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!

Transit

Ultimately, all technological systems are mediums for human systems. As much as I love computers, networking, radio, etc., I still have to wrestle with the human factor. People are why those things exist. I can study and focus and fixate on the tech, but the tech is completely, irrevocably, in service of human communications. I have to answer to other people.

At the lowest level, closest to the silicon, we all need to be a little bit of Bryce, but even Bryce knows that he has to make deals with the people who ask a lot of him. My job, my hobbies, my relationships ask lots of things of me, and I have to arbitrate expectations and deliverables. I have to be a human.

Please excuse me if I don’t look you in the eye; I’m working through some things and hope to return to humanity soon. Hope you understand.

Coded Language

After a month of banging my head, fist, and eardrums at it, I think I finally know Morse Code. I mean, it’s pretty shaky, but now I have some aural and mental understanding of the shapes and rhythms of each of the 26 letters, 10 numbers, and some punctuation.

A month after I said I was going to learn…I learned. I’m not going to say it was easy, but modern technology and some tried and tested learning techniques made it possible for this old dog to have a foundational knowledge. Seriously, use an app, any app, that teaches you code using the Farnsworth method (fast characters, long spaces) with characters in the Koch order (letters organized so you learn the subtle differences early), and have a practice code key handy.

Like I said, I’m very shaky, and could easily forget half of it in a day. But from what I understand of modern learning methods, if I could just hammer away at it with long enough sessions, and get some good sleep somewhere in the middle, then I can learn and retain it. And practice, practice, practice.

My next step is to start copying code from live conversations. Luckily, there are endless options. I have an app so I can do it anywhere, and there’s always the CW portion of all the ham bands that I could tune through to find conversations to copy. Listen, find the letters, write the letters, read the text later. That’s an operator’s job. When I can copy with good accuracy, I can start banging it out on my own and call CQ for conversations. Baby steps.

This is a milestone. Now that I kinda know the alphabet, I can work on reading words, sentences, and prosigns. The world of DX is waiting on me.

Soon, very soon.

dah-dit-dah-dit dah-dah-dit-dah

Soothsayer

Eventually, we have to start believing our own bullshit if we are going to survive in the world. The soul that’s constantly wracked by self doubt will slowly fall behind and lose its place in the fray. Can’t just stand there gagging on everything coming out of our mouths, gaging each statement for veracity, tenacity, and moral turpitude, or we will spin down into a standstill, paralyzed, paranoid, and lethargic, never really sure that what we think and know is correct enough to join the conversation.

I don’t mean the big picture truths, the major moral questions of our society. I mean the assumptions we have about ourselves, our lives, the things we learn and the truths we deduce and synthesize from smaller fragments; the stuff we talk about over coffee, the bits of chatter in the cubicles, the water cooler talk. We make jokes about know-it-alls, but to some extent, they have it right — they’re sure of things and are unconcerned with being wrong, and when they are corrected, they either learn or they double-down. The happy medium is always somewhere in the middle.

I write this more to myself than to you, but if I can say it with enough conviction, if I can believe it, then maybe you can believe it, too.

Earthbound and Down

Perhaps the most sobering thought is that, after a lifetime of dreaming, I’m still going to die on this planet. That after thinking about galaxies, looking up at the stars, writing about extra-planetary travel, reading books and listening to programs about life out there, and trying to raise myself above whatever provincial concerns that surround me in my own life (wherever I happen to be), that at the end of it all, it is on Terra Prime, a small blue planet orbiting Sol on the mid-western arm of the Milky Way, is where I will spend my last breath.

Somewhere in this black thought is a faint blue line of hope in the spectrograph, but I can barely see it.