DXHeat.com is online

DXHeat Logo App Rounded

Over last 8 month I was digging deep into Web Development. The result went yesterday public – DXHeat.com. Instead of building just “another” Web DX Cluster, I tried to build something innovative with new, unique features. Best is to check it out by yourself!

[Read more...]

My A73A presentation at the Contest Forum

Last weekend I was invited to speak in the Contest Forum at HamRadio convention in Friedrichshafen, Germany. The presentation was about our Contest Activity from northern tip of Qatar. We participated in the Multi/Multi category and used almost exclusively verticals antennas. For everyone who missed the event, here are the slides!

[Read more...]

Flex Control – Interviewing the Developer

Image of FlexRadio FlexcontrolI’m a believer in true knob and button radio interfaces… and I’m not the only one. A small team, formed around Stu, K6TU developed the Contest Knob, which is now today manufactured by FlexRadio Systems under the name FlexControl. In this interview K6TU reveals the ideas behind the Flex-Control and describes in detail the steps from the design to the industrial production. Download the MP3 or subscribe in iTunes to my podcast!

[Read more...]

Building and measuring the 2el 160m Array

Last weekend we spend quite some time to prepare our contest station ED1R for the upcoming CQWW 160m contests. The biggest task was the installation of a 2el parasitic Array of two verticals. During the installation I took the time to document the measurement results. Find them with my (preliminary) conculsion in this blog post.

[Read more...]

W7IUV Beverage Pre-Amp (2N5109)

In preparation of the upcoming CQWW 160m Contests my friend Hannes, DK1NO was so kind to give me one of his W7IUV broadband, high IP3 preamplifier. Thanks, Hannes! Without knowing the exact performance data, I ran a few measurements with my Network Analyzer on the amplifier to determine the Gain and it’s operational fitness. Read on for measurement results and additional notes on how to measure active components.

[Read more...]

2el Vertical Array for 160m

In CQWW 160m we are planning again a serious participation. This time we want to errect a 2el vertical Array for 160m towards the US. In this post you will find some detailes regarding our unique situation and some design thoughts.
[Read more...]

HC2/AL1O qrv from Ecuador

 During my stay in Ecuador I was able to operate two days under my US Callsign as HC2/AL1O. Special thanks to my host Alberto, HC2AQ who offered me his shack. Within two days, 1700 QSOs found their way into the log.

 Read on for pictures, online log & QSL information.

[Read more...]

How to exchange the GU74b / 4CX800 tubes on your Alpha91b (Alpha99) Amplifier

it finally happend…. After a decade of reliable service, my Alpha91b amplifier broke. Most likely on it’s way to Spain one of the tubes broke. During the comissioning at ED1R contest station, fire & smoke shot out of a chimney. The first shock was big, but a few measurements confirmed that just the tubes were broken. In this blog post I will share the knowledge I gained during during debugging, comissioning and breathing new life into the amplifier.

[Read more...]

When antennas come down

During CQWW CW we had a shootout from ED1R with our friends from the Bavarian Contest Club. The group around DQ4W organized a Contest-Expedition to Corsica (TK) to get on the air as TK4W. Considering the available antennas, (two A3S, and three verticals) they generated a great score. For details comparisons between ED1R and TK4W click here.

Ulf, DK5TX created a serious of cool stop motion videos of the antenna work. Unfortunately, including the moment when one of the 17m tall masts came down and damaged the mounted A3S severely.

Fortunately nobody was injured and the A3S still worked, even being a bit deformed.

A73A in CQWW SSB 2011

A73A QSL CardThis year I had to honor to be invited by the Qatar Amateur Radio Society (QARS) to operate the CQ WW SSB contest with them. The station set up in a fieldday style on the northern tip of Qatar, about 100km way from the capital Doha. We are directly located at the beach and used almost exclusively vertical antennas. A73A entered in the category Multi Operator / Multi Transmittors, running 6 Stations in parallel. Keep on reading for some pictures and lessons learned.

[Read more...]