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. …
jargon - CB v Amateur Radio - Amateur Radio Stack Exchange
Aug 16, 2021 · I am learning about Amateur Radio so as I can go for my foundation licence but I was on CB back in the days, a channel nine monitor and used the 10 code and the Q code but all I can see …
digital modes - How do you log (or not) "busted" FT8 QSOs? - Amateur ...
Oct 24, 2021 · Since it is "technically" a complete QSO I log it (in DXKeeper) but don't upload to e-qsl or LotW unless the other party does. If he does, I'll upload: if he doesn't I assume he has it as …
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: …
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 …
Antenna matching for a dipole - Amateur Radio Stack Exchange
Apr 5, 2025 · I am following 50ohm matching until balun and after that 73 ohm everywhere. Just looking at the two branches of your antenna: I'm not sure I'd say you're "violating" anything, but the model for …
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 …
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. Sometime operators will prematurely respond with their callsign, without waiting to hear if the other station has …
Core mix preferences for a balun (or unun) vs a choke
May 10, 2022 · The MnZn ferrite cores (Mix 31, 73, 75) have high permeabilities above 800 µ, have fairly low volume resistivity and moderate saturation flux density. They offer high ‘Q’ factors for the 1 KHz …
How does a folded dipole work? - Amateur Radio Stack Exchange
Per the above; although correct based on a free space dipole impedance of 73 ohms, I would suggest that very few practical dipoles are close to this based on the typical proximity to ground and the …