The airport is almost due north of me, I never hear anything on ground there and only a few flights overhead. The sound is from more toward west and HANGS IN...
18929
rfiemiguy
Feb 9, 2012 4:54 am
I have a nice Olympus recorder. I will try to remember to do that next time....
18930
Caroline Devine
linerdevine
Feb 9, 2012 9:40 am
Thanks very much for replies to Mac OSX query yesterday. Baudline installed easily and now running on OSX 10.6.4 with Digidesign MBox2Pro. I am checking out...
18931
Paul
paul@...
Feb 9, 2012 1:45 pm
Some nice risers at Sheffield yesterday morning, http://abelian.org/vlf/event.php?stream=vlf3&id=1328682379 ...
18932
Laurence Battin
beamtuner...
Feb 9, 2012 2:09 pm
One antenna that should work well is the Super Stick II 5/8 wave flexible base-loaded antenna from Smilely Antenna company. I have no connection to them, just...
18933
Thomas Olenio
tolenio
Feb 9, 2012 2:26 pm
Hello, Even an old antenna from a handheld walkie-talkie works with the Inspire. http://50.30.33.54/gaolinimages/images//product_s/61/20090820/A11380000E/VEV ...
18934
Thomas Ashcraft
heliotown27
Feb 9, 2012 5:27 pm
I have a question and posted a web page with the question here: http://www.heliotown.com/VLF_Question_Ashcraft.html I am wondering about the frequency range of...
18935
EdgarBigDog
edgarbhmfa
Feb 9, 2012 6:23 pm
Hi Tom and Group, I'm fairly sure the file can be run through Spectrum Lab for a good look. I'm hearing much of the lows being filtered out, a whistler,...
18936
dl4yhf
Feb 9, 2012 8:15 pm
Hi Tom, Edgar and group, Indeed it works, and the result looks pretty much the same as in Tom's own spectrogram. The spectrum graph (curve) doesn't reveal the...
18937
Paul
paul@...
Feb 9, 2012 8:39 pm
Last night captured 6 hours of TOGAs using a restricted sferic band, 6-12kHz. Plotted and the scatter is just as bad. I have to conclude this is working...
18938
kg4inu
Feb 9, 2012 11:47 pm
Thanks Paul, The more I read about vlf-toolkit and play with it the better I understand how it is intended to be used. ... That was indeed the case. apt-get...
18939
Tom Becker
b19063
Feb 10, 2012 2:03 am
I've had a pair of decommissioned Trimble Acutime IIs on the roof for a number of years; they provide 1pps edges. I guess I know what I need to do; I just...
18940
dl4yhf
Feb 10, 2012 7:24 am
Hi Paul, This may be complete nonsense, but what about the different (and mostly unknown) "polarity"; of the VLF receivers ? Does the sferic correlation operate...
18941
Paul
paul@...
Feb 10, 2012 1:17 pm
... I went though the whole software last night: the sferic triggering, FFT, phase unwrapping, Theil-Sen regression of the slope, TOGA calculation, assembly of...
18942
Thomas Ashcraft
heliotown27
Feb 10, 2012 3:47 pm
Hi Edgar, Wolf and all, Thank you for your listening and spectrogram analysis of my radio range. I am planning to start a new observing experiment with meteor...
18943
Paul
paul@...
Feb 10, 2012 6:55 pm
A bit of progress at last, http://abelian.org/vlf/toga/toga5.png I placed a PPS source near the antenna and straight away noticed that my timing was out by...
18944
Paul
paul@...
Feb 10, 2012 9:49 pm
Now a live TOGA map, updating every 10 minutes, http://abelian.org/vlf/atdmap2.html Clustering and hit rate is better but there is still something wrong. -- ...
18945
John/AF4EX
af4ex.radio
Feb 10, 2012 11:58 pm
Hi Thomas, I also listened and watched your signal file with Speclab. Made a screenshot for everyone to see (Speclab FFT sample size set to 4096) ...
18946
Paul
paul@...
Feb 11, 2012 8:45 am
... I did some trials to test the effect of polarity. On a sharp spike (1 sample), polarity of the spike makes no difference to its measured TOGA. Same for a...
18947
Thomas Ashcraft
heliotown27
Feb 11, 2012 5:06 pm
... Hi John, Thank you for the additional analysis. It is all very helpful to me in this moment. The original recording was made with an Edirol R09-HR digital...
18948
kg4inu
Feb 11, 2012 6:37 pm
... The map is matching up well with WWLLN for the South American storms. We're also picking up some of the activity off the US East coast right now. The storm...
18949
Paul
paul@...
Feb 11, 2012 7:09 pm
... Not bad at the moment. I shortened the FFT width - it's measuring the phase slope over the first 2mS of sferic, was 4mS before. Might shorten it further,...
18950
Tom Becker
b19063
Feb 11, 2012 7:41 pm
... Do you suggest I do not proceed? Is there any other utility in a timestamped Cape Coral stream? Tom...
18951
Paul
paul@...
Feb 11, 2012 10:58 pm
... The baselines Cape Coral/Sebring (118km) and Sheffield/Todmorden (48km) are very short and don't add much independent information into a location...
18952
Doug Welch
observingdad
Feb 12, 2012 2:16 pm
Hi Paul et al, Could you or someone remind me of the preferred was to shape the PPS pulse for use with the detection system? I do have an "old" Garmin GPS18...
18953
dl4yhf
Feb 12, 2012 3:18 pm
Hi Doug, depends on the software.. for Paul's vttime, the ideal waveform is a triangular pulse (for the centroid detection). I think a circuit has been...
18954
Jean-L. RAULT
f6agr
Feb 12, 2012 5:16 pm
Hi Wolf I checked with a fast-running FFT as you proposed, using the GPS 1PPS as time reference: I confirm that the spectrogram time grid is correctly...
18955
Tom Becker
b19063
Feb 12, 2012 5:52 pm
... Most GPS receivers yield NMEA sentences at 4800 bps in unsynchronized two-second groups, so the UTC time reported is normally as much as two seconds late. ...
18956
dl4yhf
Feb 12, 2012 6:27 pm
Hello Tom and Jean-Louis, ... A very good point .. yes indeed, NMEA standard is 4800 bps but almost none of the 'GPS mice' (including the GPS 18x by Garmin)...
18957
Peter, 54N 10E
df3lp
Feb 12, 2012 7:26 pm
Hi, ... Confirmed fully! I'm running the GPS 18LVC since many months here inside just below the roof. Mostly >9 satellites can be received. For interest,...
