I have made a Github repository if you want to take a look at the schematic. https://github.com/ZacharyLaurin/BargraphDriver
To control it I am using an Arduino UNO with a library for the DAC and communicating from my PC via serial. My plan is for the spectrum analyzer to be some kind of desk toy, so it'll be plugged to my PC 24/7. I send the data in an array of 4 8-bit integers every 10ms. I do the "tube safety" stuff on the Arduino and the data processing on a C# application on my desktop. For the tube safety stuff what I have is a delay between when the Arduino / DAC turns on and the when the +150V from the NCH6300HV is enabled, as well as taking a moving average of the last X points of data to smooth it out as to not go from low to really high instantly (see datasheet 1.3 usage notes). For the actual spectrum analyzer part I found this repository online and am just building off it. https://github.com/swharden/Csharp-Data-Visualization/tree/main/projects/audio/AudioMonitor . That way it just works with whatever sound is playing on any input or output device and I don't have to read any files. For the FFT to look good (I don't care about accuracy) I am first squaring the magnitude and then "tilting" it by multiplying by the octave, ((log(Frequency) / log(2)) - 4) (minimum 1), so that the higher frequencies have peaks as tall and noticeable as the lower ones. What I am displaying on each tube is the highest magnitude in the range of some frequency +- 10%. On Thursday, November 21, 2024 at 12:12:46 PM UTC-5 Mac Doktor wrote: > On Nov 20, 2024, at 10:28 PM, Zachary <[email protected]> wrote: > > Not all designs I found online included a potentiometer but I'm glad I put > one since the tubes I got on eBay varied wildly in glow length at the same > resistance. > > > This is my limited experience as well. One of my IN-13s began behaving > strangely after going up and down every four seconds over a period of > several weeks. > > Here's a site chock full of information about testing and burning them in > as well as some excellent technical analysis of how they work. And some > really nice photos: > > https://www.saltechips.com > > > Terry Bowman, KA4HJH > "The Mac Doctor" > > https://www.astarcloseup.com > > "Would you like to see the relevant data?"—343 Guilty Spark, *Halo 2* > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion, visit https://groups.google.com/d/msgid/neonixie-l/a397bb5c-79c8-466c-a60e-187f64c53424n%40googlegroups.com.
