Bear, My head signs still indicate more activity in the same area. CJ Michael Hebert <qrpbear@...> wrote: Dave, My QTH is Honolulu, Hawaii. Traces in the...
6539
jcal1001
Jan 28, 2007 9:40 pm
Recently I have been using a sensor using a small amount Permalloy with a small amount of Metglas layered on top of it. This is air- cored and approximatley 6...
6540
Brooke Clarke
brookeclarke...
Jan 28, 2007 9:57 pm
Hi John: Photo? Have Fun, Brooke Clarke w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml http://www.precisionclock.com...
6541
Brian
electricterra
Jan 28, 2007 10:40 pm
Yes .... a screen shot of the two using spectrogram would be nice. Perhaps one feeding the left channel and the other the right. Thanks for coming up with new...
6542
jcal1001
Feb 10, 2007 9:53 pm
I have been using a ground sensor somewhat like the one at the Elfrad site with interesting results. It consists of 2 ground rods(available at Home Depot)...
6543
Herbert E. Plett
cachureos
Feb 11, 2007 1:44 am
two rods... each an amplifier... against what? an amplifier requires a reference as my manual says... ... ...
6544
samfordca
Feb 11, 2007 1:28 pm
hi would anyone have one of their old electronic box prototypes or similar for sale that would allow me to check for elf and view such spectrum on my computer....
6545
jcal1001
Feb 12, 2007 5:31 pm
I reference each amplifier to their opposing ground rod. It would be meaningless to reference them to their own ground rod. Using the artificial transformer...
6546
rigdoctor99
Feb 12, 2007 6:43 pm
Its obvious, the amp is ref. to the weeds........ probably give a gain of 20 dbW ... rods(available ... files...
6547
jcal1001
Feb 12, 2007 7:28 pm
Is that supposed to be funny? If so, you could use a humor transplant. John ... says... ... Elfrad ... its own ... the ... very ... wherewithal to ... ...
6548
Renato Romero
reromeroit
Feb 12, 2007 10:28 pm
Hello John, can you post an electric scheme of that? I'm not sure to have understood correctly. Thanks. Renato Romero...
6549
Brian
electricterra
Feb 13, 2007 1:17 am
jcal1001, Keep experimenting. I do not mean that sarcastically either. I would like to find a way to monitor ground currents. That is a tall order especially...
6550
Herbert E. Plett
cachureos
Feb 13, 2007 5:16 am
could you, please, elaborate on that. I really don't understand. some schematic and/or picture would be interesting. ... ...
6551
jcal1001
Feb 14, 2007 10:01 pm
Another way of doing this which I think is even better is using a third ground rod situated exactly between your other two rods. This would be the common...
6552
Peter Schmalkoke
petersch60
Feb 14, 2007 10:39 pm
This evokes an interesting paradox: Assuming the ground was composed uniformly down to several multiples of the rod spacing. Further let's regard the effective...
6553
Brooke Clarke
brookeclarke...
Feb 14, 2007 10:45 pm
Hi Peter: The depth of the ground is the same in all cases so the area for a half loop is only half the area for the wide loop. Have Fun, Brooke Clarke, N6GCE ...
6554
Peter Schmalkoke
petersch60
Feb 15, 2007 2:09 am
Hi Brooke: Well, that seems to be an obvious explanation. But if true, then the effective ground penetration depth could not be enlarged by increasing the...
6555
Brooke Clarke
brookeclarke...
Feb 15, 2007 2:40 am
Hi Peter: I think it depends on what underground where you are. In the semiconductor area a 4 point probe is sometimes used to measure the conductivity of a...
6556
myamiphil
Mar 16, 2007 3:43 am
I dont have an established radio but I do read up on what your all doing.... I just came upon something in two unrelated posts that may be of interest over the...
6557
John Wilcoxen
johnwilcoxen
Mar 18, 2007 4:00 am
I have been following the reports about "low frequency earthquakes" and find it interesting they are trying to use the data for future large quakes. Maybe...
6558
Michael Hebert
qrpbear
Mar 19, 2007 5:22 am
Phil, Yes it is interesting. I spent a lot of time googling seismic sensor info over the past couple of weeks. It seems there is a new generation of...
6559
Brian
electricterra
Mar 20, 2007 2:04 pm
Renato, If you see this what is your opinion? There was quite a bit of wind when this was recorded this past weekend and the coil housing I have a suspicion...
6560
Renato Romero
reromeroit
Mar 20, 2007 10:51 pm
Hi Brian, here below your reception compared with mine: http://www.vlf.it/temp/test_200307.jpg Agree with you for the wind noise, ...but Schumann resonances...
6561
Brian
electricterra
Mar 21, 2007 12:05 am
Thanks Renato for the confirmation. I will be calibrating the coil and making a few more changes but it looks good so far. Brian ... eliminary.htm...
6562
reromeroit
Mar 21, 2007 12:14 pm
Hi Brian, di you know the impedance value of your coil at 20 Hz? Renato...
6563
Brian
electricterra
Mar 21, 2007 12:25 pm
Not yet but I acquired a new oscilloscope, function generator, and a capacitance/inductance meter so I will be determining frequency response and impedance...
6564
Brian
electricterra
Mar 31, 2007 7:33 pm
Hi Renato, I ran a few more quick field tests today and the results are the first four charts here: http://electricterra.com/preliminary.htm I did not record...
6565
Renato Romero
reromeroit
Mar 31, 2007 9:42 pm
Hi Brian, the spectrograms seem to be good. Let me know about your future coil measurement. I was looking at your front end circuit: ...perhaps the OP07 can be...
6566
Brian
electricterra
Mar 31, 2007 10:42 pm
Actually Renato I am using a different receiver. The first Amplifier is a OP27AG. That feeds a 60hz. notch filter and that feeds another OP27AG. That feeds a...
6567
Brian
electricterra
Apr 1, 2007 4:18 am
Renato, A preliminary impedance for the coil at 20 hz. is between 6k and 7k. This is derived by guessing at the coil winding turn to turn capacitance. Brian...
