home brewing zulu time
de Bill K7WXW
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.
Skills 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…