Telescope of the Maksutov-Cassegrain system USHT No. 314

An original and extremely rare telescope with an azimuth mount and a desktop tripod from the very first experimental serial production of meniscus school telescopes made in the USSR by order of the Ministry He was born in 1945 at the Novosibirsk Instrument-Making Plant (Plant No. 69). The number of telescopes in this first batch was supposed to be 1,500, but the pilot production of a certain number of telescopes was rejected.Maksutov, after which the model was discontinued, and the manufactured telescopes, the number of which is still unknown, were most likely mostly disposed of or (possibly) partially implemented by the plant itself. Nevertheless, by some miracle, several copies have survived to this day in varying degrees of preservation, and the uniqueness of this copy is complemented by the almost perfect condition of its optics and mechanics. 

 The magnification of the device is 50x, the diameter of the lens (meniscus) is 70 mm, and the focal length of the system is approximately 700 mm. In the center of the meniscus, a secondary mirror with a diameter of 23 mm is sprayed from the inside. The main mirror with a diameter of 70 mm is located inside the housing and can be removed along with the rim by unscrewing the back cover of the pipe. The telescope's optics are not illuminated, and the 3 mm thick telescope body is made of aluminum alloy and painted black with hammer paint. The tripod stand is made of nickel-plated steel, the base is cast from cast iron and also painted black. On one of the "paws" of the base there is a stainless steel plate with the refinery sign in the form of an isosceles triangle, with the telescope number and the year of manufacture. The telescope is focused by rotating the eyepiece coupling. The length of the telescope, together with the screwed—in eyepiece, is 190 mm. The weight of the assembly is 5.2 kg. Two aluminum diopters with holes are mounted on the tube to facilitate pointing the telescope at the object. The diopter installed near the eyepiece has the ability to adjust (move) perpendicular to the optical axis of the telescope.

The meniscus mirror-lens telescope system was invented by the outstanding Soviet optician D.D.Maksutov in 1941. Soon, he personally produced several prototypes, which clearly demonstrated the advantages of the new optical scheme over the classical optical schemes of astronomical telescopes. A meeting convened by the Astronomical Council of the USSR Academy of Sciences in October 1943 recognized D.D. Maksutov's invention as outstanding and considered it necessary to introduce meniscus systems into astronomical practice as quickly as possible. In February 1943, D.D. Maksutov also developed the design of a new school telescope, choosing the meniscus scheme for it, which makes the device extremely compact. Calculations for the 70 mm model were completed on April 20, 1943 — this day can be considered the "birthday" of the legendary instrument. However, not everything went smoothly in production.: For some unknown reason, the plant's technologist incorrectly set the tolerance for meniscus thickness (which is a very sensitive parameter) and put the drawings into production without consulting D.D. Maksutov. As a result, the entire first experimental batch was rejected. Unsuccessful D. D.Maksutov recognized both the mechanics of the telescope and the overall finish of the instrument.

Production of this model was discontinued and in 1946 D.D. Maksutov developed a new design of a 70 mm meniscus telescope (model USHT "B"), which later went into mass production. This is what Dmitry Dmitrievich recalled: "In 1946, I finally worked out the design of the school telescope (model "B"), and the factory, after releasing an unsuccessful series of telescopes that I rejected, finally produced a prototype of a new design. This prototype was approved by the Ministry of Education for the large-scale production of school telescopes." Although it was planned to produce about 30,000 units over the next five years (i.e. about 6,000 per year) of these telescopes, including for retail sale, in reality, by the end of 1948, a little more than 2,500 units had been produced (according to other sources, 3,500). In 1948, the production of meniscus 70 mm telescopes at the refinery was discontinued due to the complexity of their production.