The center of a Smith Chart is not 50 ohms - it's the reference load. In an ideal (TEM) environment and connector type/fixture, the center of the chart will be the reference impedance you used, whatever that may be. " If you connect the 50Ω std., it now appears at 50Ωs on a chart normalized for 75Ω," > tail off below 470, with best rejection 420 -430 MHz.probably only need > I need to pass above 470MHz, could live with 1 or 2dB through loss. > I am building a 75 ohm TVI - DMR filter using multiple stubs out of 75 ohm > Is it valid to simply do the calibrate procedure, but using R75 feeders On Thu, at 9:24 PM PETER LAWRENCE via groups.io wrote: With the outliers when they occur during my design and home brewing needs. I'm happy to have a good instrument that is devoted to 50-ohms. The trade-offs (based on Bell Lab studies in the mid to late 40's for High Pulsed Power Research applications: 0.5 to 5-ohms High Power Laser feeds: 2-ohms (slab line) If there were VNAs for every requirement:Ībout everyone in RF communications: 50-ohms
Measure the Minicircuits units for the same porpose. That way, you know precisely what you are dealing with. Or, since you have a VNA, design and measure your