4 ms·

I'm surprised its operating temperature range is so small (0-40C) given its main application.

varjag 8y ago
It was likely installed in a conditioned enclosure with a bunch of other instruments. You can stretch mid-1960s semiconductor tech only so much.
- jackhack 8y ago
  I suspect this is due to the small thermal window of (then state of the art) germanium transistors which was still in widespread use. It wasnt until the mid 1960s that the silicon transitor overtook germanium in terms of speed. And the USSR was many years behind the West, in terms of materials & design. Interesting related fact. The thermal operating range of germanium transistors was a concern even in the music world. The "Fuzz Face" pedal which helped give Jimi Hendrix his distinctive distorted guitar tone was built with two germanium transistors in a very simple circuit (< 5 components if I remember correctly). The distortion produced by this pedal was well known to change on stage, under hot lights or in cold basements, etc. To make matters worse, it was also sensitive to the supply voltage, so a fresh 9v acid battery would sound different than a dying battery. (ironically, the dying battery sounded better to most ears. The circuit only drew around 30 mV so a near-dead battery could still last a long time.) As a result, it was not unusual for working musicians to travel with several fuzzfaces and a pocket full of batteries, trying a few at soundcheck to see which sounded the best.
  - varjag 8y ago
    Correct, component base lagged behind in USSR and quality assurance was tricky. Even in 1980s there were 5 rejection classes of bipolar transistors compared to just two in the West. I counted 3-4 years R&D cycle prior to 1974 and then subtracted a few years to account lag in the technology. However for high profile projects like these it wasn't uncommon to simply source the quality Western components. One of my coworkers in the 1990s was an older guy who was developing systems like that in early 1980s. A lot of stories, not sure how apocryphal. Once they had problems with one of the copied Motorola chips produced in Estonia. The deadline was looming, so they tried to source original chips. However that chipset was discontinued for years at that point with no stock anywhere, neither original Motorola nor compatibles. So they had to restart production on one of the fabs in Asia, using a KGB shell company to handle transaction.
dogma1138 8y ago
Given the iffy translation it’s not clear if that it for the unit or the ICs hardened systems like this are usually thermally stabilized to ensure that all components operate within their temperature range and that there is no large temperature variance between redundancies.
heavenlyblue 8y ago
In Russian they say: the machine is built with triple redundancy and majority output/input selection (2/3). But they don't mention anything else besides that about stability. No environmental hardening or else.

It was likely installed in a conditioned enclosure with a bunch of other instruments. You can stretch mid-1960s semiconductor tech only so much.

jackhack 8y ago
I suspect this is due to the small thermal window of (then state of the art) germanium transistors which was still in widespread use. It wasnt until the mid 1960s that the silicon transitor overtook germanium in terms of speed. And the USSR was many years behind the West, in terms of materials & design. Interesting related fact. The thermal operating range of germanium transistors was a concern even in the music world. The "Fuzz Face" pedal which helped give Jimi Hendrix his distinctive distorted guitar tone was built with two germanium transistors in a very simple circuit (< 5 components if I remember correctly). The distortion produced by this pedal was well known to change on stage, under hot lights or in cold basements, etc. To make matters worse, it was also sensitive to the supply voltage, so a fresh 9v acid battery would sound different than a dying battery. (ironically, the dying battery sounded better to most ears. The circuit only drew around 30 mV so a near-dead battery could still last a long time.) As a result, it was not unusual for working musicians to travel with several fuzzfaces and a pocket full of batteries, trying a few at soundcheck to see which sounded the best.
- varjag 8y ago
  Correct, component base lagged behind in USSR and quality assurance was tricky. Even in 1980s there were 5 rejection classes of bipolar transistors compared to just two in the West. I counted 3-4 years R&D cycle prior to 1974 and then subtracted a few years to account lag in the technology. However for high profile projects like these it wasn't uncommon to simply source the quality Western components. One of my coworkers in the 1990s was an older guy who was developing systems like that in early 1980s. A lot of stories, not sure how apocryphal. Once they had problems with one of the copied Motorola chips produced in Estonia. The deadline was looming, so they tried to source original chips. However that chipset was discontinued for years at that point with no stock anywhere, neither original Motorola nor compatibles. So they had to restart production on one of the fabs in Asia, using a KGB shell company to handle transaction.

dogma1138 8y ago

Given the iffy translation it’s not clear if that it for the unit or the ICs hardened systems like this are usually thermally stabilized to ensure that all components operate within their temperature range and that there is no large temperature variance between redundancies.

heavenlyblue 8y ago

In Russian they say: the machine is built with triple redundancy and majority output/input selection (2/3). But they don't mention anything else besides that about stability. No environmental hardening or else.