From WWII on, the US government wrote specifications for wrist watches to be worn by pilots and soldiers. Great American companies like Hamilton, Elgin, Waltham, and Benrus made mechanical watches at scale for decades to be supplied to GIs.
The following image is from a military specification for a field watch from the early 60s:
Hamilton and others continue to make mechanical watches that follow this spec, but I don’t have the budget at the moment to buy one of those. So I decided to do a watch mod project aimed at producing a milspec watch.
The Seiko SKX is the watch with the most options in terms of available crystals, hands, bezels, etc. for modding, but at around $200 it’s pricey to get started on. Starting as low as $55, the SNK presents the cheapest way to get a decent mechanical with a fair number of mod options — so that’s where I decided to start.
Since I got this watch a couple years ago, I’ve only grown to appreciate this watch more and more, and one aspect I love in particular is the legibility. This watch is so easy to read in bright light, low light, and anywhere in between. And in the dark, the lume is bright and lasts all night—it’s on the hands, minutes, and hour indices. At 42mm this watch is about as large as I want to wear on my wrist, and it’s very comfortable on a NATO.
This project was about allowing me to turn the bedroom tv on and off via voice control. I already had an Amazon Echo Dot in the bedroom, so I had a way to capture intent. What I needed was a way to turn that intent into an infrared signal that the tv would receive as a power on/off command.
ESP8266/NodeMCU proves to be useful yet again as a cheap, low-power wifi module that can interface to analog devices, such as LED receiver and emitter.
I found this absolutely fantastic project on Github called ESP8266-HTTP-IR-Blaster which provides a ton of useful functionality, such as sending and receiving infrared signals, as well as a handy web interface for viewing codes and showing system info.
Since the software sketch was so full featured, this project would really be more of an exercise with getting the hardware working, and finished into a reasonably durable device.
The first step was to acquire the electronics, and get them working in a breadboard.
The goal of this project was to replace the simple stand-alone MP3 player I used to play a playlist of soothing music in my daughter’s room at bedtime… with a remote controlled MP3 player that could play storybook MP3s as well as the good night music playlist.
I already had a couple of infrared remotes from a strip of LED lights that quit working–I needed a way to receive an IR remote’s commands, and trigger MP3s to play. I also had a small “Class-T” audio amplifier and speakers ready to plug into.
How my uncle Jim Breakall WA3FET used amateur radio to help Puerto Rico after Hurricane Maria:
“Breakall listened and took notes as Vazquez reported the damage to Arecibo, so he could report out to the many scientists the status of the telescope. But he and other ham radio users worked relentlessly to contact family and friends of those at the observatory and in the neighboring communities to report back that their loved ones were okay.
Years ago when I first registered breakall.org, I used the now defunct Microsoft Custom Domains to manage the domain and receive email at email@example.com. This involved creating an MX record for breakall.org pointed to a Microsoft IP address. Later when I decided to build my own email server, I created a new top priority MX record for breakall.org pointed at my own server, but I left the Microsoft MX record as a secondary. Functionally this meant that for the last four years, outlook.com has been a safety net for email that might be lost if it was sent to my email server at a time when my server was down for any reason. Overall, I’ve had pretty good uptime, but there have been a few… incidents along the way that caused it to be down for a while. So I would occasionally check the Microsoft inbox to see if any emails had fallen into the safety net, and there was rarely anything in there.
Another key element to this story is that in the continuous fight against spam, I learned about and enabled greylisting on my primary server. Greylisting works by responding to an initial contact from an external SMTP server with a 451 message: “Recipient address rejected: Greylisting in effect, please come back later”. Normally, the sending SMTP server will just wait about 10 minutes, then try again, at which point, the message will be processed normally. This cuts down on a lot of spam because malicious email servers don’t typically bother to try again. (A side effect is that incoming mail can be delayed while the external server waits to retry.)
In the last month, I’ve been noticing more emails slipping into the Microsoft inbox. I hadn’t had any issues with uptime on my own email server (that I knew of anyway), and I was receiving a normal amount of email in the primary inbox, so I began to investigate.
This spring I constructed a 20/40m fan dipole and hung it up in the my backyard. I cut the lengths of each element according to the standard formula (234 / design frequency = each dipole side length in feet), and left some extra on each side for tuning. SWR was under 2:1 for both 20m and 40m, but there was definitely room to improve. Today I was able to spend some time taking measurements and tuning the antenna.
I used the excellent SWR Plotter program by K9DUR that automatically transmits across a selected band and records the SWR measured by my Flex 5000a radio.
After the initial measurements showed that the 40m element of the fan dipole was tuned too low, I folded back about 6” on either side.