Hi Piotr, Is it possible that Andy is radiating a much stronger ground-wave at that distance. I know the paths should be reciprocal, but if the weaker station ground wave was weaker, swamped in the n
Dear Rik, James,LF group it is going to be long.... sorry... Some time ago Jim, G7NKS began a new topic on this reflector. it was about a link budget for wspr at given distance. Recently, Rik, ON7YD
Roger Lapthorn wrote: If you have a well equipped, sensitive, 500kHz WSPR station in Poland, Sweden, Austria, Czech Republic or at a similar distance from S.England please leave your RX running for t
[email protected] wrote: Hello Lubos, later this evening I will be transmitting wspr,hopefully you get positive decodes, 73 Victor PA3FNY Dear Victor, LF Group despite consistent decodes of a P
Andy Talbot wrote: All designs & ideas for a 1kW+ Class E PA gratefully accepted :-) I do have a 50V 25A PSU, so it 'might' even be feasible. Two big meaty FETs in parallel may cope. There's an
Dear LF group, I know, it is rather outside of a regular LF/MF issues, however i thought it would be interesting to some readers... Recently, i got an info about Tubesat Satellite Kit: http://interor
[email protected] wrote: Hello Stefan, I will sent you the design directly because it is to big a file for blacksheep.It is a design with just 2 fets and 3 transistors. Hi Victor, please, send it
mal hamilton wrote: Observations indicate that data mode acty does not last long, the novelty wares off, whereas the traditional modes CW, SSB and RTTY are still going strong. Some will argue that cw
..... I found in another paper a formula for field strength at VLF. It uses Legendre functions to model propagation in terms of cavity modes, combined with an empirical model of attenuation. Formula
This would be the most straightforward explanation for the high signal strength. The signal expands with 1/r^2 power density and 1/r field strength until it is constrained by the Earth-ionosphere cav
The transmission was on 9.6kHz - some have asked if this was actually legal in Poland - and not on 8.97kHz, although future tests there are expected to be on this frequency. I too was a little surpri
It's a challenge - those Legendre functions with complex parameters... there's an expression involving hypergeometric functions and some code for that in 'Numerical Recipes in C', either that or (ve
Hello "Dreamers" , LF Group, A few weeks ago Paul Nicholson has brought our attention to a nice paper dealing with a EM wave propagating in earth-ionosphere waveguide: http://dspace.mit.edu/bitstream
I'd like to see a plot of signal strength against distance for 70km ionosphere and see how it compares with the simple model in http://abelian.org/vlf/9k Too bad we are stuck with their silly polyno
I'd like to see a plot of signal strength against distance for 70km ionosphere and see how it compares with the simple model in Hello Paul, LF(VLF) Group, sorry for the delay with my answer... i hav
Alan Melia pisze: Hi Piotr, Nice to see your good work again. Do you think it would be possible to present the plot with a logarithmic distance scale. It might also be interesting to try dbuV/m for t
Stefan Schäfer pisze: The link to the IEEE paper is very interesting as well! Maybe the scientists over there are interested to take part on the experiments? Do you know some of them? Maybe we can co
Dear LF Group, Dreamers Recently, after 7th Stefan experiment on VLF band i came back to the numerical programme i have written few months ago which gives us some insight about the e-field strength p
Hello LF, it must be a good propagation tonight on 500 kHz. This evening i have got my *first *positive wspr decodes upon G3XIZ , GM4SLV and EI0CF ( 100mW; 1800 km !!!; my ODX ) transmissions : 2108
