Author Archives: Jan

Si5351 VFO

By | January 3, 2019

Here is an older project of mine – another variant of a VFO. This time with the popular Si5351 clock generator, allowing to create a complete solution for a superhet, including both the VFO and BFO oscillators.

VFD hacking (again)

By | October 24, 2018

Three years ago I have posted an article about reverse engineering a large surplus VFD module that had no documentation available. Well, it is time to do some more hacking! I have attended the HAM radio meetup at La Louvière, Belgium this year again. Lot of people, lots of all kinds of gear there but… Read More »

Termination Insensitive Amplifier (TIA)

By | November 5, 2017

I have needed some RF/IF amplifiers for my receiver, so I have decided to use the design by Wes Hayward, W7ZOI, and Bob Kopski, K3NHI, originally published in 1999. This amplifier has two main advantages – it has a wide bandwidth ant it lacks any tuned circuits, so it is easy to use in a multiband… Read More »

DigiTIA receiver

By | March 27, 2017

The guys at the Solder Smoke podcast have inspired me to do a bit more solder melting and this is the result – a CW/SSB HF receiver for 40m band. It is a bit “al fresco”, with no case, built on a piece of copper clad with modules stuck down using a double sided tape. The rig… Read More »


By | March 22, 2016

It has been some time since I have posted the article on building a simple VFO/signal generator using the AD9850 module and a microcontroller, originally based on the work Richard, AD7C. I have received quite a bit of feedback from several people, along with a few requests for improvements to make the hardware more suitable… Read More »

VFD hacking – VFD 240W.401

By | March 28, 2015

The recent video by David L. Jones from the EEVBlog on VFDs has inspired me to look in my junk box – I knew I had an old VFD in there. By old I mean really old – I have bought it around 1999-2000 in Munich from an electronics surplus store, along with a few… Read More »

AD9850 VFO/signal generator

By | February 22, 2015

22.3.2016 UPDATE – if you are looking to build a radio VFO, there is a newer version of this code available, with more radio-oriented features. I have started to play with amateur radio again and wanted to have a decent VFO/signal generator that could cover most of HF without complicated part switching required. So I… Read More »

How some vendors ship chips

By | January 10, 2015

This is what I have just received from AliExpress – pair of SSD1963 display drivers. Packaged in a cut-off piece of the plastic tray and wrapped – in a plastic foil! I understand that an anti-static bag is more expensive, but this is ridiculous. I do wonder how many returns because of ESD damage does… Read More »

libndofdev-0.4 and move to GitHub

By | April 9, 2014

A new release of libndofdev is out. The only new functionality is the support for the 3Dconnexion SpaceBall 5000 device that is widely available on eBay and increased number of buttons (SpaceBall has 12 buttons!). I have moved the repository for this library to GitHub for easier maintenance: