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.

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.

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.

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.

• CY0S
• ZB2BU
• ZA/S59A

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.

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.

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:

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.

• PJ4MM
• 0J0DX
• D2TX
• J28MD
• ZC4RH

There are many internet resources that cover digital signal processing (DSP) and software defined radio (SDR), but I’ve only found a few that provide a good introduction along with practical examples. Software Defined Radio for the Radio Amateur by AC2CZ (G0KLA) is an excellent set of SDR tutorials which I found particularly useful. The sample code is written in Java, but it was fairly straightforward to rewrite the parts that I wanted in C++ using Qt.

In 2020 I took up CW again after many years and successfully completed the CWOps CW Academy Basic Course in March 2021.

In May 2021 I successfully completed the CWA Intermediate Course and now enjoy making regular CW QSO’s. You will hear me mainly on 40m and I occasionally take part in the K1USN SST and CWops Tests (CWT). I am also a member of the Long Island CW Club, a club dedicated to teaching Morse Code to beginners and helping to improve the skills of intermediate and advanced operators.