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Unihex Rotary Eyepiece Selector for Unitron Refractor


This item is contained in a wooden box with a metal latch on the front and a blue Dunlap Observatory sticker on the top. The box is hinged at the back and the lid opens to reveal to components resting on wooden supports lined with bright green felt. One of the components is a metal cylinder with threads at one end. The other component consists of six silver-coloured cylinders of differing sizes emerging from a central six-sided section. Each tube has a recessed cover with a knurled end, and ‘u’-shaped cuts through the metal to permit a snug fit with another component.

On the central section, there is engraved an arrow on a central round sect that points at the ‘selected’ tube. On the other side is a round window through which reveal a roughly circular chamber around the edge of which there are mirrors. The rim of this window is threaded for attachment to the included tube. When the cover of the ‘selected’ tube is removed, the central section can be viewed and the reflection through the window seen. The other tubes show black plastic surface.

The selected tube can be changed by turning the round disk with the arrow on it; this is apparently fixed in place by a pair of screws.

Accession Number: 2019.ast.216 (DAA-0071)

Alternative Name: Unihex

Primary Materials: Metal: Iron Alloy, Glass, Plastic.


On each of the blue labels affixed to the box and components: “UNIVERSITY OF TORONTO

Engraved on the central section, near the arrow: “UNITRON

Engraved on the central section, by the window: “MADE IN JAPAN”

Dimensions (cm):

Box: Length = 19.6, Width = 18.6, Height = 5.6


This object is used to attach to a Unitron telescope and rotate between one of six eyepieces.


Excellent: The exterior of the box is in very good condition, with a slight dirt smudge on the front of the box by the latch. The instrument components are in excellent condition, with no marks, signs of wear or corrosion. The blue labels are slightly worn, particularly the one on the tube, and in places coming away from the instrument, leaving a sticky residue. The interior of the tube component is striated where the black interior has been scraped away, revealing the silver underneath.

Associated Instruments:

Manufacturer: Unitron

Date of Manufacture: c. 1955-1990s


This item was kept at the David Dunlap Observatory until 2009. Upon the sale of the Observatory, it was moved to the University of Toronto’s Department of Astronomy & Astrophysics at the St George Campus. In 2017 it was moved to a new storage location in McLennan Physical Laboratories.

Additional Information and References:

<a href=>Information about the Unihex</a> from the Unitron History Project [04/07/19].

Historical Notes: