LHS Episode #410: The Weekender LXXI

It's time once again for The Weekender. This is our bi-weekly departure into the world of amateur radio contests, open source conventions, special events, listener challenges, hedonism and just plain fun. Thanks for listening and, if you happen to get a chance, feel free to call us or e-mail and send us some feedback. Tell us how we're doing. We'd love to hear from you.

73 de The LHS Crew


Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

Using FT8 On 6m – The Magic Band

 

(The following blog, originally published last summer, is as relevant as ever. Please pass the link to those that you think may benefit from reading it.)

 

Today’s blog is directed to those that may be new to 6m or new to using FT8 on 6m. Some of the things discussed will make your experience on the magic band better for you and better for your neigbours.


Unlike using FT8 on the HF bands, 6m presents some different challenges, especially if you operate in a region where there may be a lot of other locals also using the band at the same time.


Although the weak-signal capability of FT8 has made it possible for many smaller stations or those with makeshift antennas to take advantage of the unique propagation 6m has to offer, it also can create problems for other users of the band when used inappropriately. In regions of dense population, even small stations can create very high local signal levels, often making it impossible for their neighbours to hear weak signals. This is not deliberately-caused QRM but arises when some operators operate 'against the flow’ and transmit on the opposite ‘sequence’ to everyone else in their local area.

If you are a new arrival, with a small or makeshift antenna for 6m, it's important to realize that you may not be hearing what others near you (with bigger antennas) are hearing and can easily mess things up when transmitting at the wrong time.

On HF, one can transmit or listen on whatever time sequence they wish. Chosing ‘TX 1st’ or ‘TX 2nd’ is usually determined by who you hear calling CQ or who you wish to work. On 6m however, in a densely-populated region of local operators, chosing to transmit whenever you want to is a luxury that can create big problems for your neighbour who may be trying to hear that weak DX signal while you are transmitting!

These problem will not occur if everybody in the region uses and follows the same transmit-receive periods, so that everyone is listening or everyone is transmitting at the same time ... one or the other. Unfortunately, this ‘ideal’ system falls apart easily when one or more of your neighbours is not using the same sequence as everyone else.

For the past few years, a protocol that seeks to alleviate this problem has become popular and well accepted by those familiar with it. Those new to 6m may not know about it or understand the reasoning behind it.

Above all, I would urge new users of the band, or to the FT8 mode, to first listen carefully for a few minutes, before beginning operation, to determine what the majority of stations in their local region are using for sequencing. If they are using ‘TX 1st’, then your choice of ‘TX 2nd’ will likely cause hearing difficulty for many others, as well as for yourself.

Although there are no strict rules, there is a very successful and well-practiced protocol, and it's that the ‘easternmost’ station transmits on ‘1st’ while the ‘western end’ goes 2nd’. This is why you will hear most eastern stations in the morning hours transmitting ‘2nd’, as they are usually calling or looking for Europeans to their east, who are transmitting ‘1st’. By the same token, you will also hear western stations transmitting on '2nd', who are also looking for Europe to their east, transmitting on ‘1st’.

This sequencing protocol usually reverses later in the day when signals from Asia become a possibility, and all North Americans then become the ‘easternmost’ stations and will transmit on the ‘1st’ sequence ... unlike in the morning. I can easily see how newcomers to the band could become confused, when they hear both sequences being used! The best thing, once again, is to listen carefully first and then ‘go with the flow’.

You can read about the UK's Six Metre Group's initiatives regarding these protocols HERE.

OK... so you’re not interested in EU or Asia? Then it shouldn’t matter to you which sequence that you use and best operating practice would again be to ‘go with the flow’ in consideration of other users.

A few days ago I saw a prime example of exactly what not to do, in too many respects. I made a posting on the ON4KST 6m chat page that VE1SKY in NS (Nova Scotia) was being decoded here, mainly to alert others in my region that European signals might be coming next, as hearing the VE1s in BC is often an indicator that the European path is building.

In less than a minute, an S9+ local began calling ‘CQ NS’ on the exact opposite sequence of all others ... effectively blocking the waterfall and any possible hope of hearing weak EU signals. I’m sorry, but this is just terrible operating procedure, with almost zero chance of success, while showing no consideration for nearby users.

Just like working DX on CW or on phone, the best way, as it always has been, is to ‘listen, listen and then listen some more’. You will work FAR more DX by listening and calling at the right time, than you will by calling CQ.

I also see some local stations everyday, calling endless CQs, often for over 60 minutes straight and often with many replies that go unnoticed. With FT8, one can check ‘work 1st’, go away, and return later to see who they might have ‘worked’. Perhaps this is what these operators are doing, but they should understand that they are also creating non-stop QRM for other users ... those that choose to listen carefully to the band rather than to endlessly CQ. Once again, this is just terrible practice.

You may argue that if nobody called CQ, then there would be no contacts made. There is nothing wrong with a few CQs but CQing for an hour? And don’t worry, there will always be other stations CQing endlessly for you to hear, even if it’s not a great way to operate.

With a little pre-planning for sequencing and consideration for your neighbours, everyone can and should be able to enjoy 6m FT8 with very few problems ... and that is my hope for all of us.

After forty-nine summers of CW and phone on 6m and two summers on FT8, these are some of my initial thoughts on how to best operate for maximum success and consideration for other band-users.

The latter is part of the basic framework upon which amateur radio was originally established, when back in 1914, the ARRL described in their 'Code of Conduct' for amateurs ... "The Amateur is Gentlemanly. He never knowingly uses the air for his own amusement in such a way as to lessen the pleasure of others." 

Now, let the magic, and the pleasure, continue!


Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

VHF SOTA Antenna Tests

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.

Eagle Rock – W0C/SP-113

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 A: Arrow 3-element Yagi for 2 meters.

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 B: Rollup J-pole (N9TAX) on a fishing pole.

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.

Antenna C: RH770 Telescopic BNC dualband antenna on a monopod.

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.

CallsignEquipmentDistance/Terrain
W0BVIcom IC-2730, X200A antenna, 35 watts42 miles, blocked by a ridge
AD0WBKenwood TH72A, X300A antenna, 5 watts39 miles, blocked by mountains
KN0MAPYaesu FT-857, 10-element Yagi pointed at Pikes Peak35 miles, reflecting off Pikes Peak
WZ0NBaofeng HT, 5 watts29 miles, Direct line of sight
K0MGLYaesu FT-8900, 1/4-wave ground plane antenna, 10 watts32 miles, blocked by mountains

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.

Antenna A
Yagi
Antenna B
J-pole
Antenna C
RH770
CallsignReport Sent by K0NRReport Received by K0NRReport Sent by K0NRReport Received by K0NRReport Sent by K0NRReport Received by K0NR
W0BV463222
AD0WB5Full scale3Full scale, a little noisy4Full scale
KN0MAP46nilnil
WZ0N755454
K0MGL7611, very noisy10, very noisy

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.


Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

LHS Episode #409: JS8Call Deep Dive

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


Russ Woodman, K5TUX, co-hosts the Linux in the Ham Shack podcast which is available for download in both MP3 and OGG audio format. Contact him at [email protected].

Comparing my Endfed receive against my active antenna.

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?


Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

Monitor Marine VHF Near the Ocean

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.


Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

Ham College 76

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

Download
YouTube


George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].

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