SETI Horn of Plenty Hydrogen horn built at last

[Andrew Thornett]

Needs some deburring of ends and spray painting then build a mount for it and then be ready to go.

Andy

[David Kunsman]

you going to search for narrow band seti signals?

On Thu, May 21, 2026 at 12:40 PM 'Andrew Thornett' via Society of Amateur Radio Astronomers <sara...@googlegroups.com> wrote:

Needs some deburring of ends and spray painting then build a mount for it and then be ready to go.

Andy

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[David Kunsman]

I would like to build a horn a plenty but I would like it to be collapsible or easily taken apart easily for storage.  Any suggestions?

[Andrew Thornett]

The Horn of Plenty from SETI is for mapping Milky Way - hydrogen.

The one I have made is held together at edges by nuts and bolts so to some extent is collapsible. But it does then consist of 4 large pieces of galvanised steel sheet, around 3 feet long.

It is quite easy to produce portable hydrogen mapping antennas or antennas or smaller more portable horn. DSPIRA on their YouTube channel have a smaller horn design with details videos showing people how to make it.

Amdy

Sent from Outlook for Android

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From: sara...@googlegroups.com <sara...@googlegroups.com> on behalf of David Kunsman <dmku...@gmail.com>
Sent: Friday, May 22, 2026 12:20:44 AM
To: sara...@googlegroups.com <sara...@googlegroups.com>
Subject: Re: [SARA] SETI Horn of Plenty Hydrogen horn built at last

 

To view this discussion visit https://groups.google.com/d/msgid/sara-list/CAPVyUPBgmKm%3DvxtgzhwUbD5aubmZLXHd%2BQ_inR_BQ2UAMH1Cww%40mail.gmail.com.

[Andrew Thornett]

Also on this mailing list, Alex Pettit has described his excellent Yagi and 1m dish for hydrogen mapping, and recently Jaspn Burnfield has in the SARA meetings demonstrated his incredible fold up 150cm homemade dish. All of these work very well indeed.

.....I just wanted to try building a SETI Horn of Plenty as it is reasonably iconic.

Andy

Sent from Outlook for Android

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From: sara...@googlegroups.com <sara...@googlegroups.com> on behalf of David Kunsman <dmku...@gmail.com>
Sent: Friday, May 22, 2026 12:20:44 AM
To: sara...@googlegroups.com <sara...@googlegroups.com>
Subject: Re: [SARA] SETI Horn of Plenty Hydrogen horn built at last

 

To view this discussion visit https://groups.google.com/d/msgid/sara-list/CAPVyUPBgmKm%3DvxtgzhwUbD5aubmZLXHd%2BQ_inR_BQ2UAMH1Cww%40mail.gmail.com.

[Mike Otte]

I too had to build the "Horn of Plenty" and wanted to make it disassemble-able but ended up with this. Local menards store did not have foil covered foam sheet so I used spray glue to attach the aluminum foil. The short antenna feed was bent out of galvanized HVAC steel to hold the monopole and wings to hold the 4 foam sheets.  The aluminum foil folded around a 45 deg bevel on each wall of the pyramid to make electrical contact and aluminum tape was used for final assembly. Note the included protractor on the wood saddle for setting the elevation. Can cut the 4 walls out of 1 - 4x8 ft sheet and still have scraps left.  Worked good but now it only takes up space in the observatory. 

BR

Mike

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Mike Otte W9YS