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  • Why do hams often conclude messages with 73?
    "73" mapped to "best regards" or "my compliments" and was intended as a general valediction for transmitted messages It is still used for that purpose today in morse code transmissions and often makes its way into everyday correspondence among hams as a form of jargon
  • digital modes - How do you log (or not) busted FT8 QSOs? - Amateur . . .
    73 Dave - K1DJE Share Improve this answer Follow answered Oct 24, 2021 at 18:18 Dave Dave 81 2 2
  • What is the impedance of an end-fed half-wave antenna?
    Theoretically, (73 + j42 5)Ω When the dipole is too short, its reactance will be capacitive When it's too long, inductive Since the exactly half-wave dipole has a slightly inductive reactance, shortening it can eliminate the reactance The exact amount of shortening depends on the thickness of the wire 0 41λ sounds like a reasonable estimate
  • CW: when I supposed to send E E? - Amateur Radio Stack Exchange
    First, some history As I understand it, the "dit-dit" (E E) comes from an old practice There is a short tune in popular music that was often used to end a musical performance in a humorous way, called "shave and a haircut, two bits"
  • procedure - CW contact content - Amateur Radio Stack Exchange
    AA1BBB DE YU1NKA R OK TNX DR BOB FER ALL BT WILL SEND QSLL VIA BURO BURO BT HPE TO CU AGN ES ALL BEST FER U ES UR FAMILY IN 2015 BT TNX FER QSO 73 SK AA1BBB DE YU1NKA CL Here again, we have R, to show that whole last relation came through
  • How does one read a ferrite datasheet? - Amateur Radio Stack Exchange
    Datasheets for ferrite materials are usually filled with incomprehensible graphs with greek letters For example, Fair-Rite's 73 material: What's a $\mu'_s$ and a $\mu''_s$? What do these numbers represent, and how can I use them in amateur radio? Do they allow me to predict inductance or losses of inductors made on cores of this material?
  • How to estimate a dipole feedpoint impedance?
    An ideal dipole, at resonance, will have an impedance around 73 ohms A folded dipole, around 280 ohms How can I calculate the impedances when not at resonance? Let's assume I have a span of 15M in my property where I can hang a dipole Ideally, and very roughly, a folded dipole would give me about 280 ohms impedance at 10MHz
  • Antenna matching for a dipole - Amateur Radio Stack Exchange
    There is a 433 MHz-438 MHz transceiver terminated at 50 ohm The transceiver output is connected to 50 ohm:73ohm Balun, and from balun to two dipoles 73 ohm balun is chosen because the impedance of each dipole element is 73 ohm The schematics is shown in the picture




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