Wherein I write about things that interest me….

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

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. Two blogs I got my inspriation from are;Miguel EA4EOZ’s blog;and that of;Tony EI4DIB, so having done some reading, and some rummaging in the junk box to see if I had the requisite parts, I got to work. Read more →

Plotting Antenna Response using a Wobbulator and Return Loss Bridge

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. Read more →

HackRF One + CubicSDR on Ubuntu 15.10

I have been playing with Software Defined Radio for a number of years, but recently advances in high-speed sampling has put relatively high quality, extremely high frequency SDR within reach of everyone. A few years ago Eric Fry reverse-engineered the communications from a Digital TV USB Dongle to see that it transmitted raw samples. A;number of;email threads;followed up this research, and eventually;Osmocom;developed the first RealTek-SDR (rtlsdr) driver that began the low-cost SDR revolution. Read more →

Testing 2m Yagi for Portable Use

Now that the weather is improving, I decided to dust off the /P kit and ensure that all was working will in anticipation of getting some outdoor operation. I had bought a lightweight dual-band beam for this purpose so decided to put it on a pole and see how it performed. I have a number of fibreglass poles of various lengths, but decided to try the longest one, a 10m pole I picked up at the IRTS stand at a rally some time back. Read more →

Adding an Antenna Jack to the Mattel Im-Me

The hugely hackable Girltech Im-Me has been used for many interesting hacks. However the internal antenna leaves a lot to be desired, being basically a little piece of wire. Having the ability to connect antennas for the specific frequency range you are interested in does a lot to improve receive sensitivity and transmit range. Once opened, I removed the little wire antenna which was soldered to the point;highlighted in red;below. I then scraped back some solder mask from the groundplane nearby to which I was going to solder the coax shield,;highlighted in blue. Read more →

Lithium Ion Batteries for the Yaesu FT817

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. Read more →

Asus N56VZ Shutdown Problem with HDD Caddy

I;have had an;ASUS N56VZ;laptop for about 18 months, and rate it as one of the best laptops I have ever had. I was dual-booting Windows 8 and Ubuntu off the 750GB hard drive since I got the laptop until one day I basically destroyed the Ubuntu install while playing with I could have recovered it, but I took this as an opportunity to do an upgrade I had been thinking about for a while - adding an SSD and relegating the hard drive to a caddy which would take the place of the optical drive. Read more →

Proton Mail Open-Sourced

Proton Mail;is a free, web-based encrypted mail service founded by CERN in 2013. It uses client-side encryption, and could be termed a trust no-one mail service, since the data stored on the servers is encrypted, and the user never loses control of the encryption key. Obviously, since the client-side is served rather than being resident on the client computer, this has raised some questions as to the overall trustworthiness of the service, but Proton Mail have addressed this by Open Sourcing the code - under the very permissive MIT license. Read more →

Building the PiDP8i

The story leading up to this can be read;here. In short though, I have always had a thing for retro computers, and DEC boxes in particular, and now I have a remake of a PDP8/I in the form of a kit provided by Oscar Vermeulen another retro computing geek with an excellent site at;Obsolescence Guaranteed. I finally received the kit, and once unboxed and inventoried, I referred to the build instructions on Oscar’s site, and to the PiDP8 Google Group, where other builders documented their experiences and build tips. Read more →

My Quest for Blinkenlights

I;have always been a fan of DEC minicomputers…; I grew up in;Galway, Ireland…;often seen on the front panel of PDPs;instead of the more common;Maynard, Massechusetts, since DEC had a manufacturing plant there until the late 80s.; When in school, DEC provided a VAX 11⁄750 to the 6 or 7 secondary schools in Galway city, and provided terminals to each school. When most kids my age were getting their first computer experiences with;Sinclair Spectrums,;Commodore 64s;and;BBC Micros, we logged into a real multi-user OS,;VMS, via;VT100;and;VT52;terminals. Read more →