Olfactory Refractory

photo of Texas Ash, Fraxinus Albicans

Texas Ash. Fraxinus albicans. There’s something about this time of year in Austin where night walks are amazing. It’s the smells, the scents, the warm, muggy breezes that carry the quixotic chemistry of life to light up my olfactory bulb, to excite my hippocampus, to carry me calmly into my strolling heaven.

It’s more than the smell of newly cut grass in this central-Austin neighborhood. It’s more than the rosebuds and tiny little chirps of night birds, the exhaust of clothes dryer vents, or fragrant honeysuckle and the weeds in the creek. It’s the Texas Ash. To be walking downwind, where it’s there and then it’s gone. It’s the hunt to get back into the thick of it, to find it again. The sudden awareness of now. Texas ash. There’s something in that flowering scent, a note of latex, a long yawn of the soul, a pungent aphrodisiac. Texas ash.

I swear, if I had land, I would plant a grove of these. When I think of moving away, I only need to smell Texas ash, and I know I’m home. This is as close as you’ll hear me rhapsodize this state, but the region gives some convincing apologies.

Poder Súper

If I found a magic lamp and a genie came out to grant me one wish, I’d wish for the superpower of language. I want to be able to communicate in every human language ever uttered, to be able to teach and convince and sway with the power of my words.

That genie, though, being a pernicious bastard, will certainly grant me my wish. But instead of being a force for diplomacy and change in the world, people would only seek me out so I can give them the translation to “La Bamba”. Then they’ll look up other translations and tell me I’m wrong.

Molto Bene

Really feelin’ it. That demand to get out of here, a taste of escape.

There’s a pair of screens in my office, on the wall directly facing me. One shows a dashboard of down servers. The other screen is hooked up to a Chromecast device, and as a screensaver, it shows an endless stream of pictures of all these amazing places that I would rather be instead of my office.

Some of those pictures catch my attention.

Manarola SP, Italy – Photo by Aaron Choi

Manarola SP, Italy, is a seaside village, on the cliffs between the wine mountains and the Mediterranean Sea, nestled in a river valley. It’s one of five townships along that section of coastline called the Cinque Terre, all mostly isolated fishing and tourism villages, notable for the lack of corporate meddling. Most are accessible only by boat and rail. To me, it looks like heaven.

But it’s not for me. It’s someone else’s heaven right now. Round trip airfare from Austin, Texas to Genoa, Italy in June is $1600. Nothing cheap at all.

My wanderlust doesn’t give a shit about seasonal variations.

Am I going to Italy? No. But damn, I gotta get out. But what would I find?

Fresh air.

QRT

Guys, I’m pretty dumb, apparently, and this radio thing isn’t fun anymore. I like learning, but when it comes to doing, nothing makes sense and it’s all wrong. When it’s time to get on the air, which happens a lot less frequently these days, I keep having difficulties getting my signal out. The same problems pop up again and again.

I know what I’m doing wrong: I’m trying to do things right. Maybe stop overthinking, because when I put too much effort into a project and it doesn’t work, then that’s the biggest demotivater. Slap it together, because that’s all it’s worth. And if I’m not going to use it to actually communicate, then all the tinkering means nothing.

I need a real purpose again. Otherwise I’m going to lose faith, lose joy, and turn it all off.

Heterodyne

I just had some first-hand experience with some very wideband heterodyne mixing in my radio shack. (For those not in the know, a heterodyne is where you mix a signal at one frequency with a signal at another frequency to derive a new pair of frequencies that are mathematically related.)

My 2-meter radio was tuned to 146.940MHz, a local repeater W5KA, squelched down to silence. I was assembling a 10-meter dipole inside my apartment and working on trimming the ends for resonance. As I swept my MFJ-259 antenna analyzer around 28.718MHz, the squelch on my 2-meter radio briefly popped open with some random noise. As I scanned around and centered on that frequency, what I heard was piano music, classical piano music. Huh!

My apartment is line-of-sight with the range of broadcast towers over the river in Westlake, so it’s highly likely that what I was hearing was bleed-over from one of those stations. Sure enough, the local classical music station, KMFA, broadcasts at 89.5MHz on the commercial FM dial. So I was getting some heterodyning.

146.940 – (28.718 * 2) = 89.504

Wowza!

So why that station? Why not the others, which broadcast at higher power? Might be that my 10m dipole had hit a resonant spot and pumped enough of the signal from the analyzer into the nearby J-pole antenna connected to the 2m radio, raising the noise floor enough to open the squelch.

Also, why does the mixing frequency 28.718MHz have to be doubled? Is there a harmonic coming out of the antenna analyzer? Is it a triangle wave instead of a sine? Is KMFA itself sending a harmonic at 118.218MHz? (That’s in the restricted Air Band!) Is it because the 2m J-Pole was perpendicular to the center point of one leg of the 10m dipole? Is that where the doubling comes into play?

Radio is perplexing, and I love these mysteries.

Really, heterodyne mixing is used all the time in almost every radio device. It’s an important tool used to convert one frequency into another; you simply generate a constant modulated signal at one frequency (the “intermediate frequency”, or IF), and then use a variable mixing frequency to generate a heterodyne signal at your desired transmission frequency before sending it to the amplifier for transmission.

It’s all magic. Magic!