Bijeenkomst voortaan op WOENSDAG

Vanaf 19 juni vinden de bijeenkomsten plaats op WOENSDAG vanaf 20:00 uur in Het Volkshuis te Heerlen. Tot die tijd zullen er op maandagavond geen bijeenkomsten plaatsvinden.

Onlangs is Het Volkshuis gewisseld van eigenaar. We zijn bijna twee jaar lang gastvrij ontvangen door Corina en Michael maar helaas hebben zij door omstandigheden hun horeca moeten overdragen. De nieuwe eigenaar, Boeike genaamd, is bijna elke dag geopend maar jammer genoeg niet op de maandag waardoor wij wederom moeten schuiven. In onderling overleg en op basis van de enquête die we een tijd geleden uitstuurden, zullen de bijeenkomsten daarom op woensdagavond plaatsvinden.

Ham Busts The Myth Of Ground

Everyone who deals with electronics knows that grounding is important. Your house has a copper rod in the ground. But [Kristen K6WX] has news: the idea of ground is kind of a myth. She explained at a talk at the recent ARRL National Convention, and if you didn’t make it, you can watch it in the video below.

The problem is analogous to finding something that is standing still. You really can only talk about something standing still relative to something else. Sure, you might be standing still outside a building, but seen from the moon, you and the building are spinning around at about one revolution per day. If you were sitting on the sun and not burning up, you’d see lots of motion of everything, and, of course, the sun itself is moving in the right frame of reference.

 

So what’s ground? Just a common reference between two things. [Kristen] gets into RF grounds, DC grounds, and phasors. If you’ve ever wanted to ground your antenna or deal with RF interference, you’ll find a lot of information in this 45-minute video.

The name ground is, perhaps, unfortunate. You do want earth grounding for lightning protection, but what most of us think of as ground is just a convention. Need a -9V battery? Just reverse your meter leads, and there you go.

Getting a good common reference can be maddening. We’ve looked at way too many ground loops before.