A Close Call for #3

Seems that New Orleans came all too close to having a third Mardi Gras float run-over last week.  Article at NOLA-dot-com: Woman Rescued at Tucks Afer She Fell Under Float

Whew.

Ten Physics Effects You Need to Know

No, you won't be tested on this, and you really don't have to understand them all either (as if that's even possible for some of these).  It's just that you ought to be familiar with them, the words around them, and have some general idea that they exist.

The 10 Most Important Physics Effects, in both video and text formats.

Carnival Sunday

Another Sunday-before-Mardi-Gras in New Orleans.  Parade-went until we couldn't go any longer.  I am afraid that the only drink shots in evidence were espresso shots, but those were damn tasty.  Lots of friends and their extended family and their friends in attendance, and the food was outstanding.  A mighty good day.

Not a lot else to write here.  Carnival parades in New Orleans have to be seen live to be believed.

Vertical Off-Center Fed Dipole for 6m

An older post on VOCFDs at KB6NU's blog scampered across my field of view this week, so I had to adapt it for 6 meters.  Six meters is a really cool band: low VHF, can sometimes duct as expected of VHF, can sometimes skip like HF, is on pretty much everyone's HF transceiver, and completely is under-used.  Mostly though I'm interested in it for its local VHF properties: line-of-sight, with some ability to crawl around hills and penetrate piney woods.  Throw in that shiny new 9:1 unun (link, scroll to the bottom) and I'd have everything already in house, all ready to go.

Now a note about that antenna design post... it's largely correct, but some of the math is a shade off.  The ultimate result, X1 = 0.131 * X is correct, but if you want to work it yourself, remember that the feed Z is 450 ohms, not 50.  Also, be sure to do the arcsine calculation in radians, not degrees.  But as I said, the ultimate result for X1 is correct, and of course X2 = X - X1 (referring to the sketch at the above-linked post; but X, X1, & X2 are respectively total length, short end length, long end length), so everything's easy.

I wanted things tuned for the center of the 6m band, namely 52 Hz.  Cranking the formulae and tacking on 3% more for insulated wire gave X1 = 1.2157', and X2 = 8.0643'.  Cut some #20 wire, assemble, hang, measure resonant frequency... and get 39.2 MHz.  Hm, that's pretty far off the 52 MHz target.

A half-hour of cut-and-try and I wrestled it down to SWR = 1.5 across the 6m band, for X1 = 1.04' and X2 = 6.46'.  That's weirdly short, but it does seem to work.  Then I recalled about that LDG unun: it's only rated to 30 MHz.  But what's an extra 20 MHz between friends?  Good enough, hook up the FT-817nd and take it for a spin.  Like I said, it seems to work, with low SWR and some unknown digital somethings received.  Didn't make any contacts, but then I wasn't really expecting to under the current conditions.

Testing will continue.  In the meantime though, it was a nice afternoon to spend playing radio on the back lawn.  Here, have some pictures:

  

L: the slightly suspect unun.  R: FT-817nd in its native environment.
As always, click to embiggen.  These pics really do benefit from increased size.

ps: Looking back on this post from Tuesday's perspective, I really needed a slow goof-off Saturday last weekend, and that's what we got here.  Need another.

Like I need another dust collector.

Still, kind of cool in the "books are magic" way.  Miniature Book Nooks Belong on Every Bookshelf.

Solar Cycle Near Minimum

In fact, we may already be there.  As of last December, the NOAA SWPC is picking April 2020 ±6 months.

Not bad.  Not bad at all.  If you can make contacts on 5w and a compromise antenna under these conditions, it's all looking good from here.

Too Many Beads at Mardi Gras?

Article at NOLA dot com, by way of the Darling Daughter.

It is an interesting conundrum.  On one hand, c'mon, it's Mardi Gras.  It's all about the excess.  OTOH, when it's not fun anymore, when it's just clogging the storm drains.... yeah, it's time to dial it back in favor of quality over quantity.  And face it, even a tenth the quantity is still pretty overwhelming.

Interesting though that this whole business is less than a century old.  Anyway, read the article and find out.