Scott’s Z80SBC: Z80 single board computer


Dr. Scott M. Baker published a new build:

When I was first getting started with electronics, wanted a Heathkit ET-3400 Microproccessor trainer, but could never afford one at the time. Eventually both I and the world moved on, to fancier more capable computers. However, I’ve still always wished I had an iconic trainer, complete with LED displays and a hexadecimal keypad. So I decided to build something of my own.

Project info at and the GitHub repository here.

Check out the video after the break.

Open source Agilent 53132A 53131A OCXO ultra high stability oven upgrade

agilent_53131A_53132A_Timebase_us_oven (3)-600

Gaurav Singh made an open source 53132A OCXO Ultra stability time base, that is available on github:

While i was working with my own GPSDO project. i need to have a frequency counter with descent stability so purchased my self a Agilent 53132A which is a 12 digit frequency counter, big brother to 53131A 10 Digit Counter. Both are really nice units.
But they unusable standard Timebase. So optional oven oscillator time base need to purchase. but 53132A and 53131A both unit are no longer available for sale and neither of the Time base upgrades.

See the full post on Embedded Engineering blog.



Anfractuosity published a new build:

“Acoustic cryptanalysis is a type of side channel attack that exploits sounds emitted by computers or other devices”

Wavecatcher is a simple PCB that makes use of a MEMS ultrasound microphone, in order to capture audio to around 80kHz, with the goal
of finding interesting ultrasound sources and playing with exfiltrating data from SMPSs etc. via ultrasound.

See the full post on Anfractuosity’s project page and the GitHub repository here.



Stylophone business card project from

Printed Circuit Boards as a business card are a great gimmick. I’d seen ones with USB ports etched into them, which enumerate as a keyboard and then type a person’s name or load up their website. It’s just about possible to build them cheap enough to hand out as a business card, at least if you’re picky about who you give them to.
A couple of years ago I took a stab at making one for myself, but I didn’t want it to be pointless. I wanted it to do something useful! Or at least entertain someone for longer than a few seconds. I can’t remember quite how I got the idea of making a MIDI-stylophone, but the idea was perfect.

More info at

Check out the video after the break.

10MHz distribution amplifier


G4FRE built a 10MHz distribution amplifier:

I have had a need for a distribution amplifier for a while now. Searching around I found the design by G4JNT in Radcom, which filled my needs. I redrew the circuit for 4 outputs and had PCBs made. (if you want one contact me!)  I now have the units in my M1DST 10MHz Thunderbolt monitoring project and in my LPRO101 10MHz Rubidium source.

See the full post on his blog here.

DIY Arduino PCB Pryamiduino


A how-to on designing a DIY Arduino PCB Pryamiduino from Bald Engineer:

Continuing the DIY Arduino tutorial series, this AddOhms episode shows how to create a PCB in KiCad. I make a joke that the original design was a rectangle, which I found boring and pointless. So instead, I designed a triangle to give the board 3 points. Get it? Puns! I am calling it the Pryamiduino. To be honest, I found not having a constraint to be a problem. By forcing a specific board size and shape, many decisions were more manageable.

More details at Bald Engineer’s blog.

Check out the video after the break.

Small motor controller with integrated position sensor


Ben Katz writes:

A while ago I added the hall effect encoder IC I’ve been using directly to the motor controller PCB.  The controller sits directly on the back of the motor (with a magnet added to the motor shaft), and the phase wires solder straight in.  I also have a pair of board-mounted XT30 connectors on the DC bus for easy daisy-chaining.  Otherwise, the board is basically identical to the previous version of this controller.  I’ve now built over a dozen of these, and have had no problems.

See the full post on BuildIts in Progress blog.