Hi Stefan, wow, almost psychedelic art ... But how can the chnging colours during one WSPR session be explained? Mobile station ;-) 73, Rik ON7YD - OR7T Van: [email protected] [owner
Dear all, I have set up a small website about the 472 kHz band. The goal is: - For newbie's: to provide some basic information about this band, in the hope that this will attact "fresh blood". - For
Hello Marcus, Vinny, all, it was indeed a remarkable evening. When I came in the shack at about 19 UTC the activity was already going on and despite the fact that I had some other things to do (rushi
It's taking an early start today. Just worked DL4YHF. IZ7SLZ and IW4DXW coming in since 17:00 UTC. 73, Rik ON7YD - OR7T Van: [email protected] [[email protected]] na
Dear all, at the next IARU Regon I Interim Meeting (Vienna, 16-17 April 2016) there is a proposal that concerns the 630 m band: It is recommended that beacons will be accepted in the plan of usage of
Hi Stefan, "Now i can continue with real transmissions hmmm, shouldn't you be listening for a possible reply for at least a couple of weeks? Calling CQ and not listen for a reply would be rude ... 73
Dear all, over the past weeks Alan, G3NYK, did write an excellent article on propagation, that is now added to the 472kHz.org website (under technical topics http://www.472khz.org/pages/technical-top
Hello Chris, (1) will give you the EMRP (Effective Monopole Radiated Power) (2) will give you the EIRP (Effective Isotropic Radiated Power) The formula P = 0.0203252(Ed)^2 will give you the ERP (Effe
Dear all, over the past weeks Alan, G3NYK, did write an excellent article on propagation, that is now added to the 472kHz.org website (under technical topics http://www.472khz.org/pages/technical-top
Hello Jim, creating online version of "vertload", "tant", ... is possible, but would require the source code of these programs or a at least good description of the formulas and procedures used. And
Hello Chris, a lazy-L of 9m by 40m should have a radiation resistance (Rrad) of +/- 0.25 Ohm. If you know the antenna current (I) you can calculated the EIRP = G*I^2*Rrad where G = the antenna gain (
Hi Stefan, what about a "fatter" (length/diameter = 1) coil filled with some core stacks in parallel? For a slim coil (large length/diameter ratio) the inductance is more or less proportional to the
Hello Stefan, interesting that the cores seem to be more effective (larger effective µr) for a slim (large l/d) coil. Just a (maybe stupid) thought: could it be that the cores are more effective in t
Hello Luis, one way to change the range without opening meter is to use two 4/1 radio transformers: - first transformer high side to the TX, and low side to one and of the meter - second transformer
Hi Luis, a single transformer, as suggested by Alan, will do the job. 73, Rik ON7YD - OR7T Van: [email protected] <[email protected]> namens VIGILANT Luis Fernández
In case someone is looking for real DX: POSSIBLE RADIO EMISSION FROM URANUS AT 0.5 MHz (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19760008920.pdf). The article is however over 40 years old
Hi Lawrence, I should have mentioned that the article is 40 Earth years old, that is about 0.5 Uranus years. So not sure about the OP being retired by now ;-) Now thinking about that: it would also m
Hi Stefan, that could work. Long time ago I did read an article on magnetic amplifiers from a K7... ham (if I remember well). 73, Rik ON7YD - OR7T ________________________________________ Van: owner-
Hello Stefan, very interesting. The first question that comes to my mind: what is the Q factor of your "electric variometer" ? 73, Rik ON7YD - OR7T ________________________________________ Van: owner
