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.
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 is an easy SOTA summit: easy to access via forest service roads and an easy hike.Joyce/K0JJW operating the portable station on 2m FM.
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.
The portable station with 100 watts on HF, 50 watts on 2m/70 cm.
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.
Bob/K0NR operating from Threemile Mountain.
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).
The QSO between K0NR on Threemile Mountain (DM78) and Larry/N0LL near Smith Center, Kansas (EM09).
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).
We deployed both the SOTA and POTA flags today.
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.
Bob/K0NR and Joyce/K0JJW hanging out on the summit of Threemile Mountain.
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.
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.
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.)
A big trend in ham radio activity is the use of internet-connected transceivers commonly referred to as hotspots. These devices often use one (or more) of the popular VHF/UHF digital formats (DMR, D-STAR, Fusion) but analog FM is also used. They allow a radio amateur to have a local RF connection into one of the extensive radio networks (e.g., Brandmeister).
Unfortunately, there have been situations where radio amateurs arbitrarily chose hotspot frequencies that caused interference with existing radio activity. For example, a hotspot showed up on the 70 cm SSB calling frequency, 432.100 MHz. One of the worst examples of interference was a hotspot sitting on the input frequency of a satellite transponder. Not good.
The Colorado Council of Amateur Radio Clubs (CCARC) is the VHF/UHF frequency coordination body for the state of Colorado. Included in its spectrum management role, the CCARC maintains a detailed set of band plans (called Frequency Use Plans) for the 144 MHz, 222 MHz, 420 MHz, 902 MHz and 1200 MHz bands.
The CCARC recently decided to provide some guidance on what frequencies should be used for hotspot operation. Previously, the operator of a hotspot had to scan through the Frequency Use Plan and figure out where hotspots fit in. It wasn’t very obvious, so the CCARC now recommends 10 specific frequencies on the 70 cm band for hotspot use.
Hotspot Channel
Frequency
1
438.4500 MHz
2
438.4750 MHz
3
438.5000 MHz
4
438.5250 MHz
5
438.5500 MHz
6
438.5750 MHz
7
438.6000 MHz
8
438.6250 MHz
9
438.6500 MHz
10
438.6750 MHz
These frequencies are available for simplex hotspot use. However, for each of these simplex frequencies, there is also a corresponding frequency 5 MHz lower that can be used for hotspots that operate duplex.
Unlike repeaters, hotspots are not coordinated by the CCARC. With 10 frequencies available, it should be easy to find one that doesn’t have any co-channel interference from other users. See the complete CCARC hotspot guidance here.
These guidelines won’t solve every problem but it will help people find a hotspot frequency that plays well with others. These frequencies are valid for Colorado only. Check your local VHF/UHF band plans for more information.
73 Bob K0NR
Disclosure: I contributed to these CCARC guidelines but I don’t speak for the CCARC.
After seeing some videos about small HF transceivers for Summits On The Air (SOTA), I feel I need to set the record straight.
The following video shows the World’s Smallest SOTA Transceiver in use. Of course, it uses the UHF spectrum because shorter wavelengths enable smaller ham radio stations.
The radio shown in the video is the NKTech NK-M1 UHF transceiver.
This radio is a 16-channel UHF transceiver, available from multiple online vendors. I programmed it to operate in the 70 cm band on 446.0 MHz.
Closing out 2020, here are the top five blog posts at k0nr.com during the year. Some people may see this as a lazy way of creating one more blog post for the year without much work. This is definitely true. I hope you enjoy it anyway.
Leading the list is this blog post…a perennial favorite that seems to make the top five each year.
This is another popular article that explains some of the details behind the 2-meter band plan. This particular article is tuned for Colorado but it also provides a link to an article that covers the topic for the USA.
Coming from nowhere, this article talks about an alternative firmware package for the popular Tytera MD-380 transceiver. I don’t know why this is getting so many hits but it might just be people searching for the TyMD380toolz, which seems to have disappeared.
The fifth-place post is one of my personal favorites that talks about proper kerchunking of repeaters. It even introduced a new Q-signal for kerchunking, although I must admit it may not be catching on.
I am going to add one more post to this list. No extra charge. This one announced that Joyce/K0JJW achieved Mountain Goat status in the Summits On The Air program. You Go, Grrrrl!!!
The Arkansas River Headwaters is a unique recreation area that follows the upper Arkansas River in Colorado, extending roughly from Leadville to Pueblo. POTA has it listed as the Arkansas River Headwaters State Park, but the Colorado Parks and Wildlife website shows it as the Arkansas Headwaters Recreation Area. This area is a bit unique, a cooperative effort involving Colorado Parks and Wildlife, the Bureau of Land Management, and the US Forest Service. See map here.
Joyce/K0JJW working the pile from POTA K-1208
Joyce/K0JJW and I decided to activate this park earlier this week, enjoying a nice sunny day. We operated from the Collegiate Peaks Overlook, which has a picnic area and an excellent view of Mount Princeton and adjacent peaks.
The wire antenna is supported by a SOTAbeams mast inserted into a drive-on mount.
For POTA, our standard station configuration is the Yaesu FT-991 transceiver driving an end-fed halfwave antenna, usually on 20m or 15m. We have a collection of end-fed halfwave antennas that cover 40m and up. We have bigger and smaller transceivers available to us, but the FT-991 is small enough to be portable but includes an antenna tuner and has 100 watts of output available. (Typically, we run about 50 watts of RF output on battery power.) Our power source is a Bioenno 12V 20aH LFP battery. This battery is lightweight and compact, capable of running the FT-991 for hours.
Bob working VE4RBH and AG7KO on 20 meters.
We set up our station on a convenient picnic table. We had hoped to lash the mast to a conveniently-located post or tree, but none were present. Our backup plan was the drive-on mount, held by the front tire of the truck. The 20m band was alive so we just set up on that band and never looked back. We also worked some of the locals on 2m FM. It is always fun to see who shows up on that band.
Here’s Joyce working AA5UY in Louisiana.
I don’t think we have really optimized our POTA setup but we have found an approach that works well. Never underestimate a properly-fed halfwave antenna up in the air.
Recently, I commented on participating in the Parks On The Air (POTA) program: How About Parks On The Air? Since then Joyce/K0JJW and I have done a few POTA activations, including a few combination SOTA (Summits On The Air) + POTA activations. We are starting to sort out how SOTA and POTA work for us. I am sure this will evolve over time as there are many operating options with both programs. But here is what we’ve done so far.
Recall that we’ve been focusing on VHF/UHF operating for SOTA, although I did break down and actually made some HF contacts from a SOTA summit recently. VHF/UHF is a good match for SOTA (Height Above Average Terrain). However, for some remote summits, it can be a challenge to get enough radio contacts (4) to qualify for the SOTA points. Using HF can be a big help in generating contacts. POTA can also be done with VHF, some parks have high elevation, but many of them are not attractive VHF locations. POTA requires 10 radio contacts to qualify for points, so that raises the bar a bit, too.
Bob/K0NR on Mount Herman, displaying the SOTA and POTA flags.
Yesterday, we decided to hike up Mt Herman (W0C/FR-063) for a short afternoon VHF/UHF activation. I posted both a SOTA alert and a POTA alert. We made plenty of radio contacts (40 total) and submitted logs to both the SOTA and POTA websites. I know there were SOTA chasers out there but I’m not sure if anyone worked us specifically for POTA. As usual, a lot of hams give us a call just because it is fun to work someone on a summit (without any SOTA or POTA interest).
The majority of our SOTA activations in Colorado are in national forests, which count as “parks” for POTA. So it is easy to tack on a POTA activation when doing SOTA.
Vehicle-Based POTA
Joyce and I also did some POTA activations from a vehicle. It is pretty easy for us to get to Pike National Forest (K-4404) or San Isabel National Forest (K-4407) and set up a portable station.
The vehicle-based POTA station, as used in Yellowstone National Park during the year of the ARRL NPOTA program.
We used a Yaesu FT-991 and endfed halfwave antennas for 20m and 15m, supported by a SOTAbeams pole. This is the same configuration I’ve used for portable operating from many locations, including some Caribbean islands. I recently purchased a 20 Ah LFP battery from Bioenno Power to use as a power source so that we don’t rely on the vehicle battery.
We focused on HF for these POTA activations and were pleased to have decent pileups of stations calling us on the 20m and 15m bands. Fifty watts to a halfwave antenna works just fine. We also made it a point to call on 2m FM and usually picked up a handle of contacts on that band, too.
What’s Next?
At this point, our outdoorsy portable operating is looking like this:
SOTA Summits – if the summit is in a park, we will probably go ahead and submit a POTA log along with the SOTA log. Many of the W0C SOTA summits are in national forests, national parks or state parks. VHF-only activations will probably have less impact on POTA…those chasers/hunters tend to be on HF. On HF, we will be running QRP power levels.
POTA Parks (day trip) – another option is for us to just stop by one of the national forests or a state park and get on the air. (Pike National Forest is about 2 miles from our home.) This will be focused on the HF bands but we can always make a call or two on VHF. This will be operating from or close to a vehicle, so probably running 50 watts on HF with a wire antenna.
POTA (RV camping) – we’ve been RV camping in state parks and national forests this past year. An obvious additional activity is to set up on HF for a POTA activation. We haven’t done this yet.
I’ve already done a combination VHF Contest and SOTA activation, so this could be extended to include POTA. Three Things In One. In fact, some locations qualify for more than one POTA park, so maybe it is time for a Four-In-One.
Charlie/NJ7V invited Joyce/K0JJW and me to be on the All Portable Discussion Zone, on the Red Summit RF YouTube channel. We talked mostly about Summits On The AIr (SOTA) using VHF/UHF. It was a fun experience for both of us.
Once again, I was asked by a new ham “which handheld transceiver should I get?” This is a frequent and valid question that comes up. Often the question gets framed as “Baofeng or something better?” I say “something better.” I am not writing to bash Baofeng radios or the people that use them. The radios are an incredible value on the low end of the market…amazing what they can do for $30 or so. Besides, I own several of them. I just think that if you have a few more $$ to spend, you can get a much better radio. What’s wrong with these low-end Chinese radios? Out of spec harmonics on transmit and poor adjacent channel rejection on receive.
Digital? Probably Not
The other question that usually surfaces is “should I get a digital radio?” Here “digital radio” means D-STAR, Yaesu Fusion or DMR. My answer to that is “No,” unless you have a specific reason for going digital. Adding digital to a radio results in two things: 1) a higher price and 2) a more complex radio. Actually, the price difference may not be that significant, especially for a DMR radio. However, the complexity factor is always there.
What is a specific reason for going digital? You already know that there are digital repeaters in your area that you want to use, you have ham radio friends already using digital or you are technically-oriented and have researched the topic to know that it is something you want to try. If one of these things is true, then go for it.
Oh, you do need to know which digital format to get. No radio does them all and the industry is fragmented between D-STAR, Fusion and DMR. I find this very disappointing but life is sometimes like that.
Narrowing It Down
So narrowing the topic down, we are looking for an affordable (under $100) dual-band handheld that is not a cheap Chinese radio (Baofeng, etc.) and is not a fancy digital radio. My opinion is the quality ham radio manufacturers are pretty much Alinco, Icom, Kenwood, and Yaesu. The price points on basic handheld transceivers keep changing, so be sure to check the date on this post and do a little price shopping.
The Alinco DJ-VX50 is about $100, so not too expensive, but I am not seeing any eham.net product reviews on it. Also, it seems to be out of stock at several vendors, so I am not sure of its production status. Icom and Kenwood have exited the low-end handheld market, so nothing to consider there. This leaves Yaesu as the only “brand name” player in this space. I have been recommending the Yaesu FT-4XR as a good alternative: see What About the Yaesu FT-4XR? at about $80. I recently noticed that the Yaesu FT-65R has come down in price to about $85. With this price difference, it probably makes sense to go with the FT-65R. (I really wonder about Yaesu’s product line strategy at this point. Why are there two similar radios priced so close together?)
Here is a quick comparison of the two radios: Yaesu FT-4XR vs FT-65R, which is right for you? Conclusion: FT-65R is probably better for most people. Also, check out the HamRadioSchool.com article: Yaesu FT-65R Product Review. The eham.net product reviews are generally positive on the FT-65R, but there are a few negative themes that surface. Some people are reporting radio failures that may indicate a manufacturing issue with the product. (It is made in China.)
The Good Old FT-60
The other theme that surfaces is that the FT-65R is not a complete replacement for the venerable FT-60R. Joyce/K0JJW and I have a couple of FT-60Rs that we really like and frequently use. Yaesu still sells this older model because it is so popular and, frankly, it is a really solid radio. The HamRadioSchool.com review of the FT-65R mentions several things that people tend to like on the FT-60R that were left out of the FT-65R (e.g., dedicated VFO and Squelch knobs.) The biggest complaint I hear about the FT-60R is that it has an old-school NiMH battery (the FT-65R has lithium-ion).
My conclusion is to recommend the FT-65R to newcomers to the hobby. At ~$85, it fits most people’s budgets. There is some risk that you will outgrow it down the road and want a more capable handheld for digital or APRS or whatnot. In that scenario, the FT-65R will still be a good second/backup radio. (Ya gotta have more than one, right?)
The light-bulb dummy load has been used with HF transceivers from way back in the old days (and sometimes more recently). These “dummy loads” tended to radiate a bit and can actually be used as a (poor) antenna. A few years ago, the Lightbulb QSO Party promoted the use of light bulbs as antennas during their event.
I wanted to find out if I could do the same thing with a 5W handheld transceiver, so I scavenged a bulb from an old string of Christmas tree lights and hooked it up to my Yaesu FT-60. This video shows what happened next.
After I made the video, I checked the specs on the FT-60 and found that the transmit power settings are: 5.0 W (High) / 2.0 W (Middle) / 0.5 W (Low). In the video, I said the middle setting was one half watt, which is incorrect.
I checked the SWR on the light bulb and found it to be 2.7. I was not worried about damaging the handheld radio because they are designed to work into crummy antennas such as the standard rubber duck.
I hope you enjoyed this fun experiment. Sorry about the amateurish video quality…I just shot it with my iPhone and did some simple editing.
On some SOTA summits that are established radio sites, there can be significant RFI on 2 meters. I recently wrote about that here: RFI on SOTA Summits. There have also been discussions from time to time among VHF SOTA activators on which handheld transceiver (HT) has the most robust receiver for use in high RF environments. (Hint: a Baofeng is not going to be your best choice.)
This led me to an excellent web page by Razvan/YO9IRF that tabulates the receiver performance of HTs as measured in the ARRL lab. This is arguably the most objective look at HT performance out there. You can do a sort on a particular parameter and see which models are best.
Probably the parameter to start with is wide 3rd-order intermodulation on the 2-meter band. (I am going to ignore the 70 cm performance because most VHF SOTA contacts are on 2 meters.) The wide 3rd-order intermod performance relates to interference rejection from outside the amateur band.
Here are the best performing HTs for this parameter. (Go to the website directly to see other models listed.)
Interestingly, the Icom IC-V8 jumps to the top of the list. This is an older single-band 2m radio…and I happen to have one hiding somewhere in the basement. I am a bit surprised there are two Wouxun radios near the top of the list but they performed well. No surprise that the Yaesu FT-60 shows up…it seems to be well-regarded by SOTA activators.
The narrow 3rd-order intermod performance relates to the receiver performance inside the amateur band. Sorting based on that parameter shows these radios at the top:
The Kenwood TH-22AT takes the top position, followed by the Yaesu FT-10R, both older single-band radios. The general trend here is that some of the older radios, especially single-band rigs, have better front end filtering. Newer radios tend to include reception of a wider range of frequencies outside the ham band and have receiver front ends that are correspondingly more open. The Radio Shack HTX-202 gets a lot of positive comments from the SOTA crowd and is on the shortlist. Again, the well-regarded FT-60 makes the list.
Let’s check a few of my favorite HTs to see how they rate.
My usual SOTA handheld is the Yaesu FT-1DR. The wide 3rd-order intermod is 73 dB, or 12 dB worse than the FT-60 (85 dB). For narrow 3rd-order intermod, the FT-1DR is 58 dB vs 67 dB for the FT-60. This matches my impression that the FT-1DR does OK for most summits but is not the best radio for high RF environments.
Another radio to consider is the Yaesu FT-4XR. I often have this radio on at the house but I don’t use it for SOTA. This radio uses the same receiver IC as the Baofeng UV-5R but has better input filtering. The wide 3rd-order intermod is only 63 dB and the narrow 3rd-order is 61 dB (about the same as the FT-1DR). The table does not list any Baofeng radios but I would expect them to perform worse than the FT-4XR.
Regular readers of this blog know that I use a Yaesu FT-90 mini-mobile transceiver for most SOTA activations. I looked up the ARRL tests on it. The wide and narrow 3rd-order intermod are 85 dB and 65 dB respectively, not better than the best handhelds but near the top. My experience is that the FT-90 receiver is better than my FT-60 and FT-1DR, consistent with the ARRL lab measurements.
Another radio of interest is the Yaesu FT-818, which the ARRL measured as 96 dB (wide 3rd-order intermod) and 72 dB (narrow 3rd-order intermod) on the 2m band. This puts the FT-818 at the top of the list with the best handhelds. Actually, I would have expected it to be even better, far superior to an HT, but apparently not.
So I need to dig out that old Icom IC-V8 that is hiding in the basement. It may be a good piece of equipment to have along on SOTA activations.
One thing to watch out for when doing SOTA activations is the presence of strong Radio Frequency Interference (RFI) on some peaks. The typical scenario is that the summit is also an established radio site with transmitters that interfere with your ham radio operations.
Bob/K0NR checking out the radio gear on Mount Bailey (W0C/FR-062).
I use the VHF/UHF bands for SOTA, so I am writing from that perspective. My impression is that HF interference is much less likely because these radio sites don’t usually have any HF transmitters. However, they may have broadband noise sources such as networking equipment, power line arcing or switching power supplies that can create problems on HF. Anyway, this post is focused on 2 meters and higher bands.
In my experience, the transmitters at radio sites may include land mobile repeaters (VHF or UHF), NOAA Weather (162.xx MHz), TV/FM broadcast stations and mobile wireless (cellular) systems. The TV/FM broad stations are really bad news because they run a crapton of RF power.
The worst summit I have encountered is Sandia Crest (W5N/SI-001) near Albuquerque, NM. See trip report here. They even have a sign in the parking lot to warn you that the RFI may wipe out your car’s keyless remote.
Well, this sign did warn me of radio interference at Sandia Crest.
In a high RFI environment, your radio receiver gets overloaded such that you can’t hear stations calling you but they can hear you just fine. This results in the SOTA activator calling and calling while the chasers get frustrated that the activator never hears their call. Not good. It may not be obvious that this is happening. This blocking of the receiver may come and go, depending on which transmitters happen to be active.
Mitigation Strategies
There are a few things that you can do to deal with the RFI:
Move Away From The Source
Probably the first thing to try is just moving away from the source of interference. This may mean moving away from the highest point on the summit but it may be better overall to give up a few feet of elevation to not have the interference. You’ll need to stay in the activation zone to be a legitimate SOTA activation.
Use A Better Radio
Some radios are better than others when it comes to receiver performance including the ability to reject unwanted signals. The low cost radios from China (Baofeng or similar) generally have lousy receivers so they are a poor choice for operating from an RFI-intense summit. Many people report better results with the Yaesu FT-60, a solid performer. Commerical radios from Motorola are even more robust. I’ve been using a small mobile radio for SOTA (Yaesu FT-90) which outperforms most handheld radios.
Change Your Antenna
Using a directional antenna can help…just point it away from the source of the interference. Oddly enough, using a worse performing antenna can help improve your ability to communicate. For example, a rubber duck antenna on a handheld radio will allow less of the interfering signal to get into your receiver which may improve your ability to receive. As long as the antenna is “good enough” to complete the radio contact, it may be the way to go. One trick I’ve used is to deploy two radios, one for receive with a crummy antenna and the other for transmit with a better antenna. That way, you still radiate a stronger signal while reducing the interference into the receiver.
Use A Bandpass Filter
You can insert a filter into your antenna feedline to reduce the interfering signal. The best approach is to use a bandpass filter that passes the frequency you are operating on but attenuates other signals. SOTABeams offers a compact bandpass filter for the 2m band. (Note that it has a 5W power rating which is fine for handheld radios but not more powerful transceivers.) DCI Digital Communications offers higher power filters but they are much larger in size.
Change Frequency
Sometimes a small change in frequency might help a bit if the interference is limited to certain frequencies. Another tip is to try another band. That is, if you are getting interference on 2 meters, you may find that the 70 cm band is better. Or vice versa. It all depends on the transmitters at the site.
Congratulations to my wonderful spouse and favorite hiking partner, Joyce/K0JJW, for achieving Mountain Goat status for Summits On The Air (SOTA).
Joyce/K0JJW on Pikes Peak, working a pileup as she qualifies for Mountain Goat.
On August 10th, she reached 1000 activator points while activating Pikes Peak (W0C/FR-004). She had quite the pileup on 146.55 MHz. Her best DX for the day was WY7ATH near Cheyenne, WY at a distance of 167 miles. Not bad!
Early on, she always hiked with me on SOTA activations but didn’t start pursuing activator points until the middle of 2017. All of her SOTA contacts have been on the VHF/UHF bands, lots of 2m FM along with 2m SSB, 70 cm and 23 cm FM.
Joyce has activated 181 summits, 112 unique in 19 associations.
She is the second female Mountain Goat in Colorado (after Lynn/KC0YQF) and is the eighth female goat in North America.
I often get asked questions about the band plan for 2 meters (144 to 148 MHz). Usually, this is about choosing a suitable simplex frequency, because the repeater frequencies are already coordinated and visible.
I’ve written about 2m band plans before. This article attempts to cover the topic in a way that applies to all of the US. This is actually a challenge because VHF/UHF band plans are regional in nature.
I also wrote this article which is specific to the state of Colorado.
It is always best to check your local VHF band plan, usually supplied by the frequency coordinating body for your area. Typically, their main focus is coordinating repeaters but simplex frequencies are also listed. Most frequency coordinating bodies kind of follow the ARRL 2m band plan, while adapting it for local use.
Channel Spacing: 15 kHz or 20 kHz
A big issue for the 2-meter band is that some areas have adopted a 15-kHz channel spacing while others use a 20-kHz channel spacing. A typical FM signal is about 16 kHz wide, so the 15 kHz channel spacing is a bit tight but does allow for more channels (resulting in more adjacent channel interference issues). The 20-kHz spacing is “cleaner” but with fewer channels.
This map from the ARRL web site shows the channel spacing in use across the various states.
Map of the US showing 15 kHz and 20 kHz channels on the 2-meter band.
The channel spacing is driven by factors associated with repeater coordination, and simplex usage tends to adopt the same spacing. (There is no technical reason that simplex has to use the same channel spacing as the repeaters but that’s what usually happens.)
Some repeater coordinating organizations have done a good job of prescribing FM simplex frequencies. The Colorado 2m band plan (called the Frequency Use Plan) lists each simplex frequency individually. The Illinois Repeater Association uses a similar approach: Illinois 2m Band Plan. The Southeastern Repeater Association (SERA) 2m band plan is also very specific. Note that the SERA band plan indicates that some of the usual 2m simplex frequencies may be used as repeater pairs — an example of a local decision on frequency use.
The Arizona 2m band plan shows a range of frequencies to be used for FM simplex, such as 146.400 – 146.600 MHz along with a note that says the Even 20 kHz Frequencies should be used. So that means the preferred simplex frequencies in this range are 146.40, 146.42, 146.44, 146.46, 146.48, 146.50, 146.52, 146.54, 146.56, 146.58 and 146.60 MHz. Some repeater coordinating bodies just give the frequency segment allocated to FM simplex and don’t mention the channel spacing. And some organizations don’t say anything about FM simplex so you have to figure them out on your own.
Recommendations
So what do we make of all of this? When it comes to 2m FM simplex frequencies, try to find your local band plan. If it recommends 2m FM simplex frequencies, then follow that guidance.
If that doesn’t work, look at the map above to determine if your state uses 15 kHz or 20 kHz spacing. Then follow the guidance in the HamRadioSchool.com article: What Frequency Do I Use on 2 Meters?
2m FM Simplex Frequencies (typical usage, check your local band plan)
In all cases, remember that these are shared frequencies so you need to cooperate with other radio hams. If you bump into existing activity, go ahead and try another frequency. There are usually plenty of quiet simplex channels around.
The one simplex frequency that everyone does seem to agree on is the National Simplex Calling Frequency: 146.52 MHz. For some thoughts on how to use that frequency see: The Use of 146.52 MHz.
I do think that frequency coordination bodies would be wise to provide guidance on simplex channels. This is not frequency coordination but it helps the amateur radio community be more effective in using the spectrum.
73 Bob K0NR
Postscript
There is a set of 2m simplex frequencies that show up in both the 15-kHz and 20-kHz band plans, making them nationwide simplex channels.
McQuaid Butte (W0C/SP-019) is a 9043-foot mountain near our cabin in Park County. Joyce/K0JJW and I activated it for Summits On The Air (SOTA) way back in 2013 but for some reason, we had not been back to it. The access road (Salt Creek Road, FS 435) is gated closed from January 1 to June 15 to protect wildlife habitat, so I suppose that is a factor.
McQuaid Butte (W0C/SP-109) as viewed from the south.
Today, we decided to make a return trip to the summit and activate it on VHF/UHF. I remembered that Salt Creek Road can turn into a muddy mess but today it was dry and easily drivable with most vehicles. Salt Creek Road is accessed from Highway 285, south of Fairplay but north of Antero Junction.
Access to McQuaid Butte is via Salt Creek Road, from Highway 285. The hiking route is shown in blue.
There is a good parking spot shown on the map above at 38.95791, -106.00790. A trail begins here, heading east. It used to be 4WD road but it is now closed to motor vehicles. This trail/road heads east and then curves to the north and eventually disappears. About that time, you’ll encounter a fence that needs to be crossed as you make your way towards the summit (approaching from the west). There are pieces of a trail here and there but its mostly bushwacking up the side of the summit. In places, there is substantial downed timber that can be stepped over and around but its mildly annoying.
Bob/K0NR relaxing on the summit.
Our route turned out to be 1.3 miles one way with 650 vertical feet. We both quickly made enough QSOs to qualify for activator points, working W0BV, KD0MRC, K0MGL, WZ0N on 2m FM (and some on 70 cm). The weather was excellent, resulting in a fun SOTA activation in the Pike National Forest.
We will probably return again to this summit because it’s a nice hike that is easy to get to from our cabin. It would also be a great choice for someone passing through on Highways 24 or 285.
73 Bob K0NR
Updated 06 July 2024:
We have been back to McQuaid Butte again and have refined the route a bit. As time has passed, the trail is starting to take shape, at least part of the way. The route is not that critical but these notes may make it just a little bit easier.Follow the old road, now a trail, from the parking location. It will curve around to the north and pretty much fade out. At this point, you should see the fence line that runs roughly east/west. Follow this fence line, walking on the south side. At some point, you need to jump the fence. There is a noticeable path on the other side of the fence which indicates where most people crossover. Keep walking along the fence line (on the north side), following the worn path that later turns north. The trail is very established here and easy to follow. Later it fades a bit but you should be able to follow it. Leave the trail somewhere around the marked waypoint (McQuaid – leave trail, 38.96536, -106.00255). Hike off-trail to the summit..it will get steeper and there is downed timber but not too bad.
In 2018, Joyce/K0JJW and I did a trip to the Black Hills area of South Dakota to do some SOTA activations: Dakota SOTA Adventure. We really enjoyed that part of South Dakota and figured we would be back. The Black Hills top out at ~7200 feet and the climbs are usually interesting but not very difficult. There are plenty of SOTA summits to choose from and the scenery is beautiful.
Bob/K0NR and Joyce/K0JJW standing in front of their RV (Winnebago Paseo). Photo: K0DAJ
This summer we found ourselves on a road trip returning to Colorado from Wisconsin, so we decided to swing by South Dakota for a couple of days. Joyce is getting close to achieving the coveted SOTA Mountain Goat award (1000 activator points), so we were looking to add to her activator score. I’m not saying we only did easy summits but we pretty much did easy summits.
Looking at the SOTA database, we scanned for summits with 6 points or higher that also had a significant number of activations. On this trip, we were driving our Class B RV (basically a big honkin’ van with RV gear in it). This limited our choice of SOTA summits to ones that can be accessed via reasonably good roads. We were fine with the typical gravel US Forest Service road in good condition but not anything worse.
We connected up with Don/K0DAJ who we met at a hamfest in Loveland, CO earlier this year. Don reviewed my list of potential summits and provided valuable feedback and additional summit suggestions. Don also alerted the local hams that might want to get on the air to work us. We use VHF/UHF exclusively for SOTA, so it is easy to get skunked if there isn’t anyone around. (I found out later that Gary/KT0A also passed along the word for us.)
The SOTA Summits
We identified seven summits that we wanted to activate, which would provide 56 new activator points. They ended up being clumped into three northern summits, around Deadwood, and four southern summits southwest of Rapid City. We camped at a USFS campground in between the two clumps, activating the northern three on the first day and the southern summits on the second day.
A map showing our seven SOTA summits in the Black Hills area.
Terry Peak (W0D/NW-002)
Terry Peak is a drive-up mountain with a short hike up to an observation platform. We approached Terry Peak from the south on Terry Summit Road, off of Hwy 85/Hwy 14A. The Black Hills National Forest map is very helpful for finding all of these summits.
We discovered that Terry Peak is quite the tourist spot and several groups of people showed up while we were there. It is also a big radio site with over a dozen towers and many more transmitters. When we parked, I noticed that the VHF/UHF mobile transceiver in the RV had both S meters pegged at full scale on all frequencies. Rut Roh, there is probably some RF around here. As usual, we had the Yaesu FT-90 transceiver which has a robust receiver in it, and it performed well. Still, I noticed that strong signals would abruptly drop down to being almost unreadable when some transmitter on the site turned on.
Bob/K0NR operating 2m FM on Terry Peak, using the Arrow 3-element Yagi antenna.
Mount Theodore Roosevelt (W0D/NW-023)
Mount Theodore Roosevelt turned out to be a pleasant surprise with a really good trail to the summit (0.4 miles one way, less than 200 feet elevation gain).
The trail as it just leaves the parking lot area.
Also, at the summit, there is a tower that was built in honor of President Roosevelt. This is a fun little hike with a monument at the summit.
We climbed the stairs leading to the top of the tower and operated from inside it. The tower reminds me of the many lighthouses we’ve been inside, but it’s not nearly as tall, and no light.
Bob/K0NR working 2m FM from inside the tower.
Unnamed Summit – 5110 (W0D/NW-038)
For a third summit, Don suggested an easy-to-access unnamed summit (5110), W0D/NW-038. We got there by driving south from Sturgis on Vanocker Canyon Road (26), then west on Galena Road to USFS 171.1. Driving a short distance north on 171.1 got us to an open area where we parked. Then it was just a bushwack up the hill (no trail), 0.3 miles one way with an elevation gain of 400 feet.
Location map of W0D/NW-038. The blue line is the hiking path that we took to the summit.
Second Day
Day 2 was a repeat of summits that we did in 2018, so I won’t repeat all of that here: Odakota Mountain (W0D/BB-002), Bear Mountain (W0D/BB-029), Coolidge Mountain (W0D/BB-012) and Rankin Ridge (BB-089). Refer to the 2018 trip report for more info.
This time, Odakota Mountain was extra special because Don/K0DAJ joined us on the summit.
Don/K0DAJ and Bob/K0NR at the parking spot for Odakota Mountain.
There is an actual summit marker for Odakota, so I had to get a photo of me standing there.
Bob/K0NR standing at the Odakota Mountain High Point marker.
Most of the contacts were on 146.52 MHz, a few on 446.0 MHz. Joyce’s log and my log are pretty much the same but I did work a few more stations. In summary, we had QSOs with these stations during the two days: AD0HL, K0DAJ, KB0QDG, KC0WC, KD0AYN, KF0AFX, KF0ARA, KF0XO, KF7ZQL, NC0K, W0LFB, W0NIL, W0SEB, W0SSB, W5LJM, W7LFB, WN6QJN and WS0V. Thank you to each and every one of you for getting on the air!
In Colorado, we pretty much work Colorado stations on VHF from the summits, so it was fun to contact other states on this trip. From Bear Mountain, we worked W0NIL and W0SSB in Chadron, NE, about 90 miles away. Not too shabby. From Terry Peak, we worked Clem/KF7ZQL in Carlile, WY at a distance of 50 miles. Not as far, but another state in the log.
We caught AD0HL and KF0ARA on unnamed summit 6167 (W0D/BB-008) from both Odakota Mountain and Bear Mountain, for two Summit-to-Summit (S2S) contacts. We also got two S2S contacts with Don/K0DAJ: Crooks Tower from Terry Peak and Terry Peak from Mount Theodore Roosevelt. It was kind of an S2S festival!
Don/K0DAJ and Terry/AD0HL worked us on 6 of the 7 summits, so they were our most prolific chasers. Thanks, guys! Finally, special thanks to Don for the helpful advice and joining us to play radio in the Black Hills.
We were able to get our minimum 4 QSOs on each summit and usually had many more. This resulted in 56 activator points, so we are quite happy with that. We have just sampled a few of the many SOTA summits in the Black Hills area, so I suspect that we will be back for more.
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 29th annual event and see how many of the mountaintop stations you can contact. The covers the entire weekend but many mountaintop activators will hit the trail early with the goal of being off the summits by noon due to lightning safety concerns.
The event includes all Summits On the Air (SOTA) summits, which adds over 1800 potential 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 Colorado SOTA web page at w0c-sota.org
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
Frequencies used during the event Activity can occur on any amateur band including HF and VHF. The 2m fm band plan uses a “primary frequency and move up” approach. The 2m fm primary frequency is 147.42 MHz. At the beginning of the event, operators should try calling on 147.42 MHz. As activity increases on that frequency, move on up the band using the 30 kHz steps. Don’t just hang out on 147.42 MHz…move up! The next standard simplex frequency up from 147.42 MHz is 147.45 MHz, followed by 147.48 and 147.51 MHz.
For a complete list of suggested HF, VHF and UHF frequencies see this web page.
Warning: Climbing mountains is inherently a dangerous activity.
Do not attempt this without proper training, equipment and preparation.
There is a lot more information available here: www.ham14er.org
Sponsored by The Colorado 14er Event Task Force
Also be aware that the SOCAL SOTAFEST is happening on the same weekend, which means there will be plenty of SOTA activity on the ham bands! See http://socalsota.com
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.
