portable station for SOTA and POTA that can cover HF through 70 cm, on the most popular bands/modes including CW, SSB, FM and FT8.
Using The IC-705
The Icom IC-705 is a great transceiver for covering most HF, VHF and UHF bands. With an external battery, the transceiver puts out 10 watts of RF power. (This is a bit less than the 50 watts from our Yaesu FT-90, which is our default choice for 2m and 70 cm SOTA.) We have accumulated a number of Lithium Iron Phosphate batteries from Bioenno. They are all set up with PowerPole connectors and are easily interchanged. See a previous post, My SOTA Battery Journey.
Arguably the biggest weakness of the IC-705 is the lack of an internal antenna tuner for the HF bands. Of course, you can operate without a tuner by making sure your antenna is always 50 ohms. I find that limiting, especially under portable conditions where the antenna configuration might be compromised. Also, some common end-fed antennas that cover multiple bands are not a good match for all bands. There are external automatic antenna tuners available for the IC-705, so initially those looked like a good solution. Then I remembered that I had a small MFJ-902 Travel Tuner that could do the job. The MFJ-902 is a classic T-network with two variable capacitors and one variable inductor. I gave it a try and was impressed with how easy it was to tune using the SWR meter of the IC-705. This thing is simple and it works.
The rear panel of the tuner has two SO-239 connectors, one for the transceiver and one for the antenna. I put a BNC adapter onto the transceiver port and used a short BNC cable to connect to the IC-705.
The Travel Tuner is compact and not very heavy, so it works out well for backpack portable use. It can handle up to 150 watts, which is overkill for the IC-705 but it may come in handy when used with a higher power transceiver. Still, I am on the lookout for an even more compact (probably lower power) manual antenna tuner.
We have collected a variety of HF antennas, focused mostly on 20 meters and higher. These are typically end-fed, including single-band half-wave designs as well as multiband random-length antennas. These are used in the classic SOTA configuration with one end of the wire supported by a lightweight fishing pole and the coax connection on the ground, fed by a 25-foot length of RG-8X coaxial cable.
With the popularity of FT8 on the HF bands as well as 6 meters, I figured we should include that mode in our portable kit. My first thought was to use a compact Windows computer running the standard WSJT-X software. Ultimately, I chose the SDR Control app for the Apple iPad (by Marcus/DL8MRE), which supports specific Icom radios. The iPad connects to the IC-705 via its WiFi connection, which simplifies the connection/cabling challenge. The SDR Control app does cost $49.99, so it is not your inexpensive iOS app but I have found it to be worth the price. Because this app is focused only on iOS and certain Icom radios, it is well-tuned to be a no-fuss solution. I am currently using the app only for FT8 but it has other features and modes for me to explore.
The Powerwerx PWRbox is shown in the photo above, which we often use for operating POTA. (This box is a bit heavy for hiking.) The PWRbox holds a 20 Ah battery as described here. Also shown in the photo is a handy little stand for the IC-705, the NEEWER Folding Z Flex Tilt Head. It does a great job of holding and stabilizing the radio at a variety of angles. (Hat tip to Kyle/KD0TRD.) It is also a little heavy for backpack portable, so it usually gets left behind on a hike.
For a protective case for the IC-705, we use the Maxpedition 12-Inch X 5-Inch Bottle Holder. I’ve seen other IC-705 users recommend it and OH8STN mentioned it on his blog. At first glance, the case seems a bit large but this provides enough room inside to stow a small Bioenno battery and other accessories. The side pouch is a good place for storing the microphone and power cord.
This post shares some new equipment configurations we are using for SOTA and POTA, mostly focused on the IC-705. I really like that radio for portable ops as it is the best solution for operating HF through UHF. The SDR Control software on an iPad has also turned out to be a win for us.
What are you using for your portable station?
Do you have any tips or other operating ideas?
73 Bob K0NR
Joyce/K0JJW and I enjoy visiting the National Parks in the US, an activity that naturally combines with Summits On The Air (SOTA) and Parks On The Air (POTA). While planning a visit to Isle Royale National Park in upper Michigan, we decided to activate at least one SOTA summit as well as activate the park for POTA. The park is one large island surrounded by many smaller ones, accessible by boat or airplane. The park is actually closer to Canada than the US mainland.
There is quite a bit of information about visiting the park on the Isle Royale National Park website, so I won’t repeat that here. We opted to take the Isle Royale Queen IV ferry from Copper Harbor, MI to and from the island and stay for three nights at Rock Harbor Lodge on the northeast end of the park.
The closest SOTA summit to Rock Harbor is Mount Ojibway (W8M/UP-059), which soon became the objective for our SOTA activation. This summit had been activated only once, by Scott/WA9STI in 2017. I contacted Scott, who was very helpful in sharing his experience on Ojibway. (There are three other SOTA summits in the park, with first activations by Mark/NK8Q.)
We had four friends join us on this trip, including the hike to Mount Ojibway. Two of them were licensed radio amateurs: Paul/KF9EY and Beth/KB9DOU with Paul joining us in doing the SOTA activation.
We normally do SOTA activations using VHF/UHF, so this raised the issue of whether that was possible given the remote nature of the island. I poked around on the interwebz and reached out to radio clubs on both the US and Canadian sides. Randy/VA3OJ in Thunder Bay and Bill/KD8JAM on the Keweenaw Peninsula were particularly helpful and they both confirmed they can work stations on Isle Royale from their locations using 2m FM. The distance is not that far, especially to the Canadian side, and it is a straight shot over water.
There were two things that I worried about on this activation: bugs and rain, neither of which were under our control. For bugs, we loaded up on a variety of insect repellents and head nets. However, once we arrived at the island, it was pretty clear the bugs were not bad at all, probably because we were late enough in the year (late August). For the rain, we made sure we had rain gear and synthetic clothes, with the attitude of expecting to get soaked and being able to survive it.
There was no internet on the island (the lodge says they have it but it was not working). Occasionally we would get 1 bar of Verizon LTE service at Rock Harbor but is was not reliable. This meant that we were very limited in sending any email updates out to people. I emailed our plans to interested parties and posted an Alert on SOTAwatch before we hopped on the ferry.
For equipment, we decided to take our Icom IC-705 and an external battery pack for 10 watts of RF on all bands of interest. Our priority was VHF but we also took along antennas for 40m through 10m. In addition, I configured an iPad for FT8 but we did not end up using that capability.
Mount Ojibway is about a 7-mile hike from the Rock Harbor Lodge, so we decided to have the water taxi drop us off at Daisy Farm Campground and hike in from there, which is about 2 miles one way. We also scheduled the water taxi to pick us up for the return trip. So this set us up for a 4-mile round trip hike with modest elevation gain.
On the morning of our activation, a thunderstorm rolled into Rock Harbor delivering a good dose of lightning to the area. I checked on the status of the water taxi and it was uncertain whether it would be running due to the storm. We sat tight and the weather cleared up enough such that we could go. Still, it was cloudy and the forecast included some rain in the afternoon. I told our group, “We are going to get wet today.”
Mount Ojibway at 1150 feet is part of the Greenstone Ridge that runs along the top of the island. It is also the location of an observation tower, now used as a radio site. The SOTA database shows the summit a bit to the northeast of the tower and the ridge is quite flat with a broad activation zone. My GPS app showed our hike as 1.9 miles one-way, with 540 feet vertical. The trail is well-established and in good condition. There were several narrow boardwalks (narrow planks) over marshy areas that were unnerving for some of our group.
At the summit, we appreciated some blue sky and nice weather that appeared while we set up the IC-705 and 3-element Yagi for 2 meters. We called CQ SOTA on 146.52 MHz and soon worked KD8JAM and VA3OJ. We kept calling and picked up two more 2m FM contacts: W9GY and VA3DVE. About this time, we set up the endfed antenna for the HF bands and (just barely) worked W0BV in Colorado on 20m SSB. (My phone was not able to spot us but I used my Garmin inReach to message W0BV and he came up on frequency.) I also worked W4GO, who had a decent 55 signal at the summit. But 20m was not working very well for us and I started to consider what changes I should make to the station. However, the dark clouds approaching from the northwest made that a moot point as we packed up our gear and headed down the trail. Sorry, we were not able to do more on HF.
On the way down the summit, things got a bit more exciting, and not in a good way. The storm clouds moved in and the light rain we experienced off and on during the day turned into a downpour. My warning of “we are going to get wet today” became all too true. This is the kind of rain that turned the nice, well-developed trail into a river of flowing water. With the rain came lightning, not close by but close enough. We were walking through a well-established forest so the lightning exposure was not too bad. The muddy trail definitely slowed us down as we did not want to add injury to our adventure.
We all were thoroughly drenched by the time we arrived at Daisy Farm Campground. At that point, the storm quit and we hung out on the dock waiting for the water taxi to pick us up. The water taxi apparently had its schedule adjusted and arrived over an hour later than expected. I guess we were on island time.
It was a successful but wet activation. Thank you so much to the radio amateurs who worked us, especially KD8JAM and VA3OJ. We couldn’t have done it without you.
73 Bob K0NR
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