A VISUAL + AUDIO AIR CHECK OF DIGITAL MODE FT8 QSOs, ON THE 30-METER BAND

Here is a video capture of the reception and transmission of many digital FT8-mode amateur radio high-frequency (HF; Shortwave) communication signals. This video is a front-seat view of the software operation performed at the radio room of amateur radio operator, NW7US, Tomas Hood.

The software packages demonstrated are installed and operational on a modern personal computer. The computer is connected to an Icom IC-7610 radio transceiver, controlled by the software. While there is no narration in the video, the video provides an opportunity for you to see first-hand how typical FT8 operations are performed. The signals can be heard.

[embedyt] https://www.youtube.com/watch?v=VROGz-x9NyE[/embedyt]

The frequency used for the FT8 communication in this video is on or about 10.136 MHz, in the 30-Meter shortwave amateur radio allocation (or, band). As can be seen, the 30-Meter band was active at this time of day (0720 UTC, onward–local nighttime).

In this video you see (and hear) NW7US make two-way contacts, or QSOs, with stations from around the country and the world.

There are amateur radio operators within the amateur radio community who regard the FT8 digital mode (FT8 stands for “Franke-Taylor design, 8-FSK modulation“, and refers to the mode created by Joe Taylor, K1JT and Steve Franke, K9AN) as robotic (automatic, automated, and unattended) computer-to-computer communications, and not ‘true’ human communications–thus negating the spirit of ham radio. In other words, FT8, in their opinion, is not real amateur radio. While they pontificate about supposed automated computer communications, many of those holding this position have not installed and configured the software, nor tried communicating with the FT8 digital mode. They have perhaps formed their anti-FT8 opinion in a vacuum of knowledge. (This writer has other issues with FT8, but not on this point–see below)

As you watch the video linked in this article, consider these concepts:

+ A QSO is defined (as per common knowledge–see below) as the exchange of at least the minimum information needed as set by the requirements of a particular award, or, as is defined by law–for instance, a QSO would have at least an exchange of the legal call sign assigned to the radio station and/or control operator, the location of the station making the transmission, and a signal report of some kind about the signal received from the other transmitter at the other end of the QSO.

+ Just how much human involvement is required to make a full FT8 QSO? Does WSJT-X software run all by itself, with no human control? Is WSJT-X a robot, in the sense that it picks a frequency, then initiates or answers a CQ call automatically, or is it just powerful digital-mode software that still requires human control?

The video was captured from the screen of the PC running the following software packages interacting together as a system:

+ WSJT-X: The primary software featuring the digital mode, FT8. (See below for some background on WSJT-X software.)

+ JTAlert: Provides several audio and visual alert types based on decoded Callsigns within WSJT-X.

+ Log4OM, Version 2: A full-featured logging program, which integrates well with WSJT-X and JTAlert.

+ Win4IcomSuite: A full-featured radio controlling program which can remote control rigs, and provide control through virtual communication port-sharing.

+ Com0Com: The Null-modem emulator allows you to create an unlimited number of virtual COM port pairs and use any pair to connect one COM port based application to another. Each COM port pair provides two COM ports. The output to one port is the input from other port and vice versa.

As mentioned, above, the radio used for the communication of FT8 at the station, NW7US, is an Icom IC-7610 transceiver. The antenna is an off-center fed dipole that is over 200 feet in total length (end-to-end measurement).

Some Notes:

About WSJT-X

WSJT-X is a computer program used for weak-signal radio communication between amateur radio operators, or used by Shortwave Radio Listeners (SWLers; SWL) interested in monitoring the FT8 digital communications between amateur radio operators. The program was initially written by Joe Taylor, K1JT with Steve Franke, K9AN, but is now open source and is developed by a small team. The digital signal processing techniques in WSJT-X make it substantially easier for amateur radio operators to employ esoteric propagation modes, such as high-speed meteor scatter and moonbounce.

WSJT-X implements communication protocols or “modes” called FST4, FST4W, FT4, FT8, JT4, JT9, JT65, Q65, MSK144, and WSPR, as well as one called Echo for detecting and measuring your own radio signals reflected from the Moon. These modes were all designed for making reliable, confirmed QSOs under extreme weak-signal conditions. JT4, JT9, and JT65 use nearly identical message structure and source encoding (the efficient compression of standard messages used for minimal QSOs). They use timed 60-second Transmit/Rreceive (T/R) sequences synchronized with UTC (Universal Time, Coordinated). JT4 and JT65 were designed for Earth-Moon-Earth communications (EME, or, moonbounce) on the Very-High Frequency (VHF), Ultra-High Frequency (UHF) and microwave bands. JT9 is optimized for the Medium-Frequency (MF) and High-Frequency (HF) bands. It is about 2 dB more sensitive than JT65 while using less than 10% of the bandwidth. Q65 offers submodes with a wide range of T/R sequence lengths and tone spacings.FT4 and FT8 are operationally similar but use T/R cycles only 7.5 and 15 seconds long, respectively. MSK144 is designed for Meteor Scatter on the VHF bands. These modes offer enhanced message formats with support for nonstandard call signs and some popular contests. (The MSK in MSK144 stands for, Multiple Frequency Shift Keying.)

FST4 and FST4W are designed particularly for the Low-Frequency (LF) and MF bands. On these bands, their fundamental sensitivities are better than other WSJT-X modes with the same sequence lengths, approaching the theoretical limits for their rates of information throughput. FST4 is optimized for two-way QSOs, while FST4W is for quasi-beacon transmissions of WSPR-style messages. FST4 and FST4W do not require the strict, independent time synchronization and phase locking of modes like EbNaut.

As described more fully on its own page, WSPR mode implements a protocol designed for probing potential propagation paths with low-power transmissions. WSPR is fully implemented within WSJT-X, including programmable band-hopping.

What is a QSO?

Under the title, CONTACTS, at the Sierra Foothills Amateur Radio Club’s 2014 Technician Class webpage, https://www.hsdivers.com/Ham/Mod15.html, they teach,

An amateur radio contact (called a QSO), is an exchange of info between two amateur radio stations. The exchange usually consists of an initial call (CQ = call to all stations). Then, a response from another amateur radio operator, and usually at least a signal report.

Contacts can be limited to just a minimal exchange of call signs & signal reports generally between amateurs previously unknown to each other. Very short contacts are usually done only during contests while longer, extended ‘rag chews’ may be between newly met friends with some common interest or someone you have known for a long time.

Wikipedia has an entry for QSO, too.

My Issue With FT8 and WSJT-X

I have written in the past, on this website, about an issue that came about during the course of the development of the WSJT-X software package. The development team decided to widen the slice of ‘default’ (pre-programmed) frequencies on which to operate FT8. The issue was how the choice of new frequencies was made, and what choices were implemented in an upcoming software release. Read more about all of this, in these three articles:

+ Land (er, FREQUENCY) Grab (Part 1)

+ One Aspect of Amateur Radio: Good Will Ambassadors to the World

+ In Response — Can’t We All Just Get Along?

Has this issue been resolved? For now, yes. There appears to be more coordination between interested groups, and the proposed new frequencies were removed from the software defaults in WSJT-X. At least, up to this point, at the time of publishing this article.

..

Decibels are commonly used in electronic communications to describe and compare signal levels. I’ve often heard that one dB is considered to be the smallest change that a typical person can detect by ear. I recently came across this website audiocheck.net that is set up to generate different audio tones and to do a blind test of how small of a change you can detect.

I started with testing for 6-dB and 3-dB changes. Easy Peasy. Then I tried the 1-dB test. I could detect the change in level fairly consistently but I did have to concentrate. Continuing on to the 0.5-dB change, I had a very high failure rate. It was very difficult to detect that small of a change. So I have to conclude that 1 dB is about the limit for a change I can hear.

How about you? Take the test on the website and let us know how you did.

There are many other audio tests to explore on that site, including the highest frequency you can hear, the minimum pitch change you can hear, etc. Check it out: www.audiocheck.net

73 Bob K0NR

The post Can You Hear a 1-dB Change? appeared first on The KØNR Radio Site.

Lately, I’ve been talking with people in search of basic radio communications for their friends or family. They end up talking to me because someone steered them to ham radio as a solution and I teach ham radio license classes. Of course, I am happy to pull them into the wonderful ham radio world but sometimes the General Mobile Radio Service (GMRS) might be a better way of meeting their needs.

I have a GMRS license and have written about it. See GMRS: The Other UHF Band.  GMRS is a good fit for local communications, perhaps just using simplex or with repeaters, if available in your area.  FCC regulations (Part 95) require you to have a license (and pay a fee) to use GMRS. Unlike ham radio, the license does not require you to pass an exam and the license is valid for you and your family members.

Common Uses

GMRS works well for family communication “around town” or some local area. Depending on the type of equipment used, simplex range of 10 or 15 miles is achievable, maybe more. The use of repeaters can extend this a lot further. You might even decide to put a GMRS repeater on the air, which is not too difficult of a project.

Another common use of GMRS is when a group is traveling down the highway in multiple vehicles. Yes, you might be able to just use your mobile phone to stay in touch but a two-way radio may be a better solution (especially when mobile phone coverage is poor or non-existent). Many off-road vehicle clubs have discovered GMRS and use it for communicating during trail rides.

GMRS is also a great tool for outdoor activities such as camping, hunting, hiking and skiing. It is a handy way of staying in touch with your tribe, while not depending on the mobile phone network.

GMRS Is Not FRS

GMRS often gets confused with the Family Radio Service (FRS). They both include the use of inexpensive, low-power handheld radios and they share many of the same frequencies. When the FCC authorized FRS, GMRS was already an established radio service and it squeezed FRS into the same band. FRS radios were limited to lower output power, so many manufacturers decided to offer combination FRS/GMRS radios, which operated at higher power levels. The user was supposed to obtain a GMRS license to use this type of radio but most people didn’t bother with it. (Most people probably didn’t even know of the requirement.)  The FCC also specified 2.5 kHz (half deviation) FM for the FRS radios on the same channels as the existing 5 kHz deviation GMRS radios. Intermingling an unlicensed radio service with a licensed service was probably not a wise move. In general, the FCC regulations caused a lot of confusion between the two services.

In 2017, the FCC adopted a major revision to the GMRS rules to clean up some of the problems with the service. In particular, the regulations now prohibit the sale of combination FRS/GMRS radios. A great idea but a bit too late in the game.

The GMRS rules are pretty easy to understand, so take a look here: FCC Part 95 – Personal Radio Services

Equipment

There are basic handheld transceivers for GMRS. They look and act a lot like the FRS radios that are widely available, but GMRS can provide more capability. An advanced handheld radio will have support for using repeaters (transmit offset) and higher power (up to 5 watts).

To dramatically improve the radio range, you can use GMRS mobile and base stations that can run even more power, up to 50 watts. More importantly, you can use external antennas on your vehicle or your house. These can make a huge difference in performance. (FRS is limited to handheld transceivers and the permanently-attached rubber duck antenna.)

For radio amateurs, this should all sound pretty familiar. GMRS looks and acts a lot like an FM transceiver on the 440 MHz (70 cm) band. It is a great alternative for local radio communications for people not interested in a technical hobby such as amateur radio.

The post GMRS: Basic Radio Communications appeared first on The KØNR Radio Site.

The Summits On The Air (SOTA) program originated in the United Kingdom but has propagated to most countries around the world. The program came to Colorado on May 1st, 2010 with Steve/WGØAT sending a CQ from Mount Herman, just west of Monument. Today, the SOTA program in Colorado (called WØC-SOTA) is very active with roughly 180 activators that operate from Colorado summits.

To celebrate our 10th Anniversary, WØC-SOTA is organizing a 10-10-10 Event with a challenge for Activators and Chasers alike. (Activators operate from summits, Chasers try to contact them.)

Activator challenge: Activate 10 (or more) 10K feet (or higher) summits (in Colorado/WØC) within 10 days.

Chaser challenge: Chase Activators on 10 different (or more) qualifying WØC summits (10K or higher) within the 10 days.

Event Date: We will kick-off the event in conjunction with the Colorado 14er event on August 7th, 2021 and conclude on August 16th.

Everybody is invited to participate, either as an Activator or a Chaser. Block off these days in your calendar now and start planning for how you can participate. Feel free to operate as much or as little as you would like. It is all about having fun messing around with radios. Any HF, VHF or UHF band can be used for making SOTA contacts, with the most popular ones being 40m (CW & SSB), 20m (CW & SSB) and 2m (FM).

Note that the recommended 2m FM frequencies for the 14er event have changed to:

146.580 FM   North America Adventure Frequency
146.550 FM    Simplex Alternate
146.490 FM    Simplex Alternate
146.520 FM    National 2m FM Calling Frequency
(as needed, please don’t hog the calling frequency)

There will be a leaderboard on the W0C-SOTA website showing all participants who meet one of the challenges. More details will be announced on the WØC-SOTA Website as soon as they are hashed out.

For more information on the SOTA program in general, see the worldwide SOTA website.

Full Disclosure: May 1 is actually the 11th Anniversary, but the COVID-19 Pandemic interfered in 2020, so we are catching up.

The post 2021 Colorado SOTA and 14er Event appeared first on The KØNR Radio Site.

When discussing signal levels and power output, hams like to say things like:

Using higher power isn’t important because it only gives you one additional S unit

and

You’ll lose some power in the coax but you won’t even notice a few dB

These statements are often true and at the same time may be completely wrong. I’ve noticed that radio amateurs pushing the limits of their station pay close attention to every decibel they gain or lose. This is especially true at VHF/UHF frequencies where signals may be weak. A dB here, a dB there, the next thing you know it adds up to something big!

Definitions

First, let’s make sure we have a few definitions right. The decibel (dB) is defined as the ratio of two power levels:

dB = 10 log (P2/P1)

One decibel corresponds to a 26% increase in power level. A well-known rule of thumb is that doubling the power corresponds to a 3 dB increase. Similarly, chopping the power in half drops the signal level by 3 dB.  A 10 times increase in power is 10 dB. (Voltage can also be used to calculate decibel relationships but to keep it simple, I’ll just use power.)

The S Unit is normally defined as a 6-dB change in signal level, which is a factor of 4 in power. (Your S meter may or may not actually follow this rule but that is a topic for another day.)

Power Level

Let’s compare a few different power levels to get a feel for how decibels and S units behave. Let’s use a 5 watt QRP level as our reference power. If we crank up the power to 100 watts, we  have 10 log (100/5) = 13 dB increase in power level. This is slightly more than two S units (2 x 6 dB), so we would expect the S meter on the other end to read 2 units higher.

Now suppose we kick in our linear amplifier to produce a 1 kilowatt RF signal. This power level is 10 log (1000/5) = 23 dB higher than the 5 watt signal, or roughly four S units.

Now if our QRP signal was a solid S9 to start with, adding another 23 dB on top of it may not be that significant. The station can be heard at S9 or can be heard even louder at S9 + 23 dB. Except when there’s a pile of stations all calling that rare DX…then the loudest station tends to be heard. Crafty operating skill and good luck may overcome the power difference.

But consider the other extreme. Our QRP station is being heard right at the noise floor on the receive end. The two stations are struggling to complete the contact and the propagation path degrades by 2 dB. Now the QRP station is below the noise and uncopyable. We increase our power to 100 watts and gain 2 S units…still not very strong but the ability to receive the signal improves dramatically. Crank it up to 1000 watts and you gain another couple of S units and the copy is quite good. The key point is that changes in signal level matter most at the margin, when you can just barely copy the signal. (By the way, there is nothing wrong with running QRP…many ops enjoy the challenge of making contacts with low power.)

At the receiver, our ability to recover the signal is determined by the signal-to-noise ratio (SNR). A higher noise floor at the receiver means it will be more difficult to hear the signal coming in. The type of modulation being used may also make a big difference. Good old CW and the WSJT modes use a narrower bandwidth and will get through when wider-band modulation (SSB, FM) fails. In all cases, a stronger signal works better.

Antennas

Antenna systems also increase our signal level…and they do it for both transmit and receive. I recently did some comparisons of VHF antennas from a SOTA summit. My 2m Yagi antenna has 6 dB of gain (referenced to a dipole) and my comparisons showed that the performance of this antenna was good enough to pull some signals out of the noise to be solid copy. This occurred when the other station’s signal was right at the noise floor (using my lower gain antennas) such that the 6 dB improvement had a significant impact.

Sometimes hams will say that VHF is just line-of-sight propagation and that the signal level doesn’t matter much. This is partially true but often we are stretching for contacts beyond line-of-sight. Take a look at this article: The Myth of VHF Line-Of-Sight. This is another case where we are operating on the margin and every dB matters.

Feedline loss can cause us to lose decibels, which impacts both transmit and receive performance. If your coaxial cable is short, then the losses may be negligible. Increasing cable length and increasing frequency produce more loss. For example, 100 feet of RG-8X has only 1.1 dB of loss at 10 MHz. Increase the frequency to 146 MHz and the loss jumps to 4.5 dB, using the Times Microwave cable calculator. That means 50 watts of power at the transmitter turns into 17.7 watts at the other end of the cable. Using LMR-400 coax reduces the attenuation to 1.5 dB.

Summary

You can choose to ignore small changes in your signal level. A dB here or there may not make a big difference with casual ham radio operating. But these losses tend to add up and may become significant. Most importantly, just a few dB may be the critical difference between making a radio contact or not, when operating at the margin.

The post A Decibel Is Still A Decibel appeared first on The KØNR Radio Site.

The Summits On The Air (SOTA) program was designed with hiking/climbing in mind but some SOTA summits have roads that go to the top. Some notable ones that come to mind are Pikes Peak (W0C/FR-004), Mount Scott (W5O/WI-002), Mount Coolidge (W0D/BB-012), Sandia Crest (W5N/SI-001), Mount Greylock (W1/MB-001) and Mount Mitchell (W4C/CM-001). There are also summits that have trams, trains and chairlifts that provide easy access.

Some SOTA activators dismiss drive-up summits as not being the real SOTA experience. Everyone is entitled to their point of view and can choose their summits accordingly. I am too pragmatic (read: lazy) to worry about that. If there’s a road to the top, I am probably going to use it, whether it’s a serious 4WD road or a well-paved surface.

The Rules

The specific terminology used in the various SOTA Association Reference Manuals (ARMs) may vary a bit so I will refer to the Colorado (W0C) ARM:

The SOTA General Rules state that the method of final access to the radio operating location must be nonmotorized. The General Rules do not specify the distance, either vertical or horizontal, that this final access must cover. The use of non-motorized vehicles (e.g. bicycle) or pack animals to enter the Activation Zone (AZ) is permitted. Operations must not be in, or in the close vicinity of a motor vehicle, cannot use a permanent electrical power source, nor use a fossil fuel generator in any fashion. No part of the station may be connected in any way with the motor vehicle. All equipment must be operated from portable power source (batteries, solar cells, etc).

The intent of the rules is quite clear: SOTA is not a motorized activity…you need to operate independently of a motor vehicle. Like most rules though, there are shades of grade on the interpretation. Just how independent do we need to be? Unless you started your hike from your home location, all SOTA activations have some form of mechanized transport involved. It is just a question of how far you ride and how far you walk.

Some SOTA Associations used to suggest or require a qualifying hike for drive-up summits. This means that you hike down from the summit for some minimal vertical distance (100 feet or so) and then hike back up to “qualify” your activation. This idea seems to be on the way out and this language was removed from the W0C ARM some years ago. However, your Association may still encourage it or you could just decide that it is a practice that you want to do. (You can find ARMs here.)

Some new SOTA activators look at the rules and suggest they are too restrictive. They argue that people with limited mobility should be allowed to operate from a vehicle. These requests have been heard before and are immediately rejected. I do think the SOTA Management Team has crafted a workable approach that keeps SOTA oriented towards backpack portable operating while still allowing for minimal mobility.

Our Approach

The guiding principle that we use on our drive-up or tram-up summits is to use our normal backpack-portable SOTA station. However we get to the summit, everything goes into a pack which is carried for some minimal distance away from the vehicle, tram or chairlift. This keeps the drive-up SOTA station configured just like the hike-in variety: compact, lightweight, no chairs, no tables (unless they fit into our packs.) This avoids the “Field Day” style set up with lots of gear carried from the vehicle via multiple trips to create a Big Portable Station. Sometimes the drive-up summits are overrun with people, so a short hike away from the crowds can get you to a quieter spot.

That’s how we do it. What are your thoughts?

73 Bob K0NR

The post About Those Drive Up SOTA Summits appeared first on The KØNR Radio Site.

A perpetual ham radio question is always which antenna is best? I have several different antennas and antenna configurations for working VHF SOTA and decided to do some comparisons.

To test out some of our 2m SOTA antennas, Joyce/K0JJW and I went to Eagle Rock (W0C/SP-113) with an elevation of 9710 feet. I did the radio operating while Joyce collected the data. Eagle Rock pokes up out of South Park, which is a broad, high plain in central Colorado. This summit is kind of “mid-range” for Colorado…not as high as the 14ers but with significant elevation and prominence (~500 feet). It also was close enough to a number of SOTA chasers so I could get some good S-meter readings to compare antennas. On the summit, there is a clear 360-degree horizon, dropping off quickly in all directions.

Antennas Tested

Antenna A is our GO-TO antenna for VHF SOTA is the 3-element Yagi from Arrow Antenna, handheld so the boom is about 5 feet off the ground. Arrow does not specify the gain on this antenna but it has been measured at the Central States VHF Society conference to be ~6dBd.

Antenna B is a dual-band J-pole manufactured by N9TAX, supported by a telescoping fishing pole commonly used by SOTA activators. A J-pole has a halfwave radiator, so the gain is about 0 dBd, the same as a dipole.

Antenna C is an RH770 telescopic antenna mounted on a monopod, using a bracket that I made. See VHF/UHF Omni Antenna for SOTA Use. This antenna is a halfwave on 2 meters, so again we’d expect the gain to be ~0 dBd. The antenna is supported by a monopod which I usually just stick into the ground or strap to a bush.

The three antennas being tested were driven with short coaxial cables fitting with BNC connectors for easy changes. The transceiver was a Yaesu FT-90 powered by a small Bioenno battery.

Chaser Stations

I put the word out that I’d be doing some antenna comparisons and five chasers showed up to assist. (There were are few other chasers that were too close to Eagle Rock such that the S meter readings would have all been “full scale” and not useful.)

Most of these stations were not line-of-sight because there is mountainous terrain blocking the direct path. This makes for a good test because this is often the situation when doing SOTA activations in Colorado. We often have mountains in the way, even on the high summits. Said another way, line of sight contacts are easy-peasy and the antenna performance is not critical. Getting the signal to punch through or around mountains is when the antenna really matters.

WZ0N was line-of-sight from Eagle Rock. KN0MAP was not line-of-sight and he had his Yagi antenna pointed at Pikes Peak (away from Eagle Rock). This is a common technique on VHF…point at a high summit and hope you get enough of a reflection to make the contact. The chasers are listed below.

Signal Reports

Your typical FM VHF/UHF radio doesn’t have a real S meter, just a bar graph display, so we worked in terms of “number of bars”. This does not give us a calibrated measurement but it does provide for a valid comparison. A signal that is 5 bars is stronger than one with 3 bars, but we don’t really know how much better (in terms of dB or S units). We recorded meter readings at both ends of the radio contact. My Yaesu FT-90 meter has 7 bars as full scale. On transmit, I was running the FT-90 at 20 watts.

A quick look at the Antenna A column shows that the Yagi had consistently better signal levels than the other two antennas.  For each contact, I did point the Yagi in the direction of the strongest signal, taking care to maximize the signal. This is an advantage and disadvantage…you have to point the antenna but you do get a stronger signal.

The two omnidirectional antennas (B and C) did not require pointing and they performed about the same. My impression is that Antenna B had slightly better overall performance based on listening to the FM noise. But note that the AD0WB readings were slightly better with Antenna C.

As is very common in the mountains, we experienced multipath distortion. This occurs when the signal takes multiple paths to the other station (reflecting off mountains) and then recombines at the receiver creating distortion and variation in signal level. Small changes in antenna position can cause a change in the signal level and amount of distortion. Multipath distortion was much more noticeable on the omnidirectional antennas. The Yagi antenna exhibited multipath but at a much-reduced level. This is a well-known phenomenon: directional antennas reduce multipath effects.

Another factor that I believe is important is that Eagle Rock pokes up quite dramatically compared to the surrounding terrain. Compare this to a large, flat summit that could shadow your signal at some angle of radiation. Antenna height relative to the immediate summit terrain might be more important. Another factor is that Eagle Rock is pretty much granite and not very conductive. So there is not much difference between having an antenna 5 feet off the ground (rock) vs putting it up on a mast.

Previously, I wrote about Charlie/NJ7V’s video that compared a roll-up J-pole with a 3-element Arrow Yagi antenna on two meters. Charlie’s results were a bit different, indicating that the J-pole was about the same or in some cases better than the Yagi.

Conclusions

The Yagi antenna clearly outperformed the two other antennas. So the Arrow 2m Yagi will continue to be our antenna of choice.

The paths to K0MGL and KN0MAP were the most difficult and this is where the Yagi performance really came through. For KN0MAP, we were both pointed at Pikes Peak and working off the reflection. This method worked well with the Yagi but had significant signal loss such that the omni antennas could not make it. Working K0MGL on the omni antennas was not much better but we did squeak out two contacts.

I was a bit surprised that Antenna B did not do significantly better than Antenna C, due to antenna height. This all seems to indicate that once you are on top of a rocky SOTA summit, additional antenna height does not matter. (It would be interesting to do some experiments with the same antenna set at different heights.) I do like having an omni antenna available so that we can monitor in all directions while eating lunch, etc. If we only have the Yagi at lunch time, it is usually laying on the ground or stuck into a tree, certainly not effective in all directions. Antenna C is so easy to deploy, it will probably be my preferred omnidirectional antenna.

This is just one test and one set of results. It will be interesting to do some further comparisons from other locations. Thanks to the chasers for assisting with these tests.

73 Bob K0NR

Test data in Excel spreadsheet:  Antenna comparisons – 2m FM Eagle Rock

The post VHF SOTA Antenna Tests appeared first on The KØNR Radio Site.