General Information on Unitron Refractors

General Correspondence – 1956 (Courtesy of Jon Miles): Letter Page 1

Letter Page 2

General Correspondence – 1966 (Courtesy of Tom Brennan): Ferris 620_03

General Correspondence – 1967 (Courtesy of Tom Brennan): Ferris 620_01_0001

General Correspondence – 1968 (Courtesy of Tom Brennan): Ferris 620_02_0001

General Correspondence: 1981 (Indicates date of introduction of chrome setting circles):

Unitron DatingR

Nihon Seiko Letterhead – 1983 (Courtesy of Stephen Brennan):

Unitron-Polarex Letterhead 1983

Polarex – Unitron Specification Sheets (Courtesy of Stephen Brennan):

Polarex-Unitron Specifications - 1Polarex-Unitron Specifications - 2

Trademark DocumentationUnitron Trademarks

Technical Reports on Eyepiece Solar Filters (Courtesy of Will Thornton): 


Technical Letter from Nihon Seiko on Removal/Replacement of Objective Lens (Courtesy of Tore Engen)Letter from NS 1971

Unitron Telescope Newsletter (circa 1970, Courtesy of Donovan Brock): Unitron-NewsletterV1a

Japanese Advertisement including several for ED/APO Refractors: