Callsigns are PII…
While talking to someone way smarter than me we collaboratively determined that FCC issued Amateur Callsigns constitute PII.
For the following reasons:
PII is defined “Any representation of information that permits the identity of an individual to whom the information applies to be reasonably inferred by either direct or indirect means.” US Department of Labor 1
FCC Callsigns are issued by a federal agency specifically as a unique identifier that is inextricably linked to an individual with the sole purpose of identifying the individual.
BPF
Band Pass filters allow a specified range of frequencies pass through the circuit while limiting the impact of signals below or above the chosen frequency range.
The Calculations Both high- and low-pass filters use the same math to determine their effective frequency. The orientation of the passive components (Resistor and Capacitor in this example here) is what dictates whether high- or low-pass filtering is achieved.
The effective function for RC filters is: