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 […]
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 ! […]
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 […]
Some RF power masurements done with my Rigol DS 815TG of my Kenwood THD74.
I am not a huge fan of KiCad. However, given the limited and abysmal options that we have for free EDA packages, KiCad is quite ok, although terribly flawed in some areas. Maybe the development team should focus on some simple functionalities like support for rounded traces, net group routing, zones, a simple way to […]
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 […]
One of the biggest issues that I have, in general, while learning different stuff is lack of properly-explained abbreviations. I am starting today a compilation of Altera/ Intel Quartus list of filenames and abbreviations. Source: Intel/ Altera Glossary .qws – Quartus Workspace File. The Quartus® Workspace File (.qws) is a non-editable file that stores user […]
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. […]
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 […]
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.
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, […]
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: […]
One very interesting feature of Altera FPGAs is that almost any system can be created in its next-generation system integration tool Qsys using a standard library of reusable IP blocks. The system interconnect fabric is automatically generated by Qsys and binds the blocks together. The system interconnect manages dynamic bus with matching, interrupt priorities, arbitration […]
This week was quite busy to complete my assignments for the FPGA Course. I was running out of time because I did not estimate properly my available free time and things got crowded at the office, at this end of week. With a lot to do there, I barely found any time to focus on […]
I’ve been quite busy lately and neglected the blog. I enrolled on Coursera for a very interesting FPGA course, in what seems to be a FPGA specialization from University of Colorado Boulder. I have always had somewhat a reserved attitude towards FPGAs mainly because I believed that these are hard to understand and need a […]
Encouraged by the latest developments, today I started building a new application that will allow remote connection to Kenwood TH-D74, remote control and APRS data transfer. However, while building and running the app I got the following error: If you encounter this, be aware that it is generated by application sandboxing. You can think of using […]
Struggling to understand how Universal Unique IDs work (see here) I was wrongly assuming that Core Bluetooth is a framework from Apple that covers all aspects of communication with devices via BT. I was WRONG ! scanForPeripheralsWithServices method and, in general, what I tried to do, for almost a week, is NOT good for my intended […]
I did some more steps towards accessing Kenwood TH-D74’s services via bluetooth. I struggled for some time understanding how discovery based on UUIDs work. I was not aware that, for each service profile, there is a standard Universally Unique Identifier (UUID) documented in Bluetooth SIG specs. Specifically for Serial Port Profile (SPP) service, the UUID […]
Several days ago I received a Kenwood TH D74 portable transceiver. Although I have a Yaesu FT60 and some other smaller and unimportant transceivers, I don’t have any transceiver that is APRS capable. What’s more important, this transceiver is BT and USB capable, providing serial communication, which opens some interesting opportunities. Today I opened XCode […]
We first met — I think — in the summer of 2015 during the Hamfest in Friedrichshafen. At that time I had a mobile Kenwood transceiver TM-D710 which was quite nice by its own. However, after several months using the TM-D710 I got increasingly annoyed by some of its shortcomings, most of them purely subjective (but I […]
Over the past seven years (the age of this blog) I started writing several articles that I never finished. It’s time to trash them completely or just add them to a list for future afterthoughts. Who knows ? So, from older to newer: “Weller WD 1000 M Review – Part III – Software”, January 18, 2013 — […]
This is a beacon project started by my friend YO5VAE. He faced some issues while programming of the Si4463-based module and I thought I might give a hand. I resoldered the entire project on an empty Arduino shield to allow expansion of the project with some additional modules. Below are some pics, but probably the […]
I twenty dollars for this superb cassette deck. The playback and recording heads were in excellent shape and I used this deck for some years, playing and recording on NOS (new old stock) tapes, mostly chrome type II and metal – type IV, that I purchased on eBay. However, one day the entire head block […]
There is nothing better than marrying several hobbies and have fun from it. I have had the intention to be part of this expedition at least since I heard about this contest for the first time. My good friends from Năsăud planned this thoroughly. All our equipment was carried by three 4×4, manned by a […]
I ordered some ferrite beads for a RF circulator project I currently work on but these might also be very handy for the SWR bridge project. These are extremely efficient for RF supression, or at least this is what they say.
For low frequency projects, a fast way to prototype is using a bare PCB and scratch some dividers that allow “manhattan” style prototyping. I am especially very fond of this prototyping technique and I believe that PCB design should be avoided in the early stages of prototyping. Jim Williams was an artist in such designs. […]
A couple of months passed since I purchased two 10 MHz OCXO modules from eBay. And, to my shame, I didn’t even tried these. Yesterday I did a quick test and the devices are spot on. Both measured on my TTi TF930 3GHz frequency counter: The OCXO needs apx 10 minutes for proper warm up […]
The international amateur radio exhibition is the platform for ham enthusiasts from all over the world.
Power supply: DC 9v – 12v Antenna: 50 ohms, is not balanced, 7MHZ band, standing wave ratio below 1.8 Receive the static current: 10 mA @ 9 v Transmission power: 0.8W @ 9 v, 1.2W @ 12 v Frequency range: 7.023 MHz launch, receive 7.023-7.026 MHz (7.023 MHz crystals) Stray (harmonic) inhibition: – 20 db […]
I am pretty pleased by the outcome of my commercial endeavours on eBay. Purchasing seems to be a pleasure; until now — with just one exception — I was spared from any nasty experiences. After several small items that I ordered in part for my curiosity to evaluate speed and quality of shipments from chinese suppliers, I […]
