Following last night's misadventure, the VLF/LF/MF exciter seems to be recovering. On VLF, CW on 8.277 kHz was heard at just over 1 km using a crude DC receiver and a miniwhip. NAA on 24 kHz was loud
Great. My rx is recording again with a fresh charge in the battery. Should I be looking for your carrier? Can you reach 20uW ERP, GPS locked? If so, try sending 2 hours of unmodulated carrier between
Am 23.11.2015 20:28, schrieb Paul Nicholson: [...] It would be great to see some VLF activity. Very little sign of amateur activity seen here lately. Except for http://abelian.org/vlf/fbins.shtml#p=1
Hi Joe and all Group. I'm also recording around 137777.00 Hz and i will try to read Joe's EbNaut message tomorrow morning. Just confirm with an email the starting time of each transmissions and if
Hi Paul, The tuning coil is rather small and lossy. The best range is 5 km using a DK7FC E probe and Spectrum Lab with QRSS100. I don't have a GPSDO yet, but Markus says the dual oven osc should be s
Hi Domenico, Thanks for watching. 8K19A 2 s symbols 7 characters. Next start time 0000 UTC 24 Nov. Just started! 73 Joe VO1NA Hi Joe and all Group. I'm also recording around 137777.00 Hz and i will t
The cat sat under the stars... Confirming Paul's observation. The strong unmodulated carrier was well visible in the grabber spectrograms. Got an error-free ** decode of the 0:00 transmission: found
Hi Joe, This are EbNaut results of your carrier well received here in JN80NU (QRB=5400 km): found ** list rank 0 reference phase 0 0 0 0 carrier RMS 4.628e+005 noise RMS 1.827e+004 carrie
It was a nice but windy day today so the VLF TX was put on the air for a quick test. About 30 watts were fed to a 5:1 XFMR and a ~0.35H tuning coil to the 100m wire at 10m height. CW signals were hea
How about a long carrier, GPS or rubidium? It's a long shot but it's a low loss path and the time of year is good for several hours of coherent integration. I can easily see 10uW from 1000km in one
Hi Joe, thanks for sharing your experiment details. I have been doing similar tests on VLF, using about 120 m of wire, about 10 m of the ground. I have used initially much less power, so signals disa
Yes Paul, that sounds like a very reasonable proposal. Joe's OCXO is obviously stable enough for the task, all that's needed there is a different frequency word for the DDS. And considering the anten
Paul, Ref: " I can easily see 10uW from 1000km in one hour over a path with a lot of land. West to east over water will be lower loss and four or six hours integration will make up for the lower ERP.
Adding to what Paul says I have found that NEC needs to be treated with caution even higher in the LF range. Another thing to remember is that the skin depth at these VLF frequencies is quite signifi
The radiator, although a horizontal wire, is practically a vertical polarised Hertzian dipole with the ground as one pole and the wire as the other. Horizontal polarisation suffers very high attenuat
Hi Paul and thanks very much for the data. Unfortunately, after the experiment, the aerial current had decreased to zero. It seems a short developed in the tuning coil. A better design is being consi