Butterfly shaped feed , like a penny feed


Keith
 

A local friend Phil  VK6ZKO has an Ericsson dish for 11 ghz with a feed like the old penny feed but sort of butterfly shaped ??
The waveguide is slotted but the end is more " banana  ? " shaped and bent back towards the dish slightly.
I know i have info on this feed somewhere but I'm damned if I can find it.
Can anyone help or point me in the right direction please ?
He wants to put the dish up his tower for local terrestrial contacts back to my home qth and my slot antenna, about 20 kms .
Fingers crossed ;)
Cheers
Keith


John E. Beech
 

Hi All,
The penny feed. I've been thinking about one of these for my 10 GHz dish BUT it needs to be circularly polarized.
If I use circular wave guide ( 22 mm Cu pipe) and cut four equally spaced slots in the end & then solder the penny on,
would this work? This is assuming the signal is already circularly polarized in the waveguide. Or should I just use a co-ax
feed & crossed dipoles with a splash plate as I've done at 23cm?

de John G8SEQ

-------Original Message-------
From: Keith <Keith@vk6eme.com>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: [UKMicrowaves] Butterfly shaped feed , like a penny feed
Sent: Mar 03 '21 12:20

A local friend Phil VK6ZKO has an Ericsson dish for 11 ghz with a feed
like the old penny feed but sort of butterfly shaped ??
The waveguide is slotted but the end is more " banana ? " shaped and
bent back towards the dish slightly.
I know i have info on this feed somewhere but I'm damned if I can
find it.
Can anyone help or point me in the right direction please ?
He wants to put the dish up his tower for local terrestrial contacts
back to my home qth and my slot antenna, about 20 kms .
Fingers crossed ;)
Cheers
Keith