I was curious if the performance of our 4O3A high power Bandpass filters could be improved with additional coax stubs in parallel. We were operating at ED1R for some time now with the added stubs, and we are pleased with the results. Check out the details!
How to rapidly deploy & remove antenna radials
At our contest station ED1R we have no space for permanent Lowband Verticals. Each Contest, the verticals have to be installed temporarily in a field nearly. Especially the deployment and removal of the antenna radials is very time consuming. Over time we optimized our system which reduced the required time from 2 hours down to 30 minutes.
Can I still use oxidized coax cable?
This question bugged me after trying to exchange the connectors of a 25m long Aircell7 coax cable. During preparation I discovered a black inner conductor. I seems water entered the cable. Do I have to throw it away? Read more to discover a probably unexpected answer!
4O3A Triplexor
Until today, I’m fascinated what can be achieved with good filters. At our Contest Station ED1R we bought a Triplexor (10m/15m/20m) in order to be able to use our new Optibeam OB11-3 on the three bands simultaneously.
Double Half Delta Loop (DHDL) Low Band Receiving Antenna
A few days ago I had the time to build and try a Double Half Delta Loop (DHDL) at our Contest Station ED1R. The Antenna was built within 3 hours and can be deployed / errected within 20 minutes.
New Stackmatches for ED1R
One of last years projects was the improvement of our Contest Station ED1R. For the various Yagis we needed smart ways to combine antennas. Instead of buying commercial stackmatches (antenna combiners) I decided to build them up buy myself and adjust them to our needs.
SDR – where are we today?
At the second HamRadioWeb convention in Bolognia, Italy Claudio, I4LEC has given a great presentation about the current status of SDR. In his presentation he starts with SDR principals then analyzes then the strength and weaknesses of available Software Defined Radios (mainly FlexRadio Products) and finishes with a comparison against TS-590 and Elecraft K3. The presentation is entertaining and informative at the same time. Definitely worth having a look at!
Claudio was so generous the grant the permission to show it on my website!
Evolution of the DG8SAQ VNWA
With his low cost, high precision Vector Network Analyzer, Tom (DG8SAQ) started a revolution in Ham Radio. Thanks to his efforts, amateur (and professional!) enthusiasts have now the possibility to perform measurements which were reserved to well funded HF laboratories before. In this video, Tom explains the evolution and capabilities of his VNWA and why even NASA relies on it now as well!
A simple broadband 4:1 Balun Transformer
During the summer break it became quite here on my blog. While Instead of chilling at the beach, I spend a lot of time on new Hardware and Software projects. Most of them are done, and now it’s time to document them.
In this blogpost I want to share the construction of a versatile 4:1 Balun. In combination with ladder line and an automatic Antenna tuner you can use any dipol on almost all frequencies.








