Greetings, There were many S1-S2 whistlers occurring here in Colorado on Monday night (at least a dozen a minute) during tests upon my VLF receiver. The ...
1980
Leonard J. Kerry
leonard_kerry@...
Jul 1, 2003 11:35 pm
Shawn and Group. Just a general comment for everyone's consideration on the use of inductors in the antenna circuits of VLF receivers. For an inductor to form...
1981
vlf_ddd
Jul 2, 2003 3:16 am
Shawn, I wonder if the low pass effect you are getting with those iron core inductors are from the effects of the inductance with your input circuit, or from...
1982
vlf_ddd
Jul 2, 2003 3:24 am
It could be some intermodulation between the AC power and your computer monitor horizontal scan signal. Try turning off your monitor for a run or changing...
1983
coilcrazy
Jul 2, 2003 12:35 pm
That picture was taken with the monitor off and I have tried different sound card settings. This signal is only receivable with the coil axis NS. Thanks...
1984
Shawn E. Korgan
vlfkorgan1
Jul 2, 2003 5:39 pm
Greetings, ... The low pass effect appears to be the property of the chokes. I tried choke values ranging from 150 henries to values within the mH range and ...
1985
Shawn E. Korgan
vlfkorgan1
Jul 2, 2003 5:47 pm
Greetings, ... Could this be the Schumann resonance that you are receiving? If not, it is likely originating from any manner of electrical device in the ...
1986
Richard Gagnon
richg_1998
Jul 2, 2003 6:30 pm
Hi Shawn Could you post a schematic of your SK-1 receiver using the chokes? This option sounds interseting. Thank you. Richard Gagnon ...
1987
coilcrazy
Jul 2, 2003 6:40 pm
Thank you Shawn. I was hoping it was Schumann's, but I do not receive any of the other ones. This signal is ALWAYS there and I cannot even see a trace of it...
1988
Percy Jones
vze3t6ka@...
Jul 2, 2003 6:59 pm
Does anybody know why NAA is off the air? It's been down for a week now. Percy....... [Non-text portions of this message have been removed]...
1989
Shawn E. Korgan
vlfkorgan1
Jul 2, 2003 7:04 pm
Hi Richard and group, I do not have a ready schematic that I can post to the group at the present time. It's only on paper and is a design that is still in ...
1990
vlf_ddd
Jul 3, 2003 6:52 am
... Just curious, why do you use two antennas instead of one taller one? Also... How are they spaced / oriented w/ respect to each other and your receive...
1991
Trond Jacobsen
trond.jacobsen@...
Jul 3, 2003 10:18 am
Kalimera - good morning VLF group. Just back from a pleasant 2 weeks stay at the Greek island of Kerkyra ( Corfu ). Good to see so many interesting treads...
1992
Shawn E. Korgan
vlfkorgan1
Jul 3, 2003 1:12 pm
Greetings group, ... One very tall antenna would work better than several shorter antennas. The only problem I have encountered is trying to get a tall antenna...
1993
WarmSpgs@...
Jul 3, 2003 4:46 pm
... I am intrigued by this. White noise from several hundred ohms, in a high impedance circuit? Could we see a schematic of your receiver's front end? ...
1994
Tim Bucknall
harmonichy
Jul 3, 2003 7:07 pm
... From: "S Whitt" <Steve.Whitt@...> To: <mwc@...> Sent: Thursday, July 03, 2003 7:59 PM Subject: [mwc] South Pole VLF...
1995
Shawn E. Korgan
vlfkorgan1
Jul 3, 2003 8:01 pm
Greetings, This is true. As small as several hundred ohms of series resistance with my antenna begins to just very slightly add white noise (almost ...
1996
mdennisond@...
marky26_uk
Jul 3, 2003 9:02 pm
Hi Shawn & all, Shawn do you have a spectogram of the noisefloor when it's strong & when it's not. Thanks, Mark. [Non-text portions of this message have been...
1997
mike l dormann
w7dra@...
Jul 3, 2003 9:45 pm
you are correct in keeping the series resistance low in the series lead of your first transistor in your receiver, the most sensitive rx i ever had was back in...
1998
vlf_ddd
Jul 4, 2003 3:05 am
... Attenuation of radiowaves in a "good conductor" is also proportional to the square root of the conductivity of the medium. So a signal in seawater (cond....
1999
RWC.BOULDER
RWC.Boulder@...
Jul 4, 2003 5:51 am
Space Weather Message Code: ALTK05 Serial Number: 313 Issue Time: 2003 Jul 04 0550 UTC ALERT: Geomagnetic K-index of 5 Threshold Reached: 2003 Jul 04 0550 UTC ...
2000
drobnock2
Jul 5, 2003 4:59 pm
Hi: Man-made ELF and VLF Signatures can be received underground and underwater. And it is correct to state that under proper conditions natural elf/vlf...
2001
Dale Reed
dalereed35
Jul 5, 2003 5:13 pm
The Medium Frequency antennas at the Minuteman Intercontinental Ballistic Missile sites(Missouri, Montana, Dakotas, Wyoming...) are buried arrangements of...
2002
Trond Jacobsen
trond.jacobsen@...
Jul 6, 2003 4:34 pm
Hello VLF group Just aquired a "half handfull" of 2SK117 and 2SK170GR FET's. ( surplus components from a producer of high-end audiogear. ) The input...
2003
Peter.Schmalkoke@...
petersch60
Jul 6, 2003 5:38 pm
Hello Trond & group, the mentioned noise figure looks great and seems worth the development of an altered amplifier design in order to minimize the input...
Greetings, Both of these FETs are great for VLF work! Currently, I use a 2SK369 FET which is slightly higher in gain than the 2SK117. One note of caution is ...
2006
Leonard J. Kerry
leonard_kerry@...
Jul 7, 2003 12:40 am
Hi Trond. Firstly, I've had no direct experience with the particular FETs (JFETs) that you mention. However, don't be put off by the gate to source capacitance...
2007
Leonard J. Kerry
leonard_kerry@...
Jul 7, 2003 2:08 am
Hi Trond and group, After scanning through some old posts, I just found one from Trond, dated 27-02/02, that basically covers much of what was said in my...
2008
Peter.Schmalkoke@...
petersch60
Jul 7, 2003 5:29 am
http://semiconductors.electronica.ro/toshiba/datasheet/1027.pdf Sorry for this extra-posting, I had previously overlooked that Trond was talking of two...
