Thursday, March 30, 2023

Band Slot Fatigue

What is the meaning of life? Too pretentious? How about: what is the meaning of amateur radio? Lest you imagine that this will be a sad philosophical tract and stop reading, please stay with me for a moment.

Each of us has motivations and interests that spur us to build stations, operate and relish achievements. At the top of my list are contests, DX and 6 meters. For others these might be AM, portable operating, EME, public service and much more. As the years pass, our interests change. We may abandon the hobby for a time (as I did) or we may increasingly focus on one particular interest. There is no one right way to do amateur radio, and that's one of its great strengths. There is so much to learn and do.

I began writing this article while the CQ WPX SSB contest was raging on the HF bands. I made 100 contacts, got bored and quit. Since I have a passion for contests, my disinterest may seem surprising. That is why I built and keep improving my "big gun" station. Most hams are impressed by what I've built when they come by to visit, although, truth be told, some think that mine is a pointless pursuit. They are correct, from their perspective; they have different interests and motivations.

Too much of a good thing can be bad for you. It leads to fatigue. No matter how much you love doing something, taking breaks from it can be very refreshing. The break can be a day or 20 years. There are many days that I won't even turn on the rig or monitor DX spots. I avoid the shack and do something completely different and unrelated to radio.

DXCC Challenge

When a break doesn't refresh your interest, it may be time to find another passion. This brings me to the subject of this article: pursuit of DX band slots. The idea is to work as many countries on as many bands as possible, and even for every mode. There is an award for this pursuit: the DXCC Challenge.

With 340 DXCC entities and 10 bands (160 to 6 meters), the award pinnacle is 3400. You can work them on SSB, CW or a diversity of digital modes, but you'll never work them all. With no end in sight, what exactly is the objective? It can be a lifelong project.

I have a friend who is closing in on his 2500 endorsement for the DXCC Challenge. He'll never approach those at the top of the DXCC Challenge list (over 3200), but he is passionate about getting to 2500.  He has resorted to FT8 to find DX stations in rare entities that are not active on the traditional modes. 6 meters is another option he's pursuing. He is making progress and I expect that he'll reach his goal this year. I wish him well in his quest.

After that? Quite a few have stretched the possibilities to surpass the 3000 level. How many? Hundreds! Do the arithmetic and you'll see just how difficult that is: it's just about impossible to do it on HF alone, even by dedicating decades to the pursuit. 6 meters is mandatory if you're serious about the pursuit. But it can be done. Is it worth it? I am in no position to say.

I am close to 2000 band slot confirmations on LOTW (Logbook of the World) for the DXCC Challenge award. Over my long ham career, I have hundreds more worked and confirmed on paper that I refuse to sift through. I've gotten this far without really caring about the DXCC challenge. I'll probably never apply for the award. It's interesting to track my progress, but that's all. I have even less interest in chasing grids on 6 meters. Again, it's interesting to monitor how I'm doing on the VUCC grid count. Many hams are as passionate about the VUCC award as others are for the DXCC Challenge.

The role of technology

Despite these sentiments of indifference, I do have the urge to work DXpeditions on every band they activate. I like chasing DX, so why not. Many who fish can enjoy themselves without catching any fish: drop the line into the water and soak up the sunshine. You can enjoy the chase whether or not you log the rare DX. Catch and release of fish is a little like working the DX but not confirming the contact. I'm like that.

At the other extreme are those for whom the award is all, and they will bend and break the rules of the competition to get it. Fake contacts, paid contacts, fake confirmations, excess power and more. You see it in DXing just like you see it in any competition. I won't say more on this aspect of award chasing other than to note that it exists and I don't let it poison my enjoyment of the chase. I am not competing with either the cheaters or the non-cheaters.

DXCC Challenge is to some extent a product of technology. Decades ago it would have been a Quixotic pursuit. Without the benefit of spotting networks, live streaming and real time updates, an inordinate amount of time would be needed to hunt down each DXpedition on every band slot. In many cases the propagation is so marginal the rare DX station wouldn't be able attract callers by CQing. Sometimes they will self spot to announce their presence. 

Even retirees have limited time to spend in front of the radio. Few want to spend that time slowly spinning the VFO knob across every band and at frequent intervals become the first to find the elusive DX. Sure, the pile ups can be intense when the DXpedition is spotted or an alert comes from their we site, but it eliminates the tedium of always searching.

And when you do find the rare DX by your own hard work and work them, what do you do next? In the old days you would call your friends and they could work the DX without fighting through a pile up. You can find descriptions of these techniques in the now very old but excellent book, The Complete DXer by W9KNI. DXing was not always a solo pursuit. Groups of friends would draw up a schedule of bands and times for each to monitor for that elusive and rare DX. When one of them found the DX the telephones and pagers started ringing.

With technology these small circles of friends have become far larger. It no longer matters who you know and nothing is asked of you in return. Technology gives everyone a chance for acquiring a multitude of new band slots. The competitive playing field is more level than ever. The old ways are obsolete. DX clusters are globally networked and skimmers often find CW stations before humans do.

Digital levels the competitive field further. Those with small stations can get through the pile up far better than on CW or SSB. Digital decoding algorithms don't care if you're weak or strong, and will pull you out even when you're buried beneath stronger stations. I know many little pistols thrilled by how much rare DX they can work on FT8. With their small stations they often work DXpeditions on FT8 before I do it on CW.

Technology enables everyone -- big station or small, skilled operator or merely competent -- to climb high on the DXCC Challenge ladder. Not everyone would agree that this is a good thing: it's called a challenge for a reason.

What's the point?

There are so many possible band slots that it can lead to fatigue. Just how hard do I want to chase CY0S (a recent example) on the high bands, where working them from a short distance is not easy. I did try on 6 meters, just because 6 meter DX is a special passion of mine. They did show up on CW but quickly turned to digital since it put more stations in the log. First it was FT8 and then MSK144. 

It's possible that they logged me on MSK144, but without a definite acknowledgement of my RR73 message it's impossible to say. It is profoundly unsatisfying to wait for their log upload to learn the answer. This is a question that has to be asked far less often on the traditional modes.

(Credit: ClubLog; screenshot taken March 29, 2023)

[I can now answer my own question. As of March 30 I am indeed in their log for the MSK144 contact. However, my statements above stand. I haven't bothered to update the screenshot.]

I could try again. I won't, nor will I turn on the amp and try to break through the pile up to work them on the high HF bands. Perhaps I should write this in the past tense since CY0S is about to go QRT as this article is being published on the blog. Eventually there will be other DXpeditions to Sable Island when, perhaps, I'll feel more motivated to try to fill those band slots.

Running the bands when every DXpedition pops up can become a chore rather than a pleasure. It isn't a great challenge most of the time when all I have to do is watch for a spot to appear and apply maximum power to my large antennas. Often I create a handicap for myself, to artificially boost the challenge, by leaving the amp turned off or use whatever antenna is more or less pointed in the right direction. I enjoy practicing my pile up skills. I practice related skills by occasionally operating QRP in contests.

For me the most important challenge was in designing and building this station, and then to practice and hone my operating skills. Piling up the DXCC band slots is one way to profit from my labour. I don't do it too aggressively since, for me, the fun soon fades. My band slot enthusiasm is mostly reserved for 6 and 160 meters, finding and working rare DX on difficult paths, or by skillfully threading large pile ups. The DX doesn't necessarily have to be rare. Nor do I get too disappointed when I fail to work them. There's always next time.


The meaning of DXing, as it is with life, is up to you. It is not handed down from on high. I love chasing DX but it does not define me. I'll do a lot to bag the DX and, yes, on every band slot I can, but only up to a point. I have no interest in spending the time and effort to reach 3000 band slots for the DXCC Challenge. I don't chase any DXCC certificate. I enjoy watching the numbers increase, and that's good enough for me.

Radiosport will only grow in our hobby. Extreme DXing is one part of that, and contests are another. Participation in both is growing. Hams find meaning and enjoyment from those activities. Despite my disinterest in chasing every band slot, I would never say that others are wrong to do so. Meaning is a personal choice and I don't begrudge them their passions.

What I really need right now is spring weather and not the blustery cold and wet we've been dealing with. That would be especially meaningful. I can then spend more time outdoors working on antennas and less time writing philosophical tracts!

Wednesday, March 22, 2023

Automating VA6AM 6-band BPF

The VA6AM switchable 6-band low power BPF (band pass filter) product does not exist. Or at least, not yet. I believe that mine are still the only two in existence. Pavel has little time for this product to have a higher priority. I was fortunate that he undertook completion and testing of the relay boards and the 6 BPF modules at my request. I've used these filters in many SO2R contest operations and I'm very satisfied with their performance. 

Eventually (as I've promised a few times) I intend to say more about these filters on the blog. This will have to do for now. Pavel had not completed the control board for the filters and I needed one to integrate with my station automation

I purchased 8-position rotary switches to enable manual band selection as a temporary measure when the units were built. Rather than wait any longer I decided to proceed to integrate the filters into my station automation project with a home brew solution. 

The BPF are now automatically selected when changing bands. Manual operation remains an option when automatic switching is disabled or not functioning. There is a bypass feature for when a non-contest band is selected or it is manually turned off. I leave the BPF wired into the station at all times since their presence, in bypass mode, has no measurable effect.

The 8-positions of the rotary switch are (clockwise): Automatic (no written label); Out (off or bypass); 160; 80; 40; 20; 15; 10. Until the recent upgrade the Automatic position was equivalent to Out. The front panel control is ugly, with temporary labels and no LED indicators. Perhaps I'll add them when I get the urge. It isn't difficult but it also isn't urgent or necessary.

Manual operation is quite simple. The wiper of the switch is connected to the +12 VDC power socket on the rear panel. The relays for each band on the two relay boards for are connected to their respective positions on the rotary switch. The bypass relay is powered by diodes that leech the power from all the band relays. There are 4 relays energized when a BPF is selected. The total current draw is 120 ma. Two indicator LEDs would add another 40 ma.

The Automatic position on the rotary switch has more complex wiring. It is connected to the band selector DE9 connector on the rear panel. Of the other 8 conductors, one is power (+12 VDC), one is ground (as is the cable shield) and the other 6 are band selectors that carry +12 VDC when the band is selected. These are wired to the rotary switch in tandem with the wires to the relay boards, as described above. The straight-through DE9 shielded cable connects to the BPF driver board in the automation system.

Yes, the wiring of the rotary switch is a mess! Had I planned everything in advance it would have a connector board. The LEDs, when I get around to it, will go in a row on the front panel or positioned around the rotary switch. I'm not sure which would look better. The automatic mode LED will be a different colour than the band LEDs.

The Cat5 cable runs under the BPF boards and doesn't affect their behaviour. On the enclosure above the cable runs under one of the relay boards. I should have done them both this way but, as I said, there is no problem having it under the filters. Toroids isolate themselves very well and the more sensitive solenoid coils in the 10 meter BPF (above left) are sufficiently shielded by the PCB ground plane.

For automatic operation the power socket is redundant; power comes via the 9-conductor cable to the automation system. The BPF operates as before for manual operation. In automatic operation, the +12 VDC from the Automatic position on the rotary switch powers the switching electronics in the automation system. This is shown below (connections from the band lines to the rotary switch are not drawn).

In manual operation when the switching electronics are not powered, the GPIO pins driving the 6 band lines cannot power the BPF relays. There should never be conflicting control of the BPF relays from both manual selection and the automation system. Switching two BPF inline would be bad. However, there is an unfortunate though non-destructive interaction that I'll discuss towards the end of the article.

The software does not have to be aware of whether the BPF are operated manually or automatically. The operator decides whether to operate manually or automatically by turning the rotary switch. Software does not trigger any GPIO for bands other than the 6 HF contest bands. When only one radio is in use (SO1R) the other radio's GPIO are idle. There is no check for whether the two sets of BPF are on the same band. Conflicts must be resolved by the operator(s), software or by antenna port lockout.

There are other ways to accomplish both manual and automatic switching of the BPF than what I've built. You may be able to think of one or two. I did it this way for simplicity of hardware and software, and intuitive behaviour for the operator. At least it's intuitive to me, and I'm the one who matters most at this station! 

One alternative is to have a band decoder for Yaesu/Elecraft or Icom coding within the BPF. The decoder must manually or automatically detect the coding scheme for different manufacturers. If the band data from the transceiver is needed for other automation task such as for an amplifier, they must be wired in parallel. I have done away with hardware signalling by extracting it from N1MM's RadioInfo UDP messages. The Arduino thereby knows the band and can send +12 VDC to the BPF on each band's dedicated line. 

The BPF requires no control board when used with my home brew system automation. There is just a straight-through DE9-DE9 male shielded cable. There are commercial BPF that support a similar per-band DE9 pin, so my interface is not unusual. However, the connector pin out is likely to be different from any existing product.

Driver circuit

Two types of driver circuit were considered: electronic and electro-mechanical. The first is compact and silent, and the second is noisier and larger. I have opted to use relays for all control lines exiting the house since they are better at handling lightning surges and precipitation static. I ground the control lines via the SPDT relays for high side switching. That cannot be done for low side switching. All my home brew antenna switching systems use high side switching. The 2×8 Hamplus antenna switch is the only device in my station using low side switching.

Since the BPF and the control lines are inside the shack and not directly susceptible to weather events, I decided to use electronic switching. I have a spare Arduino-compatible 16-relay module that was my fallback in case the electronic solution became too difficult. The BPF require high side switching.

I learned something new about PNP transistors while bread boarding alternative driver circuits. A pull up resistor is needed to quench the switch and turn it off. The same appears to be true of the PNP Darlington transistors I am using. It isn't enough to set the GPIO pin High since the GPIO's 5 volts is lower than the 12 volts being switched. Since I am using reverse logic (GPIO Low is On), I naively thought I could drive the Darlington transistors directly from the GPIO with just a base resistor. A pull up resistor would be disastrous in this circuit since it would place +12 VDC on the GPIO pin and fry the microprocessor. 

I resorted to the more common 2-device solution. An NPN transistor drives the PNP Darlington. No pull up resistor is needed for proper operation and the Arduino GPIO pin is protected from the higher voltage. This may be an odd implementation of a complementary Darlington transistor but I had the parts on hand and it works. The doubled parts count, from 2 to 4, requires more PCB area. There is no cost penalty since the parts are absurdly cheap.

I bread boarded two drivers to test them before proceeding to construction. Testing a circuit is highly recommended before soldering 12 of them on a PCB. LEDs are a convenient substitute for relays since no extra test equipment is required and they glow. Keep in mind that an LED is inadequate for testing applications where the actual load is high current (an LED only consumes about 20 ma). The driver circuit schematic is shown further below.

There are 4 Omron SPDT relays energized when a BPF is selected, along with two optional LEDs. The total current is roughly 200 ma. For a PNP high side switch the voltage drop across the Darlington transistor is approximately 0.7 volts. Since P = EI, the power dissipation is 0.15 watt. Heat sink are not required on the Darlington transistors. The voltage drop itself does not affect the BPF relays since the nominal 12 VDC coils operate over a wide range.

The PCB is small and crowded with 12 drivers, connectors and wiring. A larger proto board would have been easier to work on. I chose a board with two holes per pad rather than one with long connected vertical and horizontal rows. Layout has to be sparse for the latter and there would be much wasted space in this application. Those proto boards worked well for my Beverage antenna reversing electronics since there were fewer components to mount. A custom PCB would have been easier to work on by eliminating all the wiring, but at a significant cost for just one board. 

The main cost of this board was the endless frustration of fitting and soldering small components and wires with magnifying glasses. I took care to avoid cold solder joints, bridging pads and overheating wire insulation and transistors. I was lucky to have only one cold solder joint and another where there was a high resistance leakage between stages. Aggressive cleaning of flux and spreading wires apart fixed the latter.

The cable harnesses for connection to the Arduino and BPF were another source of frustration due to their small size. A couple of bad crimps were easily repaired. The Dupont connectors with 0.1" spacing fit the board nicely. I went with all male connectors for their low profile and ease of cutting from the long chains they're sold as. The low profile eases component and wire mounting. The 9-pin connectors to the BPF are ideally female so that power pins are not exposed.

In retrospect, the layout could have been improved. I also didn't need the above board power rails. To avoid crossing wires, the 3.3 kΩ resistors are mounted below the board. In the end, what matters is that it works, and it's okay if it's ugly since it'll be out of sight.

You may have noticed the lack of bypass capacitors to prevent RFI. The cables are short and shielded, and the control lines are bypassed on the BPF relays boards. There has been no trouble with RFI. Capacitors will be added should RFI arise in the future.

The driver board was connected to one of the BPF units after testing each circuit with LEDs. That's when I discovered and corrected the problems mentioned above. I accidentally scrunched a couple of the bottom resistors when I was too aggressive pressing on the 9-pin connector. I was lucky not to do more damage when I levered up the scrunched resistors with a small screwdriver. 

Testing proceeded well after dealing with the aforementioned difficulties. But there was one problem I discovered that is not easy to resolve. It's an odd case that is very unlikely to occur in actual operation so I am not going to deal with it, at least not now. It occurs when the BPF is operated manually by the operator while the driver board is connected and operational.

Let's say you turn the rotary switch to 15 meters to manually select the BPF. The relays function as intended and the 15 meter BPF is placed in line. However, if the rig is on another band (10 meters), the BPF relays for that band are also energized. That connects two different BPF in parallel, and that's bad. 

The reason for the misbehaviour is inherent in my design of the driver board. Although there is no +12 VDC directed back to the driver board from the BPF via the Automatic rotary switch when a band is manually selected, it is present at the driver board via the 15 meter control line. It is therefore present at all 6 Darlington transistors. The NPN transistor for 10 meters turns on its Darlington and the 10 meter relays are energized.

This was an oversight in my design. Wiring the control lines for automatic in tandem with the manual controls for each band selection is responsible. There are a few ways to correct the problem but, as I said, this is not likely to every happen in real life. There is no reason to manually select 15 meters when the automation system is working and tracking the transceiver to 10 meters. The glitch can stay.

I mounted the driver board to the rear of the open frame automation system, connected the several cable harnesses, glued rubber feet to the bottom and re-installed it in the station.

Was it worth it?

With this project done, the shack hardware for my station automation is substantially complete. That is one of the objectives I set for 2023. Of course I'll continue to expand and improve the software and extend the hardware for new antenna projects. But that only involves connecting or moving wires and not hardware changes.

Use of the automation BPF band switching in a contest will have to wait. Although I set myself a deadline of CQ WPX SSB this weekend, there will not be a multi-op or SO2R operation that requires BPF. There will be other contest opportunities in the not too distant future to give the BPF switching a full workout.

Although it's done and working and ready to go, there is the question of whether this project was worthwhile. It would have been far simpler and easier to use another Arduino compatible board of 16 relays, connect it to the GPIO and stack it on top of the other 3 relay boards. While I do not regret the effort and experience of building these electronic switches, and I like that they operate silently, it was a poor investment of my time. In retrospect I would have gone with the relay board. I have one in stock, as a spare, and I could have automated the BPF in a fraction of the time.

Home brewing is fun and educational, and I had the time since it was winter and (being retired) I had time for indoor projects. Now that spring has sprung and the weather is warming my thoughts are turning to the great outdoors. It won't be long before I dig into my growing list of tower and antenna jobs.

Monday, March 13, 2023

Tilted 80 Meter Inverted Vee

I previously had an 80 meter inverted vee on the 150' tower. I took it down to make room for work on side mounted yagis when the 80 meter vertical yagi became fully operational. I've been pretty happy since then having just that one antenna on 80. My opinion has changed for two reasons.

First, a vertical antenna is great for DX and not so much for short distances. I'm having some difficulty working the population rich US eastern seaboard and Midwest. It is not a problem in contests when I run high power, but it can be with low power or QRP in contests. That includes important contests like NAQP and Sweepstakes. It's a difference between being heard and completing QSOs.

The vertical yagi does not do well pre-sunset and post-sunrise when D-layer absorption is high and propagation favours higher elevation angles. Those "gray line" openings are when a number of otherwise difficult multipliers can be worked. The openings are brief and the competition to work the DX can be intense. The same is true of DXpedition pile ups.

The second reason is 30 meters. I have no 30 meter antenna and I need one to effectively work DX. The 80 meter vertical is a poor choice on 30 due to the low pass L-network, despite its omni-directional pattern on its third harmonic. A recent example was the difficulty working 3Y0J on Bouvet Island. In my experience, an 80 meter dipole or inverted vee works pretty well on 30. It's not quite the third harmonic so the SWR will be moderately high. That can be tamed with a tuner. 

Neither 80 meter antenna is very good on 30, and I intend to have a resonant 30 meter antenna, eventually. It is not a priority in 2023.

The 80 meter inverted vee is up and working. We had several days of unseasonably warm weather in late February that I put to good use for this and other projects. The antenna was pulled from storage and I constructed a new tower bracket for the wires and common mode choke. The bracket is identical to the old one which found its way into another project along the way.

This is my only antenna on 80 meters until I repair the malfunctioning vertical yagi. With no spare ports on the 2×8 antenna switch I disconnected the yagi. I need warmer weather to work on the antenna, hopefully later in March. I did only a cursory inspection since the radial system and other critical parts are still encased in snow and ice.

Although I cannot do an A-B test between the antennas for the time being, it is worthwhile to review the design and the electrical and mechanical behaviour of the inverted vee. The antenna is interesting because the wires do not lie in a vertical plane. This is done to keep the support lines out of the hay field. Otherwise I'd have to remove the antenna during the summer when my neighbour harvests the hay. 

Tilting the antenna raises questions about the antenna pattern and mechanical challenges, topics I only briefly touched on when I originally installed the antenna on the big tower. There is also the matter of interactions since it is mounted 2 meters below the lower 5-element yagi of the 10 meter stack and 8 meters above the TH6.

Real antennas are never textbook perfect. Elements curve, the environment intrudes and there are interactions with pretty well everything near and far. Being deliberate about the deviation, as with this inverted vee, adds another variable. The deviations can be modeled and studied, though few would bother. As I've previously written about skewed wire yagis and skewed vertical wire arrays, deviations can be made advantageous. 

In this light it is very worthwhile to see what effect deviations have on this inverted vee, and whether it meets my objectives to work nearby stations (within ~1000 km) and DX under gray line conditions.


The model was done with EZNEC Pro/2+ Version 7 and the NEC2 engine. The 150' tower to which the antenna is attached is modeled as a straight wire. The model does not include tower attachments, yagis and guys. The guys, at least, are sufficiently segmented that there is negligible interaction.

When the legs of the vee are symmetrical with respect to the vertical tower (including the cables running along it), the induced currents cancel. The model confirms this. The model does not include the coax or common mode choke since, in this configuration, the antenna is effectively isolated.

To set a baseline for comparison, I've plotted several patterns for the inverted vee with its apex at 30 meters and 120° interior angle. The elevation patterns are for broadside and end fire, starting on the left. The rightmost plot is the azimuth pattern for an elevation angle of 45°. By removing the total field from the plot, we can better see the horizontal and vertical polarization patterns.

As the legs tilt outward there is a gradual change in the polarization and pattern of the antenna. For nearby contacts it is important that the horizontal component remain strong. For an inverted vee with the legs in a vertical plane, the radiation is horizontal in the broadside directions and vertical in the end fire directions. 

For my antenna the broadside directions are north and south, and it is south that is most important since it covers all of the US eastern seaboard. North may be helpful for working Asia during the post-sunrise opening. Vertical polarization in the end fire directions may prove useful for nighttime openings to Europe and the Pacific, however that's redundant with the vertical yagi. It worked well enough in the recent ARRL DX SSB contest to log numerous Europeans with just 5 watts.

Pattern impact of slant

I'll plot the patterns for tilts of 30°, 45° and 60°. Although the latter value is unrealistic for an inverted vee up so high, I am including it to demonstrate the trend of pattern change. As above for the non-tilted antenna, the plots will include horizontal and vertical polarization components, and not the total field, to better illustrate what is going on. 

The interior angle of the vee will be kept to a constant 120°. As a general rule the interior angle should be no less than 90° to keep the radiation resistance high. For more acute angles there is substantial field cancellation between the two legs. Loss increases as the radiation resistance decreases, and the antenna may require a matching network to get an acceptable SWR in a 50 Ω system. 

Boring, isn't it? The impact of tilt is surprisingly small. The nulls are less deep but there is otherwise little change in either the horizontal or vertical polarization patterns. Sometimes boring is good. I can rest easy about hauling those long support lines to the edge of the hay field, thereby making the installation permanent. In the final configuration of the inverted vee the tilt is about 35°.

I did not plot the impedance. At a reasonable height (relative to wavelength) and interior angle, the feed point at resonance can be quite close to 50 Ω. It is often possible to adjust these antenna parameters to get that desirable result. That, ground quality, environment and height dominate the impedance, and can be unique to every station. I'll describe how I dealt with it in the following section.

Interior angle

The support ropes are very long. Not only is the apex high at 30 meters, tilting the antenna and increasing the interior angle of the vee pushes the ground anchors further outward. The mechanical challenge will be addressed further along. 

I've drawn the approximate span of the antenna legs and support lines to the ground anchors (trees!) at the edge of the hay field. Yellow was my first configuration, and blue was the final one. The yellow lines are symmetric, but appear skewed because the Google satellite view isn't from directly above. Imagine the antenna apex at the tower base to correct the perspective. The opposite is true of the blue lines, with the right (east) support line longer than the left (west).

The angle between the yellow lines is close to 90°. That is not achieved in practice because the antenna wire and support rope sag. This is the usual catenary issue that I went into in some detail in a previous article about my overhead cable run. I went wider with significantly longer ropes and dragging the left (west) line through tree branches (see picture further down).

The interior angle between the yellow support lines is less than 90°. My guess is 80° (left). The antenna was resonant at 3650 kHz with a resistance of 35 Ω. After two more trials, I ended up with the blue support lines and an interior angle of about 110°. Resonance is now 3580 kHz with a resistance of about 42 Ω. A lower resonant frequency and higher impedance is what to expect by increasing the interior angle.

The SWR bandwidth is typical of a dipole or inverted vee. It cannot cover 3500 to 3800 kHz with a low SWR. I can live with the reduced SWR bandwidth since my primary interest is CW. The 80 meter vertical wire yagi is similarly optimized for CW. However in that case there is a matching network that improves the already good SWR of its omni-directional mode up through 3800 kHz. That's as high as I need for contests and DXing. I'll keep it simple with the inverted vee by using the rig's ATU or manual amplifier tuning to use it on SSB.

I was a little surprised that the impedance in its final configuration wasn't closer to 50 Ω or even higher since I achieved that with an intermediate tests with the interior angle of about 100° and resonance at 3600 kHz. There are enough variables involved that there was no obvious solution. In any case, a better match at resonance does not improve the SWR bandwidth. SWR at the edges is dominated by the rapidly increasing reactance.

Long support lines

That west support line was not easy to set in place. There are lots of trees to choose from, but the further I went the more branches of the forward trees got in the way. What you see in the adjacent photo is the best I could reasonably accomplish. That's why the final configuration is not symmetric.

Dacron rope can only last so long when battered by tree branches and foliage; there's no foliage now but it's coming. If I keep the antenna as it is I would like to replace the lowest span of rope with steel. I have ample ⅛" aircraft cable that is due for retirement from winch service. It can have a second life in this less demanding role. It should survive battering from the trees for many years, and it is far enough from other antennas to pose no interaction risk.

The catenary equation is unforgiving. Tension must be doubled to halve the sag. The lines must be longer than can be drawn on paper, and the tension higher, to achieve the desired interior angle. There is a trade off between resonant frequency, impedance, line length, tension and material that can withstand the tension and the weather.

If you keep the tension constant as you length the support line, you don't get the increase in the interior angle that you expect. Sag increases and that reduces the interior angle. You will likely have to increase tension as you increase the length of the support lines.

Small diameter rope and copper wire have modest tensile strength. In most cases ⅛" woven nylon and or Dacron is adequate. Black Dacron has good UV resistance, but I've had good success with white woven nylon surviving many years. Do not use polypropylene rope. 

Soft (annealed) copper wire for the antenna itself can stretch under excess tension. That will lower the resonant frequency and gradually convert the wire into hard drawn copper. Unfortunately that stretch will be at least 5% before the copper becomes sufficiently hard to stabilize. It may break first. In any case you'll have trim the antenna length as it lengthens. If that's a concern, build wire antennas with hard drawn copper or copper plated steel. The are less flexible and, for the latter, there is a risk of erosion and rust.

Rope and wire are thin and light. As you can see from the photo above, that doesn't avoid sag on long lines. Even if you keep the tension well within the ratings of the wire and rope, the weather has other ideas. All of that area adds. A 1' length of ⅛" wire or rope has a projected cylindrical surface area about 0.01 ft². Although that's a comfortably small number, the line is long. For 100' (32 m) of wire and rope that is 1 ft². For the 200' in my case that is 2 ft².

The approximate force of a 135 kph (85 mph) wind on 200' of ⅛" wire and rope is 40 lb. That will greatly increase the tension, which risks breakage and increased sag due to wire stretch. Don't be surprised to see the wire and rope bow out horizontally in a strong wind: 40 lb can be 10× the weight of the rope and wire. Ice is of course a further threat. I have seen long support lines collapse to the ground under an ice load.

Heavier and stronger rope and wire will increase the tensile strength can be far more expensive, and the weight and diameter will cause more sag and wind/ice load. There is no easy solution. You'll have to juggle the various parameters to come up with a design that works for your station and means. I used 12 AWG stranded THHN wire for this antenna since that's what I had lying around at the time.

I've already had to re-tension the support lines of the inverted vee that been up for 3 weeks. I'll probably have to do it again. Rope and stranded steel cable "relaxes" under tension. The resonant frequency hasn't changed so the wire hasn't (yet) stretched. Since being raised the antenna has weathered winds of 80 kph and a minor ice storm.

30 Meters

The third harmonic of 3.580 MHz is 10.740 MHz. That's 600 kHz higher than the narrow 30 meter band. It doesn't have to be ideal to work so I put it to the test.

The minimum SWR at about 10.850 MHz is 100 Hz (1%) higher than the arithmetic third harmonic. That's typical for dipoles and inverted vees. The SWR within the band would be high regardless of that additional 1%. That said, it's been working pretty well in the brief time I've spent on 30 meters since raising the antenna. The rig's ATU can handle the SWR, though I expect the tuner loss to be on the order of 10% (-0.5 db).

The pattern is obviously skewed. The model tells me that there is more gain to the north. Perhaps that will come in handy for working Asia. About the only operating I do on 30 meters is to chase DXCC countries so I can live with this antenna for now. Eventually I'll need a proper antenna for this and the other WARC bands.


I did not evaluate (model) interactions before installing the inverted vee. It has to go somewhere, and I don't expect serious problems based on my previous real world and modelling experience. I could be wrong. Refer to the pictures above for an idea of how the antennas and guy wire are positioned relative to each other.

Guy wires are a negligible risk. This is because the segments they're broken into are very small relative to the 80 meter wavelength. The longest segments are a fraction of 41 meters, which is ½λ. All the antennas on the tower have similarly short elements. Any interactions that might exist are rarely detrimental to a single element antenna like an inverted vee. The danger is more applicable to directional antennas such as yagis.

There is a 10 meter yagi a few meters above the inverted vee apex. In general, a yagi above a wire antenna with the elements at a sharp downward angle will interact too little to cause more than a negligible pattern distortion. I could have lowered the apex had there been a worry. The 10 and 40 meter yagis at the top of the tower are too far to be affected and they are not resonant at the inverted vee's odd numbered harmonics.

The greater danger is to the side mounted TH6 at 22 meters height since the inverted vee elements pass behind it. They are far enough apart and the angle of the inverted vee legs sufficiently vertical that any interaction will be minor. Even that possibility is reduced since the limited 130° rotation of yagi between about 145° and 275° true bearing places the inverted vee at its rear or side. The TH6 never points at (through) the inverted vee. By pointed away from the inverted vee, the tuning of the yagi is minimally affected for the same reason that a yagi can be tuned by pointing it up, with the reflector quite close to the ground.

The SWR of the 10 meter yagi and TH6 are unchanged. However, that does not mean there is an absence of pattern distortion. The degree of interaction has to be quite severe before the impedance is noticably affected.

Hooking it up

All ports on the 2×8 antenna switch are in use. For now the inverted vee is connected to the 80 meter port. Once the 80 meter yagi is repaired I will face a small dilemma since both antennas can't be connected to the antenna switch. An auxiliary switch will need to be built and integrated with the station automation system. The hardware and software is ready and I've collected the parts for the switch.

More about the auxiliary antenna switch will be coming in the next month or two after it is built and installed. For now I happy to have an 80 meter antenna that works. Two or more antennas per band and redundancy are valuable assets when one antenna is lost before a contest or DXpedition.

Wednesday, March 8, 2023


As I wrote in my comments alongside my score submission to 3830, operating QRP with big gun antennas almost feels like cheating. Most QRP enthusiasts believe small is good, which applies to antennas and everything else, and not just the 5 watt power limit. I admire the philosophy from afar, and not so much when I turn on the rig. The only constraint with a QRP contest entry is the power level; they don't judge your philosophical purity. It's great fun to see what 5 watts can do in a contest when connected to antennas far above the average.

After a long respite I decided to enter a DX phone contest with QRP, even though my intention was to never do it again. It's just too painful. Since I had no intention of a serious entry in this month's ARRL DX SSB contest, I thought to myself: why not? Surely it can't be as painful as it was when I had a far smaller antenna system. Well, yes, it is still painful.

I am now more likely than ever to avoid using QRP in future SSB contests. The experience impresses on you the limit to what is possible with a wide, noise-filled 3 kHz bandwidth and power that is barely enough to get useful illumination from a flashlight or a desktop LED lamp!

In the following recap, I'll include what I believe are useful lessons for anyone contesting with a small station, QRP or not. I'll include links for several of the many articles I've previously written about small station and QRP contesting.

About the contest

When I made a splash in the CQ WW SSB contests with QRP in 2014 and 2015, I was using a far smaller station: a tri-bander up 15 meters and a few wires. Many of my contacts were with US stations simply because they were easier to work. There are fewer DX participants in the ARRL DX contests because they can only work W/VE stations. From many parts of the world it is hardly worth the bother.

My current station is far larger these days. But with Americans and Canadians worth 0 points and fewer DX stations to work than in CQ WW, score potential is lower. That lack is very noticable on all bands, and not just the low bands where working us is difficult from almost everywhere. 

I wish ARRL would tweak the rules to make the contest more inclusive. They could allow everyone to work everyone while keeping the current multiplier structure and differentiating QSO points for working W/VE versus others. There are several contests like this and it makes them far more attractive to all potential participants. 

With ARRL fiercely focused on tradition there is little chance the contest will improve and reverse its limited popularity outside the US and Canada. I know quite a few VE contesters that gave the contest a pass or participated only briefly.

It is what it is, so I did what I could to make the contest a worthwhile weekend's adventure. Working DX is always fun and I didn't want to avoid the contest entirely.

Why QRP unassisted

I made a similar choice in the ARRL Sweepstakes CW contest last fall. The nature of the contest and its somewhat tired traditional features no longer attract me. Yet it can still be fun by approaching it differently. 

Not enough stations to work? Operate with a handicap, and spread those contacts over a longer time span. Spice it up further by turning down the power. Multipliers and stations too easy to jump on with the steady stream of spots? Disconnect from the internet and put your hand on the VFO knob. Relearn how to find stations to work.

A few adjustments to one's standard operating style make the difference. In this way I turned a moderately attractive contest into a real test of skill, endurance and antenna performance. I doubled the fun by doing SO2R. Practicing operating skills helps with more serious contest entries.

Band by band performance

Band    QSO   Mult
 160      0      0
  80     19     16
  40     90     49
  20    147     64
  15    304     75
  10    326     70
        886    274

It should be no surprise that 15 and 10 meters are the friendliest for QRP. The atmospheric noise is low so a little power goes a long way. Since the high solar flux opened these bands for everyone, there were lots of stations on these bands, and they could hear weak signals easier than on the lower bands. 

20 meters was poor for most because stations spent a lot of time on the higher bands. Typical for solar maxima, signals on 20 are attenuated in the middle of the day due to high absorption. At times it sounded like there were more rag chews and POTA activations than contesters on the band.

The high band stacks were a big help. I could break many pile ups with them if I timed my calls well  and relied on an assist from propagation. There is a substantial skip zone over much of the eastern US for stations in Central America, the Caribbean and northern South America that gives Canadians an edge. Unfortunately there were times when the multiplier antenna, a side mounted TH6 up 22 meters, wasn't good enough with only 5 watts. In those cases I had to turn the big yagis south or wait for the pile ups to diminish. The additional 1 to 3 S-units from the big yagis made all the difference.

Splitting the stacks gave me the flexibility to move the rotatable yagis to directions where the gain was needed. This included Japan and the Far East, Asia, and the Pacific. Since I ran very little I didn't "spray" in multiple directions like I would with high power running. 

I had expectations for 40 meters with the big 3-element yagi. The QRM is extremely high during phone contests due to most of the world being crammed between 7125 and 7200 kHz. All I can say is that the yagi did its job. Many of the European big guns were worked on the first call. In the morning I had little trouble working JA, VK, ZL, KH6 and others. In the quieter spectrum above 7200 kHz I could work the multipliers to the south using the XM240 at half the height.

The big yagi isn't enough to run on 40 with QRP,  so I made few QSOs. My focus was to accumulate as many multipliers as possible. I am happy with my result.

I wondered if I'd work much of anything on 80. I can't work Americans in this contest, unlike in CQ WW. Every DX QSO was a struggle. With the vertical wire yagi temporarily out of commission I had to use the recently reinstalled inverted vee (30 meter apex). I am pleased to have worked as much as I did. Many DX stations didn't appear to have a directive antenna to help pull my puny signal out of the noise.

I met my expectation of zero contacts on 160. I did try a few times because you never know. My best result was "Victor?" I consider that a modest accomplishment!

Call everyone

Too many with small stations are hesitant to call weak stations. The thought being: if I can barely hear them, they'll never hear me. This is wrongthink. Many of those stations are also small, no different from yours. Or they may be in a very quiet area that is excellent for copying weak signals.

My philosophy is to call everyone. Sure, most of the weak ones will not hear you at all. The attempt costs nothing. More often than you may believe they come right back to you. I had that happen numerous times this weekend from fairly weak DX stations sending "kilo" as their power. 

Nothing ventured, nothing gained.


Noise, QRM, accents and fidelity all contribute to misunderstandings on phone. Also, English is not the first language for most. This is unique to phone since language issues are largely absent on CW, RTTY and digital modes. That may limit our ability to hold a conversation on CW beyond a hello-goodbye QSO or a contest exchange. Even that much can be a challenge on SSB. Weak signals make it worse.

The most common errors in the contest were V being heard as W, and 3 as 2. There was also the more common and humorous problem where the other operator would guess at my call. They'd be obviously trying each call listed in the Super Check Partial database that resembled what they had of my call. Each time they would hopefully ask "roger?" I'd say no, repeat my call and they'd try again. About half the time they would finally stumble onto the correct call and I'd shout back "roger, roger, roger!"

Returning to the problem of V and 3, this is really a problem with phonetics. For some reason, when I was poorly copied, "victor" would be heard as "whiskey". This is perhaps understandable with Slavic languages where "victor" and "wictor" are easily confused. But the confusion was not at all exclusive to those countries. I also don't really see how "two" and "three" are confused, yet they are.

In the latter case, counting out "one, two, three" worked most of the time. Using phonetics for V, I would try "victoria" since that usually works. Other choices were less successful. For example, in difficult cases with South American operators I would try "Venezuela", thinking that would be more familiar to them. That almost never worked. Novel phonetics rarely do better than the conventional ones, yet I had to try something in difficult cases. In several cases the QSO had to be abandoned. 

In another example, if they copy my suffix as "echo norway" or "whiskey norway" (or the better known "xray norway" of Gary VE3XN), I would repeat "victor norway" several times. Many would then change the call to something like "victor norway 3 whiskey norway." This could go on for a while. For the times when they successfully copied "victor norway" I would only repeat my prefix a few times. Thankfully that almost always worked.

Operating with QRP is like operating in dreadful propagation conditions. Except that everyone but me has good conditions!


Those with small stations tend to S & P and never run. This is self limiting behaviour. There are quite a few big guns to work, and you can work them on each band. That may be good enough for casual contesters. But that's leave a lot on the table for the more serious competitor. There are many weaker stations to call and you'll never work those, who like you, never run. That includes a lot of DX stations.

Running can feel uncomfortable when you first try it. Some come to love it and will only contest from semi-rare locales so that they can run all the time. We all have our unique preferences and motivations. But if you want to do well in a contest you must do at least some running, even if you have a small station.

I left most of my running attempts to Sunday when everyone was hungry for more contacts; they'd already picked the low hanging fruit the first day. Once I get spotted, they click and call. I could tell when it happened despite operating "disconnected" when I'd suddenly receive a small flood of callers.

My best runs were on 15 meters. I expected that to be on 10 meters and I'm not sure why.  Although the rate was usually painfully slow, perhaps one contact every few minutes, they add up over the course of the weekend. It doesn't get boring because at the same time I'm hunting for stations with the second radio.

Many runs ended when my frequency was stolen by another W/VE station. They can't hear me and since I have few callers they can't tell that another station is running on the frequency. That's just a fact of life when you operate with QRP. I lose little by QSY'ing since the rate is slow. You must not waste time by fighting for the frequency since you'll always lose to the big gun. He won't even notice that there is a struggle!


Operating two radios with QRP is less stressful than as a big gun. The runs are few and the rate is usually slow. I've done 2BSIQ on CW with QRP, but CW is far friendlier to small signals. I never tried it this weekend. I was running on one band or hunting stations on both radios. I would scale back to S & P on one band after becoming fatigued from the discordant racket in both ears or when conditions didn't warrant the effort.

My station is poorly configured for phone SO2R  since I don't like doing it. I made a few additions prior to the contest without attempting a full set of features on the second radio. I don't have the cables to pipe voice messages to the second radio and I couldn't be bothered. I dealt with it by only running on the first radio. 

I had another difficulty using N1MM Logger+ with this arrangement. For two keyboard SO2R, N1MM disables the keyboard feature to manually switch transmit focus. Instead you have to do it by pressing a function key or enter (ESM) to send the appropriate message. But I couldn't transmit messages from the PC. 

My workaround was to press a function key on the second radio keyboard that does nothing noteworthy (clear the RIT, in this instance). Since the mic is routed via the SO2R Mini, I could talk on the second radio once the focus was redirected. I used VOX because the foot switch is hard wired to the first radio. Pressing a function key on the first radio's keyboard switched transmit focus back to it.

Sound confusing? It worked pretty well after a few minutes practice. It was odd to send my call and report on one radio by hitting the enter key and speaking into the mic on the other radio. 

SO2R on phone while running on one or both radios is difficult since you have to at least speak the other station's call, or computerize voicing of the letters and numbers. You can often get away with just banging on the keyboard when calling stations -- "VE3VN" and "59 ON" -- except when message wasn't copied well.

I bypassed the BPF (band pass filters) for this contest and I rarely encountered interference from the other radio. QRP allows you to get away with that most times. It is easier on SSB than CW because the phone band segments are such that you rarely tune across your harmonics.


When you can't run very well, there is little tying you to the chair. You miss little if you step out of the shack for a few minutes. I did that a lot in the contest if only to maintain my sanity! If you've read this far you will understand how the frustration builds with the constraints I set for myself. I would eat, sleep, catch the news, walk outside, read my email or talk to someone. The big guns will still be there when you're refreshed and ready to resume.

As a big gun, in my case running a kilowatt to the same antennas, breaks almost always hurt your score. Casual operators might only appear for an hour and if you're not CQ'ing at the right time and place you won't work them. I doubt I lost more than a few contacts and multipliers from all of my breaks. 

I paid no attention to the clock when I took a break. If I wanted one I took it. There is no time restriction in this contest -- you can operate the full 48 hours -- so there is no benefit to making breaks at least 30 minutes to have it count as official off time. I don't know how many actual or official hours I operated, and I made no attempt to find out. 

The point is, if you feel you need a break, take one. You'll feel better for it, your family will appreciate the visit and your score as a small station, QRP or not, will suffer very little. You can do it and still be competitive.

Did I win?

Do I care? No, not really. As I said up front, mine is not the typical QRP station. Beating those with small stations is not an accomplishment. Going by what has been reported to 3830, my score exceeds others in my category by a wide margin. Not everybody submits a score to 3830 so I won't know for sure until the logs are adjudicated and the result announced. That will be many months from now.

One lesson worth mentioning is the generosity of so many competitive DX contesters. They would hold the horde at bay as they took as much time as needed to copy my call sign and exchange. This is time they could use to work 2, 3 or 4 other stations. I won from that experience and they won my respect.

I did have fun producing a respectable score without the intensity of using high power like I did in the CW contest two weekends earlier. Maybe I'll do it again, and maybe not. When the opportunity arises, I'll give it some thought.

Wednesday, March 1, 2023

Whet the Appetite: 6 Meters

Winter is a great time to sit indoors with a coffee mug in hand. I'll pound a keyboard or do anything that doesn't involve going outdoors. Mind you, I love winter and I take every opportunity to put on my snowshoes or partake in other outdoor activities. It's just that most of the time it is easy, too easy, to sit inside where it's warm and cozy and admire the winter scene through a frosty window. 

February 27 was one of those days. There was an ongoing geomagnetic storm so, instead of paying attention to poor conditions on HF, I pointed the 6 meter yagi south and monitored the FT8 watering hole at 50.313 MHz while I went about my day. Geomagnetic disturbances are often responsible for enhanced north-south propagation. In combination with a high solar flux, the K-index of 7 and lots of DX spots for north-south propagation between Europe and Africa, it made perfect sense to pay close attention to what might develop.

When I looked over my shoulder at the WSJT-X display in the middle of the afternoon I was rewarded with a screen full of signals. They had popped up quite suddenly so it was quite a surprise. It was particularly surprising because it was not the kind of activity I was expecting. There was far more than the usual South American activity.

Off the side of the yagi I copied station across the US Midwest and California. Many of them were calling stations in the Pacific Ocean region. These included ZL, VK, FK, KH6 and 3D2. I swung the antenna to 240° to see what would show up. What I saw had me punching the amplifier's on switch and impatiently waiting 3 minutes for the tetrode to warm up.

There were many strong California stations and a few from Mexico. From here, they are in a direct great circle path to New Zealand. About 5 minutes later I copied the very first ZL station of this solar cycle. So I called, and called and called and called.

It was quite a thrill despite failing to connect. Two ZL stations were heard (ZL1AKW and ZL1RS), along with several very loud Hawaiians. I saved the decode file for searching afterward since there were so many signals that it was impossible to scan everything in real time. It's quite easy to imagine things that aren't really there. I later confirmed that no other Pacific DX was decoded at my station.

Calling CQ netted several W6 stations but nothing else. PSK Reporter showed no reception reports beyond KH6. Exciting as the opening was, I had struck out. The opening continued for about 30 minutes, with ZL heard for about half that time. Their signals were never strong, peaking at -11 db. The opening ended as suddenly as it began. I continued to monitor for the next several hours to no avail.

Expect to see more of these openings in the coming months. As the SFI rises, even when it is not enough to support F2 propagation on its own, enhancement from TEP, sporadic E and auroral E will create surprising DX openings. Don't let it catch you by surprise! If you want the DX, you will have to pay attention. The Pacific opening when I worked E5 and 3D2 last summer was an early preview of improving east-west propagation at higher latitudes.

I confess that I get tired of being asked what days and times to expect the DX to come rolling in. It is rarely that simple: there is no fixed schedule. You must monitor, listen and monitor some more. Don't count on a friend letting you know, except to brag afterward about the new countries they worked. 

I can offer a few hints to those unfamiliar with 6 meter propagation. Sitting on the edge of what the ionosphere can do, it takes only a small deviation from normal or a peak in ordinary phenomena to deliver extraordinary DX opportunities. Let's look first at the opening mentioned above. In addition to the geomagnetic conditions, there was a fortuitous daily arrangement.

Here we see the geometry of the terminator at the exact time the ZL stations were heard: 2030Z. Notice that it is noon almost exactly at the longitude mid-point between me and New Zealand. Due to our respective north and south latitudes, ZL is about the same time past their sunrise as VE3 is before our sunset. This is important since solar insolation, and therefore EUV intensity, is at a maximum in the tropics which signals between us must traverse. With sufficient propagation at temperate latitudes we can connect via the tropics. This may have been a combination of auroral E and TEP.

It is just such fortuitous occurrences that tip a dead band towards fireworks. This is not the only recent incidence of tropical assistance to propagation, and it's one I've mentioned in my 6 meter article in past years. Now let's look back several days to an opening in the opposite direction.

February 21 brought an unexpected opening. I worked about 10 stations in Europe, from England to Italy, and EA8. Particularly exciting was hearing ZS6TK calling Europeans. By the time my amp warmed up he was gone. I called CQ with the yagi pointing east. PSK Reporter shows that I was heard at ZS6WN. Unfortunately, a QSO with South Africa was not in the cards that day.

The opening was not limited to South Africa and Europe. Stations further to the east in W1 had a far more substantial opening. They were hearing and working stations in the Middle East (9K, 4X), Africa (3C, 7X) and in the western Indian Ocean (3B9, FR). I could only watch and envy their good fortune. Indeed, it turns out that great circle path to the northeast, which from here is the one for all of these stations and the Europeans that I worked, was not favourable. All signals peaked to the east, not the northeast.

This is an instance of skew path that is not unusual when the MUF is marginal. Ionization, as mentioned earlier, is higher in the tropics. Signals were scattering from the more intense ionization area south of the great circle path. The same phenomenon is common on 10 meters soon after sunrise when European signals peak while beaming east. As the day progresses and illumination of the usual path continues, signals shift to the direct northeast path.

I was unlucky that day other than the European opening. There will be more opportunities in the days and months ahead.

Closer to home, the aurora produced by the recent geomagnetic storm supported a modest amount of VHF propagation. On the evening of February 26, I worked stations in W1, W8 and VE, and I copied beacons as far afield as VE4 and VY0. W0 stations were heard. I worked little since I didn't bother with the amp and aurora signals are typically quite weak. 

Aurora propagation is interesting but it isn't DX. That's why I couldn't be bothered to warm up the amp. Going back several cycles to 1989/90, I had a blast working aurora on 6 meters and 2 meters. With sunspots come flares and CME (coronal mass ejection), and the probability of intense aurora extending to lower latitudes. 

If that's your fancy, expect instances of this kind of 6 meter propagation to increase over the next 2 years. These days I am mainly interested in auroral-E propagation for Arctic circle DX such as KL7 and Scandinavia, and as a bridge to F-layer propagation in sunlit areas on the northern hemisphere. Non-DX propagation on 6 meters rarely excites me as it once did.

During the February 27 opening to the Pacific there was an excellent opening to South America. I had to forego it to focus on the Pacific. North-south propagation is more common so it made sense to seize the opportunity of rarer DX. That said, it would have been nice to work them, including one South American country that I have yet to work on 6 meter FT8: OA.

This was not the first time I've had an opening to the South Pacific this solar cycle and it won't be the last. Worldwide DX propagation on 6 meters will only get better through at least 2024 and probably 2025. Forecasts of solar activity are full of uncertainties, yet we're far enough along to say that the current cycle will be at least equal to the last one. I was not really active on 6 meters in that cycle and it was before the advent of digital modes for terrestrial VHF operation.

Cycle 25 is likely to be the best yet for 6 meter DXers. This is despite a cycle maximum unlikely to rival past cycles. Consider:

  • Activity level on 6 meters is greater than ever. Every HF rig, and now many amplifiers, feature 6 meters. Pretty well every HF operator has a 6 meter rig.
  • No matter how you feel about it, digital modes have caused a surge of activity. Many hams, for reasons of having no CW ability or are restricted to small antennas, find VHF digital modes to be an ideal outlet for their enthusiasm.
  • Most hams are old. They are retirees with more time on their hands. Unlike when I was young, the bands are populated during weekdays. I missed many great 6 meter openings in decades past when I was busy at work.
  • The cash rich baby boomers are launching more DXpeditions than ever. These range from suitcase style operations from Caribbean vacation locales to rare islands and countries around the world. Many of them are active on 6 meters.

2023 promises to be a year to remember for 6 meter DX enthusiasts such as myself. While the MUF may not hit 50 MHz as often as we'd like, the tie-in with sporadic E and TEP, combined with the far higher activity, will generate opportunities like no previous solar cycle. With 120 DXCC entities on 6 meters, I have reached the point of diminishing returns without the aid of F2 propagation. I expect a significant jump in my DXCC count this year.

Have I whet your appetite? Have you been thinking of becoming active on 6 meters, but have yet to make the leap? Get ready. When the equinox arrives in a few weeks the DX openings will become more frequent. As April turns to May, sporadic E will arrive. In combination with improving F2 propagation it could get wild. I'll be there, and I hope to see you there as well.