Transmission Lines for the Terrified
Jeff 9V1AS Filename:BB249_70
Hopefully, by the end of this talk, you will be able to answer the questions:1. "What is reflection coefficient?" 2. "What is VSWR" 3. "What is matching?" 4. "What are standing waves?" 5. "How much of my transmitted power is going out when my VSWR is 2?" 6. “What happens if the XYL keys up the 300W Linear while I am adjusting the spacers on the open wire feeder?”7. Why 50 ohms?8. Explain velocity factor
Jeff 9V1AS
Jeff 9V1AS
What is characteristic impedance?
Jeff 9V1AS
Yes, I can see your formulae, but I still can’t grasp the concept of characteristic impedance!
OK, let’s try again
Jeff 9V1AS
Characteristic Impedance Formulae for common transmission line types
Jeff 9V1AS
Why 50 ohms?
Jeff 9V1AS
Why 50 ohms?
Jeff 9V1AS
Why 50 ohms?
Jeff 9V1AS
Transmission and reflection
Jeff 9V1AS
Standing waves along a mismatched line (1)
Jeff 9V1AS
Standing waves along a mismatched line (2)
Jeff 9V1AS
What happens to the voltage and current for various terminations.
Jeff 9V1AS
V and I distribution for the special cases of ¼ and ½ lambda
Jeff 9V1AS
Lumped equivalents for TLs just less, equal, greater than ¼ lambda
Jeff 9V1AS
Different lengths can behave like different lumped circuits!
What’s the catch?.....
Jeff 9V1AS
Some special properties of ¼ and ½ lambda lines
Jeff 9V1AS
Jeff 9V1AS
"This is the last time you're coming home late from your ham radio club meeting"!
Jeff 9V1AS
