Comments

  • Wilkinson resistor test
    It seems to me if you are worried about shorted resistors after a solder operation that you have a design and/or process problem. Fix those and testing becomes less important. Just sayin'.

    (And by the way, solder shows extremely well on xrays.)
  • Wilkinson resistor test
    Geez, we just printed identical resistors to nowhere adjacent to the "real" resistors and measured those. Did this for space products. The ohms per square of the resistor material is set and stabilized with a high temperature bake. The alternate resistors verify the process.
  • Group delay in a receiver
    You can achieve negative group delay in a medium with anomalous dispersion (like seawater). This just means the signal arrives prior to the carrier (group velocity > phase velocity; what makes it anomalous). Media with high insertion loss can also yield negative group delay such as just outside a bandpass filters passband.
  • Standard topology for SMA attenuators?
    Not sure what you mean by topology? If you mean Tee or Pi type you may be surprised that most are neither, relying instead on a 2D slab of resistor material (which ohms out properly as if it were Tee or Pi). The big trick is broadbanding techniques especially when trying to ground the shunt. I would need to find an old paper to explain this type of attenuator. Madengr should know.
  • YIG detection - DC Magnetic Field
    YIG is a very expensive single crystal. Yes the sphere would resonate but to "see" it at 6 feet would probably require gain (dc power, cost, etc.). I guess cost in quantity >~$40.
  • Silver Plated Brass Screws for tuning
    Buy and plate standard screws. However, when you make the cover (or whatever) with the threaded holes use an oversized tap to ensure a fit after cover plating (i.e. adjust the taps pitch diameter). This is how we did it in combline filter world. You can get almost any p.d. you want. I stripped a 2-56 hole and had it tapped up to 3-56 to save an expensive device. A good designer can figure out the appropriate p.d. depending on screw size and plating thickness. In contrast, screw manufacturers probably wouldn't make nonstandard screws unless you were willing to buy maybe 100,000 of them.

Desert Sage

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