What Dish Is This?

[bobvick]

I have always heard (not verified) that if a #2 pencil would go through the mesh, then it will not work well for Ku band. I do not know if that statement is factual however.

 

[lost_mesa]

The conventional wisdom seems to be that the holes should be no bigger than 1/10 of a wavelength. The wavelength at Ku band is about 1 inch, so the holes should be no larger than 1/10 inch. Some say that holes up to 1/4 wavelength in size is probably OK, with some reduced efficiency.

Equally important, IMHO, is the accuracy of the dish surface. The parabolic curve should also be accurate to within 1/8 to 1/10 wavelength. I suspect this is why a lot of BUDs fall short at Ku band.

 

[Lone Gunman]

UPDATE ON MESH SIZE: Looks like this Raydx with the large opening mesh will be a keeper after all. I've been playing with it now for a few weeks and finally put a Standard DMX741 LNBF on it last weekend and started looking at Ku satellites with it and so far it's as good or better than anything I've got mounted here now. I'm lockingOETA, PBS and Montana PBS on 125w West with 70+ % Q using an Openbox S9 receiver.

The polar mount does have some issues though and I'm probably going to have to do some fabricating to make the declination adjustment part work like it was designed to work. More on that in another thread though. Just wanted to let everyone know that the larger opening mesh is working fine with Ku at this point.