Looking at VHF/UHF SOTA Data

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.”

Frequency QSOs % of Total
Above 50 MHz 1,346,206 21%
Below 50 MHz 5,144,547 79%
Total 6,490,753 100%

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%.

Frequency QSOs % of Total % of >50 MHz
50MHZ 48,035 0.74% 3.57%
70MHZ 10,921 0.17% 0.81%
144MHZ 1,202,311 18.5% 89.3%
220MHz 1064 0.02% 0.08%
433MHZ 126,202 1.94% 9.37%
900MHz 204 0.00% 0.02%
1240MHZ 12,526 0.19% 0.93%
2.3GHZ 1554 0.02% 0.12%
3.4GHz 142 0.00% 0.01%
5.6GHZ 468 0.01% 0.03%
10GHZ 1186 0.02% 0.09%
24GHZ 167 0.00% 0.01%
Microwave 382 0.01% 0.03%

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 1,186,542. 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 activate 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. However, 2m propagation tends to be a little better than 70cm, on average.

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”, including 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

6 Replies to “Looking at VHF/UHF SOTA Data”

  1. At the beginning of this year, my buddy and I decided to do most of our activations on VHF FM here in the Mid Atlantic region. I have a VX-7r, so I always try 6m to start with. I’ve only managed 4 QSOs on 6m FM using the VX-7r and a 6m j-pole, but the last activation netted me one in Georgia from Virginia.

    • The activity on 6m tends to be SSB (or more recently FT8), with FM lightly used. The exception is when there is a 6m FM repeater in the area but they are not that common. But good for you trying to make some contacts on 6m FM!

      • Thanks! I do it mainly for the novelty and potential for a long distance contact with an HT.

  2. Thanks for posting this. After recently installing a Comet GP-1 2m/440 for my base antenna, I was thinking “hm, maybe I should’ve popped for one that does some other bands as well.” With 98.7% of QSOs listed here covered by those two bands, these would likely just be several more bands of mostly silence. (yes, of course this will vary by region, but still it’s a fair sample) So yeah, I kind of wish that I had 6m capability on that antenna as well, but for the lower wind profile — it’s a consideration here in FL — the 4′ tall 2m/440 will work just fine.

  3. Bob your VHF journey inspired me to start and finish my first MG all VHF. I’ll have to look at my log but I believe your in it! I recently passed 100+ summits activated via VHF/UHF and just started adding 6m to the mix!

    Of all the summits I’ve tried to activate I’ve only had 2 where at least 1 QSO was not obtained. I am planning a Colorado SOTA blitz this coming fall.

    Till then,

    “73”

    Erik
    KE8OKM

    • Erik,
      Fantastic!
      There are not that many VHF-only SOTA folks, so it is good to connect.
      Let me know when you are in Colorado.

      Bob K0NR

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