6 Meter Season Has Begun

It is interesting to me that in speaking of a beginning to the annual 6 meter season is less anachronistic than it ought to be. After all, here we are on the cusp of the peak years of solar cycle 25 when ionospheric 6 meters propagation should be common throughout the year. But that is just hyperbole --the truth is quite different. The F2 layer DX propagation that I saw during the far better peak of 1989 and 1990 was episodic and never routine.

Thus we continue to speak of the 6 meter season when sporadic E propagation marches towards its annual peak at the summer solstice in late June. I have already worked Europe via sporadic E (May 1) and more sporadic E openings, if only weak ones and with shorter paths, are already an almost daily occurrence. TEP linked propagation to South America occurs every few days even at my high geomagnetic latitude.

That said, this year's season appears likely to be different from those during the trough of the solar cycle. The reasons go beyond the rising solar flux index. It is worth reviewing those reasons now that DX propagation is beginning on paths other than the usual north-south TEP-assisted propagation between North and South America. It isn't just us, of course, since the same annual cycle of sporadic E is emerging in Asia, Europe, Oceania and elsewhere, and usually better than what we have in North America.

No matter the sporadic E expectations and the various predictions for the current solar cycle, working DX on 6 meters requires dedication and effort. It is never easy. Let's look at why this year may be different and why, I believe, better.

Digital

With regard to DX on 6 meters, digital modes have almost all of it. When you decline to operate digital modes you refuse the opportunity to work almost any DX at all. I've worked DX on CW and SSB over the past few years but it has been rare. That's the new reality no matter your like or dislike of digital modes. That ship has sailed.

The migration to digital has brought many benefits to 6 meter operation, and it also has brought annoyances. It is to be expected that more hams operating on a band will include a cross-section of the personalities in our hobby, which is really a cross-section of our societies. 

Although I enthusiastically embraced digital operation on 6 meters after initial misgivings, I strongly prefer the traditional modes. Each has its place in my ham activity. For example, when I participate in a VHF contest I solely operate CW and SSB. I appreciate that ARRL added the analogue category to their VHF contests. I do not enjoy digital contests on any band.

Increased activity

Many bemoan the lack of HF activity on most days. It is surprisingly sparse. Compared to decades ago, there are far fewer conversations taking place. Activity only seems to spike during DXpeditions and contests. The number of hams hasn't declined, it's just that preferences have changed. The conditions are there but not the interest.

With digital modes and 6 meter capability on rigs, amplifiers and multi-band antennas, the amount of activity on 6 has been increasing every year for at least the past 6 or 7 years. With more stations monitoring and transmitting there are more opportunities to make contacts and, important to many like me, to discover more openings. We now know that in the past many DX openings went unnoticed due to the lower activity and the difficulty of discovering openings on CW and SSB.

Additional enticements are DXpeditions. It has become routine for them to include 6 meters. They may only monitor FT8 most of the time and transmit only when propagation is likely. With internet connectivity they announce when and where they are CQing or monitoring for callers. 3G0YA is a recent example which successfully worked into at least the southern US. HD8M was worked by a few of my friends. I was busy when signals were at their best so I missed them. Expect several rare DX entities to be on 6 meters this summer.

Not all of the activity is always welcome. Consider the many robot operators. We can't stop them but we can make use of them. They are better than CW beacons since we'll hear the robots while monitoring the watering hole. There is no need to repeatedly spin the VFO knob to scan for beacons. 

It will not be long before regular 6 meter activity won't fit within the 3 kHz watering hole at 50.313 MHz. It already gets tightly packed during openings. That should not be seen as a problem. We can use the faster FT4 mode at 50.318 MHz or try the intercontinental window at 50.323 MHz. That is one way we can effectively spread out the activity. When a supplement to 50.313 MHz is eventually needed there is ample spectrum available. 

Over time we can expect that our rigs will accommodate digital channels far wider than 3 kHz, which is simply a limitation of the SSB mode that many of us must use with the current and older generation of equipment in our shacks. SDR rigs will be able to monitor multiple digital windows, one per receiver slice, without the clumsy workarounds that are currently needed.

We can and should accommodate more activity on 6 meters. The technology is already moving in that direction and the increasing number of operators migrating to the magic band demands it. The future is bright.

Chaining

The entire path doesn't need to be solar flux driven F2 propagation. By jumping from a sporadic E cloud at our high latitude to the higher F2 MUF or TEP at low latitudes it is possible to extend DX paths world wide. 

Crossing the equator to the south is easiest for us. It can be done even at solar minima, but DX to the east and west are more difficult. Chaining to low latitude propagation makes the path more likely. I expect better openings to Africa and Oceania in particular. Going over the pole by F2 propagation alone is unlikely in this solar cycle so that will continue to depend on relatively rare sporadic E. Chaining sporadic E to F2 over the pole is unlikely but it is possible. With increased activity this year the chances of discovering these unusual openings will improve.

Summer is not the best time for propagation on the high HF bands when absorption tends to be high. The same is true for F2 propagation on 6 meters. Since sporadic E is a primarily summer phenomenon, chaining is what we must hope for until the early fall when F2 propagation is better at this latitude, if the solar flux is high enough. It may be but there is no guarantee. Sporadic E will continue to be necessary for working DX over the next several months.

Solar flares

Solar flares are responsible for high x-ray radiation. Luckily the atmosphere protects life on Earth from most of the potential harm. One of the ways the protection manifests is x-ray absorption in the ionosphere when electrons are separated from gas molecules. The high ion density causes radio wave absorption on the sun facing side of the planet.

Flaring is associated with sunspots so their frequency and intensity increases a lot during solar maxima. As you can see from the following graph covering May 3 to 5, there are a lot of flares nowadays. Despite this, many DX and North American stations can still be worked on 6 meters.

The effect of flares is more keenly noticed at lower frequencies where HF blackouts occur. As you go up in frequency the degree of absorption declines. Depending on the flare intensity and duration there may be little to no discernible impact on 6 meters. You should take those blackouts as a sign to QSY to 6 meters. Don't be too quick to turn off the radio!

Geomagnetic storms

Flares are frequently associated with CME (coronal mass ejections). Fast proton streams can impact the Earth within a few hours (proton storms). Solar wind storms can take up to two days to reach us and cause high latitude geomagnetic storms. Both types of storms can disrupt propagation on HF and 6 meters.

Those at tropical and subtropical latitudes are less affected than those of us at higher latitudes. Europe is less affected than North America since we are closer to the geomagnetic pole. That said, unless there is an aurora there may be little effect on most sporadic E propagation paths. In the aftermath of a storm, there can even be enhancement of propagation paths between the north and south hemispheres. Aurora propagation brings an opportunity to work grids and states that are difficult on other propagation modes. This is one case where you must use CW or SSB.

Monitoring

In our busy lives we cannot constantly monitor 6 meters. Yet it is desirable since openings are not as predictable as on HF and they can be painfully brief, especially over long DX paths. This is a topic I've covered in this blog many times. 

Spotting networks have gradually become less valuable as a 6 meter monitoring tool as it has for digital modes on HF. It is so easy to discover all of the activity on a band by monitoring the usual water hole for a minute or two there is less incentive to spot. It may also be because it is less convenient to do so since WSJT-X doesn't support spotting so that a separate Telnet application may be required. Don't depend on spotting networks to discover 6 meter openings. Monitor 50.313 MHz.

This time of year when I'm not active on HF or away from home I leave the rig monitoring 50.313 MHz. I check activity occasionally and turn the yagi for likely propagation. I search the decode window to see if anything interesting showed up while I wasn't paying attention. I can also count on my friends to email me when I'm not in front of the rig. Monitoring the band has never been easier.

I don't really know why I am so popular but the act of simply monitoring is enough to attract callers. I glance at the monitor and notice that someone has been calling me for some time. You may be wondering how they know I'm listening. The answer is PSK Reporter. From my announced presence via WSJT-X, it is easy to discover that I am monitoring 50.313 MHz. They want to work me (for the grid?) so they call and hope for the best.

That strategy rarely works with me since I am most often doing other things while I'm monitoring. One near miss was FK8CP earlier this spring. I had called him a few times without success early one evening. I didn't hear him for a few minutes so I left the shack. When I returned several minutes later I discovered that he had been calling me for a few minutes. 

Of course it's far more likely that he made a delayed reply rather than finding me on PSK Reporter. However, you never know. Many of those we call rare DX consider VE3 to be an enticing catch on 6 meters. Monitoring can pay unexpected dividends.

Prospects

From all the positive indications I've touched on, I expect this 6 meter season to be a good one. How good remains to be seen. Last year's sporadic E season was relatively poor despite many of the same good indications. If you have been considering becoming active on the magic band, this year is an excellent time to do it.

I will consider the 2024 season to be a success if I can add 10 DXCC entities. It would be a spectacular season if I can add 20. Those are reasonable goals considering that my current total is 136 worked and 127 confirmed, accumulated since my return to 6 meters almost 10 years ago. Hope springs eternal.

I have a plan to make a modest improvement to my 6 meter capability this year. More on that in an upcoming article.

Another Prop Pitch Rotator Direction Indicator Prototype

For a long time the ugliest presence on my operating desk has been the controller for the two prop pitch rotators. When I say ugly, I mean really ugly. Have and look and see what you think. It's sitting on top of an Icom 7610, which makes for quite a contrast.

The controller is home brew and very old. The repurposed CDR direction meter failed over a year ago. As an interim(!) measure I installed a pair of op amp circuits on a prototype board feeding an outboard milliammeter pulled from my junk box. A rotary switch was installed to select the motor and direction, and also select which rotator direction to display. 

Despite its deplorable appearance it works quite well. Just don't breathe hard when you get close to it! I never did get around to putting the circuits on a PCB. My intent was to gut the innards of a couple of orphan Hy-Gain rotator controllers to serve as the prop pitch controllers. Then I had second thoughts. I put off doing anything with it until I was certain of what I wanted for a permanent solution.

Earlier this year I decided to set aside the orphan controllers that I picked up at local flea markets and took an entirely different approach. So I built a new prototype. It's been languishing on the operating desk due to family issues, thus adding to the ugliness for months. I recently made an effort to move the project forward. 

I have all the parts and a plan to complete the controller. The first version will only display the direction of the rotators. Turning the motors will, for the time being, continue with the ugly controller. One reason is that, in the midst of this project, the power supply developed serious problems and needs repair or replacement. Troubleshooting has been difficult with the fragile prototype board perched on top of the transformer and filter capacitor.

Although not assembled, even in its first version, enough has been done to be worth an article. Another will follow when it is done, and perhaps another when the rotation activation features are added. After that it will require refinement, which will be easier since the work should be almost entirely in the software.

Design objectives & features

I had a variety of objectives in mind for the controller, some critical and others for convenience or personal interest. They are listed below, but not in any particular order. I developed the list organically as I considered options to replace the existing controller and as I formed opinions on functionality as I proceeded.

• Compact size: I want it to fit well and look good on the operating desk
• Remote power supply: The 24 VDC power supply for the motor is fairly large and does not need to take up space on the operating desk
• Future PC integration: Integrate rotator control with my station automation system to provide easy access from each operating position (multi-op contests) and, possibly, for remote operation
• Software: Ease of modification and extension
• Support a variety of direction pot methods, and possibly other direction indicators
• Over 360° rotation: Handy in a pinch, but with strict limits to avoid coax damage
• Digital display and control: No mechanical meters or user-activated switches for motor power
• Front panel calibration: No need to open it up or to climb the tower

There are commercial products that can do most of what I want. However, regular readers will have learned by now that I prefer to design and build what I can. This project is well within my abilities. Indeed, it should be within the abilities of many hams. It's an opportunity to learn and to have the satisfaction of building station equipment that will be used every day.

Architecture

This version of the controller requires that the direction potentiometer on the tower be 10:1 and 10 kΩ. The manufacturer is Bourn and they are available from most large component suppliers. There are knock offs available on other sites that are not the same quality but are cheap and work pretty well. They need to be well protected from moisture. You can see one in the picture below being used to emulate the tower pot.

An op-amp differential amplifier compares the tower pot to a 10 kΩ zeroing pot in the controller and feeds that to an Arduino analogue (ADC) GPIO pin via a linear protection circuit. The op-amp circuit is very similar to that in the prototype sitting on the old controller. The differences are described in the next section.

Software measures the voltage and converts that to a bearing. In the present implementation, north is at the centre of rotation and over-360° rotation is supported. This is the most useful arrangement for HF propagation in this part of the world. Any centre can be set in the software, as can rotation limits.

The display is a 2×16 LCD (1602A). These are very common and cheap. A friend made a few bezels for the display on his 3D printer from designs available online. We haven't yet settled on which one to use.

The controller is powered from a 12 VDC (13.8 VDC) external supply. Onboard converters and regulators provide ±15 volts for the op-amp circuits and external pots and 5 VDC for the Arduino and LCD. The prototype is driven by a pair of 9 VDC batteries which, as we'll see, is insufficient.

There will be connectors on the rear of the enclosure for the direction pots on the towers and to drive relays in the 24 VDC motor power supplies. I have two power supplies so that both motors can be run concurrently. The software will sequence the relays and, in a future version, detect motion faults to prevent damage to the motors and power supplies.

Op-amp circuit

The op-amp circuit is almost identical to that of the earlier prototype, the one that is currently in use. I reverted to this circuit after exploring alternative differential amplifier designs that never quite did what I wanted. I developed a simple spreadsheet to predict performance. The circuit has to be linear within the range the tower pot covers with predictable and adjustable gain and zeroing.

In the end, simplicity won out over perfection. I can live with a few quirks.

There is one important difference between this circuit and that of the earlier prototype. A physical meter responds to current while the analogue GPIO pin ADC responds to voltage. I set a fixed circuit gain (negative feedback) and used a pot as a voltage divider to lower the net gain of the circuit. The protection circuit protects the Arduino microprocessor from adjustment errors and voltage surges.

For ±15 VDC op-amp power, one turn of the 10:1 tower direction pot has a 3 volt range over 360° (10% of 30 volts). That corresponds to the motion of the direction pot on the 1:1 rotation of the chain-driven prop pitch motor. On the other tower, the belt drive for the pot has an approximate ratio of 2.5:1 for 360° rotation. The circuit supports both with the fixed resistor for negative feedback. All that's required is to set the level pot.

The protection circuit design is linear between 1.5 and 4.5 volts, which is a range of 3 volts. With the 10 kΩ feedback resistor the gain of the op-amp is above unity, so the direct drive motor will cause a range higher than 3 volts at the op-amp output. The gain isn't so high that the op-amp is pushed beyond its linear curve; that is, output voltage approaching either power rail. It is however recommended that the tower pot be roughly centred within its 10 turn rotation so that there is no risk of the inputs approaching the power rail voltages. The 741 data sheet specifies what is allowed.

The same spec sheet shows that the minimum supply voltage for the 741 is ±10 volts. The 9 volt batteries are not quite enough and I did see a few anomalies when I let the input voltages get too high. Consider that for a 3-turn rotation of the tower pot the input voltage range is 5.4 volts (30% of 18 volts), or 9 volts for ±15 volt supplies.

Because the voltage for counterclockwise south (180° bearing) is 1.5 volts and not 0 volts, adjustment of the gain (level pot) also changes the 1.5 volt value. This does not occur on the earlier prototype because there is a true zero volt point for the meter movement. This is an unfortunate quirk  but one I can live with. Both the zero and gain pots will be exposed to the operator for calibration. For a true zero point circuit the gain control can be a trim pot within the enclosure, calibrated to the the turns ratio driving the tower pot.

The circuit requires protection from RFI and surges (e.g. lightning) since the tower pots are permanently connected. Op-amps are sensitive devices and microprocessors are fragile. Modular connectors rather than barrier strips will allow rapid disconnection for added safety. RFC and capacitors will bypass RF to ground. GDT (gas discharge tubes) will shunt high voltages pulses to ground. These will depend on the RFC and capacitors to "slow" the rise time since the pots must be DC coupled. Component selection has not yet been decided.

Arduino hardware & software

Perhaps one of the most critical requirements of a processor for control applications is the number and type of GPIO (general purpose input output) pins. Despite its simplicity, quite a few are needed:

• LCD: 6
• Direction indicator: 1 analogue input per direction pot
• Rotation selection: 2 digital inputs per prop pitch motor
  
• Rotator activation: 2 digital outputs per prop pitch motor, and 1 more for power sequencing
• Rotation sensing: 1 or 2 analogue inputs per rotator
• Wi-Fi connectivity: if not integrated, at least 1 RX/TX pair is needed

For control of my two prop pitch motors, the initial version requires 18 GPIO pins, of which 2 are analogue. There are ways to reduce the GPIO requirement that I won't delve into in this article. I am keeping the design simple for the initial version of the project.

I dug into my junk box and pulled out the clone Arduino Uno that you can see above. It is barely sufficient in this application since almost every GPIO pin will need to be used. Something like an Arduino Mega would be needed to support more than two prop pitch rotators. Processor speed and memory are unimportant in this application.

The display is a bottleneck so it's helpful that not a lot is needed in this application. An LCD with two lines of 16 characters, with each character a 5×8 matrix (like dot-matrix printer of the past) is good enough. Above you can see that the top line is for labels and the second is for the direction information. There is a limited character set native to these cheap and ubiquitous displays (a few dollars each) but it is easy to create custom characters. I created characters for the degree symbol (shown), arrows for rotation direction and alert symbols for faults and warnings.

The trim pot on the left side of the protoboard sets the display contrast. It is very sensitive to the voltage, with the required value in the vicinity of 1 volt. There are pins for powering the backlight, and that's mandatory for almost all environments. Visibility of the display is better than it appears in the picture. 

Although the dimensions are almost an industry standard, not every LCD of this type is identical. When you 3D print a bezel be sure it's the correct size and that there is a way to tighten it to the enclosure front panel. Our first few attempts were deficient. I am eagerly awaiting the latest print since it appears to be what I need.

The replacement of physical with digital direction indication requires smoothing. The signal from the tower pot is constantly changing, whether the motor is running or not. The mast rocks back and forth and the pot has imperfections and glitches, especially as it ages. Physical meter movements naturally smooth brief glitches (perhaps up to 100 ms) but we want to see all real motion of the mast. With a readout precision of 1° and Arduino cycle times that are quite short, the displayed direction is constantly changing. Active smoothing is desirable.

Smoothing can be done in hardware or software, or both. A time constant circuit (T = RC) easily takes care of brief glitches. For example, a 20 μF capacitor across the 10 kΩ level pot has a time constant of about 200 ms. Glitches will be smoothed but not normal rotation, which includes rocking in the wind. The same can be accomplished in software with a moving average. A simple example is to display the average of the last 5 measurements, where the loop interval is 50 ms. Software can do even better by identifying glitches -- unexpected and impossible changes between successive measurements -- and discard or modify them. 

With these methods it is possible to keep the bearing display sane. However, if the pot has degraded to the point that glitches are common or the voltage is unreliable it will have to be replaced. Software can't solve every problem.

Glitches are common with buttons and will have to be dealt with in a similar fashion when, in the next version, they are used to turn the rotators. Again, both hardware and software measures can be used. In this case, the term for the process is debouncing.

Notice in the picture above that the right hand bearing is "---°". This is done in software when the signal at the analogue GPIO pin (ADC) is out of range. In this case the pin has been grounded (not used for now). If it is not grounded the display might show a value, and that value would be related to that present on the operational pin for the bearing on the left. This is necessary since the Arduino multiplexes the analogue GPIO pins into a single ADC circuit and continuously scans each input. 

Due to the high input impedance and stray capacitance, an open but used analogue GPIO pin will measure the residual voltage stored in the stray capacitance. When the pin is in service the phantom reading vanishes. Unused inputs for disconnected tower pots may have to be grounded or pulled high to avoid this phenomenon. It can be done by modifying the software but that can be inconvenient.

Next steps

Circumstances to which I previously alluded are serious enough to keep me away from contests and most station work, and the blog. I've climbed towers only thrice in the intervening two months and two of those weren't mine. The list of station work to be done is growing. This will be a busy year.

At least the prop pitch controller can be worked on indoors and during evenings which gives me more opportunity to get it done. I have the enclosure, the power supplies and other components to box up the controller. Aspects of those details are interesting and well worth another article. Time permitting, that will come later in May.

12 VDC Prop Pitch Motor

The aviation electrical power standard has been 24 VDC for a very long time. Since this also holds for US military aircraft, prop pitch motors require a 24 VDC power source even though their design dates all the way back to WW II. It turns out, much to my surprise, that there exist 12 VDC prop pitch motors. I first learned of their existence several years ago when a friend purchased one at a flea market. 

They seem to be quite rare. It is difficult to identify them from the outside. At the very least it is necessary to remove the motor cover and read the print on the motor. You don't even need to do that since the external appearance is quite different. I had occasion recently to become more familiar with these motors when the motor developed a fault and I offered to inspect and hopefully repair my friend's motor. The loss of any rotator is an inconvenience. Luckily he has enough antennas that the temporary loss could be tolerated.

Those of you with an interest in prop pitch motors and, like me, have never seen a 12 volt motor, this tear down and repair should be welcome. I had no information about them and I could not find any. All I had from a friend was confirmation that they exist. He was happy to receive the pictures I sent him since he had none in his files.

Separating the motor and gearbox (reduction drive)

In my workshop I carefully began disassembly. Although I have experience working on prop pitch motors, this one was a novelty. There was minor damage on the outside due to mishandling in the distant past. I filed down metal spurs on the motor body and motor retaining nut. The method for mounting the after-market rotating reed switch magnet was poor and did some damage to the exterior of the top motor bearing. I put that aside while I worked on the motor.

Pulling the motor off the gearbox was more difficult than I expected. It uses the same large threaded nut that is found on many of the small size prop pitch motors. I was surprised that the motor did not come free when the nut was removed. I carefully pried up the motor with a large gear puller to discover the reason for the resistance. 

It turns out that there are no electrical contact pins on the motor and the drive side of the gearbox. The motor wires are directly threaded through holes in the gearbox housing. Once I realized that, I removed the connectors crimped onto the wires and pushed the bare wires through the holes while pulling up on the motor. The motor and gearbox were finally separated. 

It is a good idea to label the wires at this point so that they are correctly placed for reassembly. I had to puzzle it out during reassembly since I forgot to do so. Luckily the wire arrangement is the same as the 24 volt models. This one is a right hand motor.

Note: After K7NV passed, his web site full of prop pitch motor information went offline. I have an archive as do many others, but at the time of writing there are no reliable links to point you to due to copyright and other issues. In any case, he had nothing on the 12 volt motors. I will not publish his wiring diagrams in this article. Hopefully at a later date there will be a permanently accessible archive of his material.

The next surprise was that the drive side of the motor axle was loose. That is, there is only one bearing, and that is located at the top of the motor axle. The motor cannot be spun unless it is attached to the gearbox. I thought that was very odd. On the other hand, I suppose there's some benefit in having one less bearing to deal with!

Unlike the splines on the more common 24 volt motors, the coupling is done with a blade. There is a matching receptacle for the blade on the gearbox shaft. The fit is precise so that the axle doesn't wobble. I have heard that this alternative appears on some 24 volt motors but I have never seen one.

Gearbox

At this point I checked the gearbox for freedom of movement. After leaving it outside during a cold spell (it was too large for my usual freezer test!) there was evidence of a poor grease choice. I didn't open the gearbox but the owner told me that he'd previously opened and lubricated what he could access. Not all parts are accessible without disassembling the planetary gears. 

I didn't open the gearbox since there was no evidence of a problem other than perhaps a poor choice of grease. I set it aside for when the motor was ready to be reassembled. Although I was curious about the design of the gearbox, that wasn't a good enough reason to open it for an inspection. Perhaps another time.

This is a picture of the drive side of the gearbox. Notice the lack of provision for electrical contacts, just the holes through which the wires are threaded. In the usual design the contact receptacles slot into holes and are held there with retaining rings. With this motor, care is needed to avoid tugging the wires and abrading the insulation during assembly and reassembly.

Since the contacts, where they exist, are part of the gearbox housing, I wasn't surprised to see that the part number was different. Other than that the housing looks the same as for the 24 volt design. The motor base is the same, and there is the same key in the gearbox housing to secure the motor position when the motor is mounted. The motor axle has to be rotated during assembly until the blade aligns with the slot on the gearbox axle.

Note the key at the bottom. It has a mating notch on the flange at the base of the motor. Its importance during reassembly will become apparent towards the end of this article.

Inside the motor

With just one bearing, it was easy to knock out the axle and armature assembly. With an appropriately sized tube, the bearing was then knocked out from the inside. This was done carefully to avoid damaging the bearing. I should say, damage the bearing further, since I already suspected that it was damaged. 

The two pictures of the armature show the axle and commutator. I later cleaned the carbon from the commutator and saw that it was in good condition. The bearing seats on the shaft up against the top washer. When disassembling prop pitch motors it is critical to take note of where the washers and shims came from so that they are put back in the same place during reassembly. A mistake can damage the motor when it is run.

In the 12 volt motor the brushes are at the top of the motor; they are at the bottom (drive side) in the 24 volt motors. You can see how the wires are routed to the field coils and brushes. The brushes appeared to be in good condition so I cleaned the interior as well as I could and set it aside. I filed down metal spurs on the exterior that may have been caused by rough handling in the past. That was done mostly for aesthetics and to avoid skin damage during handling. It also made it easier to slip the motor cover on and off.

Motor bearing

My attention next focused on the motor bearing. The symptom when it was on the tower and not turning was excess resistance to manual rotation of the motor axle. An application of modest force freed the axle and the motor worked again. When it happened again my friend brought it to the ground. This is not the first time I've dealt with bearing trouble in a prop pitch motor so I proceeded with the confidence of experience.

Since there was no sign of mechanical scraping or other damage on the armature or field coils the problem had to be in the motor bearing or the gearbox. A bearing or gear failure in the gearbox typically doesn't result in locking the motor axle. The reason is the high reduction ratio. It usually takes several rotations of the gearbox axle to take up play in the many gears before it locks up. Since the gearbox axle turned smoothly, even after the low temperature test mention earlier, the bearing was the primary suspect.

Turning the bearing by hand was smooth. At least it was at first. Eventually I noticed an intermittent roughness. I tossed the bearing in the freezer. When I retrieved it an hour later, he imperfection was pronounced. There was also a small amount of play between the inner and outer sections that indicated worn balls.

I found a compatible modern bearing for the "201" shielded bearing by perusing my catalogues. It is the same as the top bearing for the 24 volt motor. The old 201 has shallow concave races that do not support axial loads; that is, it works best as a thrust bearing. The 6201 double sealed replacement is a deep groove bearing that is suitable for high axial and radial loads at speeds greater than that of the motor. I ordered two so that I can replace the ancient top bearing on one of my 24 volt motors.

You can see the difference between them in the picture above. The larger surface of the inner section is handy for firmly securing the aluminum arm that contains the magnet for a reed switch. My friend has a Green Heron controller for his other prop pitch motor that supports this arrangement, but for direction indication with this motor he uses a 4O3A compass on the antenna. 

I use 10:1 potentiometers for my chain drive and upside down prop pitch motors. There are many ways to accomplish direction indication for prop pitch motor rotators. There are both commercial and home brew solutions.

Reassembly

Installation of the bearing highlighted a curious aspect of the design. Since it is installed from the top there is no resistance to axial force pushes it upward. Normally this shouldn't be a problem since the bearing should only experience radial loads. 

The method by which the direction indicator bar and magnet (parts visible at the lower right) were mounted on the axle prevented vertical migration of the bearing. In the 24 volt motor, both motor bearings are pressed in from the inside so they cannot move. 

After pressing in the bearing I pushed the axle and the attached armature into it from the open bottom end of the motor housing, taking care to have it seated against the axle washers. There is a flange on the axle that seats the washers and bearing in their correct positions. 

I had difficulty aligning the blade on the motor with the socket on the gearbox. It isn't as easy as one might expect because there are two pairs of items to align: the axle blade and socket, and the key on the gearbox body with the notch in the motor flange. What makes the task particularly difficult is the near press fit of the motor into the gearbox housing and lining up those two mechanisms must be done blind; all are invisible when the motor is pressed into the gearbox housing. Another complication is that the wires have to be inserted through the gearbox holes during this procedure, and they can't be twisted far while pushing on the motor and axle into their respective slots. Needle nose pliers come in handy.

One solution to the alignment problem is to mark the motor and gearbox and lining them up during assembly. That might work if the motor axle is simultaneously oriented correctly. After fussing with it for 10 minutes without success, I tried another method. I removed the armature and axle assembly, seated it on gearbox axle socket and then pushed on the motor housing. I did it with an aluminum tube that fit over the axle and rested on the bearing surface (not the rubber seal!) and tapped it downwith a rubber mallet. When the motor flange struck the key it was easy to slightly rotate the motor until the key fit into the slot since the axle blade and socket were already engaged.

In retrospect, it would be easier to put the bearing aside while the armature and motor housing are installed. That avoids dealing with the press fit of the bearing while simultaneously aligning the axle and key. The bearing can then be pressed in over the axle into the motor housing.

Test

The P and Q wires are to the right in the adjacent top view. One of those is common and other is not used. Which it is depends on whether the motor is right-handed or left-handed. The R and S wires are close together on the left side. One is for CW (clockwise) and the other for CCW (counter-clockwise) rotation. Only the slots for the R and S wires are imprinted on the gearbox housing.

My initial tests with Astron 13.8 VDC linear power supplies failed. The crowbar protection circuits of the 10 A and the 25 A supplies shut down the power due to the high starting current. The protection circuit acts too quickly to permit the motor time to start. I inserted a high power resister of a few ohms in series with one lead but that dropped the voltage too much to operate the motor. It wouldn't turn at all.

I tried the same setup with a 24 VDC power supply and the same thing occurred. I dispensed with the resistor and the motor came to life. I didn't leave it running for long since the higher voltage could stress the motor. DC motors can often run quite well at lower and higher voltages than specified, provided the motor will start (low voltage) and not run too hot and fast (high voltage). Hams in decades past used this "feature" to vary prop pitch motor speed with a 120 VAC auto-transformer (e.g. Variac) on the primary side of the power transformer

My small multi-meter didn't fare well on its 10 A scale during these tests. Something sparked but it still seems to work afterward. They're cheap to replace so I was not too concerned. As you can see on the meter, the clip leads themselves lower the voltage at the motor from the approximately 26 volts measured at the power supply. The wires get quite warm, more than on the 24 volt motors I've tested. That makes sense since P = EI and the power consumption of the 12 and 24 volt motors should be similar.

My friend uses narrow gauge wire up the tower to lower the voltage from his 24 VDC power supply. It also cheaper than larger conductors! I know that he measured the current as 7.5 A, but the voltage at the top of the tower is unknown and probably has never been measured.

Although my friend doesn't need it, I plan to remount the aluminum bar and magnet on the motor axle. I prefer to have it there for two reasons. It can be used as a handy lever to test freedom of motion of the motor and gearbox, which is how my friend used it to discover the intermittent bearing problem. The other reason is for insurance against the bearing working loose. Although the risk is low, it is easy to prevent. I will change the hardware since the lock washers previously used put uneven stress on the bearing. The bearing is strong but that is no reason to take an unnecessary risk.

Conclusion

The motor will likely be reinstalled on my friend's tower later in the spring. I'm hoping that it will now work well for him. He had pretty much given up on the motor before I offered to work on it.

I hope you enjoyed this tour of a rare variety of prop pitch motor. I doubt that I'll ever see another like it. If you come across one, you now have an idea of what to expect.

Eclipse Science & Amateur Radio

What is science?

Science is a process for understanding our natural world, encompassing fields as diverse as particle physics and biology. Science is memorizing or listing facts. Data (empiricism) is critical for developing and testing scientific theories. A robust scientific theory explains the data, makes testable predictions and is falsifiable.

Quite a lot of science will be done during the upcoming April 8 solar eclipse. A portion of what is planned to be done by amateur radio operators is science. There is overlap between the two which is quite interesting. Which is, measuring the change of the virtual height of HF reflections as the ionization density first declines and then recovers during the full 3 hour duration of the eclipse. Rockets will measure the ionization profile over a long vertical path while hams and professionals sound the ionosphere at various frequencies.

Almost everything else hams will be doing is not really science. That may sound unfair so I'll explain my position.

Imagine that, like Galileo, you roll balls down an inclined surface to measure the acceleration of objects due to Earth's gravity. This was fairly innovative at the time and he was able to generate data good enough to generate theories about gravitational action on bodies. The experiments were repeatable, the measurement error bars reasonably good, and the theory was falsifiable. That's science.

If you repeat these experiments today, are you doing science? In my opinion, no. Although that statement may seem to be inconsistent with what I said above, it really isn't. Many centuries have passed since those early experiments. The quantity and accuracy of data gathered from countless experiments over the centuries has generated increasingly excellent theories of gravitation and related field of physics. 

Should you perform Galileo's experiment now, the data gathered will be paltry and of woefully inadequate accuracy. You will discover nothing that is not already known, and any differences will be attributed to experimental error or large error bars.

Operating during the eclipse and observing propagation is very interesting and should be encouraged. However, other than for the very precise sounding experiments there will little of note added to the tome of science. The data collected will tell us very little or nothing that we don't already know. Just like redoing Galileo's experiments with rolling balls down an inclined surface.

If it isn't science, what is it? It's a combination of science education and perhaps entertainment. Considering the woeful lack of science awareness in our science-dependent civilization, public education has value. How much of that education makes it out of the relatively cloistered amateur radio circle into the public consciousness may be underwhelming. That would be unfortunate but hardly surprising. I can only hope that organizations like HamSci can raise public awareness. 

As for myself, my radios will be turned off. I live in the path of totality and the weather forecast is promising (as I write these words two days before the big day). Where I live the duration of totality will be a little less than 2 minutes. That increases to about 3 minutes directly south on the shore of the St. Lawrence River. I gain about 2 to 3 seconds of totality for every kilometer travelled south from my QTH. Crossing into the US isn't worth the trouble since travel to the shadow's centre only adds another 10 to 15 seconds.

I have friends planning to visit to view the eclipse. Since the zone of totality eclipse ends about 15 kilometers to the north, many people will drive south for the event. If plans change and they don't come over, I'll probably trek south to gain that extra minute. I know several obscure parking areas where I can do that without battling the massive crowds that are expected. The experience is better in a crowd but I don't want to waste the entire day since I'd have to leave early to find a place to park.

This is not my first solar eclipse. When I was a child there was one that passed through northern Manitoba. It was partial where our family lived in Winnipeg. My father smoked bits of broken window glass for us to look through. Yes, that's a terribly dangerous way to view a partial eclipse but what did we know. I just remember how wonderful it was. 

The experience left an indelible impression on me and kindled my lifelong interest in astronomy. I still wonder whether I ought to have made that first love my career. I'll never know. After that first eclipse I pored over astronomy books in the local library. I discovered that Winnipeg would be on the path of totality during an eclipse in 1979. What luck! But when you're 6 or 7 years old that's an incomprehensibly long way off. It was always in the back of mind as I grew into adulthood.

The years ground on and February 26, 1979 finally arrived. It was my final year of university in my home town of Winnipeg (VE4). The Canadian prairie gets a lot of sunny days during winter but it is very cold. The administration opened the roofs of many of the buildings on campus and that's how many of us viewed the eclipse. It was fun but cold: about -20° C with a mild breeze. As the Moon crept across the sun the temperature dropped. We'd duck inside occasionally to warm up.

It was an awesome experience that I've never forgotten during the following 45 years. That eclipse occurred near the peak of the solar cycle, and it was a big one so a lot was going on (on the sun and on 10 and 6 meters). During totality there was one very large prominence and a few smaller ones scattered around the solar disk. Many stars were visible as our eyes adapted to the dark. Totality lasted only a couple of minutes although I don't recall the exact duration where we were. It was long enough for a thoroughly amazing experience.

It is well worth the trouble to travel to view a total solar eclipse if none comes to you. I've found that most people who've never seen one don't appreciate what they're missing. Once you experience it you'll understand how worthwhile it is to make the effort.

I can only hope for clear skies and a prominence or two on April 8. I may update this article after the eclipse. Is viewing an eclipse science? No. It is educational and entertaining, and that's good enough for me. I'll put amateur radio aside for that one day. Hams not in totality's path may enjoy monitoring the bands to discover its effects.

After the Fall - Tailtwister Trauma

You may recall an article in late 2023 about the 110' tower of a silent key that was cut down for scrap. Once it was down we discovered that rotator at the top of the tower was a Hy-Gain Tailtwister rotator. The rotator model and condition were unknown beforehand and deemed not worth the time and trouble of retrieving it before the tower was cut down. 

I took the Tailtwister home despite its visible damage. I wanted to learn how it had fared from the trauma of impacting the ground. If nothing else it might provide a source of parts for repairing other rotators. The investigative work served as a wintertime diversion. I still don't know whether it is worthwhile to complete repairs and put it to use. 

Readers might be interested in my description of the damage it suffered and how I dealt with it. If you are unfamiliar with the insides of these rotators you might benefit from first reading the article where I refurbished an old rusty Tailtwister.

To begin, I'll reiterate that the entire tower and antenna system was derelict for years. I suspect that the rotator was never serviced since it was installed approximately 30 years ago, nor its condition at that time -- it likely was not bought new. The silent key was not a climber and it hadn't been used for years due to damage from a lightning strike and his deteriorating health. Now let's dive in.

I didn't expect the bell housing to survive the impact, yet it did. The cast aluminum alloy cannot withstand a large bending stress. That is why it is important to place the antenna load close to the top of the rotator. Longer masts can be used if two thrust bearings are employed to protect the rotator from bending stress due to wind load of the yagi(s) and the leverage amplification of a long mast. 

There was just one thrust bearing on the tower so there must have been quite an impact shock to the bell housing when the yagi struck the ground and pushed the mast upward. In this case the thrust bearing served as the pivot of a large impact force with the mast as the lever. 

Although the bell housing passed the test, the mounting bolts did not. I don't know the grade of the bolts since they were lost when the impact sheared them off the tower's steel rotator plate. It may be that, by shearing, the mounting bolts saved the bell housing. But it was not without cost. Notice that when the bolts broke off they took a chunk of the rotator's main body with them. In only one case was a portion of a bolt left inside rotator body. 

It is lucky in a way that so little of the rotator body was lost. The mounting bolts must have been quite short. Since the mounting holes are long and threaded deep, there is no impediment to their reuse. The only new requirement is that the spacers placed on the bolts must be wider so that they bear on the undamaged metal of the rotator. Two of the 6 mounting holes were not used and were therefore not damaged. With 5 holes remaining it really isn't necessary to remove the one bolt shank still inside. I'll probably do it anyway since it isn't a difficult task.

There is a surprising amount of rust on the lower half of the rotator. As you can see in the above pictures, the bottom bearing races are rusted or covered with rust deposited from the ball bearings. The lowest ring of balls (⅜") can be replaced and the races cleaned. The brake system is very rusty but works just fine. It should be okay to leave it alone, which is good since cleaning its many components would take a long time.

The other damage you may have noticed is that the terminal strip has broken from its mounting screws. Also, the plated metal is badly rusted. Testing the rotator was difficult due to the resulting poor electrical connections. The terminal strip can be replaced or repaired. The metal can be cleaned if the screws are removed. Suitable stainless screws can be substituted if you keep in mind that the original screws have their tips crimped to make them difficult to fully unscrew, and thus accidentally fall to the ground while attaching wires on the tower.

I have one more observation to make about corrosion, involving stainless steel. It is a myth that stainless steel doesn't corrode. Depending on the alloy and the metal they are in contact with, they can indeed corrode. However the result isn't rust.

The stainless bolts that hold together the upper and lower halves of the bell housing were substituted for the original bolts. That may seem like a good idea but beware! In this case the alloy quality is suspect and the bolts were not coated with a lubricant to prevent galling and galvanic corrosion due to contact with aluminum alloy of the bell housing. The piles of oxide dust used to be metal! 

If you insist on using stainless bolts in this and other antenna system components, at a minimum please use 304 (18.8) hardware. It is also perfectly acceptable to use grease or an anti-seize coating on non-stainless steel bolts. Stick with grade 2 steel rather than grade 5 so that you are not tempted to over-tighten them. The same goes for the 6 mounting bolts. The stainless u-bolts for the mast clamp are especially prone to galling due to repeated tightening and loosening that is typical in a ham station. Coating the threads with a suitable compound is advisable.

Next is a very common problem in Hy-Gain rotators that has nothing to do with the fall. In the adjacent picture notice the small indentations in the bearing race. That is due to fretting. It can happen with similar metals but is more pronounced when metals with different hardness are in contact under load. In this case, steel balls rolling on an aluminum alloy race.

Fretting does the damage when the rotator isn't used for a long time. Continuous wind-induced rocking under vertical load is responsible. 

I encountered a similar fretting of steel headset bearings and races in older generations of bicycles (another passion of mine). The bicycle generally points straight ahead with small deviations left and right while being assaulted by minor jolts due to road imperfections and debris. These impacts are transmitted to the bearings from the high-pressure tire and wheel through the forks and steer tube to the headset bearing. Newer bicycles often avoid fretting by the use of cartridge bearings that can be easily rotated during regular maintenance. A similar maintenance procedure is possible with rotators but is rarely done.

The races must not be filed or sanded to remove the indentations since that will cause unwanted bearing play. Rotators can survive some bearing slop provided that thrust bearings are deployed in a manner that prevents radial (side to side) forces. What I do is lightly polish the races with steel wool and carefully file off the raised rims surrounding the indentations. In most cases the steel bearings do not develop flat spots, so I only replace them if they're rusted. 

When the rotator is re-assembled it is unlikely, by random chance, that the bearings will contact the indentations when the rotator is pointed in the same direction. Better yet, don't leave your rotator pointing the same direction all the time. Turn it occasionally when you're not active.

When the motor broke loose and bounced around inside the bell housin, the motor was damaged and it damaged other components. Of particular concern was the direction potentiometer bolted to the top of the motor.

There are 4 bolts that bind the steel laminations of the motor body. Two of those are extra long and serve as motor mounts. Their long shanks are mechanically connected to the top plate of the gear assembly. Rather than threads and nuts, they narrow and pass through the holes in the plate. They are "crimped" to secure them to the plate. In normal operation that is sufficient. It is not sufficient when the rotator is dropped from 100'.

I removed the long bolts from the motor and inspected the damage. It turned out to be easier to repair the damage than I anticipated. Since the bolts were able to pull out of the holes it is not a surprise that I could push them back through. The small metal lips of the crimps were easily abraded by the impact force, which allowed the bolts to pull out of the plate. They were press fit back in and lightly crimped with a hammer and the hardened tip of a flat-blade screwdriver. You can see one of the re-mounted bolts in the picture of the fretted races.

The motor resisted turning by hand. The formed sheet steel brackets on the top and bottom of the motor were bent. The black common wire of the field coils was also severed. The remaining motor and pot wires were desoldered to free the motor from the rotator. It was then disassembled by pulling the drive gear off the axle and drilling out the two rivets that secured the brackets and that served as two of the 4 bolts that held together the steel laminations. The motor armature was then easily slipped off the bushings that are fit into the brackets. Although bearings are superior, bushings are sufficient for the low torque, low speed motors used in Hy-Gain rotators.

The top bracket was bent back into shape and aligned so that the armature was properly centred within the field coils. When properly aligned the armature should spin freely. It helps that the bushings pivot within rubber shock mounts. While some care is necessary this is not a high-precision device.

A new wire was soldered in to replace the severed common wire. Stainless bolts replace the rivets that hold the brackets and bind the laminations. 

I had some concern about replacing the rivets since ferrous metals can induce circulating magnetic flux that "steals" power from the motor and can cause heating of the bolts. I couldn't discern any problems with motor torque or noticable heating after several minutes of continuous operation. Stainless 304 is not the perfect choice but it seems to work fine in this application. Non-ferrous hardware can be used instead.

The drive gear was pressed on and the motor mounted onto the rotator body. It worked fine during this bench test. There was no damage to the reduction gears. The motor was removed once more to work on the direction pot which was seriously damaged.

The impact damage to the pot is evident in the pictures. The reason there is so much damage is because it is bolted to the heavy motor: it had a lot of momentum while bouncing around inside the bell housing. The plastic body has several stress cracks (not visible in the pictures). It is possible that the cracks can be repaired with glue. The tangs on the wiper can probably be bent back into shape with care. 

There isn't too much damage to the protrusion deep inside the bell housing (centre picture) that engages the wiper tangs. This is ordinary wear for a Hy-Gain rotator. There really ought to be improvements to this weak area of the design. The hard copper alloy of the sharp-edged pot tangs abrades the aluminum alloy of the bell housing. The wear goes on 24×7 as the antenna system rocks back and forth in the wind due to the play within the brake system. Wear does not only occur when the rotator turns. 

I have seen otherwise perfectly good rotators rendered useless due to excess wear of the bell housing protrusion. Alternative aftermarket solutions are easy to imagine. I am unaware whether anyone has done so or marketed a solution. It could be done with thin spring steel covers for the pot tangs or on the bell housing protrusion.

The damaged ring of resistance wire is not as bad as it looks. There is continuity through the worst kinks. It may be possible to bend them back into shape so that the wiper glides over the damaged areas. However, there is a break near one end of the wire due to a crack in the plastic body. That will be more difficult to repair since the metal of resistance wire is often difficult to solder. 

If I do attempt repairs it will only be out of curiosity to see if it could be done. A replacement pot is the more sensible option. MFJ charges an exorbitant amount for a replacement direction pot: about US$80 the last time I checked. A friend mentioned a less expensive local source that I may pursue should I attempt to return this rotator to service.

I hope you enjoyed this look inside a damaged Hy-Gain Tailtwister rotator. I don't know how serious I am about putting it back in service. It served as an interesting and educational diversion during a few cold winter evenings.

Computer Monitors: Too Much Information

Contest results regularly include pictures of hams and their shacks. Pretty well all shacks, not just those of contesters, include computers, and often several. That's a good thing -- our hobby evolves with the state of the art. However, what I often see in these pictures mystifies me. In particular, the number of computer displays.

Okay, that's an exaggeration. But there are an awful lot of monitors perched on so many of our operating desks. Here are a couple of examples that I scraped from the internet (identifying information removed).

Most modern computers support more than one monitor. Indeed, it is possible to have more monitors than there are connectors. Since it's possible, many take the plunge. That much screen real estate makes quite an impression. The possible applications are endless. The question I like to ask is: why?

Just because you can do something does not mean that you should; there should be demonstrable value to the practice. For many that does not matter -- entertaining yourself (and visitors) is perceived as a valid use case. 

I have a different perspective due to my interest in contesting. Too much information on the monitor(s) is either a distraction or ignored. I am interested in essential information on the monitor and nothing more. Essential information is that which measurably improves my results: higher scores and fewer errors.

To avoid fatigue it is critical that my eyes and neck need to swivel the minimum amount. The critical information needed to find and work stations should be directly in front of me. That's simply good ergonomics. Everything I need should be on one screen dead ahead. Rarely consulted information can be on another screen, on a background window or pulled up with a mouse when needed. For the same reason I place the rigs off to the side since I don't often touch the controls. I can use the important ones (e.g. the VFO knob) without taking my eyes off the monitor.

I won't say more about what I have on my screen since that depends greatly on the software that I use and my operating objectives. Your station may be quite different. I will say that, despite my strict attention to the essentials, it is difficult to fit all that I want onto one reasonably sized monitor. 

The challenge is greater when operating SO2R since there are applications and windows for two rigs and two bands. Further economizing is desirable and guides my plan for future improvements.

• The window for my station automation software will eventually migrate to a small touchscreen, either connected to the same or a different computer. That will make it easier to use, while also moving at least one window off the main monitor.
• Spectrum displays are increasingly being used and might not be easily fit on the monitor. One solution is to substitute the spectrum display for the band map, which is a feature of N1MM+, my usual logging software. Alternatively, rigs like my recently purchased Icom 7610 has a screen and a waterfall display. Unlike the spectrum display and band map, it is not labelled with call signs but I still find it very handy for locating stations and finding clear frequencies to run. By using the 7610 waterfall, I do fine with the legacy band map that plots call signs by frequency.

Computer technology is cheap, very cheap. When I enhanced my station for multi-op contesting last year, I could build a very capable shack computer for around $250 (CDN): $100 refurb PC (Win10, 8GB, SSD, WiFi), $110 24" monitor and $40 wireless keyboard/mouse combo. That's remarkable! No wonder so many of our shacks are sprouting multiple monitors and software applications. Consider a few of the many potential uses:

• Gray line world maps
• SDR
• Digital modes
• Software control of transceivers, amps, rotators, antenna switches, SO2R and more
  

The possible applications will only increase as the typical ham operating desk continues its transition from hardware boxes to software.

As I said earlier, if you want to see it all at once, well, you can! It's really just entertainment or eye-candy since you really can't pay attention to all of that information. You can achieve the same outcomes with less monitor area by pulling up what you need only when you need it. 

In a contest, you need less information, not more, but it has to be the essential information. Too much information is a distraction that will lower your score and accuracy. As an experiment, challenge yourself to fit everything you want onto one monitor. Since it won't all fit, you'll have to prioritize. That can be an educational exercise. Focus on what you need, not what you want.

Remove or hide windows that don't need to be constantly visible. Know how to bring them forward if and when you do need them. If you insist on their constant visibility, put those windows and applications onto a second monitor that is placed off to the side where it won't distract you. It should be out of the line of sight while you are focused on scoring points and multipliers.

Choose wisely and focus on the essentials. Don't be seduced by the allure of too much information. You''ll soon discover that you can accomplish more with less.

Interlude

As happens to all of us from time to time, I am currently dealing with a serious family matter. My usual pace of blogging will have to be reduced for the rest of March. What articles I write may be "lightweight" since my operating and station building activities are at a standstill. The previous article only got published because it was 95% complete and the final 5% served as a welcome distraction. 

I had to cancel my plan for the ARRL DX SSB contest. Upcoming contests will also be sidelined until at least CQ WPX SSB in late March.

On the positive side, this unfortunate event has given me an opportunity to peruse old photo albums that were kept by a deceased family member. It goes back more than 100 years, following my family from its roots in Romania, to my parents' move to the Canadian prairie, and eventually to my arrival into the world. I knew that somewhere among those dusty albums was a picture I had long since lost track of. It brings back pleasant memories and may be of interest to readers. The picture was taken by my father.

The year was 1972. I was newly licensed (VE4OY) and 15 years old. In the months after I earned my license I was thrilled to work anyone who could copy my weak signal. DX was difficult. It would be two more years before I seriously caught the contesting bug and then another year until I put up my first tower.

Those of you familiar with old equipment will recognize that the receiver was a Hammarlund HQ129X. I bought it from an older ham who no longer needed it. It was by far the most expensive component of the station. It was general coverage with band spread for the ham bands. Even with a new tube and replacement of select capacitors the local oscillator barely functioned on 15 meters and rarely on 10. Tuning on those bands was so touchy that it was difficult to receive CW and SSB. We were slipping into a solar minimum so it hardly mattered.

By the front panel design and colours, the transmitter is clearly a Johnson. I purchased it at a local flea market for very little. Originally a mobile AM crystal-controlled transmitter, a previous owner built an AC supply and added a Johnson VFO. Resolution of the VFO dial was so poor that the only way to get on frequency was to swish the VFO back and forth until it was heard in the receiver. The tubes on top of the VFO are merely for show.

I never did figure out a good way to remove the modulator tubes so all three of the 807's had to be lit. I stuck a flea market open frame 117 VAC relay on top of the power supply for T/R switching of the coax with the knob provided on the receiver. A short length of RG58 through the window frame connected to a 40 meter dipole up ~15' (4.5 m) that was used on all bands. I later added 20 meters to make it a fan dipole.

Without any metering (the one you see was not functional) I burned through a succession of 807 tubes due to high SWR and poor tuning. Used ones were cheap at local flea markets. The soft ones were plugged into the modulator tube sockets to keep the filaments of the others lit.

I used that equipment for a year. In 1973 we moved to a new house and with money from a summer job I upgraded to an HQ170 and HT32B. In 1975 I purchased a brand new FT101B and put up a tower with a TH3jr and 40 meter inverted vee. 

That kept me going until 1979 when I earned my M.Sc. and moved from Winnipeg to Ottawa. But that's enough woolgathering. If you want more, tune in to my 2023 interview on QSO Today.