Sri for the amount of mails but i have forgotten to attach the screenshot of DHO38 by reception with the 1m^2 single turn loop... Now finished for today ;-) 73, Stefan Attachment: DHO38 in 1m^2 loop,
Hello Jim and the group, Today i did the test with the 1m*1m loop again. It was necessary to go down to abt 750 mHz and indeed, the DHO38 signal appeared at about -100 dB when turning the loop for op
Stefan, I you could measure the power delivered by the earth antenna to a correct load you would be able to calculate the efficiency of the antenna (knowing distance to and ERP of DLF) 73, Rik ON7YD
At ELF/VLF I think the earth electrode pair must act in several ways simultaneously. (a) As an induction loop. This certainly ties up with behaviour and loop orientation locally in my experiments awa
Dear VLF interested OMs, This mail is written with dirty hands out of my car, now in 520m ASL. Raindrops are falling on the car roof and i am listening the CW-beacon "HDL" at 426 kHz (AM mode) in my
Hello Rik, VLF, Yesterday i have measured the receiving voltage of DHO38 on my earth antenna. I used an impedance converter with an OP AMP, so the input impedance can be seen as infinity. I got a sig
Dear Stefan, LF Group, The EMF induced in a small loop is: V = 2.1e-8 * fNAE f = frequency N = no. of turns A = area E = Electric field strength V/m (this assumes E/H = 377ohms, i.e. not near field)
Dear Stefan, LF Group, Taking a guess at ERP of DHO38 as 100kW, the FS at 411km distance would be about 5mV/m (if ERP were only 10kW, FS would be 1.7mV/m, if it were 1MW, 17mV/m, so 5mV is probably n
Hello Roger, VLF, Maybe it will give us some ideas of the propagation of such an earth antenna if i try to receive even lower frequencies on my grabber QTH. Then we can see if the effective area incr
Dear Stefan, LF Group, It gets confusing when the bandwidth changes! In this case, both measurement bandwidths are much smaller than the modulation bandwidth, and the signal has a continuous spectrum
Members of the Cave Radio & Electronics Group have been using and investigating earth loop antennas for some time. The theoretical basis of such an antenna has not been clear to us, but Dr David Gibs
...and it was possible to drive a 10mm green LED on the earth antenna, just by connecting! It was possible to watch the AM modulation of DLF! 73, Stefan
How earth-current antennas really work -- With cave radio equipment such as the HeyPhone and Nicola system there has been a trend away from the use of induction loop antennas towards earth-current a
Jim, G .. Dear Stefan, LF Group, ...and it was possible to drive a 10mm green LED on the earth antenna, just by connecting! It was possible to watch the AM modulation of DLF! 73, Stefan You can do so
Hello Jim, VLF, Thank you for your helpful suggestions! Es tnx for calculating the FS at the earth antennas QTH! This was what i didn't know how to do ;-) Yes, i have a low pass filter attached at th
Dear Stefan, LF Group, ...and it was possible to drive a 10mm green LED on the earth antenna, just by connecting! It was possible to watch the AM modulation of DLF! 73, Stefan You can do something si
Am 15.07.2010 20:07, schrieb Roger Lapthorn: Has Dr Gibson written anything already to give us a clue what he thinks is going on? ...and John, ask him if he wants to start a project with us! Maybe he
Stefan, if I remember well the antenna voltage of an unloaded and untuned small loop antenna is proportional to the loop area (all : please correct if I am wrong). So, as Marcus suggested you could m
