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  1. Why do hams often conclude messages with "73"?

    Oct 25, 2013 · The usage of "73" for such a purpose comes from the Phillips Code, originally devised in the era of telegraphs to speed up transmission of common messages by mapping them to numbers. …

  2. CW: when I supposed to send "E E"? - Amateur Radio Stack Exchange

    Jan 8, 2020 · I'm new to CW and one thing I couldn't figure out is when I supposed to send "E E". Let's say I'm calling CQ and somebody answers me. The QSO is almost over. Should it be ended like this: …

  3. What's the difference between saying “CQ” or “QRZ” in a contest?

    The best thing to do is to listen for a while, and notice which stations are being responded to. Sometimes operators will prematurely respond with their callsign, without waiting to hear if the other station has …

  4. Dipole increased CM current using choke balun - Amateur Radio Stack ...

    Aug 23, 2019 · I've read that an inverted vee lowers the 73 ohm dipole impedance closer to the 50-ohm coax impedance but connecting a coax unbalances the antenna, so I wanted also to test using a …

  5. How to estimate a dipole feedpoint impedance? - Amateur Radio Stack ...

    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 …

  6. How does one read a ferrite datasheet? - Amateur Radio Stack Exchange

    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 …

  7. Adding a choke to the feed point

    Dec 13, 2024 · 1 I recently installed a vertical antenna and was surprised by the loud noise. I am thinking of adding a choke to the feed point, but is it sufficient to simply add one? Or should I adjust …

  8. Impedance Matching Different Feedlines - Amateur Radio Stack …

    A folded dipole will increase this impedance to the square of the number of parallel elements (for the ultralite sr. with 3 parallel elements, I calculate 9 * 73 = 657 ohms impedance).

  9. What is dB (μV/m), and what are its applications?

    Dec 22, 2017 · A dB (µV/m) is a decibel relation for a sub-unit of V/m, which is appropriate for units of the e-field intensity of a radiated e-m wave existing between two physical points in space separated …

  10. Calculation of transceiver current draw - Amateur Radio Stack Exchange

    Feb 14, 2020 · Your radio is 13.8V nominal, but it's probably rated for 13.8V +/- 15% (11.73 - 15.87 V) and it probably makes rated power at 12V (people tend to be unhappy otherwise). Combining the …