Working via the moon on 23cm with my small, 1.75m diameter dish is possible, but sometimes difficult. Stations with a dish diameter of 3.0m and above were easy to work with, as were smaller ones down to 1.8m, provided they were optimally configured.

In recent months, the popularity of foldable 2.4m dishes has increased significantly. These antennas are equipped with a disc patch feed and a 90° hybrid coupler to provide circular polarization. To switch between LHCP and RHCP, a power relay and a set of cables are required. This combined effect causes noticeable losses. During EME experiments with such stations, I noticed that they are significantly weaker and less sensitive than comparable 2.4m stations equipped with septum feeds. For this reason, it was often very difficult, if not impossible, to complete a successful QSO with them.

Therefore, I decided that it was time to enlarge my solid 1.75m dish. First, the parabola was calculated and a template was created for the new intended size. Enlarging the dish results in a reduction in the f/D (focus/diameter). As a compromise, I opted for a new diameter of 2.35m, which corresponds to an f/D of 0.31 (previously 0.38). Good illumination with the existing septum feed is still given. The calculated additional gain resulted 2.5 dB for received signals and about 5.0 dB for my own EME echoes.

After completing the expansion, solar noise measurements showed an increase of Sun noise between 2.5 and 3.0 dB, which corresponds to the calculations. This was also noticeable in practical operation; stations with folded 2.4m dishes as well as stations with Yagi antennas can now also be worked, provided they are well optimized.