Hello friends, my comments to the discussion WSPR vs. CW: (1) Modes only can be compared at a specified data rate. Of course, CW is "better" than every thinkable digital mode if we allow it to be slo
Dear LF Group, we should clearly differenciate between all aspects. A propagation study does not need any information transfer via the radio path other than confidence on the identity of the station
Hello Andy, Jim, Rik and all, yes it is just that what I wanted to point at: In a beacon mode we need not communicate information other than the confidence on the identity of the station "heard". Thr
Hello Markus and all, if the reflector scatters isotropic then we have the decay of fieldstrength on the ways hence and forth which has the consequence that the received energy decays by the inverse
Dear Members of the Group, since years I use a very simple method of measuring the output sample rate of the soundcard: (1) Choose an LF frequency normal such as HBG, MSF or DCF77 (2) Generate a sine
Hello All, two years ago someone disturbed my breakfast by a deeply hammering disco sound. So I took my car to search for the source. Surprisingly, the sound decreased to nearly zero when I drove som
Hello Lowfwer's Suppression of noise only works well when its behavior is known at the place where the suppression acts. A suppression of pulse type noise by a DSP will work even in the very narrow b
A Comment on Antennas for Transatlantic QSO == 2 kilometers is a good wavelength. Then you have the chance somewhere to find some Hams living about a quarter of the wavelength apart from each other.
Hello LF-Friends, the negative result of the recent transatlantic experiment only says that the usual ham methods for LF contacts are not adequate for a transatlantic distance. A weak signal never ex
Hello dear LF Friends, thanks for the many and divergent replies to my post! My Mother celebrated her 90th this weekend, so I didn't have any time to give an answer immediately. Now, let me quickly t
Hello LF-enthusiasts, some of you obviously use the DSP56002EVM. Therefore, let me again mention a simple method to synchronize an LF-receiver to an atomic clock. I do it the following way: The 24576
... <There is another modulation scheme suitable for this band that <does allow constant amplitude, and hence highly efficient class D <amplifiers. That is Continuous Phase Modulation (CPM), of which
If you plan to combine steps 3) and 4) by doing first decimating and then narrow band (sub-Hz) filtering, shouldn't you low pass filter the signal produced by the mixdown at 2) to have a bandwidth l
Hello all, if PSK is done by choosing an appropriate continuous base band impulse form (raised Cosine, Gauss or Sinc) and modulating the phase at constant envelope (CPM), then the spectrum of PSK rap
Hello Alberto, hello all, I thought again and, yes, the high order bit of the phase accumulator is not the squared up version of the sine output, but, after the phase accumulator, a DDS has a sine lo
You have heard of the proverbial sledge hammer to crack a nut, well this suggestion is like using a JCB to crack the same nut, and for what purpose. To exchange a few details like a callsign and rep
Dear all, nearly two years ago we had a discussion about Phased Arrays and Diversity on this reflector. Diversity is a method to choose the temporarily best signal from receivers that are many wavele
Hello all, Thank you for your good humour and patience in answering my dumb questions. It's embarrassing for me to show my ignorance in public, but it's worth it if I learn something useful. The math
Hello and thanks for the replies! As a lecturer, I never present all that can be said, and when posting the idea of a DDS basing on the Chinese Remainder Theorem, I hoped to get response. And it was
