How to use Matlab PCBReader objects

Recently I installed a trial version of the new PCB toolbox from Matlab. From Mathworks website: RF PCB Toolbox provides functions and apps for designing, analyzing, and visualizing high-speed and RF multi-layer printed circuit boards (PCBs). You can design components with parameterized or arbitrary geometry, including distributed passive structures such as traces, bends, and vias. […]

RF Proto Board v2.0 — arrived from JLCPCB !

RF prototype boards arrived today from JLCPCB. The service was, as always, very fast and flawless. Seems they have a direct arrangements with Customs because I was not required to pay anything. I ordered 100 pcs for a total amount of 157 euros, apx 1.57 euro per piece. This includes manufacturing and shipment via DHL. […]

How to embed script in wordpress footer

Another “tip of the day”. I ran into this while testing some carousels and swiping banners. All needed the associated js scripts to be loaded lastly after the main page/ post content was already available. It seems that using wp_enqueue_script last argument as true will do the trick: Hope you will find this useful. Cheers […]

Why CSS margins collapse

While working on my new theme for this site I ran into a problem: CSS collapsing margins. Well, from the beginning let me be very clear: this will not be a comprehensive article on this subject. There is already one written by Josh Comeau and is excellent: “The Rules of Margin Collapse“. I urge you […]

Malamute SDR

I have to confess that I fail to comprehend this obsession for cheap chinese devices. Although I understand the “cheap” part of the rationale, what constantly amaze me is the fact that usually people that buy such stuff are not necessarily financially challenged — a fact that could justify such a choice. Let’s be honest: […]

Cold shrink tubes

I discovered this technology rather recently on YouTube and I was instantly hooked by the opportunities. I bet most of you who had to insulate connectors or sections of hardware (like antenna segments, for example) relied heavily either on self vulcanizing tape or on electrical insulation tape. Both had disadvantages but for me the deal […]

Field Day, Tuzla, 2023

The fourth edition of Tuzla Field Day took place this year on 14-17 September, 2023. Some pictures:

ColorFabb elastic filament

Today I received my latest order from Prusa, a TPU filament from ColorFabb along with some bronze inserts for 3D print assembly. Extremely fast shipment by DHL, the package arrived in only one day. Next days I will print some belts for a device that I have and will publish the results and my impressions. […]

Multipurpose RF Proto Board v2.0

This is a general purpose PCB that I designed in KiCad as a helper board for my Manhattan-style mounted RF projects. It allows connection via SMA connector (vertical or edge mount) and BNC. The two completely separated prototyping sections can be interconnected by using the SMAs in the middle or, if you want to save […]

KiCad 7.0 – Footprint does not match copy in library

Another one in KiCad 7.0. I work on a project these days and I face all kind of weird stuff in KiCad 7.0. While running DRC in PCB editor, I ran into a “Footprint [whatever footprint] does not match copy in library [whatever library]” warning: This seems to be related whenever the 3D file is […]

KiCad 7.0 – track has unconnected end

A lot of microscopic tracks that needed to be cleaned up in your KiCad PCB project might end up messing with your DRC report: You just need to select and delete the culprit, then DRC gets cleared: Hope this helps. Greetings !

Motor drivers for antenna rotator

I made some progress on my antenna rotator project and installed the stepper drivers and the Raspberry Pi computer. I bought two drivers from and these should work just fine. They are based on Toshiba TB6560AHQ, PWM Chopper-Type Bipolar Driver IC for Stepping Motor Control. The datasheet can be downloaded from here. My projects […]

Mini N connector – timelapse in Fusion360

I needed this 3D design for a mini N connector that I have in my shack but I was unable to find any 3d file (.STEP etc) online. The connectors are used for my 101dB attenuator project. Enjoy ! Greetings.

Kicad & Autodesk Fusion 360

I published on YouTube a video about how to export ecad files in KiCad and import them in Autodesk Fusion 360 to create nice electromechanical assemblies. Captions in english.

Short Assembly test in Fusion 360: RoLink + Raspberry

A very short clip with assembly test in Autodesk Fusion360: Raspberry Pi and a hat I designed for mobile radio. This type of simulation is extremely useful to pin point issues in mechanical design and assemblies (see at 0:35), that can be avoided early in the manufacturing process. I will create a more detailed tutorial […]

Build SvxLink on Orange Pi — aide-mémoire

This is mostly a memory helper, to remind me some steps in the setup of Svxlink on Orange Pi Load packages sudo apt update sudo apt install g++ cmake make libsigc++-2.0-dev libgsm1-dev libpopt-dev tcl8.5-dev libgcrypt20-dev libspeex-dev libasound2-dev libopus-dev librtlsdr-dev doxygen groff alsa-utils vorbis-tools curl libcurl4-openssl-dev git rtl-sdr libcurl4-openssl-dev Create svxlink user and add to groups […]

Build SvxLink on Raspberry — aide-mémoire

This is not really a post, but mostly a reminder with some information to help me remember the steps. Meanwhile I wrote a much more extensive documentation here, on my wiki (in romanian). And I think I also made a video tutorial but I have to upload it to YouTube. Load packages sudo apt update […]

First steps with Orange Pi

This is rather a reminder, not a real post. This is a collection of links to help me in my quest to control this device.

Tuzla 2020, Field day

I published on my YouTube channel a video about the ham radio Field Day event at Tuzla, Romania, 2020.

Genetic algorithm mutation coded in Python

This example is adapted from Clinton Sheppard’s excellent book “Genetic Algorithms with Python“, a book that I encourage you to buy and read. The very simple example shows how easy is to design in Python a simple mutation algorithm that merges to the optimal solution in 24 iterations. The example below uses romanian language accents […]

KiCad Templates for Orange Pi Zero

KiCad templates for two different hat models for Orange Pi Zero boards can be downloaded from my GitHub repo. Two different KiCad templates can be downloaded in the same GitHub archive: one uncut, 46×48 mm exactly same size as Orange Pi Zero; the other one has some cuts for network and USB connector, to accomodate […]

LTSpice simulation of Baofeng UV5R band selector

I was quite busy the other day trying to understand how Baofeng is using RDA1846 transceiver in their products. While analyzing the schematic it struck me the overcomplicated way they do the switch between UHF and VHF. This is an excerpt of the schematic: The entire selector block is made up with discrete components ! […]

Jabra Evolve 65 repair

A couple of weeks ago during what should have been a routine firmware upgrade, my Jabra Evolve 65 simply died. Have no idea what happened and maybe that will make an interesting future project, but because this headphone is my main headset used for teleconferences and other communication required by my job, I was kind […]

How to start with FPGA

The title of this post might seem a bit too pretentious because it might imply that I am in the position to provide the ultimate recipe on how to train yourself into FPGA. However, it is more like a review on how I did it and some advices based on my limited experience. But this […]

Time Capsule Repair

Some time ago, my old Time Capsule died. It simply did not start. I read that this is an issue that plague all older (first and second generation) TCs. The culprits are four electrolytic capacitors inside the switching power supply, two 1,500 µF, one 1,000 µF and one 470 µF. The 1,500 µF were badly swolen. […]

AD8307 RF Power Meter III — build

This will be another short post. I also made the GitHub repo public, but please be aware, current design is flawed. If you use it, you acknowledge that you use it on your own risk. Today I managed to build the revision 1.0 of this power sensor, not without some lessons learned. It was my […]

AD8307 RF Power Meter II — boards from JLPCB

I ordered the boards for this project with JLCPCB in China. This is my first attempt of working with a professional PCB manufacturer and I am extremely pleased by the results.