Elektronika MK-61 - today I ordered one NIB

[Hlib]

A few days ago it came to me (new in box) MK-61 of 1988 year of production yet with the native display plastic sticker protection and original warranty factory seal.The indication of sign "-" is absent, but it is not difficult to repair. These calculators do not represent a collection value and are sold for $ 5...10 in the Ukraine.
Black color is a classic option.


Before and after the collapse of the USSR the manufacturers of MK-61 were not adhered to strict standards of design and quality. Nonetheless the following instance (1991) is working 20 years without any repair.


As the voltage DC-DC converter provides operation of the device within 2.5...8 volts, it is possible to use any battery. For proper readout voltage of discharge of a given type of battery (the appearance of many decimal points on the VFD) you need to adjust the values of R5, VD3 in the scheme of the converter.
For some strange reason, this is one of my favorite RPN-calculators.
Thank you jebem, wolter b, Katie for interesting and useful information