Feedhorn Gibertini: crazy idea(s) !

[LAURO2008]

Dear All,

I really need your assistance: a friend of mine has compared a feedhorn Gibertini with a feedhorn Channel Master C120 on a Gibertini dish 125 cm.

According to him the CM feedhorn performs (much) better but he is not convinced as GB feedhorm should go or fit perfectly with a GB dish.

The GB feedhorn diameter-cone is too small and it does not take advantage of the all dish diameter, that's why now he wants to put the GB feed as distant as possible from the dish. But how? Have you seen or done something similar?

2 possible solutions may be:

-A bigger ring in order to "grap" the feedhorn by the cone (and not by the neck)

- Cutting the tube of the neck.

Do you have better (crazy) ideas ;) in order to gain more cm between feedhorn and dish? But first of all: will it work?

Many thanks in advance for your concern;)

 

[guest poster]

We do this sort of thing all the time on any dish..

Try it first ... undo the feed and place/move the feed horn where you want with a meter to see if it gains at any distance (remembering to compensate for elevation if you hold it higher to get position).


You have to remember the best focal distance versus the best f/d ratio when moving it back as far as possible. If the focal length is best suited longer then the f/d ratio will be wider but the f/d ratio is less critical unless there is a lot of noise behind the dish.

When you know you can get a better signal.. make a bracket to suit... If the feed clamp is in the way.. you can piggy back it on and alter the elevation a bit for the higher position.