Availability Dates

Based on a survey of Sky and Telescope magazine archives and Unitron/Polarex Catalogs, the following indicate dates on which specific models and/or modifications where referenced or when models were no longer listed as available:

  • October 1951: NS Models 127, 114, and 128
  • February 1952: Unitron Models 127, 114, and 128
  • June 1952: Unitron Model 142
  • March 1953: Unitron Model 145
  • April 1953: Unitron Models 140 and 150
  • May 1953: Unitron Model 152
  • January 1955: Unitron 6″ Test Model
  • January 1955: Unitron Model 155
  • August 1955 Unitron Models 114, 128, 140, 142, 145 (New Mounting Bracket)
  • October 1955: Unitron Model 166
  • April 1957: Unitron Models 160V and 166V; Graduated Focusing Scale for Models 160 and 166; Coated Eyepieces; Astrograph Model 100
  • September 1957: Unitron 6″ Pre-production Models
  • April 1958: Unitron Models 600, 610, and 620
  • September 1958: Unitron Satellite Scope
  • January 1960: Unitron 5″ Photo-Equatorial
  • November 1961: Unitron Models 510 and 530
  • November 1961: Optional Motor  Drive and Setting Circles offered on Unitron Model 128; optional Motor Drive offered on 3″ and 4″ Models
  • September 1962: Unitron Models 740, 750, and 760
  • Approximate 1966: Introduction of chrome setting circles
  • November 1966: Untron Models 740, 750, 760, and Satellite Scope no longer offered
  • May 1975: Widefield 80mm Spotting Scopes
  • March 1977: Unitron Model 131C, 3″ Compact Refractor
  • February 1979: Unitron Model 105, 2″ AltAz Refractor and Model 132C, 4″ Compact Refractor*
  • September 1984: Unitron Models 425N and 426N,  4.5″ and 6″ Catadioptic Reflectors
  • May 1985: Unitron Models A-755 and E-758 Richfield Refractors*

* Earliest Price List Reference Found