On Twitter, someone recently commented that it would be nice to have more 2m SSB activity for Summits On The Air (SOTA). It is well known that FM is a more commonly used mode but that its performance suffers for weak signals. This got me wondering about which bands and modes are being used for SOTA above 50 MHz.

Above and Below 50 MHz

First off, I wondered what portion of SOTA radio contacts are on VHF/UHF. Looking at the SOTA database Facts and Figures page, I simply grouped the number of QSOs as “Above 50 MHz” and “Below 50 MHz.”

So we can see that about 1/5th of the SOTA QSOs are done using VHF and higher frequencies. Certainly, we’d expect that the HF bands would dominate the total but this VHF+ percentage is higher than I expected.

Breaking Down > 50MHz

That leads to the question of what bands are used above 50 MHz? The table below shows the >50 MHz data broken out by band. The % of Total column indicates the percent of all QSOs (Above and Below 50 MHz), while the % of >50 MHz column shows the percentage relative to only >50 MHz radio contacts. Simply put, the % of Total column will sum to 21%, matching the number in the first table. The % of >50 MHz column sums to 100%.

Well, it doesn’t take a degree in statistics to see that the 144 MHz band (2 meters) is the most popular VHF/UHF band for SOTA. Almost 90% of the QSOs are on this band. The next most used band is 433 MHz (70 cm) at a little over 9%. The 6m band (50 MHz) comes in at third with about 3.5%. The other bands are so small, they don’t really add much to the total.

The data on the SOTA page does not break out mode used by band but it does provide some aggregate mode numbers. The number of FM contacts (using any band) is 1186542. It is reasonable to assume that almost all of these FM QSOs were made above 50 MHz. (FM is used a bit on the 10m band but that combination is rare in SOTA.) That means, for frequencies >50 MHz, 88% of the QSOs (186542/1346206) were completed using FM.  We don’t know how the remaining 12% splits out but I would expect them to be a mix of SSB and CW, but dominated by SSB.

Given the high number of 144 MHz contacts in the mix, it is safe to say that 2m FM is the dominant mode for VHF/UHF SOTA. After all, it is The Utility Mode. The reasons are obvious…almost every radio ham has a handheld transceiver that can do 2m FM. It makes for an easy way to get on the air and active a summit. More importantly, it is an easy way to chase a summit. When I plan a SOTA activation, I think about the kinds of operators that will be within range and what kind of gear they are likely to have. It does me no good to drag along equipment for 2m SSB/CW if there is no one around to work that band/mode.

This analysis does confirm that the number of non-FM QSOs on VHF/UHF is relatively small. The 12% of non-FM QSOs above 50 MHz corresponds to only 2.5% of all SOTA QSOs. So why is this? Clearly, the affordability and popularity of the FM handheld transceiver is a big factor.  There are portable radios that can do “all modes” on VHF/UHF such as the Elecraft KX3 (2m option), Yaesu FT-818, and the Icom IC-705, but these are much more expensive.

What About 70cm and 6m?

Now, it is interesting that the 70cm numbers are small compared to 2m. Many of those handheld transceivers that get used for 2m also have 70cm included, so you might expect there to be more 70cm QSOs in the mix. For a given boom length, a 70 cm Yagi antenna will have more gain than a 2m Yagi. So gain is easier to come by on the higher band.

Note that the SOTA rules do not encourage working the same station on more than one band. You only get credit for working a station once on an activation. (Compare this to VHF contest scoring which usually adds in additional credit for working stations on multiple bands.) So if a chaser works someone on 2m, they typically don’t bother working them on other bands.  I am not saying this is bad, I am just trying to explain why we don’t see more QSOs on 70cm.

The other band you might expect to see more activity is 50 MHz (6 meters). This band is available to Technicians in the US and, when the band opens up, you can easily work a thousand miles or more via Sporadic-e propagation. (Sometimes F-layer propagation, too, but we’ll need a whole bunch more solar activity for that to happen.) Many HF rigs include 6m as a “bonus band”, even some of the QRP radios popular with the SOTA crowd (KX3, IC-705, etc.) So why are the 6m numbers so low? This band offers a metric ton of fun, but it dishes it out randomly. There is a reason they call it the Magic Band…sometimes the Magic is there and sometimes it is dead quiet. When it’s dead quiet, it is a poor imitation of the 2m band. It also requires larger antennas, so if an activator decides to use antenna gain to help their signal, a portable Yagi for 2 meters is going to be a lot handier than one for 6 meters.

CW and SSB

This data does show that CW and SSB are lightly used for SOTA on the VHF/UHF bands. This is an opportunity. If more of us used these modes, it would improve our ability to squeeze out contacts when the signals are weak.

Bob K0NR

The post Looking at VHF/UHF SOTA Data appeared first on The KØNR Radio Site.

While I did not originate the idea, I have been promoting the use of 146.58 MHz as the North America Adventure Frequency.  (Rex/KE6MT and George/Kj6VU came up with the idea.) My previous blog post explained the thinking behind it, along with my own personal biases, I’m sure.

When presented with the idea of The Other Simplex Frequency, I generally get three types of reactions:

1. Great idea! These people generally live or operate in locations where the 2m FM calling frequency (146.52 MHz) can get kind of busy, so they see that having an alternate frequency that everyone knows about has value. They may or may not still call on .52 but having another designated frequency is a plus.

2. It will never get used in my area This reaction comes from locations where people tend to congregate on 146.52 MHz and will probably not monitor any other frequency. The SOTA activators say stuff like “I’ll never contact anyone on 146.58 MHz so I’ll have to just use keep using 146.52.” This is not a problem, do whatever makes sense.  The North America Adventure Frequency will probably not get used everywhere and that is just fine.

3. What, people actually talk on 2m FM simplex? These folks are just plain missing out. I don’t know how to help them.

73 Bob K0NR

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Way back in the Wayback machine, when I was working on getting my Technician license (in the 20th century), I recall looking at the frequency bands available to Techs. Technicians had operating privileges for everything above 50 MHz, which looked like a lot of useful spectrum to me. The idea at the time was that Technicians were exploring the new frontier of amazingly high frequencies. Since then, the Technician license has morphed to be the entry level license.

ICOM has a good graphic that shows all of the ham bands and shows the common subbands for various modes. I snipped out the portion that covers the most popular VHF/UHF bands (below). Wow, look at all the stuff you can do! Also, it is 4 MHz of spectrum, big enough to fit eleven 20 meter bands inside it. (Yeah, yeah, the propagation is a lot different.)Speaking of bandwidth, take a look at the 70 cm band, with 30 MHz of spectrum. (Not shown is the 23 cm band, which spans 60 MHz.) The higher you go in frequency, the more spectrum there is.

Most people think of the 2-meter band as just FM and repeaters, but it is much more than that. I copied the 2-meter band graphic and added my own notatation on the various uses of the band.

Much of the band is allocated to FM, which is consistent with the popularity of the mode. I didn’t mark all of the FM segments, so refer to the color coding to see them. But there is much more than FM simplex and repeaters. Down on the low end is the CW-only segment and EME activity (Earth-Moon-Earth or moonbounce). The “weak-signal” enthusiasts tend to use the SSB portion, with the SSB calling frequency of 144.200 MHz. You may often hear CW in the SSB subband and radio hams flip back and forth between the modes depending on propagation.  Meteor scatter is mostly done via the WSJT-X mode of MSK144 around 144.140 MHz.

Automatic Packet Reported System (APRS) activity is mostly on 144.390 MHz, using FM-based 1200-baud packet radios. Other packet radio usage is not shown but is usually around 145.01 MHz. The 2m band is very attractive for satellite use, with VHF propagation properties and manageable doppler shift for Low Earth Orbit (LEO) satellites. The downlink from the International Space Station (ISS) is usually 145.80 MHz.

Over time, I’ve used all of these 2m modes mentioned above, with the exception of EME. I am still working on that one and I hope to have a new 2m Yagi installed sometime this year that will enable it.

73 Bob K0NR

The post The 2 Meter Band: Much More Than FM appeared first on The KØNR Radio Site.

I see a lot of cows standing around in Colorado ranch land, and I often wonder what they are thinking. As a result, I’ve been experimenting with a series of graphics that show cows standing out in the field thinking great thoughts. Surprisingly, they are often thinking about ham radio topics. Who knew? I’ve posted these on Twitter (@K0NR) which usually generates some responses.

Recently, the cows were thinking about the 2m FM calling frequency.

Some of my international followers pointed out the 2m FM calling frequency is not 146.52 MHz in their country. Sometimes it is difficult to localize VHF content, so sorry about that.

EA3IEK commented that the calling frequency should also be the listening frequency. (This is the crux of the problem with calling frequencies on 2m FM…what is the best ratio of calling and listening?) So I quickly modified the photo.

Then I could not resist posting this one, inspired by Joey on the Friends television show. Moo. It’s just a cow’s opinion.

73 Bob K0NR

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Lately, for the ARRL January VHF contest, I try to find a SOTA summit to activate. Operating time is usually just a few hours, so it does not make for a big score. The main advantage is for VHF SOTA (Summits On The Air) because there is a lot more activity on 2m CW and SSB. This year, I wanted to go for the mountaintop trifecta of SOTA, POTA (Parks On The Air) and VHF contest in one activation.

Threemile Mountain (W0C/SP-107) emerged as the activation summit because it is not too far from our cabin and accessible in the winter. (This time of year, the roads to many of our favorite summits are blocked.) For POTA, it is located in the Pike National Forest (K-4404). Because it is a short hike, I concluded that I could carry the Yaesu FT-911 and the 20 Ah Bionno battery. This would cover all the bands, give us more RF punch and still have plenty of battery capacity.

I carried quite a collection of antennas which gave us plenty of operating choices. We started out on 2m and 70 cm FM, working mostly local stations. This quickly got us enough contacts for SOTA and POTA points. We used a rollup J-pole for 2 meters and 70 cm, until it became intermittent and the SWR went wild. Then we switched to the Arrow 3-element Yagi for 2 meters.

About that time, I decided to see what was happening on 2m SSB. There were a number of contest stations on the air, mostly from the front range cities (Denver, Boulder, Colorado Springs, …). I worked a bunch of them using 50 watts from the FT-991 to the 2m Yagi antenna (horizontally polarized).

Suddenly, I was surprised to hear N0LL from Kansas calling me. I’ve worked Larry before from Colorado but it usually was from a really good location such as Mt Herman or Pikes Peak. Even then, we often had to switch to CW to complete the contact. Today he was louder than many of the Denver stations. We easily worked on SSB, which turned out to be a new personal best DX for me from a SOTA summit (372 miles).

After things slowed down on 2m SSB, I decided to make some HF contacts. The North American QSO Party (SSB) was active, so I decided to set up for 20m and see who I could work. Running 100 watts to an endfed halfwave kept me competitive with the contest stations. Then I moved up to 17m SSB and worked non-contest POTA and SOTA chasers.

We both accomplished the three-in-one mountaintop activation for SOTA, POTA, and the VHF contest. I also worked the NA QSO Party, so that makes it four-in-one, but who is counting?  The January weather cooperated with us with almost no wind on the summit, about 28 degrees F. We sat there in the sunshine and just enjoyed the view before hiking back down.

73 Bob K0NR

The post Radio Fun on Threemile Mountain (W0C/SP-107) appeared first on The KØNR Radio Site.

Charlie/NJ7V and Gaston/KT1RUN did a comparison of VHF antennas during a SOTA activation. Specifically, they compared a rubber duck antenna, a J-pole antenna on a tall mast, and a 3-element Yagi antenna. Spoiler Alert: the rubber duck sucks (they all do) but the Yagi and J-pole performed about the same.

Joyce/K0JJW and I use the Arrow 3-element Yagi antenna for most of our SOTA activations, so I am very familiar with that one. We also have a rollup J-pole that we use once in a while.

Charlie used the Yagi the same way we do: handheld at ground level. The J-pole was on a mast, maybe 12 feet (?) in the air. Although they were on a summit, there is some performance improvement getting the antenna higher than the surrounding terrain. The gain of the Arrow 3-element Yagi has been measured at about 6 dBd. The gain of a J-pole, being a halfwave radiator, is 0 dBd. The additional height of the J-pole has to make up this 6 dB of gain difference to be roughly equivalent.

A big difference, though, is that the Yagi antenna has to be held and pointed. The J-pole is always pointing in the right direction so you can just focus on operating and logging. We may have to consider using a omni antenna instead of the Yagi.

Good stuff!

73 Bob K0NR

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Recently, on the nasota group,  there was a discussion about designating an alternative 2m FM frequency for Summits On The Air (SOTA) use (instead of 146.52 MHz). The main driver for this is that 146.52 MHz can get busy with other radio traffic and/or a busy SOTA activation can tie up the calling frequency for a long time.

Rex KE6MT (SOTA W6 Association Manager) kicked it off with:

A friend of mine, George KJ6VU, has been talking with me and several others about the idea of an FM “Adventure Frequency.”  It would be for more than just SOTA – other *OTA’s could also use it.  There are other ideas to layer on top of it, such as tone signaling so that you don’t have to hear traffic you don’t want to hear, and repeater infrastructure for announcing someone’s on the frequency with a given tone, etc.  But the core thing would be to decide on a frequency and really get it in use.  The National Calling Frequency (146.52) can be great for a few contacts sometimes, but other times it’s problematic either because it’s being hogged or because nobody’s listening.  Of course, this Adventure Frequency could have the same issues present themselves differently, but would alleviate some and pave the path for future additions mentioned above.

I have previously written about the challenges of using 146.52: The Use of 146.52 MHz

One important idea is to include the other “OTAs” in adopting this frequency, most notably Parks On The Air (POTA). Hence the name “Adventure Frequency,” and not “SOTA Frequency.” It is really about hams operating portable in an outdoor setting. Of course, like all amateur spectrum, this frequency must be shared with other users.

It may seem like a simple thing to choose a nationwide simplex frequency but VHF band plans are managed regionally. In particular, there is a mix of 15-kHz and 20-kHz channel spacings. (For more background on this see Simplex Channel Confusion on 2 Meters.)

After some discussion, the group settled on 146.58 MHz. There was some dialog around using CTCSS for signaling but nothing specific surfaced.

Some key points:

• The NAAF is 146.58 MHz.
• This frequency is in addition to, not a replacement for, the National Simplex Calling Frequency 146.52 MHz.
• Local usage will likely vary depending on needs.
• Program 146.58 MHz as The Other Simplex Frequency in your radio.

What does this mean to you?

Program 146.58 MHz into your radio and have it available. If you are doing SOTA (or POTA) activations, consider using this frequency, especially if you are in an area where 146.52 is used a lot. (I’ve already started using this frequency for SOTA activations near urban areas.)

73 Bob K0NR

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