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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
- 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!"
- antenna - What happens if I “open” a folded dipole so that the two . . .
Half wave is around 73 ohms, folded is around 292 ohms That's why you can feed one directly from 300 ohm twin lead, and even make one from it like those old FM radio antennas $\endgroup$ – GodJihyo
- 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
- 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?
- 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
- 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
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