Daily Archives: 2/5/2009

MEPT beacon

VK6DI reported that he was picking up W1BW’s 100mw beacon signal (a distance of over 11,000 miles) today, so propagation was obviously pretty good. Here’s the screengrab that he sent to the Knights mailing list:

moz-screenshot-941

Bruce also sends out a simultaneous WSPR message, and David recorded a simultaneous capture of his WSPR beacon.

Right around 23:30 UTC, I started getting reception reports for my WSPR beacon from both VK6DI and W1BW, both of whom operate online grabbers for the visual portion of the 30m spectrum. It’s only in the last few days that I’ve had reception reports from VK6DI and W1BW, so my beacon was actually configured just to do WSPR. I logged into my computer, hastily reset my computer to send both WSPR and MEPT beacons, and then watched. W1BW picked me up clearly:

grabber

grabber2

But sadly, at this moment, VK6DI has stopped yielding WSPR spots, and I see nothing on his grabber. I seem to have about an hour of time where he’s active, so maybe I’ll be able to get him tomorrow. I’ll leave it in this mode for now.

Dead Reckonings » The Art of Nomography I: Geometric Design

In the days of slide rules, before electronic computers, many engineering problems were solved using nomograms (also known as nomographs). In its simplest form, a nomogram is a kind of graph that shows the relationship between three variables in a very special way: by drawing a line between values for any two variables, you find the value of the third.

In these days of digital computing, the use of nomograms have faded, and they now are mostly of historical interest, but like many things of historical interest, they are of personal interest to me. Hence, I was delighted to find this reference which provides a reasonable introduction, and also a good list of reference books.

Dead Reckonings » The Art of Nomography I: Geometric Design.