plywood fresnel

slugworth

4 page article scanned from october 1985 Radio Electronics magazine describing how to build a flat plywood fresnel C band dish antenna.
The lnb mounts behind it.

Attached Files

plywood_fresnel_C_band.zip (1.81 MB, 34 views)

Channel Hopper

Ahh, fresnel lenses, like boom/stick antennas, are the sort of thing one looks at when there is really no other alternative, (and then give up, or bribe the man next door).

Search for Mawzone(s) and then look in your neighbourhood for something similar.

Flat dishes!!


Some interesting reading below, Fourier transforms, Maxwell and Huygens formulas abound.


_http://books.google.co.uk/books?id=Ik21bBBOYyIC&pg=PA5&lpg=PA5&dq=diffractio n+antennas&source=bl&ots=7e3KraTQnk&sig=X44aglc6KJ gKZdYp3Qin1WpFcmQ&hl=en&ei=NtsqSvrSFZTKjAfq7JD6Cg& sa=X&oi=book_result&ct=result&resnum=7#PPP12,M1

There is a very fine line between "hobby" and "mental illness"

slugworth

I was thinking of a ku band version.
Good for areas where they won't let you have a dish antenna.
Tell them it's "a work of art".

BombedOne

Relatively small one for ku band can be easilly made at home, using blank PCB.

Channel Hopper

The problem with Ku band is the extreme bandwidth between 10.7 and 12.75 GHz.

No Fresnel design will perform well over such a range.

There is a very fine line between "hobby" and "mental illness"

BombedOne

u can have 2 different ones, connected via 22khz switch

slugworth

That is the max range, but in reality the freqs are from 11.7 to 12.2 or so.(In north america anyway) see 123w as an example.

Channel Hopper

For that satellite at your location you could easily construct one from any bit of ply, or make a template out of a piece of aluminium if you own a jig-saw.

There is a very fine line between "hobby" and "mental illness"