sight unseen

the habit of trusting people

de bill K7WXW

Almost every piece of radio gear I own, outside of hand tools, a DVM and the task light over my bench, is used. I love a good bargain as much as the next ham but that’s not my primary reason for buying other people’s stuff.

I recently purchased a magnetic loop antenna from a ham in Oklahoma, whom I will call Sam. He’s decided to focus on portable operations that don’t involve lugging stuff up and down mountains; the loop is “excess to his needs”. I love being outdoors, have been putting together a backpack-sized kit for portable operating, and enjoy mucking about with antennas. We are a match made in heaven.

We exchanged emails. Sam offered a fair deal and I didn’t haggle with him. Before I dropped the postal money order into the mailbox, I sent an email to confirm his address. He replied, confirming his address and letting me know he had already shipped the antenna. I mailed the money order.

Wait… he’d already shipped the antenna?

Sam and I have not met. We’ve not had a QSO, live approximately 1900 miles apart, and only know each only through our postings to an email list to which we both belong. We are, by conventional measures, strangers. Yet he sent me an antenna without having cash in hand and I did the same thing going the other way. Are we crazy?

Perhaps. I do prefer Paypal to money orders and I checked his QRZ page to be sure that an enterprising con artist wasn’t using an unsuspecting ham’s name and call sign for a scam. That was the extent my diligence, a fact which an younger version of me finds quite remarkable. But our email exchange was so straightforward that the QRZ bio page check just confirmed my gut call: this is a honest guy, I don’t need to to anything else.

Truth is, most of my ham gear buying and selling goes this way.  Sure, I’ve encountered a few cranks, grouches and one or two outright thieves but mostly I deal with people like Sam, honorable folks that follow the golden rule.  And the pleasure of encountering them, even if it is only through email, is one of the benefits that the exam study guide didn’t cover.

And each one still surprises me coming, as I do, from a world which valued besting the other guy above just about everything else. I am fortunate: as a ham, people like Sam happen along often enough to suggest a different kind of world is possible. I am grateful for the reminder.

Thanks Sam. I hope I have a chance to work you on 40 meters sometime.

A Homebrew QRP Radio Station

A Two-Watt Transmitter – 40-Meters and 80-Meters.

The Radio Shack DX-392 Served As The Receiver.

The key is a US Navy Flame-Proof Key.

It may be twenty years since Ernie, KB7HCW, and I were busy building low-power radio stations and seeing what they could do. If Ernie hadn’t passed on we might still be at it.

Ernie served on 11 ships during 22 years in the US Navy. After retiring he earned an Electrical Engineering Degree and a second Class Radio Telephone License. I met him after he’d set up a shop for repairing CB radios. However, I’m not sure he ever fixed a CB. Instead, he and I spent our time playing, seeing how far we could communicate with “flea-power”.

This particular station is built for Morse code – CW. It still has the crystal we used for participating in the Idaho-Montana Section Net. We moved some messages, but we didn’t hurt anyone’s ears doing it.

We had fun fun fun.

 

Ground Bars and Bolts

By Bill

The ground bar is bolted down on the shelf. The grounding straps of tinned copper braid, between the bar and my rig, power supply and tuner, are done and installed. I am holding the last one, which will connect to the case of the filtered AC outlet box, in my hand. The filter is on the floor near the wall outlet, as planned. But it is not going to work. If I follow my original plan, the strap will be a four-foot long invitation to a ground loop. I set it on the floor and look around for my notebook.

Other design choices I made aren’t working out either. I start making a list. For example, to work behind my rig, I have to move the desk. To move the desk I have to get out a quarter-inch socket driver and unhook the copper strap that ties the ground bar to the rod outside. Inevitably I drop the bolt holding the strap and end up crawling under the desk to retrieve it. When I am done, I have to reverse the procedure. I try to skip over the dropping-the-bolt step. It is not, as they say, an optimized process. Or as I say, this is a drag, gotta fix it.

As an engineer, I learned quickly that paper designs failed in unexpected ways in the real world of voltage, screws, panels, and cable. As in what could have possibly been thinking when you designed that? Mostly, the stuff I built fails to work in small ways: screws that hard to reach, transistors pushed a little too close their specs, current requirements not quite met. I am not alone in this, for it is practically impossible to figure out beforehand how exactly the thing we are designing is going to be used until someone actually uses it.

A ground bar. A piece of gear can’t get much simpler than a copper bar with holes drilled in it, a couple of standoffs, and a fistful of 4-20 nuts, lockwashers, and bolts. Bolt the bar to the desk, secure each ground strap with a bolt, lockwasher, and nut. Easy, right? Not so much. The way I designed it, unbolting the main ground to get behind the desk is a giant hassle. The ground strap to the AC line filter is way too long for comfort. And with a single bolt, nut and washer per strap it takes two hands and two tools to work on a connection. This stuff clearly needs to be fixed. Should be easy.

My first inclination is to fix it now! But giving into this inclination almost always turns out, even in the simplest cases, to be a bad idea. Like most people, my first unvarnished solution to a problem is usually (never) my best one. It is rarely even my second or third best one. I don’t automatically trash the first thing that comes to mind, I just make it the first item in a list of possible fixes.

Bench engineers know all about engineering change orders. Even the best product designs don’t get through the design-build-ship cycle without them. ECOs are another version of my lab notebook: what is the problem, what is the fix, what does it affect, how much does it cost? An engineer that has to fill out an ECO form and get it approved by the people who have to live with the change – manufacturing, marketing, testing – is an engineer that has to think through the problem he or she is trying to solve. Whether I was the designer or the design team manager, ECOs were my antidote for the spontaneous fix.

I don’t have a marketing department and I manage all the manufacturing and testing around here. The only person that needs to sign off on what I do is me. If I end up spending a lot of time fixing the damage one of my fixes causes, I am pretty sure I know who screwed up. Since I don’t enjoy fixing my own mistakes, I’ve adopted the spirit if not the form of the engineering change order process.

In my case, I start by looking at my original design. What was I trying to do? I want to be sure I understand my original design goals. Then I make a list of the problems in the current design and I ask myself if any of the problems are a result of the original goals. If they are, and I can’t come up with a fix, I either live with the problem or I change the goal. If I start fixing stuff before this work is done I am pretty sure I am going to have another oh yeah I forgot I needed it do to this! moment sometime soon.

I start listing possible solutions once this work is done. And when the list is done, I set it aside for a bit, and on returning, try to improve the solutions. The list rarely has more than three or four choices; I just don’t have that many good ideas. A little work here and the best answer starts to stand out. Yes, I write all this stuff down. Why? Because I don’t like having the same bad idea more than once. This is my version of the ECO: a detailed lab notebook record of what I am fixing and why, without all the check boxes and signature blocks.

Sometimes I discover that I actually don’t know what to do next. When that happens, I set my list aside and go do the research I need to do. Better not to fix something than to try something, hoping things will turn out okay. Addressing the issues with the ground bar was straight forward but I decided to do a little research anyway. That research validated my ideas. I was good to go.

I worked through my fix list. The bolts are installed from the bottom of the bar with a lock washer and nut on the top side. Now they don’t need to be removed when I have to disconnect a ground strap. The ground that runs outside has a wing nut instead of a nut, so I don’t need a wrench or nut driver to take it off. I mount the AC line filter to the underside of the desk. Now its ground strap is six inches, rather than four feet, long. I can’t do much about disconnecting the outside ground every time I need to get behind the desk. That strap has to be as short as possible and unless I put the desk in the middle of the room, I will continue to need to move it to get to the back side of my gear.

After the fact, the fixes seem pretty simple and might hardly worth all the writing stuff down. Bill, that sure seems like a lot of work for a small problem. Couldn’t you just try something and see how it worked? Perhaps. But experience suggests that simple fixes are simple because they are thought through and thinking it through requires a record of what one is doing and why. Honestly? It took me longer to write about this piece about documenting the design process than it did to actually do it. That isn’t always the case. The chance of getting something wrong in a design goes up as the square (or worse) of the complexity. Building time into the process for making, testing and documenting changes at the front end saves a lot of confusion and frustration later.
I disconnect one of the ground connections to re-route it so it won’t block access to one of the antenna feeds. After I check everything against my wiring diagram, I plug gear into the new AC filter and the filter to the mains before pushing the desk back against the wall. Getting behind the rig is a lot easier than it was two hours ago, which was the goal. And three months from now when I am trying to remember why I did what I did, I have my notes. It works.

Writing It Down

Building a radio station from scratch is involves more planning and work than meets the eye. My friend, Bill, has demonstrated this in the  a series of articles that  follow.

By Bill

 

I need an entrance panel for my antenna feeds. Snaking them through a partially open basement window isn’t working out so well. I look over the ready-made options and decide to design and build my own. What I come up with will work electrically but I have a problem: I have no idea how to bolt it all together.

Figuring that out involves a notebook, one 6×12 inch sheet of aluminum and a pile of lightning suppressors, all of which are on my desk, next to the keyboard. I’ve been doing this for a while; it’s a hard problem. A bigger piece of aluminum would be better but won’t fit in the space I have, the components are oddly shaped and the whole thing has to go together in a way that allows me to easily attach and route cables. Every once in a while, I re-arrange the pile, make a quick sketch and write another note.

The notebook is a product of Mr. Sivak, my junior high school science teacher. To get a passing grade, our notebooks had to formatted in a certain way and include certain stuff: the hypothesis, lab setup, initial conditions, experiment protocol, and results. There was, being high school, a lot of grumbling in the ranks. More writing? More rules? More stuff that I will never use again? Me? My resistance faded when I figured out that keeping records of my experiments enabled me to understand why things worked the way they did.

In science class, the notebook trained me to capture information in a way that made it useful. It also taught me cause-and-effect: I did this and that happened. As a vo-tech student, it cut down on the number of times I made the same mistake.

Later when I was learning electronics on a tube trainer rack made up of a pre-built plug-ins – power supplies, amplifiers, oscillators and such – I used a lab notebook to keep track of my choices. Recording what I did mattered because passing the class involved (a) developing a  design by the deadline and (b) not letting the smoke out of the same type of plug-in twice while doing so.

In the years that followed I filled a lot more notebooks. I stopped doing engineering bench work, but I kept using lab notebooks. Whatever name I used for them, the essential components – initial conditions, hypothesis, setup, protocol and results – that made up my high school lab notebook didn’t change. Whether I was building or managing or monitoring, whether it was a new product or a new company, using this format to guide my decisions simply made whatever I was doing turn out better. The notebooks of my professional career helped me develop, test and, most importantly, assess and tune good solutions to complex problems, which is what I got paid to do.

Today, I am on the eleventh arrangement of the panel. I have solved a couple of problems that I didn’t know I had when I started. I notice that the difference between the tenth and eleventh versions is pretty small, so I probably have a design that meets my goals. But if I build it and find a new problem, the next version can skip past all the designs I have already tried and rejected. The sketching and note taking added about an hour to the process. From past experience, I am certain that hour will save me from having a, “wish I had thought of that before I started drilling” moment, and rework or starting over, later.

I decide to try one more arrangement of the panel. It looks familiar. Reviewing my notes, I see it’s a repeat. But flipping one of the components around solves a spacing problem that’s stumped me until now.

Finished! I make one last sketch. Later I will use some LMR400 coax I have (my worst case scenario) to make sure my cabling assumptions are okay. Finally, I will dimension the components and make a drawing that will serve as the panel’s drilling template.

After measuring each of the components and making the drill template, I make a final parts list so I know what I need from the hardware store. It will take just an hour or two to drill the aluminum and assemble the panel. With all the arranging and sketching, I am confident that my cabling problem is solved, I’ve addressed the lightning and static charge problems, and I have a way to review my design choices if I want to make changes. Not a bad day’s work.

Why should hams bother with lab notebooks? It’s a hobby. Diplomas, promotions and stock certificates do not hang in the balance. An hour writing is an hour not devoted to making contacts. But anyone who has invested days in building an improvised piece of gear that doesn’t work or fit or last knows my answer: I suck at making things up on the fly. Every hour of designing, paper testing and documenting saves me two or four or more hours of rework later. And six months later, when I don’t remember why I made the choices I made – whether it is an antenna setup or homebrew balun or the way I configured my radio – my notebook has me covered.

A Raspberry Pi Adventure

 

The thing on the left is a Raspberry Pi Monitor.  On the right is the Raspberry Pi computer. It’s not very powerful compared to those we are used to these days. Even computing power of a cell phone exceeds the Pi many times over. So why mess with it in this day and age? Because it opens the field for experimentation, new things to learn, new challenges, new things to accomplish.

A few years back I acquired an interest in the Pi and attended a few group-meeting at the University of Texas, Dallas. A software engineer seeking new ideas headed the meetup and I took a lot of knowledge home with me.

Along the right-hand edge of the computer is a double row of small vertical pins. The monitor has a matching plug that mates like a sandwich. I bought the monitor. When I plugged it in and turned it on the display was hard against the right margin. That didn’t hurt anything, but it bugged me.  I wanted it centered. I began experimenting with the placement code and after a dozen times the monitor turned dark.

In my search for the cause I discovered the codec (the black square just below the raspberry symbol) was hot enough to cook my breakfast. Shucks! Disheartened, I stored it in an iPhone box and thought about it for a few years.

Today, I ordered another Pi and a terminal node controller. When everything is assembled and I better understand what I’m doing I’ll start sending amateur radio messages without the Internet, drawing power from a solar panel and eventually joining up with the emergency communications (EMCOMM) and strut my new toy.

I won’t be using my cool monitor. I’m not sure what took the codec out, my coding or something in the monitory bit the dust.

So, the saga begins.

 

Living In the Henry Mountains

I earned my amateur radio license nearly 30 years ago. During that time my primary interest has been the use of Morse code. As a result I’ve read extensively about Samuel Morse, the man credited with the development of this language.

Morse searched for someone who understood the principles do electrical magnetism. And in his quest he located this person, a West Virginia country school teacher, Joseph Henry who went on to become the first president of the Smithsonian. The wisdom Henry shared with Morse made the telegraph system a reality.

By this time all the North American mountain ranges were already named except for a small range up in Southeast Utah, which was named in his honor.

About 20 years ago Barb and I found ourselves within a half-day’s drive of Southeast Utah, so we headed north for a look at the Henry Mountains. ONce there, we discovered the Butler Ruins.

(I apologize for the grainy photo. Evening comes early to the Henry Mountains, and the shadows were already gathering.)

However, a closer look at the “backwards “C” will reveal a cliff house tucked into the back wall.
This photo made the entire trip a success even if the quality is poor. It was taken with 35mm film asa 100. Trying to reproduce it with a Google Tablet hasn’t made it any better.

meatloaf surprise

hbe2bw

part two: the price of not failing

de bill, K7WXW

I make awesome hard boiled eggs. Seriously. People love my hard boiled eggs. I could have a website or a cookbook cover devoted to them. It was not always so. I have ruined uncountable eggs. Under-boiled. Over-boiled. Hard to peel. Mushy. Chalky. Rubbery. Whatever sort of badly made egg you have ever eaten, I promise you I made one (or two or ten) of the same kind. I am the king of bad eggs.

Early on I was taught that failure was the province of losers and fools. My schooling and professional life were grounded in that idea. Badly-made eggs were not tolerated, let alone eaten. Good jobs, promotions and stock options were the province of people that did not make mistakes, at least publicly. So, like many of my peers, I became a guy that had to know how something was going to turn out before I tried to make it happen.

This approach got me the stock options, paid for with a bland, cooking-to-eat world. I seemed to be rewarded in direct proportion to how often I said no. Being a winner was equated with avoiding failure, which is synonymic for not taking chances. It worked, in the sense that I looked like the kid with the cake, but little that I did – designing a new product, cooking a steak, making a new friend – meant much because I was always pretty sure how things would turn out before I started.

Figuring out how to make a reliably good egg – or almost anything else – involves making some bad ones first. You have to try things, take chances. But if you can’t abide failure, you don’t risk bad eggs and you either give up eating them or have someone who makes a good egg make them for you. You do eat and don’t fail but live a bland life.

When mistakes are okay, an untasty egg is a provocation. You bite into one and you think, egg, water, fire. How hard can it be? You give free rein to curiosity and think about why and how and when (does it make a difference that I use an electric stove? how fresh are the eggs? how big?). You might even ponder big questions, like how does Anthony Bourdain do it?

Curiosity, the ability to think about the big picture and the willingness to learn from others is what makes good eggs, elegant designs, and lyrical translations. If all your projects have good outcomes – if you are almost always that kid – it is highly likely your recipes require little or none of these three ingredients. As I learned, stock options or not, it isn’t a very tasty sort of winning.

meatloaf surprise

part one: fulfillment and failure

de bill, K7WXW

The first birthday present I remember is a Betty Crocker cookbook. On the cover, two boys and one girl. The older boy, cake held high, is (of course) being admired by the girl. Her look says, he has done it again! He is triumph. I wanted to be that kid.

I remember cooking only one dish from it: Meatloaf Surprise, a ground beef encased hunk of ketchup-coated velveeta. Knowing my dad, who deeply disliked surprises, I am certain that my mom made a side of pork chops that night. I don’t remember rave reviews but I was quickly hooked on (sorry) the joy of cooking.bettyc_cookbook

I worked in kitchens in high school and college and owned a decent chef knife before furniture. Way before. Turning something (eggs, flour, water) into something else (bread) for people to eat was a big part of my life. A menu didn’t have to be complicated, or have fancy ingredients, or take five hours to prepare, to make me happy. A couple of well-scrambled eggs? Good enough!

Cooking taught me that making, transforming ideas into tangible reality, can be remarkably fulfilling. Cooking, photography, computer design, language translation, home brewing electronic gear; I fell in love with the process of turning ideas into stuff. I decided, what could be more awesome than that?

If the web is your guide, nothing. It is filled with triumphant boys showing off. Translations that sing, barbecue that falls off the bone, antennas that generate world spanning QSOs on five watts. It pictures a world in which stuff works. Amazingly well. On the first try. And if you come to believe this is representative of the process of making, you are going to be miserable.

I do not have one of those websites. Many of my meals are a reason for ordering take out. I have a zillion boring, blurry photographs, a resume with more than one spectacular product failure, and a junkbox of non-working homebrew gear. Stuff that works when I turn it on the first time is rare. Tasteless stew, overexposed photos and hundred foot long dummy loads are not. The truth? To be a maker is to be intimate with failure.

I can’t say that I learned this quickly or with any grace. I did not. For a long time, I let other people’s advertising determine the value of my making. I really wanted to be that kid, the one with the website who always got things right. Unable to abide the mistakes, screw ups, and disasters that are an inevitable part of cooking, designing, writing and so on, I turned it all into work and drudgery. I cooked to eat and made things when I was paid to do so but it certainly wasn’t fun, let alone awesome.

Meatloaf surprise? I don’t think so!

 

Bicycle Mobile Radio

Battery is mounted non the stem.

The HF radio is in the pouch hanging from the handlebar.

The ham stick is behind the seat by the flag.

I’ve been an amateur radio operator for a few years. My goal, back in 1989 when I first earned my license was to put a side-band station on the air that generated a kilowatt carrier. During those subsequent year I’ve tried many of the available digital modes. But none of them, with exception of Packet, caught my interest like that of the old tried and tested Morse code. Eventually, I abandoned my quest for the 1,000 Watt station and went the other way – low power, or QRP.

For a few years I concentrated on mobile radio, not with a car, but with a bicycle, and then a tricycle. I’m not a pioneer of this area, by any stretch. And I probably haven’t done as well as many others have. But I’ve had fun. A lot of fun.

One afternoon while pedaling around some Texas back roads with my five-Watt rig (about the same power required to light a Christmas tree lamp), I checked in with the Maritime Net. The net control was somewhere in Wisconsin, as I recall. I received a fair signal report – a home-run considering the power I was using.

I was preparing to sign when a Musher, a lady who drives sled dogs, broke in from North Dakota, stating she’d like to talk with a person on a bike.

That was my greatest distance with 5 Watts from the eat of a bicycle and a store-bought ham stick antenna.

magnolias and antennas

magnolia_antennas

bending with the wind

de bill, k7WXW

The magnolias, one in the open, the other behind the scotch pines, are a couple of days from full bloom. Like most of the flowering trees around here, they happen in a burst. When they do, Amy harvests a branch or two for flower arrangements but mostly we enjoy them where they are.

This morning, however, there are two buckets of branches in the dining room, and on the porch, a pan piled with not-quite-flowering buds. My phone beeps while we are filling the second bucket: high wind alert. Old news around here. The gusts are sweeping flowers from trees all over the neighborhood and both magnolias will, I think, be bare before noon.

My antenna masts are two scotch pines, a birch, and a cedar. At this moment, the top of the birch is sweeping eight foot arcs, the cedar and pines, three or four. The dipole and end fed are, so far, moving with them. I finish helping Amy and head out to take care of the antennas.

At the base of each tree is an eye hook and a cleat. The pulley lanyard is cleated and the line that runs through it is attached to one end of an antenna. I can take the antennas down (and put them back up) without climbing. My original design included a tensioning spring between the eye hook and the antenna rope. Then I decided I was over-engineering things and didn’t install them. I watch the treetops bend, untie the rope, add four feet of slack and retie it. I move to the cedar and repeat the process. The gusts come and go. In the calm moments, the antennas dip toward the yard, forming deep, graceful curves. I’ve probably dodged losing one or both of them. Good thing I was home.

I spend the morning apparently working, but mostly I am watching the trees. The magnolias are holding up better than I expected. Of course. Trees are built to bend. On the way to more coffee I take the long route, through the yard. The dipole lifts and drops eight or nine feet in the middle. Amy is in the living room, turning blooms and branches into flower arrangements.

My antenna wasn’t built for this. If I hadn’t been around this morning, I’d have a tangle of wire in the middle of the yard rather than an antenna above it.  I am reminded that an antenna on paper is one thing, spanning my house, it is something else entirely.

On my laptop, a dipole is a wire of particular length and height, fed with more wire, and connected to a radio. EZNEC tells me it will have a certain resonant frequency and radiation pattern. A couple of websites help me estimate the cost, and so on. Before I get an antenna into the air, my problems have names like efficiency, loss, and noise. It’s all straight lines and numbers, like this diagram from the ARRL. Later, when 18 gauge wire, three or four insulators and a couple of pulleys are involved, the problems become unrelentingly physical: wind, tangled ropebranches, house-in-the-way. After all this time, I should not be surprised by this but I am.

Pines and magnolias move with the wind. In good years, they weave their branches around one another, grow over the house, drop some buds in a storm. In bad years, not so much growth, maybe some lost branches. They are not impervious to the weather – witness the ragged stump that is the top of one of the antenna-free scotch pines – but their organic responsiveness helps them survive most sudden or severe environmental changes.

Good designers can’t work slow as trees but they can mimic their way of adapting by asking questions. Sometimes obvious, what if something that isn’t part of the system changes? and sometimes not: how to get the feedline away from the gutter? Questions can be in the form of calculating or simulating or breadboarding or just going outside and looking at the trees. Whatever works! The important thing is asking. Don’t get lulled into thinking, there’s never lightning around here or when was the last time the wind really blew?

Good design isn’t organic like a tree growing, it is methodical and pragmatic. But the designer who blends good design practice with the willingness to not-know ends up with a tree-sturdy design: it doesn’t fail whenever the world outside isn’t quite as neatly organized as one’s lab notebook.  Which, by the way, is pretty much always. How do you not-know? Simply questioning everything during the design process is a good start. Your assumptions, the boundary conditions of the problem, your taken-for-granted knowledge? Put it all up for grabs, at least for a little while.

I used to begrudge the time required for this kind of questioning. git ‘er done!  was my motto. The reward for such parsimony was often a tangle of wire, glowing transistors and the like. Or when I made time for questions, I would dismiss the answers, as I did with the springs. Oh, that will never happen!  By now I’ve let plenty smoke out of stuff; I allow lots of not-knowing time.  My “dump the springs” decision suggests that I still need work on the pay-attention-to-the-answers-you-get end of things.

Late afternoon. The wind is a slow steady breeze. I was wrong, the trees aren’t bare. The porch is covered with petals but the magnolia is still mostly flowers. The dipole is drifting up and down a foot or two. I decide to give the wind another hour or two of free rein before taking the slack out and head to the basement to find some springs.