MEP EP#293: Tom Anderson, the Gold Ear Sympathetic

MEP EP#293: Tom Anderson, the Gold Ear Sympathetic

Tom Anderson

• An old-timer engineer working from HP/Agilent/Keysight


• Currently still employed at Keysight


• Volunteering at Alembic, where he designs electronics for bass guitars


• Career includes:
  
  
  • Design of firmware
  
  
  • Digital
  
  
  • Analog
  
  
  • Microwave
  
  
  • Optical
  
  
  • Power supplies
  
  
  • Software
  
  
  • Information systems
  
  
  
  

Metrology and You

• Do I need to worry about all of this? (as a hobbyist, is accuracy important?)-


• Measure with micrometer...


• Taking Measurements
  
  
  
  • voltage, current, resistance, inductance, capacitance, Q, frequency, time, noise, RF/microwave
  
  
  • Measurement Uncertainty
    
    
    
    • +/- 0.1dB specification - what can go wrong?
    
    
    
    
  
  
  
  


• How do you make things more accurate?
  
  
  
  • System engineering - when the boards are put together, does the system work?
  
  
  • Testing the idea that multiple resistors are tighter tolerance than single
    
    
    
    • Are the values random?
    
    
    
    
  
  
  • Sources of errors - narrow things down to the path between a sensor and an ADC
    
    
    
    • Temperature
    
    
    • Noise, thermal
    
    
    • Noise, switching power supply, rectifier diodes
    
    
    • Noise, clock, data, address
    
    
    • DC shift - where does the ground current flow? Screws, contact resistance, and X-Acto blades.
    
    
    
    
  
  
  • Offset voltage and current
  
  
  
  


• Connector Repeatability


• Temperature
  
  
  
  • Repeatability/Skid
  
  
  • Controlling temperature (room air, coffee cup, fingers, oven proportional control)