Category: Blog

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. …

Fresh breath of air for this website

Greetings ! I completely neglected this website for a considerable amount of time. Simply I didn’t have either time or desire to write anything here. With this coming spring in 2023, with all this war and madness around us, I dug out my older passions, let them see the light again, made more time for …

Tuzla 2020, Field day

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

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 …

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

My first finished KiCad project is a prototype of a RF Power meter with input attenuation built around an Analog Device AD8307. An excellent tutorial about log amps can be read in March 1999 edition of Analog Dialogue. KiCad PCB: And the 3D rendering of the same PCB: The next step will be PCB ordering, …

How to install Python 3.7 on Raspberry Pi

This short guide explains how to install Python version 3.7.0 on a Raspberry Pi running Raspbian. First, get rid of old versions: Ensure system is up to date: Install the dependencies needed for building the distribution: build-essential tk-dev libncurses5-dev libncursesw5-dev libreadline6-dev libdb5.3-dev libgdbm-dev libsqlite3-dev libssl-dev libbz2-dev libexpat1-dev liblzma-dev zlib1g-dev libffi-dev Get the python src distribution: …