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سؤال 385

What is a beta or hairpin match?

  1. A shorted transmission line stub placed at the feed point of a Yagi antenna to provide impedance matchingپاسخ درست
  2. A 1/4 wavelength section of 75-ohm coax in series with the feed point of a Yagi to provide impedance matching
  3. A series capacitor selected to cancel the inductive reactance of a folded dipole antenna
  4. A section of 300-ohm twin-lead transmission line used to match a folded dipole antenna

توضیح

A beta or hairpin match is a shorted stub of transmission line, electrically an inductor, connected across the feed point. Used with a driven element cut slightly short so it looks capacitive, it forms an L network that transforms the low feed point impedance up to the feed line impedance.

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شروع تمرین
سؤال 385: What is a beta or hairpin match? · FCC General Class (Element 3) · Questena