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Elektronika MK-61 - today I ordered one NIB
09-26-2014, 07:41 PM (This post was last modified: 09-26-2014 11:59 PM by jebem.)
Post: #29
RE: Elektronika MK-61 - today I ordered one NIB
The Elektronika MK-61 Operations Manual includes the schematic in A3 paper format.
It was a nice feature from the old CCCP/USSR manufacturing plants, allowing the owners to peek around and do their own repairs if they wanted to.

From the schematics, we can identify the following main components.

IC's:
D1: К745ИК1302-2 (K745IK1302-2) - Control Unit for Processor, Display and Keyboard;
D2: К745ИК1303-2 (K745IK1303-2) - Arithmetic Processor;
D3: К745ИР2-2 (K745IR2-2) - Memory Registers;
D4: К745ИР2-2 (K745IR2-2) - Memory Registers;
D5: К745ГФ3-2 (K745GF3-2) - Clock Generator.
D6: К745ИК1306-2 (K745IK1306-2) - Additional MK-61 Processor features not present on the B3-34 series;

The VFD:
VL1: ИЛЦ2-12/8Л (ILC2-12/8L or ILZ2-12/8) - Vacuum Fluorescent Display. Filament voltage: 2.15 - 2.9 V. Filament current: 20 - 24mA. Brightness: 700 cd/m^2. Number of sign: 12 (including 8+2 digit sign). Size of the sign: 2.4 x 4.3 mm. Color: Green. Lifetime: more than 10000 hours.

The Transistors:
VT1: кт361г (KT361G) - PNP Si 250MHz, hfe>50, 35V, 0.05A, 0.15W
VT2: кт315б (KT315B) - NPN Si 250MHz, hfe>50, 20V, 0.1A, 0.15W (schematics diagram wrongly present it as PNP);
VT3: кт814г (KT814G) - PNP Si 3MHz, hfe>60, 50V, 3A, 10W
VT5: кт315б (KT315G) - NPN Si 250MHz, hfe>50, 35V, 0.1A, 0.15W

The printed schematics was scanned at 300dpi in grey, and cropped in 6 overlapping parts to maintain the resolution after the upload.

[Image: MK-52_schema_jm1_grey_part1.jpg] [Image: MK-52_schema_jm1_grey_part3.jpg] [Image: MK-52_schema_jm1_grey_part5.jpg]
[Image: MK-52_schema_jm1_grey_part2.jpg] [Image: MK-52_schema_jm1_grey_part4.jpg] [Image: MK-52_schema_jm1_grey_part6.jpg]

Jose Mesquita
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RE: Elektronika MK-61 - today I ordered one NIB - jebem - 09-26-2014 07:41 PM



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