TTi-1906 5.5 Digit DMM Refurbishment and Overview

Finally got a NNNIce bench DMM, but just one digit short of 6.5. Still an amazing meter.
- Service and Instruction manual GitHub repo: github.com/NNNIIndia/TTi-1906...
- Processor datasheet: datasheets.chipdb.org/Hitachi/...
- Interesting stuff about the processor: cowlark.com/2020-10-19-6303-ar...
- ADC Falstad Simulation: tinyurl.com/y3pmn3zw

[@Wes8761]

Thanks for having me! I had a blast learning about the 1906 and learning how to speak on video LOL! I hope you are able to get the meter cal'ed up and all working. LM337s incoming!!!

[@NNNILabs]

You're welcome! It was nice having someone else take over for a change, if I had to cover that part it would have been sleep-inducing. Consider this training for your "first" video.

[@HoorGuvLabs]

You did better than NNNI.

[@chrizlax]

When you measured it's own reference with it, and saw it was in range, wouldn't it have said that even if the reference was "wrong"?

[@NNNILabs]

The meter does not "know" what is connected to the input, so it measures the reference just fine. But if there was something seriously wrong with the reference (for example it was shorted out), then the readings would be nonsense. You're right, measuring a meter's own reference through its inputs is not really the most reliable thing, I only did it because I had prior information that the meter was functional.

[@adam207321]

Touch and hold...man I need to get a life

[@NNNILabs]

👊🤣👌