2013年10月25日 · "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 …

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?

2022年5月10日 · Manganese-zinc (MnZn) available as Mix #31, #75 and #77 (and others) – work well for common mode chokes Nickel-Zinc (NiZn) available as Mix #43, #52, #61, (and others) – generally preferred material for baluns/ununs Palomar Engineers uses mix 31, 43, 52, 61, 73, 75 and 77 for most applications from RFI/EMI common mode suppression, multi ...

2023年11月1日 · 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.

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.

2021年8月16日 · 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!".

2021年10月24日 · 73 Dave - K1DJE. Share. Improve this answer. Follow answered Oct 24, 2021 at 18:18. Dave Dave. 81 2 2 ...

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.

2020年1月8日 · 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".

2015年12月15日 · 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 slanting, inverting or angle of …