[NLRS] 10GHz feed horn design & question

[jcplatt1 at mmm.com]

Thanks for the excellent feedback Donn.   I may go ahead and build a new
feedhorn, heck its Winter anyway.

Regarding the focal point, the good news for this dish is that the feed-arm
positions the feed so the only adjustment is in (closer to the dish) or out
(farther from the dish) .... I assume along the axis of the focal point (??
note to self .... something to check).

Regarding building horns (feed or otherwise), I am looking for input from
other horn-builders regarding the following.

1.   What material do they use for the horn itself ?    Cutting and bending
is the issue (brass vs copper, and at what thickness).

2.   Because the horn bends in on it self, its hard to get a sharp corner
.... you can't get a brake in on all the bends.    I think AUS mentioned
that he built a jig ?   I think this issue works in concert with my
question #1 above.

3.   What do others use for a mounting flange and with what material.    I
suppose that you can home-brew a small flange with a .400" x .900" opening
with standard home tools.

I've noted with some interests the aluminiumized (??) plastic used by
M/ACom for their 17 dB horns .... lightweight and strong.    There is no
reason that the horn has to be brass or copper.   For example, can you
build a horn out of a non-ferrous material (cardboard, wood, plastic, etc)
then give it a good coating with silver spray paint on the inside assuring
that all seams are indeed covered (no gaps) ?    Another version of this
may be to use aluminum foil to line the inside of a non-conducting horn
.... the advantage being it may be easier to work with these materials.

73, Jon
W0ZQ