1. Take a bottle and roll a kitchen cloth over it up to diameter 3.3 in (84 mm).
2. Roll over the cloth the aluminum foil. Do a couple of turn over. The more – the better, because of harder final shell.
3. Stick tape over the foil to fix the construction
4. pull out the bottle
5. stick the tape inside the aluminum tube to fix the construction
6. Make an aluminum cover for the tube
7. measure the inside diameter on the both side of the tube.
8. calculate an average value of it
9. find the value D in the table: http://flakey.info/antenna/waveguide/
10. find the appropriate value ¼ Lg
11. Drill a hole in the tube with this distance from the cover side
12. find the appropriate value ¼ Lo
13. mark on the Linksis antenna the distance ¼ Lo + 0.2 in ( + 5 mm)
14. fix a aluminum strip on this mark as shown on the picture