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2016-06-04

Juma PA1000 harmonic measurements

Update (15 June 2016): the team at Juma have posted their professional measurements here: http://www.jumaradio.com/juma-pa1000/JUMA-PA1000-performance.html Travelling light with a 500W+ station The Juma PA1000 is a remarkably light 1000W solid state amplifier, and offers high levels of gain so that a QRP radio can be used to drive it to full output. You can read […]

2012-12-02

5 Things I Love (and Hate) about Windows Phone 8

Not long ago, after many years using a Apple iPhone I decided to give Windows Phone 8 a go, and bought a Nokia Lumia 920. There are a lot of attractive features in the Nokia (especially the camera) and I guess I was also ready for a change. It’s one of those risky situations when […]

2012-07-25

Palstar HF-Auto

I few months ago I bought a Palstar HF Auto, which is a stepper motor driven ATU with high power handling. Although I don’t run a big amp, I do tune my Tokyo HyPower into some strange loads, and I was attracted by the precision of being able to give the solid state finals an […]

2012-06-15

Wellbrook loop on 160m

I live in the centre of a reasonably busy village, near a sub-station for the electricity board. My main antenna for 160m is an inverted ‘L’ with a fair earth system, but it’s a noisy receiving antenna. With little prospect of getting a beverage deployed, I’ve been looking into the Wellbrook ALS 1530 magnetic loop […]

2011-11-24

Electret microphone element on the Elecraft K3

I recently bought a new set of headphones, to replace my old Heil headset. I met Dave Bottom WI6R of Arlan Communications at Visalia 2011, and he introduced me to his fantastic headsets, a by-product of his motorsport business and repurposed for ham radio. These are wonderful headsets with comfortable gel pads and great build […]

2009-03-06

160m Vacuum Variable Capacitor project

While operating on top band at ZD8UW I had quite a few problems getting the inverted “L” to match at 50 ohms. Even after adjusting the element length this is virtually impossible due to the nature of the antenna. To make a suitable match I’ve now built a capacitive loading unit, using a vacuum variable […]