EM83
The EM83 is a display tube in a miniature tube flask with a Noval base . The electron tube has two identical, independent electrode systems and is therefore suitable for the optical representation of two different electrical signals ( magic scales ). Their original task was to visually support the exact tuning of the FM - VHF radio receivers then emerging by evaluating control voltages on the FM discriminator : the same length of both light bars means that the VHF tuner is precisely tuned to the transmission frequency ( ratio center or zero crossing ) and thus the optimal quality of the playback, if the tuner is detuned downwards or upwards, the left or right light bar is shorter by analogy.
The EM83 was produced exclusively by the tube industry of the GDR : when it was presented at the Leipzig trade fair in 1956, the filigree construction caused a sensation and was, as it were, a symbol of the high performance of the East German electronics industry, since no comparable tube type is available on the world market apart from the American 6AL7 was.
The display is made with a shell-shaped luminescent screen surface, which is divided into two green illuminated bars by an upright sheet, the length of which depends on the respective control voltage at the two control bars.
Due to the possibility of a direct voltage comparison to various applications arise: as tuning in radio receiver circuits, as VU in Stereo - Elektroakustik or as simple qualitative display help in measurement technology .
Web links
- Data sheet for EM83 (PDF; 1.9 MB)
Individual evidence
- ↑ RTT (tube pocket table) 10th edition, Franzis Verlag Munich