Thursday, August 10, 2017

Battling the Calendar: Time to Set Priorities

It's August and warm. This is great weather for building towers and antennas. Unfortunately it won't last. My plans for 2017 are ambitious and I am increasing worried about running out of calendar room before contest season gets seriously underway this fall. Worse, winter comes in fast and hard around here. This calls for setting of priorities so that if I do run out of time I will have the best station possible before winter puts an end to antenna farm construction.

Before getting into the topic of this article -- setting priorities -- there is one important observation I would like to make: the interchangability of money and time. It is always possible to accelerate the plan with money. For example, I can hire a company to put up towers. I have quotes and experienced hands ready to go to work. Another example is antennas. I can buy commercial products rather than design and build my own.

For me the building of a competitive station is not only about achieving a result. The journey is itself an objective. Designing and building what I can is a tremendous learning experience and can be a lot of fun. I am willing to forgo or delay some projects so that I can do it myself (or with friends). At the other extreme I need only sit at my desk with a telephone, credit card and cheque book and soon enough I will have a complete and highly competitive station. That approach does not interest me.

Therefore I resort to picking and choosing where to apply my effort. Spending where necessary and applying my own time to projects I want to do myself. With that preamble I will now jump into the main topic: how I set priorities for the time remaining to me this year.


The tower is in fact perfectly vertical. It's the
photographer (me) that has developed a lean.
For DX and contests height cures many antenna ills. Even an inverted up high will usually outperform a low yagi or vertical. Therefore the 150' tower is my highest priority. If it's all I get done this year I can put up a few inverted vees and side mounted a couple of tri-banders, and in combination with the TH7 up 21 meters I can do very well in the fall and winter contests.

This is why there have been few antenna articles lately. The tower is consuming most of my available time. It is not that I haven't been modelling and planning antennas and gathering construction material, but that these are very much works in progress and dependent on the tower being built.

As you can see in the picture I am not quite there yet! However this is one of the most difficult 20' of tower I've ever done. Getting to this point took a lot of time, worry, effort and money.

As I write these words I am ready to put up the remaining 13 sections. I have the parts and the tools and all the problems I've encountered have been solved. I will write more about all of this in one or two future articles.

Minimum viable antennas

In the high tech industry we are always talking about minimum viable products. The same thinking can be applied to contest stations. My time and resources are limited so I have to think about the least amount of antennas that will make me effective and competitive this fall.

Assuming the big tower will be ready I have tentatively selected my minimum viable antennas:
  • Rotating at the top of the 150' tower will be the Cushcraft XM240 and, preferably, a long boom yagi for 20 meters. The XM240 will go at the top of the mast and the 20 meter yagi at the bottom. They'll be turned with a prop pitch motor. With just the one tall tower I had to decide between a large yagi for 20 or 40 meters. I decided to go with the easier project for this year. Design and construction plans are underway.
  • TH6 at 110' (35 meters) side mounted and fixed on Europe.
  • Explorer 14 at a to be determined height side mounted and fixed south.
  • Inverted vees or wire yagis for 40 and possible 80 meters on one long boom at ~80' to 85' (25+ meters). If built the wire yagis will be electrically reversible between Europe and the US/Pacific. Design work will be required to allow effective interlacing of elements.
  • Vertical for 80 and 160 meters, using one radial field as the core of a future 80 meter 3-element vertical yagi. I've already warned my neighbour that this will take 1 acre out of hay production due to the radials.
  • One or two small flag or pennant receive antennas to the west and south to complement the Beverage to Europe.
  • The Trylon will continue to support the TH7 at 21 meters. The 6 meter yagi will be left where it is atop the mast and will occupy that mast space in preference to any HF yagi. I may install a multi-band inverted vee on the Trylon to complement the low 80 meter inverted vee and cover short paths on the low bands.
High bands

My strategy for the high bands is to have good all around coverage on 20 meters with a decreased emphasis on 15 and 10 meters. For this part of the sunspot cycle I will take my chances with less height, less gain and fewer direction choices for the upper two bands. I may miss some multipliers but I will have decent coverage for the most productive paths: Europe, South America and US.

The long boom 20 meter yagi up high will catch marginal openings to Europe in the early morning and overnight and allow pursuit of long paths to Asia, South America and the Pacific.

On 10 meters I will only have the TH7 at 21 meters and perhaps the Explorer 14 up higher and pointed south. Even with a low solar flux the South American path will open and I want to to be ready. I expect nothing on 10 meters with the TH6 fixed on Europe.

I am most compromised on 15 meters with this minimal plan. The TH7 will adequately cover the US and Caribbean and other short paths. With the only other 15 meter antenna -- the TH6 -- fixed on Europe I will have to do all other 15 meters operation on the TH7. Hopefully I won't miss too many multipliers in South America, the Pacific and Africa. I don't expect much from Asia on 15 meters this winter.

My best performance will be on 20 meters, which along with 40 meters are the most productive contest bands at this point in the sunspot cycle. With a large yagi up high, the TH7 low and two tri-banders fixed on Europe and to the south I expect to do quite well.

Low bands

The XM240 rotatable at ~46 meters height should perform well on all DX paths. If I can get a wire yagi completed I can search out marginal openings with the XM240 while the wire yagi is dedicated to Europe and the US. While not ideal antennas I expect this combination to be effective. If the wire yagi doesn't get built in time an inverted vee at 35 meters would still be an asset.

On 80 meters an inverted vee at 35 meters can address most of my needs, although it is not going to be very competitive. That changes if I can expand it to a 2-element wire yagi, switchable between Europe and the US. The vertical, which I fully expect to get built, will complement the horizontally-polarized yagi or inverted vee.

The 80 meter yagi array, for which the vertical is the driven element, can be worked on over the winter by adding switching systems at each element. However the radial system will need to be put down before the snow arrive or the array will be deferred to 2018.

For 160 meters I would like to make the 80 meter vertical switchable between those two bands. This is per my design plans from some time ago. As a backup plan I will run a vertical wire up the big tower and lay down temporary vertical for the winter. This is not ideal since it can compromise SO2R operation with the other antennas on the big tower.

Receive antennas

The one Beverage pointing northeast is a good start but wholly inadequate. The lack is especially acute if my minimum viable antennas do not include directional antennas for 80 and 160 meters. Without directivity copy on weak signals (whether QRP or marginal paths) will suffer, and that means lower scores. As it is said: you can't work them if you can't hear them.

For reasons I may elucidate in a future article I am strongly leaning to a set of 4 bi-directional Beverages (8 directions) as my preferred receive antennas. Those take some time to design and build. Not only must almost 2,000 meters of overhead wires be run there are the transformers, terminations, grounds, switching system and feed lines.

That's a lot of work to fit in this fall. Unfortunately receive antennas must be placed lower on my priority list. Simple but efficient transmit antennas come first. Low band directional antennas, if any can be built by the fall, are higher priority than receive antenna since they give some receive advantage and also a transmit advantage.

Work on Beverages can proceed during the winter when work on towers and other antennas slows or stops completely.


Burying cable on my property is a problem. Although hay farming doesn't interfere with shallow burial there is a greater concern: trees. The previous owner did a wonderful job planting trees and plants everywhere, with flowers blooming in sequence throughout the spring and summer. There are apple trees and other kinds of fruit I haven't yet determined. Trees provide shade where shade is useful and visually complement the house, stone walls and field boundaries.

All very pretty but ever try to bury cables where there are tree roots? I don't recommend it. When we were excavating for tower anchors near the edge of the field I purposely sited them to be far enough away to avoid roots. I was wrong -- those roots extended horizontally farther than I'd thought possible.

Because of that and as a matter of expediency I will run the cables overhead, with grounding for lightning at select locations. How this will be done is not finalized. Many cables will, I expect, lie on the ground for the winter. Once haying is completed in early autumn there will be little traffic in the fields.

In the yard itself I will likely stay overground up to a central switching location. From there I may go underground for the final 10 or 20 meters to the house (and another ground). Again, this may all end up lying on the ground for the winter.

Station automation

Effective contesting requires integration of the rigs, logging software and antenna switching. The requirements are even greater when operating SO2R or multi-op. However I expect that what I'll have time to design and build this year will be mostly manual rather than automated.

As a minimum I will simply run multiple transmission lines from the switching box location into the shack and use manual coax switches to select antennas. While hardly modern and an operating inconvenience the automation can be done over the winter or next year. The QSOs I'll miss due to long duration antenna switching and verbal negotiation between operators are relatively few.

Alternatively I may purchase one or two remote coax switches that would be located outside at the switching location. I can always sell them later when a fully automated system is in place.

What I must do this year is buy a new computer for the shack that can handle the multitude of connections and have the CPU power and RAM to support all the features of N1MM Logger. My ancient laptop can only handle 3 windows open concurrently and even then will occasionally fail to keep up with operating demands.


QRO is in my plans. Whether I get to it this year I don't yet know. Buying an amplifier is easy enough, and wiring it for 240 VAC is not a problem, but there are other issues that power will only exacerbate. For example, the filtering requirements are more onerous with a kilowatt compared to 100 watts. Building receive and transmit filters takes time I likely won't have.

To operate SO2R or multi-op requires two amplifiers. That's another burden that may not fit into this year's schedule. My alternative would be to use low power on the multiplier or S & P band.

Back to work

Writing for this blog takes time that could be put to building the station. The same could be said of every other activity in which I partake, including seeing family and friends. I am not so fervently dedicated to station building that I will exclude everything else from my life. Sometimes I even like to relax and read or do nothing at all.

With the garage and workshop built I now find that evenings can be put to use. With the doors closed and windows open the hordes of biting insects can't get in. It's almost cozy in there. Of course it'll get cold in the winter but for now it extends available work time into the evenings and darkness. For example, this evening I spent an hour in the garage fitting thimbles to turnbuckles. It's a job easily done indoors and therefore perfect for doing in the evening.

Of course I already have a tower and there is maintenance to be done by the fall. All the cabling on the Trylon will need to be redone and the antennas adjusted.

Lots of work remains to be done on the station this year. All I can do is prioritize, keep at it and hope for the best. Luckily I have a few friends who will help on the big job. Doing the work with others can make it more enjoyable and sooner strike the high priority items from my list.

No comments:

Post a Comment

All comments are moderated, and should appear within one day of submission.