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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
- 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
- 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
- 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
- Understanding how antenna mismatch can damage a transmitter
Antenna impedance is largely due to radiation resistance: a center fed half wavelength dipole has a radiation resistance of about 73 ohms Resistance due to heat loss is negligible, and I believe reactance negligible as well Let's say we have an oscillator consisting of a 1 MHz voltage source (30V RMS) in series with a 75 ohm resistor
- Why are contest signal reports always 59 or 599?
Manufacturers muddied the waters somewhat by putting S-meters in receivers, with S9 set as -73 dBm, which was reinforced by an IARU Region 1 technical recommendation Because contests are competitions, parts of the QSO not necessary for efficient communication resulting in points are streamlined as much as possible
- 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"
- jargon - CB v Amateur Radio - Amateur Radio Stack Exchange
None of the above There are no "73 codes" like 10-codes, 73 is just 73 Yes, I know about the 92 code, but it's well and truly dead, with no survivors other than 73 and occasionally 88, so realistically speaking they stand on their own And 73 doesn't mean "end of transmission", it means "best wishes" or "warm regards" or just "have a great day!"
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