Curious. Appears to fade down with the background, so distant? Well, nothing stands out here in Todmorden, 00:00 to 03:00 UT in 96 uHz. PS some photos of my loop antenna, rebuilt last weekend to be a
Thanks! Very nice. I particularly like the spectrograms which reveal the shifting cavity mode spectrum of the distant sferics as the ionosphere height increases. Have you seen anything more of the m
Carrier comes on and off at irregular times each day. Here is a plot of 82Hz over the last three days http://abelian.org/vlf/tmp/zevs-140829a.gif (1.67mHz bandwidth, 10 minute samples) It's a strong
In only a few weeks we will be half way through the VLF season. Is there any interest to try some more experiments? - Extending the T/A distance record further into Europe? - Try lower frequencies -
Recording. LWPC prediction for the path assuming 150uW ERP http://abelian.org/vlf/tmp/141130a.gif Looks like stable phase from 22:00 UT to 08:00, a much longer window than we had in June. -- Paul Nic
Maybe something is not working. No sign of W4DEX at Forest, VA, range 254km, checked 17:30 to 19:30 UT. Should be a strong signal at that range. There's a bit of a signal, unstable, varying 3 to 5 mH
Certainly transmitting - but where is the carrier? Without GPS lock, the HP source should be OCXO stable anyway? I searched at Forest +/- 0.5Hz now maybe I have found you, 0.1Hz low? The frequency lo
Spectrogram of W4DEX at Forest, VA (range 254km) through Mike Smith's receiver which is streamed over the Internet, http://abelian.org/vlf/tmp/141201a.png Appeared close to 8819.9 Hz then after the s
Glad you found the problem Dex. Will look forward to another test tonight or soon. I'll try to put out my new E-field receiver this evening if I can finish some alterations quickly. It has much lower
Bearing looks a few degrees south of bearing for DJ8WX and signal is a bit weaker than normal for Uwe. It's a lovely sharp line at about 0.12fT and the frequency appears exact. -- Paul Nicholson --
Strong signal at Forest VA, frequency looks good. http://46.4.26.83/sp8820_vlf35.png updates about every 10 mins with the last 20 mins of signal. New E-field rx running tonight at Todmorden, alongsi
Spectrogram of W4DEX at Forest, VA (range 254km) http://abelian.org/vlf/tmp/141202a.png No sign of any frequency lock problems now. All the energy is concentrated in one frequency bin so the signal a
Another plot from Wolf's receiver at Bielefeld, http://abelian.org/vlf/tmp/141202e.gif This covers the full transmission from 22:30 UT in 50.5 uHz bandwidth. The line at 8820.0000 is 11.7 dB above th
Indeed it is tempting. With that 50.5 uHz spectrum the odds of a false peak is probably one in a few tens of thousands. Perhaps Dex should change frequency a small amount before tonight's transmissio
LWPC prediction for path W4DEX to KO85HA http://abelian.org/vlf/tmp/141130b.gif Signals are ~20dB weaker because of the extra distance which is mostly over land - much higher attenuation. Map http://
I swept a range of times and bandwidths and this one from Bielefeld is even more convincing http://abelian.org/vlf/tmp/141202j.gif That's 13.4 dB S/N averaged over the 3 hours. More from LWPC Bielefe
Oh well, never mind. Another try soon. The receivers all continually record on 10 day loops so fire up any time. There's plenty of data to examine from last night. Have to try to understand how the s
Examining W4DEX at Todmorden overnight on 1st/2nd Dec... S/N dB in 278uHz and signal phase in 1 hour steps: From dB phase 22:30 7.6 80.4 23:00 8.9 90.9 23:30 9.1 115.6 00:00 6.3 106.2 00:30 7.9 30.6
A spectrum from the natural radio receiver at Sebring Florida 27.516N,81.517W range 869.4 km run by Joel Gonzalez, http://abelian.org/vlf/tmp/141204b.png S/N is 12.6 dB in 55.5 uHz. The noise level t
