Klub Niezwykłych Łączności
Last time I tested earth electrode I felt encouraged to work on this some more. Beneficial propagation during this time of the year and the fact that I’ve been well drilling on my land were more than a good excuse for experimenting with an electrode dug 13 meters below ground level. The electrode was placed … Continue reading “Testing earth electrode once again”
Successful experiment with earth dipole about 150m long encouraged me to experiment with a longer antenna about 600m long. I used industrial earthing on one side and steel beam with ‘C’ cross section immersed in the water on the shore of a small lake served as the other electrode. I used industrial earthing on one … Continue reading “Experyment with antenna earth elektrode about 600m long”
I conducted my first tests with earth electrode antenna in the nineties with the use of hot water installation. While drilling a well on my piece of land in the countryside I thought this could be just the right moment to explore this idea a bit more. A test drill for 5 meters provided a … Continue reading “Earth Electrode Antenna Tests”
Encouraged by our last experiments with ground dipoles we decided to do a transmit experiment with this antenna on VLF 8.270kHz, 36km (36000m) wavelength. Thanks to Fab LAB Trójmiasto we had a great location on the see on a cliff near the Baltic Sea in Gdynia. Our goals for this experiment were: Try transmitting from … Continue reading “VLF transmit tests from a ground dipole”
Stefan DK7FC did a succesful transmit experiment utilising a ground diole on VLF. This resulted in a really strong signal on our Warsaw grabber (over 900km distance):
Encouraged with the outcome of latest earth dipole tests I decided to continue testing of those interesting antennas. This time, however, I aimed at: testing the possibility to transmit in 136 kHz checking how a good quality electrode will impact the antenna confirming that an earth dipole can work effectively above the ground with low … Continue reading “A bridge on the Vistula river as an element of an antenna – earth dipole tests continued”
Recently we’ve done a successful transmission from an earth dipole on 8270 Hz. This is the first amateur transmission on VLF from Poland which has been received in another country. This is also the record distance for a transmission using a ground dipole antenna – over 1330 km. Link to Paul Nicholson’s post about it: … Continue reading “Record distance for a VLF transmission from an earth dipole antenna.”
Stefan DK7FC transmitted at 6 aptil 2019 20:25 UTC at 2970.1Hz. The TX power was 487W into a 1130m ground dipole antenna. The ebnaut transmission parameters were: f = 2970.1 Hz Start time: 06.APR.2019 20:25:00.3 UTC Symbol period: 6 s Characters: 7 CRC bits: 16 Coding 16K21A Antenna current: 2.4 A Duration: 02:04:48 [hh:mm:ss] The … Continue reading “ULF 2970.1 reception record”
Due to the ongoing (on 20 august 2019) rescue operation in the Wielka Śnieżna Cave in the Tatra mountains we decided to write about cave communications. Rocks and soil attenuate radio signals well. Despite of this some means of communications in caves and mines are needed. The attenuation rises with frequency. Normal VHF communications gear … Continue reading “How Cave Communications works”
Introduction Having built a 472kHz – 10MHz antenna autotransformer able to handle 136kHz on ferrite cores, I was considering building one capable of working at 8.27kHz and above (36km wave). VLF, LF and MF air-cored coils are quite huge for 8.27kHz, which makes them difficult to operate on outdoors. This was the reason why I … Continue reading “Universal antenna autotransformer for 8.27kHz, 136kHz and 472kHz”
