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

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

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)

WSPR – A killer tool

Due to some local activity with WSPR with a fellow playing with a Raspberry PI QRP transmitter I decided to dabble with WSPR again.

The concept of WSPR beacons and the WSPRnet – Weak Signal Propagation Reporter Network is simply awesome.

http://wsprnet.org/drupal/wsprnet/map

This is the ideal tool for any one that has an interest in propagation and possibly even with evaluating the performance of antennas.

Imagine if the WSPR beacon had a feature whereby the transmitted data string included a ‘flag’ to indicate which antenna was selected A or B. The WSPR beacon software then selects antenna A or B, then sets the ‘flag’. Alternatively the time of transmission could be a function of the A or B antenna.

Doing some data mining on the WSPR web site will then reveal the real world performance data to prove the antenna performance, not some hairy fairy theoretical data which we normally have to rely on.

The image below shows propagation paths on 40m. My transmit power was only 5 watts. I see the majority WSPR beacons run on either 1 watt or 5 watts.

WSPR 40m with 5 watts and dipole