We have been looking for an opportunity to activate a SOTA summit in our home state of Indiana. Joyce/K0JJW and I were both born there and misspent our youth there. Of course, you might be thinking “there are SOTA summits in Indiana?” Yes, there are three. Two of them are on public land, one is on private land and apparently inaccessible. These three summits are in the southern part of the state, not too far from the hills of Kentucky.

We were headed south towards the Smoky Mountains and passing through southern Indiana and decided to activate Jackson County HP (W9/IN-002). First, we camped at one of Indiana’s best state parks: Brown County State Park, about an hour away from IN-002. The next day we headed to the Jackson-Washington State Forest, where the summit is located. The Indiana Dept of Natural Resources supplies this trail map. As you’ll see, there are a number of trails that can take you to IN-002, but we chose the most direct route, starting at Knob Lake.

There is a State Forest campground around Knob Lake, so that would be another option for camping out.

We headed up a gated road that was labeled “Trails 2 and 3”. This road narrowed into a trail and we took a left turn at the Trail 2 sign. This is slightly tricky because Trail 2 goes off to the left and it continues on straight. The “left” Trail 2 ascends up to IN-002, for a total elevation gain of 465 feet and a distance of 0.7 miles. Go Left.

Once on top, we unpacked our recently purchased Icom IC-705 transceiver. This seemed like a good choice for this activation. While we were sure to try good old 2m FM, there was a good chance that we would get skunked on VHF at this rural and not-too-high summit. Sure enough, 2m FM was silent, even using the mighty 3-element Yagi antenna.

Next, we set up the end-fed halfwave for 20 meters, hoisted by the popular extendable fishing pole. OK, I admit that I had to do some fiddling around with the antenna to get the SWR to behave. Somehow, the test run at the campsite the day before was not sufficient. The SWR was way too high for the “I like 50 ohms” Icom, so some adjustments were required. After an unreasonable amount of fiddling, we put out an SSB signal on 20 meters that seemed good.

The band conditions were not great but they were not terrible. Calling CQ did not seem to work very well, so we tuned around and worked a number of Parks On The Air (POTA) stations to get our 4 QSOs. At that point, we declared victory and headed back down the hill.

This summit was easy to access and an easy hike. If you are in the area and want to knock out a Hoosier SOTA activation, this one is a great choice.

73 Bob K0NR

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

Pikes Peak (W0C/FR-004)

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

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

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

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

Mt Herman (W0C/FR-063)

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

Threemile Mountain (W0C/SP-107)

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

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

Conclusions

So what conclusions can we draw from this analysis?

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

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

73 Bob K0NR

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In January 2021, I wrote about the North America Adventure Frequency (NAAF) which originated in the North America SOTA community. About a year later, how is this working out? Is anyone actually using it?

A few key points to remember:

• 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.

I’ve noticed that quite a few SOTA activators are posting Alerts and Spots with 146.58 MHz. For example, K2CZH and KN6OUU posted these SOTA Alerts:

Here N8FN and WJ7WJ are spotted on 146.58:

Of course, the National 2m FM Calling Frequency (146.52 MHz) still gets a lot of use. I tend to use Five Two when I am activating in rural areas, some distance from the major cities. The frequency is usually quiet AND there are a number of folks that tend to monitor it. I use the NAAF when I’m near the big cities (Denver, Colorado Springs, Boulder, …). Putting out a Spot is usually important, to get the attention of the more dedicated SOTA chasers watching SOTAwatch. That is, I don’t think there are a lot of people monitoring the frequency (compared to 146.52), so a spot on SOTAwatch gets them on frequency.

Some of the Parks On The Air (POTA) activators are also using NAAF. Here’s an activation alert by KD7DTS from the POTA website:

So I think the NAAF is working as intended. It is not a replacement for 146.52 MHz but a standard choice for portable operating when you want to stay off the calling frequency. Thanks to everyone that has given it a try.

73 Bob K0NR

The post How’s That North America Adventure Frequency Working? appeared first on The KØNR Radio Site.

Stuart/KB1HQS has been experimenting with various modifications of the Arrow II antennas. Recently, he put together a video of the various mods, well done and interesting:

Ultimate Arrow Antenna Modifications

I am a big fan of the Arrow II style antennas for VHF SOTA. Initially, I used the dualband 2m/70cm antenna for satellite work as well as mountaintop activity. This started before SOTA was even a thing, as I hiked in the Colorado mountains and made radio contacts just for fun. These days, we normally carry the 2m-only version of the antenna, with split boom and 3 elements. My personal seamstress (Joyce/K0JJW) worked up a really nice rollup case for it. Sometimes, we’ll take along a separate 5-element 70 cm Yagi, which can remain fully-assembled and strapped onto my pack.

All antennas are a compromise between cost, size, weight, performance, convenience and durability. I have found that the 3-element Yagi from Arrow fits my needs really well. I have not been motivated to modify it. The Arrow antenna has a gain of about 6 dBd and is 37.5 inches long. We handhold the antenna and that is about as big/long as I’d like to hold. I am still in search of a higher-gain antenna for those special situations when I know that a few more dB of gain could make a difference. I’ve not really found anything I like. A longer boom would likely require a mast and, therefore, a guy system, which adds more weight and complexity.

Antennas are a never-ending source of options and experimentation, so go out and try something new.

73 Bob K0NR

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I’ve been interested in the idea of a microphone-centric radio and wrote about it here: How About a Mic-Centric Mobile Transceiver? Shortly thereafter, I discovered that QYT has introduced a VHF/UHF ham rig that has the display and controls in the microphone (Model KT-WP12).

You may want to watch the video by Tech Minds, which does a good job of introducing the radio.

I was very keen on trying this radio out, so I purchased one, paying about $110.

On the Bench

First, I did some bench tests to check the basic performance of the radio. The receiver sensitivity, transmit frequency and FM deviation all looked very good. The one specification that was disappointing was the RF power output. On the 2m band, the output power was 20.6 W, while the 70cm band was 15 W. The specification for the radio is 25 W. The power was measured using an HP 8920A RF Communications Test

I’ve noticed this on other radios from Chinese manufacturers: the basic specs of the radio check out, except the RF power level is low.

User Interface

As you might expect, cramming all of the controls into the microphone is a challenging user interface design. I spend quite a bit of time playing with the radio at home before actually using it on the air. Overall, I found the user interface to be acceptable, but several areas that should be improved.

QYT relies on the menu system to provide control of many of the settings. This is similar to the various Chinese handhelds where you push the MENU button to access the menus, followed by UP/DOWN to sequence through the menus, followed by MENU to access the specific setting. Then the UP/DOWN buttons choose the value of the setting and another push on MENU to accept it. The volume control setting is buried in this menu system, which seems like a poor choice. Fortunately, Mick/M0VMK pointed out that the volume can also be set by enabling the monitor feature (big button on the top of the mic) and hitting UP/DOWN.

This design depends too much on the menu system. A few user-defined buttons would be a real help. This radio could benefit from a serious redesign using User-Centered Design.

This radio has one receiver but allows for three independent frequencies to be displayed simultaneously. There is a scanning mode that tries to emulate a multi-receiver radio. This too is all too common with the Chinese radios…somehow they have it in their heads that this adds value for the user. My experience is that it mostly confuses the user. Most users would be better served with a single frequency display, supplemented with dual-watch and scanning capability.

You probably won’t be surprised that the user manual is terrible, also common with Chinese manufacturers, but this one is particularly bad. Same with the programming software…it mostly works (I had a few crashes) but it is poorly written.

On The Air (SOTA)

I was very interested in trying out this radio for Summits On The Air (SOTA) use. The idea is that the radio can be stuffed into a fanny pack, with the microphone, speaker, display, and controls in your hand.

The basic concept of holding everything in the palm of my hand worked out quite well. The display was visible in bright sunlight, the speaker audio was clear, and the microphone worked great. I made a number of SOTA contacts and received good signal reports. I held the microphone in one hand and pointed the 3-element Yagi antenna with the other hand. (Joyce/K0JJW assisted with logging and we took turns working the SOTA chasers.)

As soon as I fired up the radio, I heard interference on the 2m band, not very strong but noticable. It sounded like it was coming from an FM broadcast station. Pointing the Yagi antenna in the direction of the FM station on the adjacent mountain seemed to confirm the source. I did not hear any interference on the 70cm band. I’ve operated from this SOTA summit before and have not noticed any interference with other equipment, including Yaesu handhelds. Also, I switched to my Yaesu FT-90 and the broadcast station was not heard. As various people have suspected, this indicates that the receiver in the QYT is not very robust in terms of rejecting off-channel signals. Of course, this is an anecdotal report, not based on bench measurements.

I also encountered an anomaly where after my transmission, the radio did not revert back to receive quickly. There was a few seconds where no audio was coming out of the transceiver. This caused me to miss a few responses to my CQ call. This issue requires some additional investigation. It may have just been operator error on my part. However, I suspect that the radio was probably locking onto another frequency but I am not sure (see previous comments about the three frequency scanning mode). So file this issue under “stay tuned for more information.”

Note that I did not use the radio very much on repeaters, focusing on SOTA simplex operating with no transmit offset or CTCSS.

Conclusion

On the positive side, I really like the microphone-centric approach that this radio uses. The user interface can be improved but it is good enough.

The two big limitations of this radio are 1) low RF power output and 2) weak off-channel receiver performance. Now you might say that the RF power is not off by that much but my interest is having a SOTA radio that greatly exceeds the power of a typical 5 W handheld. On the 70 cm band, this radio only put out 15 W, so only 4.7 dB better than a handheld. The poor receiver performance will tend be an issue on summits that have radio installations nearby. In some cases, this can completely prevent a VHF SOTA activation.

I will probably use this radio again for SOTA activations but I’ll be bringing along a backup rig, just in case.

The post Checking Out The KT-WP12 Transceiver appeared first on The KØNR Radio Site.

Lately, Joyce/K0JJW and I have been doing combined Summits On The Air (SOTA) and Parks On The Air (POTA) activations. Most of the SOTA summits we activate are inside parks as defined by POTA. Our primary focus is using VHF/UHF from SOTA summits with POTA is being a nice addition. Although the two programs have a lot of similarities, there are some significant differences that need to be understood.

SOTA / POTA Differences

Let’s compare the two programs to understand the differences, so you can have a successful activation with both. We will focus on differences when doing an activation so this is not an exhaustive list.

• Summits Vs Parks. Well, this is the fundamental difference. Summits tend to be small in area, defined by a specific lat/lon coordinate and the surrounding activation zone (AZ). The activation zone is roughly defined as the area surrounding the actual summit, staying within 25 vertical meters. Parks can be almost any size and may cover many square miles. Both SOTA and POTA maintain lists of official summits or parks, so it should be clear whether one of these is valid for an activation.
• Accessibility. While there are drive-up and easy walk-up summits, most SOTA summits require a hike. Many of them are physically challenging. Parks often have easier, park-like access. Or you can always do a 50-mile backpack trip for a POTA activation.
• Equipment restrictions. SOTA allows you to reach the activation zone in a vehicle but you must move away from the vehicle an unspecified distant and operate totally independent of the vehicle. On drive-up mountains, our practical application of this rule is to load up our normal SOTA gear into backpacks, hike away from the vehicle, and set up for the activation. SOTA requires the use of portable power sources but not fossil-fuel generators. This pretty much means battery power, perhaps augmented with solar panels. POTA does not have such restrictions, so if you meet the SOTA requirements you’ll be valid for both.
• Scoring. SOTA emphasizes the accumulation of activator and chaser points, while layering in other challenges such as Summit-to-Summit (S2S) scores. Each summit has a point value assigned to it, based on elevation. In POTA, all parks are created equal and the main focus tends to be on the number of activations and the number of parks hunted (chased).  POTA also has awards for the number QSOs. For example, the Kilo Award is achieved by making 1000 QSOs from a single park (usually over multiple activations). Both programs have quite a bit of variety and flexibility built into their awards and operating objectives, which is one of the reasons people enjoy the programs.
• Successful Activation. SOTA requires only one radio contact for a successful activation. But to receive point credit for the summit, which is what most people are after, you need to make at least 4 contacts. So most SOTA activators define success as getting at least four contacts. The 4 SOTA contacts must be with 4 different stations, with no credit for working the same station on multiple bands. In contrast, POTA requires 10 QSOs for a successful activation.  POTA does count QSOs with the same station on different bands. For example, an activator could obtain the required 10 POTA QSOs by working just two stations on 5 different bands.
• Same Location QSOs. A SOTA activator does not get credit for working another station on the same summit. That is, the other station must be outside of the summit activation zone to be counted. POTA allows an activator to work another activator in the same park for QSO credit. In fact, the activators can receive park-to-park credit for such a radio contact.

VHF SOTA and POTA

Racking up lots of contacts on VHF/UHF from a summit can be a challenge, dependent mostly on the range of your gear and the ham population in the area. Most of the time, we can get four contacts without too much trouble but at times even that can be a challenge. Getting ten contacts for POTA raises the bar higher.

We noted that most of the hams we work on 2m FM are also workable on 70 cm FM. So an easy thing to do is to ask 2m chasers (hunters) to switch over to 70 cm and work us there, doubling the number of POTA-valid QSOs. Interestingly, the SOTA QSO count recorded in the database includes these QSOs. (But you must have contacted at least four unique stations to get the summit points.)

Because Joyce and I usually activate together, we can also work each other for POTA credit. I have discovered that many POTA activator teams make it a standard practice to pull out a couple of handheld radios and work each other on 2m FM when they first set up. OK, maybe that’s not the most exciting QSO of the day, but it is allowed.  With a dual-band HT, you can make two QSOs this way. And it is a good idea to put out a call on 2m FM to work any locals that might be hunting parks. On a summit, these QSOs would not be valid for SOTA, unless one of the operators leaves the activation zone. Yes, we’ve done that, too, taking turns hiking down out of the AZ to make a quick contact.

Summary

This covers some of the things we’ve learned about doing combined SOTA and POTA activations. Again, this is with an emphasis on VHF/UHF operating. You should study the SOTA and POTA rules carefully because this article does not cover everything. However, some of the issues I’ve outlined here are not obvious from the SOTA and POTA rules, so I hope you find this article helpful.

73 Bob K0NR

The post Combined SOTA / POTA Activations appeared first on The KØNR Radio Site.

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

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

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

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

Sneffels to Pikes

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

Capulin Mountain

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

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

Capulin Mountain (W5N/SG-009) VHF SOTA

Mount Scott

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

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

Threemile Mountain

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

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

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

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

Power and Antenna

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

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

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

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

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

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

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

Summary

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

73 Bob K0NR

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