Just a further thought. WSPR doesn't of course spread its power over 6Hz it actually transmits full carrier on each of the four frequencies for 0.682 mS and sometimes several of the same element foll
Hi Roger Good stuff! In my recent experiments on 9KHz Earth mode I discovered my laptop's on board sound card was very noisy particularly when operating off battery. As a result, I added a quality US
First calculate S/N alone : WSPR has a signalling bandwidth of 1.46Hz which is the value to use for noise level calculation. QRSS600 has a bandwidth of 0.0017Hz. They both rely on non-coherent po
Hi Eddie (et al) It is highly unlikely you'd copy Andrew on VLF remembering that the WSPR signal spreads around 6Hz in the transmission burst, so the energy in any narrow FFT bin would be tiny. Also,
Great stuff Roger and Andrew If you are RX'ing on an 80m dipole it may be worth a look here, I would never say can't until I have tried. Bearing in mind I should be able to observe signals which woul
Hi Roger Yes quite so, re such comparisons and very very weak signals, I am just considering the possibility of telling if a signal is there or not by eye. BTW before anyone notices in my idea of com
Just a further thought. WSPR doesn't of course spread its power over 6Hz it actually transmits full carrier on each of the four frequencies for 0.682 mS and sometimes several of the same element fol
Hi Roger Highly unlikely is very good compared with 'impossible to get past your own garden fence' and good signals from the Czech Republic. Also 'no intention to radiate' doesn't prevent it happenin
Andy/Marcus Many thanks for your most interesting analysis. 73s Roger G3XBM On 27 April 2011 22:18, Andy Talbot <[email protected]> wrote: First calculate S/N alone : WSPR has a signalling bandwid
As an experiment I changed over to my wife's laptop and got immediate decodes of G6ALB's VLF earth mode signal (3km) at -17dB S/N, suggesting the issue with lack of decodes may be with my soundcard a
Hi Roger, WSPR should decode from about -29 dB SNR in 2.5 kHz (ie. 0 dB in 3.2 Hz). On the other hand, a clearly discernible carrier in a 0.42 mHz FFT ("DFCW-6000") would require about 6 dB SNR in th
Check your sampling rate on the machine that's failing. Although most modern soundcards are based around 48kHz older ones are 44.1kHz based, and give errors when interpolating to 12kHz based rates.
