homebrew electronics

mcHF: a Next-Generation QRP SDR kit - Part II

Submitted by gerry on Mon, 03/13/2017 - 13:01

Since the last post, I had gotten involved in a Facebook group with a focus on the mcHF transceiver. As well as being a great forum for sharing knowledge and experiences, it gave me the opportunity to get a very nice case in a group buy organised by one of the members. The case is 2-part design, which is easier to work with than the one I bought  previously. It also comes with buttons, a speaker and very nice machined aluminium knobs.

Morse Code Beacon for the Raspberry Pi

Submitted by gerry on Wed, 08/10/2016 - 22:38

Among other great features of the Raspberry Pi is the General Purpose Input Output array (GPIO). This is an array of pins that can be programmed to behave as pretty much any I/O type that can be represented digitally. The pins can be switched on or off to represent binary 1s and 0s and controlled so as to emulate any communication protocol that uses bits (I2C, SPI, RS232 etc. etc.). However, as a first attempt at working with GPIO, I took a recommendation from Steve EI5DD and wrote a program that will key a transceiver and generate morse code.

a small matching unit to use the watson w2000 triband antenna on 70mhz

Submitted by gerry on Tue, 05/17/2016 - 15:34

I recently upgraded my shack to an ICOM IC7300, which in the EU specification includes the 4 meter / 70MHz band. I do not have a vertical for 4m, or space for one right now, but had read about others using a small matching unit to provide the necessary match using the Diamond V2000, or Watson W2000, as my version is badged.

Plotting Antenna Response using a Wobbulator and Return Loss Bridge

Submitted by gerry on Fri, 05/13/2016 - 15:21

At the Mayo Amateur Radio Rally a couple of years ago, a NI ham, Tom Herbison, MI0IOU was selling an interesting kit for the Raspberry Pi. It combined an Analogue Devices Clock Generator (AD9850) and an RF power meter (AD8307) to give a programmable sweep generator & detector... commonly known as a Wobbulator. I bought one and had anenjoyable afternoon not long afterward building it. It was a relatively easy build, and I got some use out of it tuning some Band Pass Filters I had built for use on multi-station portable ops.

Lithium Ion Batteries for the Yaesu FT817

Submitted by gerry on Wed, 12/02/2015 - 15:05

The FT817 from Yaesu is still the most featured portable radio available. The Elecraft KX3 might have better HF performance, but for sheer spectrum coverage, it doesn't come close... unless you spend a few hundred more Euros for the 2W output 2m or 4m transverter. You will definitely have a world class radio, but it still won't do UHF, and would cost something between twice and three times what an FT817 would.

Thrustmaster F22 USB Conversion - Part 2

Submitted by gerry on Fri, 03/13/2015 - 13:46

Having done some more research, it turns out that the chips in the handle are not MCUs, or at least not all MCUs. A few are shift registers, and, according to this post, talk SPI. The post also has a bit of code to capture the buttons.So, despite having the matrix all built, if I can just use a Teensy and build on that code, all the better.

Homebrewing an Off-centre Fed Dipole

Submitted by gerry on Wed, 03/04/2015 - 13:44

During HF field day 2010, I had occasion to get some experience with the off-centre fed dipole, in this case, a commercially made unit from Buckmaster.
Prior to this, I had heard that OCF dipoles ‘are a compromise’, ‘are noisy’, ‘are deaf’, ‘have wildly varying radiation patterns’ and many other negative comments. During field-day, our experiences definitely gave me cause to doubt the nay-sayers.

Thrustmaster F22 USB Conversion

Submitted by gerry on Thu, 02/26/2015 - 13:42

A friend of mine bought me a Thrustmaster F22 for my birthday (thanks John!) a good number of years back, and I had many a fun sortie on DID's excellent EF2000 or F22 sims. It spent much of the last 10 or 12 years gathering dust rather than blowing away bogies, however, and due to the progression of technology, is no longer useful. Or at least this is what I thought, until I came across the controller modding community.