Horn Construction

The horn is the telescope. It is a pyramidal sheet-metal antenna on a wooden mount, and the design is deliberately constrained to materials and tools you can buy locally: foil-faced insulation board, aluminium tape, dimensional lumber and a one-gallon square paint-thinner can for the feed.

The cradle holds the horn and lets it turn on one axis, so elevation is easy to set. It bolts to a base of your choosing; the wooden stand documented here is sturdy, cheap to build, and no more than 75 cm across so that it fits through a standard doorway.

These lessons take it from a flat sheet to a finished, mounted instrument. The electronics that go behind it are in the Receiver Electronics module.

Two parts of the build are documented as drawings rather than as lessons:

• The horn cradle — the frame that carries the horn and sets its elevation.
• The base stand — a simple, sturdy base for the cradle to bolt to.

A completed horn assembled is a short video showing how the horn-can, cradle and stand go together.