Saturday, 22 August 2015

AFRICA-DX 2015 contest results

IMHO the inaugural AFRICA-DX contest was a success. A total of 123 logs were received.

We had some issues with overlap with the RSGB Commonwealth contest and a few minor issues with the log checking process. Igor UU0JC the author of the “LogChecker” has been very accommodating with our requests for software features.

Next year we hope to gain momentum, with a bit of luck the AFRICA-DX (all mode) contest will become popular for the contesters and the DX hunters alike.

Thanks to all those that participated, the next one will be bigger and better.

The next contest will be held on Friday 11 March 2016 starting at 1800 utc and ending on Saturday 12 March 2016 at 1759 utc

The certificates ready for posting

The results listed by ITU zone

Sunday, 19 July 2015

2015 SARL Winter QRP contest

As you all know I am a huge fan of QRP, but after reading the feedback below from Roger ZS6RJ (the guy with the rather loud headset) I could not resist sharing his feedback "Ode to a QRP contest".

Conditions on the higher HF bands were rather poor and working QRP DX from the southern tip of Africa was not easy to say the least.

I did not work a single DX station, I sure hope others fared better.

Ode to a QRP contest:

“Come help with QRP”
“It’ll be a hoot, you’ll see”

I raised the hex beam with great glee
Ignoring the fiberglass stuck in me

Calling ad-nausea for more than an hour
Left me disillusioned and rather sour

So as the QRP leader broke down the camp
I whacked him over the head, with my linear amp.

Roger ZS6RJ and Nick ZS6NCK operating ZS6WR club station  

Thursday, 12 February 2015

Building the Ultimate-3S WSPR kit

I set aside a few hours to build the U3S from QRP kits.

The build went fairly well, the instructions are fairly clear. When I first applied power it was obvious that something was wrong. What I saw on the display was not what I expected to see.

I did some fault finding and came to the conclusion the 20 MHz clock was not functioning. I carefully removed the crystal and replaced it with a temporary 10 MHz crystal.

I then powered the U3S up and I was very pleased to see “Diagnostic mode” displayed on the display.

Tomorrow, I will try and find a suitable replacement crystal. Then hopefully I can set it up to WSPR to the WWW on 10m.

What a relief……

Start of build

This is a problem !!

Problem solved

Mainboard, display (not visible), synthesizer and 10m low pass filter

Wednesday, 11 February 2015

WSPR - Antenna performance evaluation

I believe WSPR is a great tool to evaluate station/antenna performance.

I used the WSPRnet’s data base and downloaded the 10m WSPR data for all stations decoded by myself and a fellow amateur, Kevin ZS6KMD located some 20 km north of me yesterday.

The graphic below reveals quite a lot of detail: Number of decodes, strength of decodes (min and max).

I was using a simple dipole beaming E/W at 8m agl, I think Kevin also uses a dipole, but I am not sure of the orientation and height agl.

IMHO this is a sure fire way of comparing apples with apples.

Info gleamed from this test:

The band opened and closed at about the same time (Duh...)

I decoded a few more stations than he did, 569 vs. 468.
The strongest signal decoded by me was +2 dB vs. -5 dB by Kevin.
Weakest signal decoded was -32 dB !!
It appears as if my antenna was performing slightly better (between 2 and 13 dB)

I should stop playing and build my Ultimate 3S WSPR beacon.....

WSPR ZS6A vs ZS6KMD 10m decodes

Thursday, 18 December 2014

WSPR’ing on 10m

My interest in WSPR has been rekindled. WSPR is a fantastic tool; it is most useful in understanding the behaviour of propagation.

I believe WSPR can be also be used obtain other meaningful data for example: making antenna comparisons, dispelling many of the wild claims made by the antenna designers and manufacturers. At some stage I would like to pursue this aspect of WSPR.

Today I was playing a bit with WSPR on 10m. Initially I was using 5 watts (37 dBW) and that worked very well. I then reduced the transmit power to 1 watt (30 dBW)

The image below clearly shows what can be achieved with 1 watt and a simple dipole at 8m (25 Ft) agl.

Tomorrow I hope to reduce the power to 100 mW (20 dBW)

WSPR combined with the Reverse Beacon Network is simply amazing. The persons behind WSPR program and the Reverse Beacon Network deserve our heartfelt gratitude.

Click on image below for a more detailed view.

WSPR 10m 1 watt (30 dBW)