What Time Is It?

home brewing zulu time

de Bill K7WXW

IMG_1399

Amateur radio operators are obsessed with time. Maybe, more accurately, knowing what time it is right now. Usually we want this information in two or more ways or in two or more places. We want to join a net that starts at a fixed time, schedule an on-the-air meeting with another ham or see if our signal will get from point a to point b. We are always calculating the time somewhere else or the time difference between here and there.

We address time zones, daylight savings time (a particularly American oddity) and the-number-of-hours-between-here-and-there by using zulu time, also known as universal time. Zulu time is the same everywhere on the planet. There aren’t adjustments for daylight savings time or Nepal’s fifteen minute shift or time zones. Sunday at 4:00z is Sunday at 4:00z for everyone, everywhere. That makes it handy, for example, when scheduling a time to meet someone on the air and it doesn’t matter whether she is zero or six time zones away. Zulu time makes such things a lot simpler.

There’s one issue… I live in local time. To convert zulu to my time, I have a handy chart. Okay, it works but it isn’t handy. I wanted something that required less effort.

Which is why I spent yesterday and today designing a dual display clock. I decided to homebrew one after a web search revealed that my choices for a commercial version were either expensive: four hundred dollars for a LED dual display clock? really? Or fairly expensive and looking like, well, a cheap travel alarm. Seeing my options, I immediately thought, i can do better than that.

Parsimony isn’t always why I choose build over buy though it’s true that spending sixty or seventy dollars is less fun than coming up with a homemade alternative. Being cheap and fun-oriented, I found a kit clock and spent a couple of hours developing a dual display clock that uses two of them: deciphering schematics, figuring out what to modify, writing a list of changes, making a bill of materials, and ordering parts.

Puzzling out how to build something, making it, and then using what I’ve made is addicting. Home brewing almost always involves picking up some new skill, learning how to use a different set of tools or figuring out how to re-purpose other people’s castoffs. It is also a great way to connect with other people and hone practical skills.

IMG_1386Skills like working plexiglass. About a month ago, a neighbor put out a bag full of plexiglass scraps. She thought trash and I thought, project boxes, lots and lots of project boxes. The fact that I hadn’t ever made anything with plexiglass? how hard can it be? An internet search, a few online videos, and a visit to the local plexiglass supply store (did you know there are stores that sell nothing but plexiglass and stuff for making plexiglass things? me either.) and I was cutting and drilling.

The stand I made has a rough edge but the clocks look pretty cool mounted on it. Seeing my mistakes, I looked for a better way to make accurate drilling templates and cleaner cuts. That’s another thing I like about home brewing: when you find ways to make things work better, you can do something about it. If I buy that seventy dollar alarm clock-looking thing, it is what it is. Not so with my home built gear.

The home brewing process is the same whether I am soldering transistors or drilling acrylic. I specify what I want: what is this thing I am building supposed to do? I look to see what I can learn from what others have already done. After that comes design: the why, what, and how. The design products — schematics, drawings, parts lists, and so on —  are the basis for what I do on the bench. The last step is a non-step: when I have everything I think I need, I let it sit for a bit before starting.

That pause is important. Some of the best upgrade ideas happen after the design is finished and before soldering or drilling begin. New concepts float to the surface, along with oh my, that won’t work, will it? insights. I learned this from experience and saw good home brewers verify it; whether they are building a complex receiver or a simple box, they use the pause to catch mistakes and make improvements.

My dual time clock is on the shelf above my rig, doing what it is supposed to do. My investment? Six hours of design and build time, including a run to the hardware store, and about fourteen bucks. Mission accomplished: I filed my chart. I learned how to work plexiglass and a little about making and using drilling templates. Best of all, my new clock doesn’t work quite as well as I would like, which gave me an idea for an arduino based version with an LCD display. I just have to learn C first…

The Coffee Shop

Brad lives alone in a Chicago studio apartment some fourteen blocks from his favorite haunt, Tony’s 105th Street Coffee House. Many folks call it a Starbucks look alike. Brad used to call them on it, reminding them that Tony Sabatto opened here fifty years before Starbucks came along. But no one listens. Its hopeless.

He and Tony discussed a Chicago coffee house many times while in  foxholes during the big war. Of course, Brad considered it a pipe dream. It was something fot Tony to cling to. That was okay. Talking about The Loop and The El seemed to make life a little more bearable. Sometimes he even forgot about his wet socks and K-rations in that cold, muddy foxhole.

Eventually, the war ended and Tony made good on his coffee dream, opening at a 105th Street address on New Year’s Day, 1946. Folks who had stayed on the homefront and dwelt with coffee rationing poured in the door.

Though coffee was free until eleven o’clock, few took, advantage of Tony’s generous offer. Some even paid double.

More than sixty years had passed since that day. Brad’s leg, the one that was wounded in Europe in 1942 is bothering him more these days and his trips to the 105th Street Coffee House are less frequent, reduced to weekly occasions or when he could manage the fare on the El.

This morning, however, Brad awoke with a start. He’d heard Tony call his name. He stared at the dark ceiling trying to separate fact from fiction, but he couldn’t. It seemed too real. The clock indicated it was almost straight up four. Tony would open at five. He must go check on his friend.

Dressing for the frigid Lake Michigan wind, he hurried down the three flights of stairs and flagged a cab. He was rapping on the front door in ten minutes.

“I was trying to send someone to fetch you. He’s on a cot in the back room, Brad,” said Tony’s daughter, pointing and then locking the door behind him.

Tony’s complexion was ashen. His breathing was shallow and rapid. But he managed a faint smile and then moved his lips. Brad leaned in close to listen and grabbed hold of his hand.

“We could have used a cup of this java back there in those foxholes, huh?” whispered Tony.

Before Brad could respond Tony was gone.

That Transmitter Could Have been Mine

From Internet

Not the same transmitter, but close.

Dave, was my father’s age, and a casual friend. We often met at the Braille Cafe for lunch. Dave was a Scotsman. He was forever telling me about the Scottish Clans and “slinging the haggis”. In time, the conversation always turned to radio, rehashing his experiences in the Army Signal Corps during World War II.

While we chatted another mutual friend, Pete, joined us. He, too, was a long-time ham, long enough to recall the government taking away the amateur radio bands during World War Two. And then the two of them urged me to earn my novice license.

The theory is okay, but Morse code is difficult for me,” I complained.

That’s what make Morse unique. It is difficult to learn. It’s not like someone overhearing a telephone conversation. Few understand the exchange.

Between the two of them, I caved. The following evening I dropped by Dave’s radio shack where he made a practice tape, dits and dahs at a very slow speed.

Two weeks later, the three of us gathered at Dave’s dinner table where they administered an ARRL approved test. An hour later, scoring with a passing grade on both theory and code, I was admitted to the ranks as an amateur radio operator. Of course, I enjoyed limited privileges – power output not to exceed 250 Watts, Morse only on portions of the 80-, 40-, 15-, and 10-meter bands. Actually, a very small segment of 10-meter allowed a novice to operate on single sideband. But I didn’t own a transmitter, so 10-meter or no, it made little difference to me.

Do you own a receiver?” asked Dave after we were finished.

Yes, I have a receiver.”

How about a transmitter?”

No, I don’t own a Transmitter.”

He said nothing more, but as I was leaving he followed me to the driveway and then asked me to wait. A few minutes later he reappeared pushing a hand truck bearing a transmitter the size of a foot locker.

This transmitter is from a World War II battleship and in its original condition. You will have to convert the input power over to 117 VAC. It’s still set for military frequencies. You will have to figure out how to make it work on the ham bands. It’s yours, if you want it. You’ll have to take the hand truck too. It’s heavy.

I turned him down. And now, after thirty years have passed, I realize the historical value of the transmitter Dave was offering me.

The realization came after my contact with a retired coast guard radio operator and reading experiences this man shared while he operated a powerful land based radio.

In one instance he received a distress call from a ship that was sinking. After learning his coordinates he put out a call for any ship that could come to the rescue. He found one that could be on the scene in four hours.

How long do we have?” the coast guardsmen asked.

Captain says two hours.”

There was nothing more could be done, so I stayed on frequency with him, chatting and taking personal message to family members and friends. I stayed with him until the radio room was flooded.”

I wondered if that transmitter resembled the one Dave offered me.

The only possible answer was to visit The USS Lexington which is open to the public at Corpus Christi,Texas. The Lexington manager responded to my email, informing me the radio room was not part of the tour.

Philip, the editor of K9YA Telegrah, a Chicago Radio Publication, authorised me to visit the USS Lexington on the Telegraph’s behalf. Their response was positive. They would provide an escort.

Three tall ladders stood between the hanger deck and the radio room. The only thing my escort knew about the radio room was where to find the door key and the light switch.

The room measured about eight by fourteen feet. Though the radios had long since been removed there was a panel in which about one hundred phone Jacks were mounted. Each jack was accompanied by a frequency. My escort couldn’t tell me the purpose, so I still don’t know if each jack provided a specific notch filter for that frequency, or what.

While there I searched for an exit. There was only one way out – the way I had come in. A sobering conclusion.

The radio operator is the last hope for a sinking ship. Is he obligated like the captain? I’m asking.

How I wish I’d taken Dave’s offer.

Toroid Whisperer

learning patience one turn at a time

de bill K7WXW

On the bench in front wire coils of me is a half-empty printed circuit board in a vise, that I am not working on right now, and a just-finished one, which I am. It is supposed to be a QRP antenna tuner, a piece of gear that matches antenna impedance, which can vary, to an unchanging radio impedance. While a careful physical inspection of my work doesn’t reveal any misplaced parts, solder bridges or other assembly calamities, the tuner isn’t tuning. It is doing nothing other than being about as passive as any grouping of passive components I’ve ever worked with. Signal in, nothing out.

I have a suspect or two. This kit involves winding and installing toroid inductors, something I’ve never done before. The instructions are straightforward but the details are daunting: counting turns of wire around a tiny ferrite donut, with taps along the way and making three sets of overlapping windings. I find it easy to miscount turns or put a tap in the wrong place and getting the enamel insulation off the 24 AWG wire so the coil can be soldered into the board at five points is a real challenge.

Unlike most components — capacitors, transistors, switches, lights — that a kit builder buys in ready-to-use form, inductors usually arrive as a ferrite core of some sort and a bundle of wire. The sight strikes fear into the heart of a new builder: winding inductors has such a longstanding reputation for being difficult that there are folks who get paid to make them for hams that don’t want to make their own. I am not one of those hams. So far.

Since getting my license, I’ve built half a dozen small kits like this antenna tuner. When I figured out that I wanted to explore home brewing, it seemed better to start with gear that someone else had already designed and which works if built as instructed. Kits provide a gentle introduction (or in my case re-introduction) to schematic reading, soldering, electronic components identification and all the other things that make up the how of building electronic gear. Kits were a good entry point for me; though I’ve had to do rework on every project, I’ve not had an unfixable failure. Yet.

This time, though, I am stumped. After trying and failing way more than once to correctly wind and install the two inductors in this kit, I am starting to think it’s time to call a toroid whisperer. I didn’t account for left vs right handed winding consistently, so some of the wire ends finished on the wrong side of the coil. I miscounted (twice) the number of turns to a tap. I wound one of them correctly (I think) but didn’t get all the enamel insulation off two of the wires, which I figured out after I had soldered three others in place. I am not sure what other variety of mistake is possible but it seems likely I will discover them all before I get this thing to work.

Toroid winding is a lesson in accuracy, patience and letting go. Especially letting go. When I find it hard to admit that I’ve made a mistake — like I did while winding these inductors — I end up investing a lot of time and energy making less-than-well-thought-out repairs. Let me spare the new toroid winder some pain: trying to fix a badly wound toroid is always a mistake. Even if you manage to move the tap into the right position or whatever — which is hardly ever possible – the end result inevitably has some other kink or nick that will haunt you later in a much harder to find way. The only thing than a not-working toroid is one that sorta works. So… lesson one is admitting when I’ve bungled something, stepping back from it, and almost always, starting over from step one.

Winding toroids also teaches that accuracy is paired with patience. Twenty-two turns is not twenty-three or twenty-one-and-one-half. Ending up inside the toroid is not the same as outside. When you make an inductor, if you get it wrong, the circuit doesn’t work as it should or doesn’t work at all. And the only way to get it right is to work slowly, methodically, and patiently. It is difficult to count turns or get wire to lie flat if you are in a rush and easy if you aren’t. A well-made toroid inductor is a physical manifestation of accuracy borne of patience: it has the right number of turns going the right distance around the donut with the right spacing. It looks like it was done by somebody who cares about doing things right as surely as one that doesn’t says the opposite.

The inductor sitting in front of me, which I have clipped off of the printed circuit board, does not have this look. I can see where I rushed the winding: it isn’t evenly spaced and doesn’t lay flat against the toroid. Under a magnifier I can also see where I left enamel on two of the leads, which means they weren’t making good contact in the circuit and at least two spots where I kinked the wire trying to correct the winding direction.

After clearing the printed circuit board through holes of the wire bits and solder left when I removed the inductors, I set it aside and start clipping the wire from around the each toroid. I will work on them during tomorrow’s bench session, after I read the instructions again, study the drawings and track down a fresh roll of wire. I will set aside an hour for each, rather than fifteen minutes, and check all the connection points with a meter before I solder either of them onto the board. I figured out a way to check the windings for direction and count: make a photo of the finished inductor, print an enlarged copy, and tick off the windings with a pen.

I imagine that this approach will greatly improve the chances of my antenna tuner tuning. Maybe I won’t need the whisperer after all.

Raspberry Pi Adventure (revisited)

MY Terminal Node Controller kit – PI-TNC – arrived last week. I don’t know how soon I’ll start assembling it. It’s will be the grand to our present day email. It’s wireless and very much slower. Due to bandwidth restrictions policed by the FCC our baud rate will be 1200 rather than tens of thousands. I’ve lost track. Next week I’ll publish a packet of an Arizona packet adventure that occurred in the 1990s. Pure hands-on fun.

Careful where you trod.

Same Train, Different Track

We walk by them

Those buried in the graveyard

Remember them

Those buried in the graveyard

Where are they now

Those buried in the graveyard

Are they at peace

Those buried in the graveyard

Who are they

Those buried in unmarked graves in the graveyard

Are they remembered?

Should we not kneel and bow our head

For those buried in the graveyard

Will they ever know we visited

Those buried in the graveyard

May they continue to rest in peace

Those buried in the graveyard.

(c) Chris Black 2017.DSCF0957

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Post Number 997

This post makes number 997. Where have all the ideas come from? It boggles my mind because this isn’t the only place I leave words in my wake. For several years I’ve published radio related stories and articles with the K9YA Telegraph, a Chicago e-zing.  Just last month I finished a 22 chapter story called Rose. Before that it was Red Barger’s Story. I think it ran 17 chapters. In 2013 I accepted the National Novel Writing Month challenge, hammering out 50,257 words during the 30 days of November. (My fingers still haven’t gotten over that.)  During the 1990s it was a monthly column for a bicycle magazine for seven years, I think. I can’t recall any further back – this has been going on steady by jerks since 1964.

In

 

It’s In the Details

During a three-way email discussion this week we reviewed a World War II movie where Morse code was sent on the sly by a tap dancer while the Tommy Dorsey Band played in the background. Our discussion was not so much about the move, but what language was used to send the secret message. It was tough copy, whatever it was.

I finally decided the message was sent via American Morse and by means of the old Sounder. In this manner one doesn’t copy the length of the tone. Instead, one copies the length of time the electromagnet is engaged – the time span between the click and the clack.

It was still difficult, but I was able to copy along with the person who was printing the characters. The movie reviewers thought he was writing it ahead. I found they were wrong, especially when she stamped her heel and then hesitated before continuing signifying a “T” in the word BOAT. In American Morse the T is three times longer than in International Morse.

 

Multitasking

I’ve often heard references to multitasking, and that it’s a common belief that women are more skilled at it than men. I suppose child rearing makes multitasking a necessity. But in all this discussion I don’t recall any reference to the animals with whom we share this planet – our pets, for instance.

Yesterday, while my dog, Mr. Black, and I were engaged in our morning constitutional he paused in a grassy area to relieve himself. Midway through his “job” a neighborhood cat appeared. The dog’s ears moved, nothing more. The two are well acquainted, and the intruder read more into the ear movement than did I. Quite sure of himself, he settled into a comfortable cat-posture to waiting mode.

When the task was complete Mr. Black hit the end of his leash like a cannonball, but not before the cat had vanished into a nearby hedge.
Mr. Black is a male. Therefore, his multitasking skills may be lacking. Had he been a Ms. Black would the confrontation ended differently?