Background

Recently I’ve started experimenting on 10GHz and as I have no test equipment above 6GHz I decided to build a noise meter that would cover 10GHz as well as possible IF’s of 432MHz and 910MHz.

There are several noise meter designs using the AD8307 (DC - 500MHz) and AD8313 (0.1GHz - 2.5GHz) rf log detector devices and I’ve been using two AD8313 devices in an Arduino based RF power meter since 2021.

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

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 If you want to be included on the map, or if your information is out of date please visit MMMonVHF - My VHF-Database data and add/update your entry.

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: