It would be a poor sort of geek indeed...

... who failed to mention Leonard Nimoy's passing on his blog, even though you've probably heard the news hours ago.  Here's a link to an article at the BBC. Consider the occasion mentioned.

I'm going to go bounce EM waves off the ionosphere now.

Your Daily Dose of Surreal

Sixty-ish middleschoolers playing a Led Zeppelin medley... on xylophones.

You're welcome.

When Hobbies Collide

ps, 11/21: here's a link to a much-improved version of the antenna described below.

Two years ago I rode in the Tour of Southern Rural Vistas (TOSRV), a two-day bike tour from somewhere just north of Tallahassee FL to Albany Ga.  Had a great time, you can read all about it here in a previous blog post.  One of the cool things about the whole production was that a local ham radio club, the Tallahassee Amateur Radio Society (TARS), provided support communications all along the route.  In these days of cell phones, perhaps this is not as completely crucial as it used to be, but there are still many backwoods spots with little-to-no cell coverage and besides, but it's not about doing things the easiest way, it's about doing things the fun way.  It's a good excuse for these hams to get out in the fresh air and use their portable VHF/UHF capabilities.  After all, if the sole objective was to simply get from Tallahassee to Albany with the least amount of trouble, why bother with a bicycle when I've got a perfectly good car?

OK, so I kept looking at these hams having a good time in the sun at every rest stop, and I couldn't help but thinking that, while I was having fun on the bike, I could be having fun on the radio at the same time.  With this in mind, I started gearing up to do both in at TOSRV-14 when *screech* the event was canceled.  Damn.  Well, I was busy with The Shop in the same time frame anyway.  So the project was sidelined until this winter.  Finally wrapped things up this weekend, as you can see:

Here's a close-up.  

Saddlebag, as well as any other gear can still be attached to the rack.  Perfect for touring.

The radio's just sitting on the rack, you don't actually ride with it like that.  Sooner or later I'll have to rig something where it can clip on the handlebars (there's more than enough coax to reach) but for last Saturday's test I just stuffed it in a jersey pocket for the ride to the Bay Bridge.

The view from the top is spectacular, either in the visible or VHF spectrum.

The 85' crest gives a 13 mile radio line-of-sight radio horizon, making it easy to hit both the Biloxi and Slidell repeaters, each 25 miles away, which have antennas at 300' and 1000' respectively.  On a mere 5 Watts, I easily made contacts through each repeater and received fine signal reports.

Construction Notes
This is pretty easy.  I started with WX2NJ's Jurassic Duck 2 meter VHF antenna design.  It's essentially a J-pole stuffed up a piece of CPVC pipe.  The big innovation was that all of the lengths were adjusted for the change in c due to the CPVC's properties.  To add a few notes: 
(1) Cut the radiator wire about 12" longer than specified in the plans, then trim to adjust the SWR.  I cut and hoped, but ended up soldering on an additional 8" of wire to get things right.  
(2) Get a rack with pannier side struts.  This makes it easy to zip-tie things on, far easier than that the weird shower fixture in the original plans.  Stronger too.
(3) Leave the PVC pipe a bit long, so that the matching stub inside it is positioned well above the rack.  Otherwise the stub can interact with the rack's metal, leading to unknown but probably bad performance.  Extra antenna height is always a good thing anyway.
(4) 300 Ohm twin-lead is a pain to work with, but about the only material that's right for the job.  Get the real twin-lead type, not the encased jacket type, which is nearly impossible to work with.  Take your time, be ready for several tries.  Trim out the solder points for the coax on the stub before you cut the whole thing to length off of the roll of twin-lead.  That way, you can whack off unsuccessful tries as they happen and only lose a few inches of twin-lead each time.
(5) Punch a little hole through the twin-lead near the top and hang it inside the pipe with a short length of string.  That'll keep it from sliding down and bunching up.
(6) You can leave the bottom end open, but a quick wrap of electrical tape will finish it nicely and discourage bugs from crawling up in the thing.

Well, as I mentioned earlier, it works and works well.  In fact, I've made a second on to go on a backpack as a hiking antenna.  Back to bikes, TOSRV may be gone but there'll be other ham-supported bike events in the future.  In the meantime, it's always good to have around for hurricane season, and good for occasional fun during less-serious times.  Finally, to allay the fears of fellow cyclists who are not so technically inclined:

it detaches and re-attaches as needed in less than a minute.

One more note: Thanks to Jeff KK4SNA for pointing out the original Jurassic Duck antenna plans on the web, and to Gary N5AHM for help analyzing and sorting out this antenna's fine tuning.

ps: adding "CX" to this post to make it show up better in searches.

Tips for 80 meters

I've had this 40/80 meter trap dipole for a couple of years:

Shown coiled-up for shipping.  In use those four loops are uncoiled and straightened out.

Works great, especially on 40 meters, with an SWR < 1.5 across the entire band.  The big advantage is that it can also work on part of the 80 meter band while remaining yard-sized.  A full-on 80m antenna is about 135 feet long, but by using some LC resonant voudou (that would be those funky PVC-core coils in the above picture) this thing is a good 50 feet shorter.  Back to the qualifying phrase "can also work on a part of the band," the downside to this contraption is that it only works on about a fifth of the 80m band, maybe a third of the band when persuaded by my transceiver's little 3:1 tuner.  The sensible thing to do in this case is to set it and forget it in the sub-band you mostly want to work, which I've done up in the General-class phone end of things, 3.8-4.0 MHz.  That's where the action is.

But I occasionally want to use PSK31 on 80m too, and that's centered down on 3.580 MHz.  I could go through an hours' exercise in adjusting the outer ends each time I want to change sub-bands, or just:

clip on an extra length of wire to each end of the dipole to lower the resonant frequency.  In practice, it came out to about 12" for these tip wires, but if you're tuning from scratch start with about 20" and trim it down a couple of inches at a time.  The black clip on the left attaches to the end of the antenna; the red clip on the right holds things stretched out with paracord and a little ceramic insulator.  Once everything's tuned up, it takes about 2 minutes to step into the back yard and attach/detach the tips to switch sub-bands.  It even pulls in the bottom-end of the Extra-class phone band, a nice bonus.

It took an hour or so to trim everything just right, but it's worth it to get PSK31 coverage on 80m.  Because PSK31:

It's kind of like The Matrix, only much, much nerdier.

Back in the Saddle Again

Man it was great, 18 sloooow miles today.  But they were miles!  And now I can breathe!  Still, probably didn't have as much fun as these guys:
Ah hell, blogger.com is being all stupid and won't let me insert the video.  Here's the link, do the clicky yourself and embiggen.  The musical mash-up is almost as good as the biking.

Anyway, it's good to be back on two wheels, even if it is on the road.

Good news on the collarbone.

In a nutshell, it's healing, I can do everything now except for contact sports, and those will have to wait about another month.  Road biking, workouts, everything else, check.  Mountain biking... better give it a month.  Man oh man, can't wait to hit the – no re-phrase that – ride the seawall this weekend.

Here's a happy video of people riding their CX bikes somewhere up north of I-10.  Blow it up to full screen size and crank up the volume, the music is impressive.

Yeah, that's about how good I feel!  Without all the snow, of course.

A History of Chillin' Out

Over at the BBC.  Yes, they do mention home-town inventor John Gorrie.