I did a new Dualfeed-System for a friend with some new ideas. Mill a brass tube. There is no need to reduce the outer diameter of the rocket but removing the lense flange. Clean it with sand paper. The brass tube has a new flange to carry the lense. All three parts can be sticked together. No loss in LNB because all is original.
Solder the patch and the reflector disk to the tube. One can mill 3mm (plus copper thickness) shoulder to the tube to get the right distance between the patch and reflector. Don't forget to drill the "feed hole" when both parts are fixed flat together with a srew before soldering. In this case, the reflector disk hole has a reduced diameter to stay on the shoulder.
This is the ready LNB. It gives a compact unit and can be mounted with the most dish equipment.
If the upper bracket gives no room for the S-Band-Cable, take a metal bracket. The picture shows my own feed with heavy Cellflex cable. The transition to SMA-Surplus-Cable is fixed with an alu bracket
By the way, rockets with 25 MHz TCXOs are extremly stable. No fast changes in the final frequency can be observed like it was with 27MHz from Connor Whinfiled mounted in Octagons.
There is only little change with outside temperature which can be easily regulated with SDR Console.
Many Thanks to Simon in this way ! He did a great job all over the year. We appreciate this very much.
Finally, the feed is a compact unit. It can easily be changed and compared with other antennas, probably a helix.
73s, have fun
Happy New Year to all "Helians"