Advantage of a double quad for 23cm over other designs is a great front/back-ratio and a large opening angle. I will use the 23cm transceiver mainly for chatting on a local repeater PI6NOS. There is a free-line-of-site from my roof to PI6NOS. No need for a huge gain to open the repeater. I’ve chosen a fixed antenna position.
A few guys at my local club build a 23 cm double quad themselves. It isn’t a very difficult job. Only thing I didn’t like about it is it has to be placed in a plastic container to be weather proof.
Last radio market I attended I walked by a stand of EPS-antennas. The owner Paul PA3EPS, builds beautiful antennas for HF and higher bands. In his line-up Paul PA3EPS sells a double quad for 23cm. It’s a bit pricey in comparison with DIY. But then again, if you focus on construction, used materials and the fact that is weather proof as is…. anyway,it wasn’t a difficult choice. I prefer excellent quality antennas on my roof in order to avoid unnecessary presence there. That has something to do with a fear of heights.
Before I attach the EPS double quad for 23cm on its final position in the mast, it might interesting to see if there is a significant difference in performance between the DIY double quad (not yet tuned) and the EPS double quad. Unfortunately I don’t own much measuring equipment for 23cm so the only way to roughly compare the two is to check the signal of PI6NOS on my 23cm transceiver with both antennas in the same place, connected with the same cable.
The result you can see in this video.