ADS-B receiver with paper cup as radome. The radome was soon replaced with a transparent one from the Albert Heijn radome shop ;)

Both transmissions at 0900 and 1200 UTC were successful, and the MP3s can be found here:

recording of the 0900UTC transmission
recording of the 1200UTC transmission

recording of PW-SAT

It has been quite a while since the last update. A lot has happened in the mean time. Apart from my fulltime job in the space business as RF designer, I’m also still involved in AMSAT-UKs FUNcube project. I’m designing, building and testing the FUNcube RF board, which contains the transceiver. This work is sucking up LOTS and LOTS of spare time, but the reward is a functional radio, ready for launch! Bear with me for a while!

In the mean time the Delfi-C3 groundstation is finally taking shape again, now being defunct for almost a full year (!). I’m planning to move back the WebSDR soon, and also adding a 137kHz receiver to the setup. This is all in that precious spare time, so do not expect short-term miracles ;)

For some time now, the PA3WEG.NL server has been hosted on aprs.pa3weg.nl in Delft, while te main server is down due to a faulty harddisk. I’ve replaced the backup on this server, so everything should be working apart from database driven things. To make matters worse, Delft University of Technology has given the orders to replace the rooftop of the EWI building on which all my antennas are located and decided not to notify me. They’ve chosen a cheap company employing monkeys to do the job. This results in bended antenna elements, snapped cables, flooded rooms and lots of dust in the ground station room. The University is going to send a pretty large damage claim to the contractor, so I believe they will not make any money from this deal. (and thats a good thing!). Meanwhile. I cannot guarantee any of the offered services, like the aprs server or websdr, to the public. My apologies for this but it is out of my hands.

Today, SAQ will transmit on alexanderson day. Transmissions will be at 17.2kHz at 09:00 UTC and 12:00 UTC in CW and can be followed through the websdr

The 09:00 UTC transmission was successful and received S9++ in Delft. An MP3 can be found here
The 12:00 UTC transmission was also successful and received S9++ in Delft. An MP3 can be found here

The harrdisk of the PA3WEG.NL server has crashed. the site now runs on aprs.pa3weg.nl, but you may experience broken links!

After functioning 30 years on the roof, the Active nordholt antennas used for the WebSDR receiver failed. One failed during repositioning of the supporting masts, and one did shortly after. If the large RADAR next to the antennas former place acted as lightning “rod” for all these years remains unknown. I opened up the antennas for closer inspection to find one damaged capacitor, looking like it suffered from severe over voltage (lightning?) and no visual defects on the other antenna.

However, this was not the most important finding! After some reverse engineering I found out that both antennas which worked fine for many years are NOT exactly what articles from Ernst Nordholt described. Interestingly enough, there are at least two more transistors, and only one rare FET instead of two!

More info will follow on my Nordholt antenna page!

I finally got the two VLF antennas off the roof. TU Delft decided to change the roof lock without notifying all the keyholders. Nice job…. The small Nordholt has been damaged by water ingress. When I opened the case, water was pooring out of it. The larger Nordholt is still closed and glued shut. It will take some time to carefully open and inspect it. Apart from the water damage, the small version also has an exploded tantulum. This might indicate lightning damage. However, the antenna would continue to work without this tantulum cap. Probably lightning is what has caused the reception problems, and the Nordholt finally had to give in to the force of mother nature after working fine for more than 30 years…

While VLF is now out of order, there is one other thing which you could listen to. On the Delft WebSDR there’s now a mirror of the CAMRAS WebSDR. This mirror service is provided if the main server would overload.

Funcube news: Last weekend we had the so-called FUNsquare meeting. Its objective was to test the interfaces between several boards and to do an end-to-end system test with all the prototype hardware. The meeting was very successful. please see funcube.org.uk for more info.

The WebSDR server now temporarily acts as a mirror for the CAMRAS server. More than 140 listeners tuned in to this backup system, as the primary server has a user limit of 170 due to network contraints.