This website contains notes on my amateur radio activities and projects that I have worked on.

First licensed in 1979, my main interest is weak signal operating on 144MHz, especially Moonbounce or EME (Earth-Moon-Earth) communication.

You can contact me using the email address on my QRZ.COM page or via admin (at) g8rwg.uk

73 Niels, G8RWG


2m DXCC award

Dec 3, 2023

In October 2023 I gained DXCC award #227 for 2m - all QSO’s were via EME.

EME Station Map

Nov 9, 2023

This EME station map is based on data from the call3.txt database file maintained on the MMMonVHF site. The red dot indicating the location of a station is shown at the centre of their grid.

I have only included stations that have a 6 character QRA locator and an "EME" label and ignored stations marked as "Expedition".

This call3.txt data is maintained by users and therefore only as good as the information they supply. There may be stations that are inactive on EME, QRT or SK. If you want to be included on the map, or if your information is out of date please visit MMMonVHF - My VHF-Database data and add/update your entry.

Feeding XPOL Yagis for RHCP

Nov 8, 2023

In May 2021 I changed the feed arrangement on my 144MHz XPOL EME array to transmit right hand circular polarisation (RHCP). Circular polarisation (CP) is frequently used for EME on 1296MHz and above, it’s not so common on 144MHz or 432MHz. The main advantage of CP compared with horizontal or vertical polarisation is that losses due to Faraday rotation are minimised but there is a -3dB penalty when one station is using CP and the other is using linear polarisation.

Antenna relay problems

Oct 31, 2023

In January 2022 my SSPA shut down with a high VSWR warning when I was operating the 2m EME station. I tracked the problem down to the masthead control box that contains the antenna changeover relays and LNA’s. After testing on the work bench I found one antenna changeover relay sticking in the “on” (energised) position after control voltage was removed. The relays are setup to be energised during receive cycles so if it’s stuck “on” I would have been transmitting into an open circuit. See Station - RHCP arrangement.

Prototyping an Arduino Uno based sequencer

Oct 28, 2023

Background

The existing switching unit for my EME station is built around a sequencer designed by DL4KH that I bought at Ham Radio, Friedrichshafen back in 2005. This unit provides sequential control logic for the transverter, power amplifier and LNA and antenna changeover relays mounted at the masthead to prevent hot switching. The sequencer has five relay driven outputs with a 40ms delay between each stage. The delay can be changed by swapping out a resistor and jumpers can be used to set relay outputs to either the switching voltage or ground.

3 new DXCC entities worked in 2023

Sep 26, 2023

So far this year I have worked 3 new DXCC entities on 144MHz EME, bringing my total to 102. Once I’ve received the confirmations I’ll make an application to the ARRL for 2m DXCC.

Improved quarter wave line connections

Aug 27, 2023

On my 2m EME array the dipoles on the DG7YBN design GTV 2-12n XPOL Yagis are fed via quarter wave balancing lines made up from Andrew Heliax LDF4-50A. These lines are constructed using similar methods described on the DG7YBN web site - A serious QRO Quarterwave Line and have been in use since July 2020.

2m EME WAS - States needed

Feb 8, 2023

I recently worked KS but still need the following states to complete WAS on 144MHz EME - NV, OK and VT. If you're active in any of these states, or know of anyone who has 2m EME capability please contact me via the email address on my QRZ.COM page to arrange a sked.

Building this website

Feb 5, 2023

Having been involved in software development for most of my career I wanted to use a toolchain that that was lightweight and low cost to build my own website. After some research I chose Hugo as the static site generator, Amazon S3 as the hosting service and GitHub as the repository for site customisations and content.

I spent a couple of hours getting Hugo, Amazon S3 and GitHub setup using the comprehensive documentation and examples found on their respective websites. In addition, I found the following pages extremely useful:

5 more DXCC entities worked in 2022

Jan 6, 2023

During 2022 I worked 5 new DXCC entities on 144MHz EME, bringing my total to 99. Just need a couple more confirmations to make my DXCC application.