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.

Hello and welcome to the 409th installment of Linux in the Ham Shack. In this episode, we have an interview with Jordan Sherer, KN4CRD, the creator and developer of JS8Call, an amateur radio weak-signal application for having complete QSOs during poor band conditions. Jordan is also the winner of the 2021 Amateur Radio Software Award so we have the board of ARSA on the show discuss Jordan's achievement and the efforts of the ARSA board to promote free, open-source software in the amateur radio space. We hope you enjoy!

73 de The LHS Crew

The first test did not work out well did not connect ant

 When I was at my QTH in Cambridge Ontario (about 7 years ago) one of the antennas was the LF Engineering H-800 active receive antenna. At the time I was using a screwdriver antenna and to go from one band to another to see the condition of the band meant I had to re-tune the screwdriver antenna (the High Sierra sidekick )  I am not even sure if they are still in business.   This antenna was ground-mounted in my backyard and was removable. I was in a very antenna restrictive area so it was very portable and only out when I was using it. 

 The active antenna gave me a fast way to check on band conditions and it worked very well. It was mounted in the attic of my home. Over time I moved from the screwdriver antenna to an attic-mounted Alpha Delta DX-EE antenna. No longer did I have to retune when going from band to band. So I ended up selling the active antenna as I figured I would not need it anymore. Well fast forward to us selling our home in Cambridge and moving to downtown Toronto and having to use an MFJ mag loop to get on the air the good old active antenna was needed again! I purchased it and once again it worked very well for me. 

Endfed decodes

Then it was time to retire and get out of the city as the only reason we moved to Toronto was both Julie and I worked there and we were getting very tired of the 1.5 hours each way commute from Cambridge. We once again sold our place and now we live in Atlantic Canada in New Brunswick. It is amazing here very slow lifestyle, the people are very welcoming and the ocean is just minutes away. 

So here we are in New Brunswick and my antenna is a 56-foot Endfed antenna and I really don't have a need for the H-800 active antenna but it is set up at the back of our home just for poops and giggles.  Today I decided to compare how it receives compared to my Endfed antenna. I went onto FT-8 and did some decoding using the Endfed and some decodes using the H-800. It was early afternoon here and 20m seemed to be doing very well. I did some decoding with the Endfed and then the H-800. I found 2 things.....the Endfed seemed to receive more DX stations but the H-800 did receive some DX but totally different ones than the Endfed did. Now the Endfed is horizontal and the H-800 is vertical so is that the reason? 

H-800 decodes

Here we go down that road again of whether or not I need the H-800?

When on a road trip, I usually monitor the 2m FM calling frequency, 146.52 MHz. For the most part, that frequency is pretty quiet but sometimes a fellow traveler, camper, SOTA activator or random ham shows up on frequency. I don’t usually bother with tuning into local repeaters as that requires frequent adjustment of the radio while cruising down the highway.

Our RV has an Icom IC-2730A transceiver that covers the 2m and 70 cm bands. This radio has two receivers, so one receiver is set to 146.52 and other one is set to “something else.”  Sometimes, I’ll go ahead and put one of the local repeaters in the other receiver, especially if we are going to hang out in one location for a while.

When driving near coastal areas, I often put the second receiver on the VHF Marine Channel 16 (156.80 MHz). This is the International Hailing and Distress Frequency for marine radio. You will hear boats calling each other on this channel, then switching to another working channel. It is also common to hear the U.S. Coast Guard come on the air with an announcement. (The USCG may say switch to Channel 22 to hear the announcement.)

Some other useful marine frequencies:

Channel 22   157.100 MHz   Coast Guard Liason Channel
Channel 68   156.425 MHz   Non-Commercial Working Channel

The complete list of VHF Marine frequencies are available here:

U.S. VHF Marine Radio Channels and Frequencies

Just another frequency to listen to when on the road.

73 Bob K0NR

The post Monitor Marine VHF Near the Ocean appeared first on The KØNR Radio Site.

Ham College episode 76 is now available for download.

Extra Class Exam Questions – Part 14. E3C Radio horizon, ground wave, propagation prediction techniques and modeling, effects of space weather parameters on propagation.
1:01:28

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We get all sentimental about the ARRL Founder, Hiram Percy Maxim. We probably should. But he’s only the titular leader of what became the amateur radio movement in the United States back in the early 1900’s. Did you know he didn’t found the ARRL by himself? Yea, and Joe Namath was not the only quarterback that the New York Jets drafted in 1965 either. Can you name the Heisman Trophy winner whom the Jets also drafted that year? Well, I taught a graduate course on the sociology of sport so I got a head start on you, perhaps. There was a co-founder of the American Radio Relay League. And there were many other early hams that gave life to this amazing hobby! I call them the Blue Collar Scholars who made the blue lightning pass the spark gap and set the foundation for ham radio to become what it is today.

It is also important for us to understand the blue collar scholars and pioneers in that movement as much as it is the role of Mr. Maxim. We may never know who the original ham operator was or if there was a single first op. And where was that movement birthed? It’s often said (and I did in a couple of books I wrote) that time cannot be fully understood without a consideration of space. Historians and geographers make very good bedfellows! So where in the world was Waldo…uh, the first ham operators?

I’ve been digging into that ever since a club in my state claimed to be the “oldest” one in Mississippi. Since they said in a brochure to have been started in 1949, I really doubted that this was an accurate statement. I checked into the first experimental licenses given through online libraries containing what was then the Federal Radio Commission records. Mississippi A&M (Now MSU) and the University of Mississippi each had one and a club to go with it. So those darn historical facts get in the way of perfectly good bragging sometimes. That memory gave me the intellectual itch to examine what we can know about the earliest hams in the U.S.

We can get a firm glimpse of who those early ham operators were by looking at FCC and ARRL records. The first Blue Book published by the FCC was in 1909. And, when Mr. Maxim and his co-conspirator founded the League, they published Issue 1 of the modest magazine, QST. In it, they also published a list of amateur operators with call “letters” (signs). Gosh, where were these people located in the United States? Where was Maxim living at the time? He died in Colorado and is buried in Maryland. But did he light the “spark” (pun intended) to the spark gap in his neck of the woods? Was it a widely spreading thing due to the newfangled “radio” (they had to invent a name for it) being in the newspapers from coast to coast and in other continents?

It is written here that Maxim may have spent some of this life on Third Street near Smith Street in Brooklyn NY. Today that might carry him right by the Ugly Baby Takeout and the Hannah Senesh Community Day School (see map excerpt):

Over at my companion website, foxmikehotel.com, I’ve posted a reasonable set of answers to these questions. And, an interactive map to see not only where the earliest record of licensed hams (that I could find thus far) were located and just how big were their coils? Some of them are noted to be KW in their capacity. (I wonder if those were in California, giving an historical grounding to that contemporary phrase, California Kilowatt!) I’ve looked at all of them and just wonder what things were like back then when they were learning to communicate through the ether, the first wireless capacity being developed by the grass roots efforts of both kids and grown ups.

They weren’t all boys and men (see, among others, here). Miss Kathleen Parkin was on the cover of The Electrical Experimenter magazine. She was called “youngest successful female applicant for a radio license ever examined by the Government at that time,” or as The Mary Sue blog says, “Parkin began her hobby at age five with her brother, and was the first woman in California to pass the first-class radio license.” They labeled her “a total badass.” I don’t disagree. One bit. She and her own “apparatus” is shown on the right. She started the itch for radio at age five with her brother. She was reportedly the “first and youngest successful female applicant for a radio license ever examined by the Government at that time.”

There is a graphic on the home page at foxmikehotel.com with a link to the page with a fuller story under the Maps tab. It’s called The Lost Tribes of U.S. Radio Amateurs. Were any in your area where you live today? Are you perhaps related to any of the original license holders? Isn’t it as important to know who some of these lost tribe members were, the ones who persevered into the night experiencing the propagation vagaries that we now predict (well, try to) with software? Without them, Maxim may just be known as the guy who developed a gun silencer and a few mufflers for the motorized horse.

I may continue to look at this, adding additional years to track and estimate the diffusion of this most important innovation of the last century. But for now, give the interactive map a go. You can reach me at my email for thoughts or suggestions. I’m good on QRZed.

Getting out on the road and exploring is always fun, especially if you have ham radio on board. Joyce/K0JJW and I have been doing quite a bit of travel lately and we just completed our longest road trip so far with our RV.

Our main destinations for the trip were four national parks: Congaree NP, Biscayne NP, Everglades NP, and Dry Tortugas NP. This determined the main route but we also found plenty of other things to do along the way. We started in Colorado, cut the corner across New Mexico into Texas, then east through Oklahoma, Arkansas, Mississippi, Alabama, Georgia and South Carolina. Then we headed south to Florida and ended up in Key West. Our return trip followed the gulf coast back to Texas, then back home.

Travel Philosopy

Planning a trip is full of trade-offs, so it is useful to have a general approach that the participants agree on. Our approach to this trip was to not drive too far every day but drive enough to hit the various places we wanted to visit. We are still working to find the right balance. This trip lasted 39 days, covering 6000 miles, which is about 150 miles per day. Some days we drove very little and other days were longer, maybe 400 miles.

Although the trip was created around the national parks, we filled in with interesting stops along the way. In particular,  we like to camp at state parks: the campgrounds are great and there’s usually something interesting about the park to enjoy. And did I mention they are natural Parks On The Air (POTA) opportunities? We also tried to work in some Summits On The Air (SOTA) activations that are relatively easy to access.

Rocky Victoria

Our recreational vehicle (RV) is a 2018 Winnebago Paseo, built on a Ford Transit chassis. We named her Rocky Victoria, using non-standard phonetics, but usually just refer to her as “Rocky”.

Compared to your typical car or SUV, this Class B RV is huge. Compared to other RVs, this vehicle is small, about 22 feet long, usually fits in a standard parking space. With all of the normal RV stuff installed (stove, microwave, sink, refrigerator, toilet/shower combo, bed, etc.) there is not a lot of room left for personal gear.

Rocky fits us really well because it is easy to drive, getting in and out of places without much hassle. Also, setup and tear-down time at a campsite is minimal. One limitation is poor ground clearance, which is fine for forest service roads in good condition but not appropriate for offroad use. This affects what SOTA and POTA activations we do.

Radio Gear

We have an ICOM IC-2730A in Rocky, for normal 2m/70cm FM comms while running down the road. The antenna (not visible in the photo) is just a short whip on the driver’s side of the hood.

Rocky is not a big RV so by the time we load up all of our stuff, it is full. So the radio gear (and everything else we take along) must follow the backpacker principle of “take only what you need, use what you take.” No room for extra stuff you don’t use.

For this trip, we took along two ham stations:  A basic VHF SOTA station and a capable, picnic-table POTA station.

VHF SOTA Station

The VHF SOTA station is very compact and easy to carry. It covers the 2m and 70cm bands on FM, which is usually sufficient for us. The RF output power is only 5W, so it does not have the punch of one of our higher power radios. Not a bad tradeoff though.

Two Yaesu FT-1DR 2m/70cm handheld transceivers
Arrow 3-element Yagi 2m antenna
Two RH 770 dualband SMA antennas
HT chargers and other accessories

Picnic Table POTA Station

The POTA station is built around the FT-991, which is a 100 watt transceiver (HF/VHF/UHF) that is reasonably compact. We use a 20 Ah LFP battery to power the radio so it is portable and independent of the RV power sources.

Yaesu FT-991 Transceiver (HF, 6m, 2m, 70cm)
End-fed halfwave antennas for 40m, 20m, 17m, 15m, 10m
Roll-up j-pole antenna for 2m/70cm
20-foot fishing pole to support antennas
Two 25-foot lengths of RG-8X coaxial cable
12V, 20 Ah LFP Battery (Bioenno Power)

The POTA station does a great job at a campsite, usually on a picnic table. The POTA station fits inside my Kelty backpack so it can be taken for a hike. It is a bit heavy for a typical SOTA summit but works OK for drive-up and short-hike summits. It can also be set up inside the RV if required.

Typically, we are going to try operating on 20m or 17m so that the halfwave antenna easily hangs from the fishing pole support. Depending on conditions, we often have to use 40m which takes a little more work to hang. Not a huge problem, though.

For portable operating, I’ve tended to use a variety of end-fed wire antennas supported by a non-conductive pole of various sizes. For this trip, we used a 7 meter (21 feet) telescoping fishing pole that collapses to about 30 inches.  This pole will fit into my SOTA backpack.

To support the fishing pole directly from the RV, I attached a short length of plastic pipe to the ladder. It is a simple matter to slide the pole into pipe, resulting in the top of the pole being about 26 feet off the ground.

The combination of the two stations gives us a lot of options for ham radio operating.

Summits On The Air

We activated three summits along the way: Mount Scott (W5O/WI-002) in Oklahoma, Choctaw County HP (W5M/MS-001) in Mississippi, and Monte Sano Mountain (W4A/HR-002) near Huntsville, AL.

Monte Sano Mountain turned out to be a unique location because it is located in the Monte Sano State Park. The park surrounds the summit, which is broad and flat. We determined that the park campground is within the activation zone, so we camped there and did both SOTA and POTA activations.

Parks On The Air

We did a number of POTA activations along the way. This was done opportunistically, typically in the afternoon after we had set up our campsite. Our radio operating used SSB on 20m or 40m, along with a few 2m FM contacts.

K-0688  Lake Meredith National Recreation Area   US-TX
K-1090  Lake Chicot State Park   US-AR
K-1048  Monte Sano State Park  US-AL
K-0017  Congaree National Park US-SC
K-1832  Anastasia State Park  US-FL
K-0024  Everglades National Park  US-FL
K-0635  St. George State Park  US-FL
K-2992  Brazos Bend State Park  US-TX

Every one of these activations was a lot of fun. There’s nothing like sitting outdoors in the sunshine working a pileup of enthusiastic POTA hunter stations.

Summary

In this post, I emphasized the ham radio activity during this trip. Radio operating was not our main goal but it was a big part of the overall experience. Joyce and I had a fantastic time touring this section of the country, and we are looking forward to our next trip.

73 Bob K0NR

The post Parks, Summits and Roadtripping appeared first on The KØNR Radio Site.