Hi VLF I’m in contact with a local group of espeleo enthusiast, big enought to count with some electronic tecnicians with them They have been developing their own equipment at VLF. A transmitte
Hi Luis, You seem to generate much activity on all bands in your Spanish region Am 01.02.2018 19:58, schrieb VIGILANT Luis Fernández: As this is the “near field” it is supposed to
Luis, Thank you for the underground mapping example; nice work by the speleo team. “As this is the near field it is supposed to work only at magnetic field due to the small size of the antenna
Hi Jim, I've found a graph showing Z_Wave over D/. Near the loop: Z_wave = 377*(2pi*D) / lambda 73 Clemens DL4RAJ Attachment: Wave Impedance.png Description: PNG image
Hi Jim, Here is another informative figure. probe) How did you calculate the 45 dB disadvantage for the E-filed probe? 73 Clemens DL4RAJ Attachment: E_H Loop.png Description: PNG image
Or here: https://de.wikipedia.org/wiki/Nahfeld_und_Fernfeld_(Antennen)#Nahfeld 73, Stefan Am 03.02.2018 11:24, schrieb Clemens Paul: Hi Jim, At 38kHz the impedance of the transmitting loops field at
We did a loop tx experiment with Marcin SQ2BXI on 20 january 2018. The tx was a semi-horizontal 1-turn loop about 150x50m (from memory), 1A current at 8270Hz. The tx frequency was generated via Paul'
Thank you all for the very interesting comments. Looks like there is a lot to investigate in this field and that is good. Wide room for further investigations :-) Jacek, you mentioned what I was midn
Jacek, you mentioned what I was midnight oiling here " If you want some semi-DX in the H-field, then try coupling into some long conductors (pipes, power lines, railway tracks etc)" And i forgot pho
I have to say that I am also lacking in theory, but the tests carried out on airborne and core coils have been successful and are working. The most relevant loop antenna has been an octagon-shape
Hi Leandro, One of your questions was: even in the near field of a magnetic transmitting loop at 38.4kHz and at 100m distance while in the far field the E-field is 51.5dB stronger. 73 Clemens DL4RAJ
Interesting. I built a similar loop and transmitted on MF. The maximum power was about 30 W RF because the resonating Cs (WIMA-FKP-1, 2kV) became warm and the resonance drifted away. But i managed up
Interesting. I built a similar loop and transmitted on MF. The maximum power was about 30 W RF because the resonating Cs (WIMA-FKP-1, 2kV) became warm and the resonance drifted away. But i managed u
Hi Juan, Good luck with your tests. Do you have/need a special license for transmitting on that frequency or is it free for everyone unless you stay below a certain ERP level? Oh, i have another ques
Hi Stefan, VLF Appart from CB license. Ref your other questions there are other group of Hams and also Cave explorers in Galicia. They have made very interesting test of RX inside the cavity. Last te
Hi Stefan, VLF Appart from CB license. Ref your other questions there are other group of Hams and also Cave explorers in Galicia. They have made very interesting test of RX inside the cavity. Last
