Wednesday, April 15, 2015

Spring Checkup

It took a while for spring to arrive in Ottawa. Yet it is now here and the snow is mostly gone. This gives me an opportunity to climb and inspect the towers and the antennas they support. It all looks quite good.  In the days or weeks following erection of a tower or antenna it is normal to be slightly anxious no matter how much care went into the task or even if over-engineered for the local conditions. After a few big winds and coatings of ice when nothing happens you gradually relax. I am now very relaxed.

I'll take this as a sign that I've perhaps done something right. Rather than repeat myself you can refer to the following articles (and their links) for the major structural components of my miniature suburban antenna farm. The only mid-winter work I did was to secure with tie wraps the foam bumpers on the coax up the mast to the inverted vee. The tape loosened in the cold air so the bumpers slid out of position and the coax resumed noisily slapping against the steel mast.
As I hinted in my year-end recap I have some thinking to do in 2015. I can either make the best of my present QTH or I can move somewhere more amenable to bigger and better antennas. However that is a discussion for the future once I've made some personal choices. For this article I want to cover the successes and failures over the past winter season, both in the antennas themselves and in operating.

Rotator

My now ancient Ham-M rotator performed well though not without some difficulties. Internally it appeared fine when I opened it up for inspection before discovering my cabling faults. That argued for leaving well enough alone, and putting it up to see how it fared. Although it showed no serious problems it did have some difficulty dealing with the brutally-cold temperatures we suffered. February, for example, was the coldest on record.

Starting around -20° C rotation was sluggish. Below -25° C it turned only very slowly, and only started turning after 5 seconds of power to the motor. Although the grease should be good enough for these temperatures I either need to completely clean the bearings and races or use something even better. Some care is needed since low-temperature grease is not always the best at the height of summer when the temperature inside the bell housing can climb far above the air temperature.

Another factor that is almost certainly contributing to slow rotation is the motor capacitor. The replacement I selected is not what is specified for this motor. This is a simple change in the shack when I purchase the appropriate part.

Of more concern was behaviour of the wedge brake at the lowest temperatures. I had a couple of instances below -25° C when the brake would not engage. That is, it would retract to allow rotation but not fully extend when power was removed. When this happened and it was windy the rotator freely turned. Even though it cannot turn past the end stops it was disconcerting and an inconvenience. After some minutes it would engage properly. This is likely a grease problem.

Rain, snow, wind and ice

There wasn't much rain during this cold winter since thaws were absent for a long time mid-winter. Build up of snow and ice did affect resonance and performance of all antennas. Ice also added mechanical load though never enough to be a concern. These are routine matters that did not really test my design of the masts and towers. Of course I'd rather not test them!

Bolts can loosen in extreme cold and metal becomes more brittle. A survivable wind in summer can prove disastrous in extreme cold. Luckily the strongest winds don't occur here in winter. It is critical to do regular inspections -- preferably twice annually, but at least once -- to ensure nothing is out of spec. Nothing untoward has been discovered during my spring inspection.

DXCC

The numbers are gradually mounting at VE3VN with very little effort at all. With a yagi and 100 watts it is almost too easy. There are enough DXpeditions and decent propagation to give everybody a chance. I worked over 200 countries with QRP (5 or 10 watts) and at least 100 countries on each of 40, 30, 20, 17, 15 and 10. Now that total stands at 243 countries. Included in that is 200 countries on 20 meters, just shy of 50 on 80 meters and 198 confirmed on LoTW alone. This is all CW, though I am well past 100 on SSB. I am only counting what I've worked since returning to the air in early 2013; my actual total is well over 300 mixed, though I can't be bothered to count them.

Perhaps it is my imagination that it seems so much easier to climb the DXCC ladder now than before my 20 year absence from the hobby. I suspect that it is partly due to demographics. Aging baby boomers have accumulated wealth that is spent on their stations and DXpeditions. The quantity of booming signals on 80 and contest super-stations amazes me in comparison to the 1980s.

This may be as good as it gets since younger generations are less involved in amateur radio so this spurt of frenetic activity will wane with the decline of my generation and those older. At least in the USA and Canada, and to a lesser extent in Europe.

When the next solar maximum comes around don't expect quite the same level of DXCC country-hunting opportunities. I think that's a good thing since it ought to be a challenge. If it's easy it quickly becomes boring. My preference is work hams that are native to those currently-rare countries, which is also necessary to the longer term global health of amateur radio.

Contests

My time as a QRP contester can be best described as: big fish in a small pond. I do well because those with bigger antennas and ambitions also run more power. I didn't go into QRP contesting with the intention of winning anything yet I do well regardless. For example, I achieved #1 world in SOAB QRP in last year's CW WW SSB contest.


Going up to 100 watts and the results are less impressive. Here the competition is already more fierce. My antennas are not equal to my ability so my results are relatively poor. This is true on both high bands and low bands. Still it is fun to work more stations, including frequently good runs, regardless of how I place. Jumping up to a kilowatt will hurt rather than help since in that category there are many impressive antenna farms. And my otherwise friendly neighbours would form a mob and lynch me.

I will continue to return to QRP with my KX3 in some of the larger contests, since with the high participation I can work many stations and place well. If nothing else it stokes my ego. For bigger scores I will do better to join a multi-op effort at a station with more substantial antennas.

Low bands

My results on 40 are good for a simple wire antenna though less good on 80. Even with no antenna for 160 I have had some surprising success. Unfortunately it won't get much better at this QTH. With a larger tower I could have a small yagi on 40 (wire or rotatable), and by finessing the placement of radials I could do better on 80 and even on 160.

My neighbours are reasonably accepting of my present towers and antennas. Putting up a taller tower (over 15 meters) requires crossing the regulatory threshold to consult with my neighbours and deal with push back from the city. If I were prepared to go that distance there is another less-correctable problem: noise.

Noise

The number of residential noise sources continues to grow. In tightly-packed suburbia it can get quite bad. In recent weeks I have been plagued by even worse noise than before. Starting a few days back after some strong winds S9+ power line noise appeared on all bands from 80 through 10. As I write this it has become intermittent and I can only hope it disappears before the Ontario QSO Party this weekend. Another recent noise source peaks to the north, often wiping out most signals on the path to Asia.

No matter the time of day or day of week there seems to be noise on at least some bands. Often the only noise free periods are in the middle of the night when everyone's lights are out and asleep. Since I too am asleep then it does little good. Even with 100 watts I prefer to stick with CW where I can narrow the filter bandwidth.

The only true solution is to get out of the city. Even then it is no longer a sure thing to escape the noise from our modern electronic appliances. Investing time and money into a big tower in the suburbs is often not worthwhile.

Going forward

With the warmer weather my operating activity will, as usual, decline. This is a good idea even for the greatest enthusiast since it replenishes the energy when we do return to the shack. I do have a few antenna experiments in mind for this year which I will undertake as time permits. My schedule includes numerous non-ham activities. However, as I said above, there is little reason for significant changes at the station this year. I am not terribly happy about that.

I will continue with antenna modelling and other planning activities with an eye firmly set on the future. Blog activity may temporarily decline since much of what I'll be doing will not be interesting to others. Reading, studying and planning are boring to watch though worthwhile for the one doing them.

Whenever something that may be of interest to others comes up I will write about it. As I've pointed out before my web site statistics clearly tell me that those of you who visit this blog want to hear about antennas more than anything else.

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