The radiotelephone is a device for two-way voice communication over radio waves. The FM302 was widely used by the state services in communist Poland. After the device was withdrawn from use, some units were acquired by ham radio fans and, after retuning, they were used for building amateur FM communication networks in the 2m band.
The design of the device is based on vacuum tubes. Operating frequency stabilisation is ensured by the built-in thermostat, which adjusts the ambient temperature for the components whose parameters are sensitive to temperature change. The unit presented here is a stationary version with a 220V power supply unit. There was also a portable version powered by a car battery through a vibrating converter, and in later units – through a transistor-based power supply unit.
The device could operate on one of four channels selected using a rotary switch. Their frequencies were determined by a set of replaceable quartz resonators.
The Radmor enterprise in Gdynia was established in 1947, and at the beginning of its existence it used the name MORS (Eng.: walrus), the acronym for „Morska Obsługa Radiowa Statków” (Marine Radio Servicing of Ships). In reality, the factory’s products were also widely used in land communication. In 1971 the company’s name was changed to “Radmor”. It was the main provider of communications equipment in communist Poland, and in the late 1970s its product range was expanded to include high-class home audio equipment. Currently, the company produces advanced communication equipment used by the uniformed services.

The Koliber 2 is one of the three versions of the Koliber travel radio produced between 1962 and 1966 by the Zakłady Wyrobów Elektrotechnicznych Eltra in Bydgoszcz. The Kolibers are a development of the Eltra MOT-59 – the first portable radio manufactured in Bydgoszcz. The solutions adopted also became the basis for other travel radios such as the Sylwia, Minor, Kama and Dominika.
The Koliber 2 is a superheterodyne, improved from the original version through the use of seven transistors and a germanium diode on a printed circuit board. The first semiconductor diode was developed by Russell Ohl in 1939. The “barrier” in the form of a fissure that separates areas with positive and negative charges enables the flow of current only in one direction. The prototype transistor was designed a decade later and was developed by a team comprising John Bardeen, William Shockley, and Walter Brattain (who were jointly awarded the Nobel Prize in physics for it in 1956). It enabled the outdated electron-array vacuum tubes to be replaced in the electrical circuits of radio and television equipment. This was important as the tubes were characterised not only by high power consumption, but also high heat emission.
In contrast to the tubes, the transistor has a lower power consumption, does not emit heat, and has smaller dimensions, thus enabling devices to be miniaturised.
The monophonic Koliber 2 was equipped with five tuned circuits, which allowed reception of medium and long wave bands. Thanks to its small dimensions it fulfilled the role of a portable, battery-powered radio (with the possibility of connecting it to the mains, but only using a special converter). The Koliber 2 has a built-in ferrite antenna and a Tonsil GD 7/0,2 magnetic electric speaker.
The device is enclosed in a cuboid housing of grey plastic with rounded edges and corners. The surface of the front wall is divided with vertical bands placed at regular, narrow intervals, in the form of isosceles triangles with trimmed top corners. On the right side of the front is a transparent tuning knob with digits of different sizes in an art déco-style typeface. On the left is a speaker covered with a light-coloured fabric that is visible through the square hole with the vertical bands described above. Below it is a light-coloured inscription with the name of the radio. On the sides, there are two metal belt clips, and on the top wall there is a volume knob with a power switch and a radio band switch.

Author: Filip Wróblewski

The Stolica tabletop radio receiver was manufactured in 1955-1959 by Zakłady Radiowe im. Marcina Kasprzaka (ZRK), located in Warsaw’s Wola district. It is a six-circuit superheterodyne designed to receive long, medium and short wave in the amplitude modulation system (AM), powered with alternating current. The Stolica is a modernised version of the Syrena radio – the first radio fully developed and manufactured by ZRK.
The radio was installed in a box housing made of wooden parts, plywood, and fibreboard. The entire device was covered in a mahogany, clear-coated veneer. The front was slightly arced, with gently profiled side edges. The side walls and parts of the front wall are decorated with inlays of rounded, modelled strips of thin sheet metal, close to the top and bottom edges. There are also decorative cutouts on the front wall. Edges of the recess are also emphasised with metal strips. The name emblem of the radio is placed at the bottom in the middle, under the cutout. The inside of the front panel is divided into two fields. The broad upper area is made of a light-coloured fabric, behind which there is the speaker, mounted directly to the housing. There is a magic eye tuning indicator in the upper right corner. The narrower, bottom field is made of black plastic, separated from the upper area with a metal slat. The scale, located in the centre, is made of delicate yellow lines, and stripes with white and grey fillings. There are two symmetric rotary switches on either side. A different technical solution for control was adopted for the Stolica than for the Syrena. The knob of each switch is designed so that it consists of an outer ring surrounding the knob and a slimmer shaft, protruding outside of the ring. This allowed adjustment switches to be located coaxially. On the left there is a volume and tone switch, while on the right – a tuning knob with a range switch. The tone adjustment used in the radio, together with the bandwidth selection, is an advantage of the system as it allows fuller reception of musical broadcasts.
The radio was manufactured in five model versions. Apart from the base version, with no Roman numeral in the name, they were: the Stolica II 3262, Stolica III 3263, Stolica IV 3264, and the Stolica V 3272. The devices differed mostly in shape and profile of the housing, as well as the range of available frequencies. The ranges differed depending on the foreign market to which the model was to be exported.

Author: Filip Wróblewski

The Commodore SX-64 is a portable (“suitcase”) version of one of the most popular computers of the 1980s, i.e., the Commodore C64. It is also the first portable computer equipped with a colour screen (a 5-inch CRT monitor). It has 64 kB of built-in operating memory. As business users were the main target group for the computer, it was also marketed under two other names: Executive 64 (in the USA) and VIP-64 (in Europe). A prototype of the device was presented during The Winter Consumer Electronics Show organised in Las Vegas in 1983. The computer went on sale in 1994, and production ended two years later.
Technically, the device is fully compatible with its desktop version, and it supports the same software. However, while the Commodore 64 was a computer intended for a wide group of users, the SX-64 was designed with business users in mind. The computer was supposed to serve people who travelled frequently, as well as those worked both in the office and outside of it. For that reason, it was advertised in the American press with the slogan “designed for the movers of this world”.
The device was sold during a period of accelerating globalisation. It was also the period when Ronald Reagan was President of the United States and Margaret Thatcher was Prime Minister of the UK, a time when the neoliberal free-market economic model, with a global reach, was forming. One of its components is the mobility of people, services, production, and technology. In the end the SX-64 did not fulfil the hopes it raised, mostly because of the lack of advanced software for business purposes.
Contrary to the home computer models manufactured in the 1980s, the SX-64 occupies a separate development line of portable computers. Commercial sales started in 1975 with the IBM 5100 model, a development of the SCAMP prototype of 1973 built by the same company. The assumption was that portable computers were to be relatively small and lightweight. The SX-64, whose form resembled a suitcase with a detachable keyboard panel (in the international QWERTY layout), weighs around 10 kg, making it lighter and smaller than the computers produced at the time. The model, however, does not have a built-in battery, which makes it necessary to use a mains power source and prevents the device from being used while travelling. In contrast to the Commodore 64, the computer has only one built-in 5.25-inch floppy disk drive (model Commodore 1541). In addition, its ports allow connection of peripherals such as a tape recorder, audio-video devices, or an external monitor.

Authors: Marek Więcek, Filip Wróblewski

The Krokus 66 photographic enlarger is used for projecting and enlarging negative images of a photograph onto photographic paper in order to obtain a print. The device was produced by Polskie Zakłady Optyczne (PZO), operating in Warsaw from 1921. In the late 1960s, PZO merged with the Warszawskie Zakłady Fotooptyczne and expanded its production to include photographic cameras and accessories. The design of the enlarger was prepared by a team of designers comprising Zbigniew Orliński, Bohdan Ufnalewski, and Wojciech Wybieralski, who designed several enlargers in the “Krokus” series for PZO in 1974–1980 as part of their work for the Artistic and Research Unit of the Academy of Fine Arts in Warsaw. The devices were manufactured from 1953. Successive improved iterations include the Krokus 2, Krokus 3, Krokus 4, Krokus 35, Krokus 44, Krokus 66, Krokus 67, Krokus 69, and Krokus Mini. The Model 66 supported the 6×9 and 6×6 cm negative film formats. The device has a compartment for correction filters, which is why the name includes the word “Color”. The hard-edged form of the enlarger was in line with the contemporary trends and aesthetic preferences of the users. The rounded shape of the housing of the earlier version, i.e., the Krokus 3, was related to the sheet metal stamping technology implemented by the manufacturer (bending and die casting). Modernisation of the outdated design of the Krokus and launching production for export was a response to the limitation on access to raw materials and the embargo for components and technologies, put in place towards the end of the 1970s.

Authors: Piotr Turowski, Filip Wróblewski

The inductor-based resistance meter is an instrument used by electricians to test proper insulation of cables conducting electrical current. Devices of this kind are used on construction sites, in residential and industrial buildings, with electrical power networks and telecommunication installations. The presented instrument measures the value of resistance thanks to the built-in crank inductor. It can operate independently of a power source, because the voltage required for making the measurement is generated by the user himself. In modern metres, analogue measurement of this type has been replaced by electronic systems, and the device is battery-powered. The presented device is manufactured by the German company Telegraphen-Bauanstalt von Siemens & Halske, which was founded by inventor Ernst Werner von Siemens and a precision mechanics expert, Johann Georg Halske in 1847. Initially, the company manufactured and refurbished telegraphs, over time its telecommunications and electrical engineering product range was expanded and new areas of production were entered. Finally, the company grew to be today’s International Corporation dealing with electrical engineering in the broadest sense.

References:
Siemens history, official Siemens website, https://new.siemens.com/global/en/company/about/history.html, accessed 2.06.2021.

The Syrena is the first radio receiver completely designed and manufactured in Zakłady Radiowe im. Marcina Kasprzaka in Warsaw (ZRK). It works with the short, medium, and long wave bands. With some modifications, the design was based on the electrical system produced by ZRK and Diora in Dzierżoniów for the RSZ-F Aga radio manufactured under a Swedish licence.
The year 1954, when the radio was marketed, was a breaking point in the history of radio. It was then that the operating range of the radio was extended and new content began to appear in radio transmission. In October 1954, the first Polish station broadcasting in the UHF band, which was soon to become one of the standards, was inaugurated in Warsaw. The Syrena was a model that did not yet support UHF. A new regular broadcast named “Sports Chronicle” was included in the timetable of Polish Radio Programme I – sports content would soon become an important, permanent part of radio and television broadcasting (both in terms of entertainment and economically).
Near the end of September 1954, an officer of the Public Security Ministry who had escaped from communist Poland, Col. Józef Światło, started hosting a programme on Radio Free Europe titled “Behind the scenes of the security and the party” and laying bare the functioning and abuse of the communist regime. That information fuelled social unrest and was one of the factors that led to the political changes in Poland related to the “October Thaw” of 1956. It also emphasised the significant degree of listener interest in content of this kind of sensational or criminalistic nature – the trend to provide such content is referred to as “tabloidization”.
The Syrena receiver, named after the Syrenka (“little mermaid”) – the symbol of the capital city of Poland – is a mains-powered, six-valve superheterodyne. It has a magic eye tuning indicator and a built-in GED 20/2 magnetoelectric speaker. The Syrena was designed to receive programmes broadcast using amplitude modulation (AM). In comparison with the Aga, the design of the drive of the scale was changed by moving it from the top part of the wooden box to the lower part of the front panel. The radio receiver also had stepwise tone adjustment that is made simultaneously with the change of the width of band received. It is one of the solutions distinguishing the first receivers made at ZRK, such as the Stolica, Wola and Etiuda. ZRK’s trademark became the closing of medium frequency filters in square aluminium cans, while the competing Diora used round cans.

Author: Filip Wróblewski

The Rozyna radio was designed and sold in 1962 by Zakłady Radiowe im. Marcina Kasprzaka in Warsaw. The distinguishing features of the radio are its small dimensions, achieved thanks to the use of miniature components and structure. The radio allows reception of radio waves in the short, medium and long wave bands, with the possibility of amplitude modulation (AM). Due to the parameters achieved, its relatively low price, and small dimensions, the Rozyna was highly popular.
It is a superheterodyne receiver powered from the mains through a built-in transformer, having three vacuum tubes and a selenium rectifier. The device’s chassis is installed in the housing by sliding it into two guides on the side walls. The device’s electrical system is identical to that of the Figaro radio. The device has a Tonsil GD 9,5×14,5/1,5 magnetoelectric speaker. Reception of radio frequencies is possible thanks to a built-in, static, directional, ferrite antenna. This means that in order to improve reception it is necessary to move the entire radio around, so that the antenna receives the signal in an optimum position. A ferrite antenna works on the basis of coupling with the magnetic field of the electromagnetic wave. It is an electric circuit wound in the form of a coil on an elongated core made of non-metallic ceramic materials having ferromagnetic properties, i.e., those in which matter exhibits its own spontaneous magnetisation. It is achieved through a flow of magnetic charges through the windings of the coil surrounding the ferromagnetic core.
The radio was produced with housings of Bakelite or wood. The device in the Bakelite housing had a shape similar to a cuboid, an openwork raster of the front wall and a longitudinal but narrow scale, sloped towards the inside. The radio in the wooden housing is slightly shorter, its width is slightly larger than the width of the scale, the sidewalls slope towards each other, with a slightly arced connection with the top wall. Above the scale is a perforation in the form of a horizontal grille behind which the speaker is placed. On the right side there is a slider that activates the rotary switch for changing the radio band. There are two knobs on the scale – the one on the right adjusts volume, the one on the left is for tuning.
The Rozyna was produced in three versions – apart from the base version, users could buy a Rozyna N (with a modified design), and in 1962-1963, a Rozyna 2, more than twice the size of the original and equipped with a stepwise adjustment of tone and a magic eye tube.

Author: Filip Wróblewski