I'm slowly working towards building my own cross yagis for my home setup. I started learning to use MMANA-GAL in order to model the antennas and also looking for materials to build them. I found 8 mm aluminium round tubing for the elements and 3/8" square tubing for the boom. The cross boom is going to be 2" fiberglass, so I don't necessarily have to choose for foremast installation.
I decided to settle on loop fed array yagis (LFA) because they are directly fed with coax cable. First question: any reasons for not using LFAs for cross yagis?
Second question: what is the sweet spot between number of elements, beam width and boom length (for both 2m and 70cm antennas)? A lot of elements means more gain, a narrower beam width, but also a longer boom and more careful tracking. I haven't got any experience with working sats and I wonder what is better: a couple of more dB gain, or a slightly wider beam and a more compact antenna?
So far I modelled a 4-element and 5-element LFA for 2 meters. The 5-element has a 1 dB gain advantage over the 4-element one, a 3 dB better F/B ratio, but is 2 meters in boom length, so that is quite substantial. Any input appreciated. Cheers. --Hans (BX2ABT)