Archive for February, 2008


February 29, 2008

Csaba (pronounced “Chaba”), HA3LN is operating from ZS6AA as ZS6/HA3LN for the ARRL International DX SSB Contest. QSL his home call via the bureau. Good luck for the contest Csaba!

HA3LN operating ZS6AA

Dancing in the dark

February 27, 2008

In January this year almost the entire country suffered from what the electricity generating utility, Eskom, euphemistically called “load shedding”. Whole suburbs were disconnected from the grid (so no mains power) for 2-3 hours at a time. In my municipality, Sandton, this was happening as many as three times a day, although reports were that this was one of the worst affected areas.

The explanation that we were given by the government was that unprecedented economic growth had resulted in electricity demand outstripping supply. However it soon emerged that the 1998 Energy Policy White Paper, a government document, warned that the reserve margin would be insufficient by 2007 unless additional electricity generation capacity was added. However due to policy uncertainty resulting from a failed initiative to privatize electricity generation, the incompetence of the responsible cabinet ministers, and the failure of Eskom management to draw public attention to the impending gloom, nothing was done about it. So right on schedule, at the end of 2007 and beginning of 2008, demand outstripped supply due to a combination of planned and unplanned maintenance which exceeded the reserve margin.

Horror of horrors, the power cuts did not only occur during the week, when I work, but also on weekends, when I contest. The prospect of six or eight hours of enforced radio silence during a major contest was enough to spur me into action, so I installed an Uninterruptable Power Supply (UPS) system. The UPS consists of a battery charge, a bank of six 100 A-hr lead-acid batteries, and an inverter to generate mains voltage (230 V 50 Hz) from the batteries when the mains supply is off. I cabled up power sockets around the house so that essential equipment like the refrigerator, alarm system, television, computer and of course the entire shack can be run off UPS power. I also installed a few neon tube emergency lights on the UPS circuit.


The UPS system sits on top of a home built battery cabinet. Its output is connected via the red socket to a small distribution board, which I included primarily to have earth leakage protection in the UPS circuit. The white socket on the left is one of the seven around the house to provide emergency power for appliances. The small 18W neon light at the top is one of several around the house that are also connected to UPS power. The UPS can provide 2400 kVA peak (enough to run the microwave, fridge and television simultaneously), and has sufficient storage capacity to supply an average power of 500 W for 8-10 hours.

I have also installed energy efficient lighting, replacing 50W downlights with Osram Decostar IRC 35W halogen bulbs and incandescent bulbs with compact fluorescents wherever possible. I’ve also set the pool pump timer to run from during off-peak times, from 8pm to 6am. However this may be self-defeating since the timer is itself mains powered so any load-shedding will “time shift” it back towards peak hours….

ARRL International DX Contest 2008

February 20, 2008

ARRL DX CW was the first international contest I entered (in 2003 as ZS1AN with 131,100 points) and still one of my favourites. For me it is a bit more relaxed than CQWW, WPX and IARU as the bands are not always open to NA from here so it is possible to spend some time with my family and still achieve a reasonably competitive score. The pileups are also noticably better mannered than in some other contests thanks to all the fine NA ops.

Propagation was poorer than last year for the first 36 hours of the contest, with only 40m and 20m opening to NA. My new two-element beam helped me to play on 40m, but I didn’t hear even one NA station on 80m where I have only an inverted L. After taking Sunday morning off, I knew that I would need some multipliers on 15m in the afternoon to turn in a reasonable score. This didn’t seem likely given my total of five 15m QSOs on Saturday, all with big guns.

Fortunately conditions improved on Sunday afternoon and I managed a nice run on 15m, and then continued on 20m until about midnight local (2200 Z). For the last couple of hours I was really struggling to put callsigns together in my head, so appologies to those of you who had to give multiple repeats and thanks for your patience.

Needless to say there was no trade on 10m, although I kept a watch for openings with the second radio.

I didn’t have much opportunity to SO2R as it was rare for two bands to be open simultaneously, except during the 15m opening on Sunday afternoon when I didn’t want to divide my attention as I was desperate for as many 15m mults as possible. Overall I was satisfied with my effort, although I need to try to be a bit more focussed next time (and get more sleep before the contest!).

Here’s a summary of my claimed score:

Class: SOAB LP
QTH: Johannesburg
Operating Time (hrs): 28

 Band  QSOs  Mults
   40:  603    50
   20:  929    55
   15:  217    37
Total: 1749   144  Total Score = 755,568

The image shows my QSO rate (number of QSOs per hour) through the contest:

ARRL DX CW 2008 Rate