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 …
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, …
CW: when I supposed to send "E E"? - Amateur Radio Stack …
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 …
How does one read a ferrite datasheet? - Amateur Radio Stack …
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 …
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 …
How to estimate a dipole feedpoint impedance? - Amateur Radio …
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 …
Coaxial Folded Dipole Antenna Matching Impedance
Apr 22, 2015 · The site above depicts a regular dipole, with a simple matching system. First, a bit about dipole impedance. The impedance of a dipole is 73 Ohms at resonance, but away from …
Understanding how antenna mismatch can damage a transmitter
Nov 1, 2023 · 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 …
How to mark SWL contacts on eQSL? - Amateur Radio Stack …
It is interesting to have SWL reports because i was a SWL when i was a kid in the 50's and receiving distant stations was very interesting, BBC, VOA, Radio South Africa RSA, HCJB of …
Antenna tuning confusion - help! - Amateur Radio Stack Exchange
Aug 21, 2023 · A dipole antenna in free space ( no ground effects like capacitance or wire resistance) is 73 ohms. So if you had a dipole, @ a specific frequency, terminated into a 1/2 …