On 10/1/2024 2:24 PM, David Woolley wrote:
Re: output impedance: Not the output impedance, but the optimum safe load impedance. The actual output impedance is generally a lot lower. The value being matched to 50 ohms is approximately, but less than, the supply rail voltage divided by the maximum safe current, for the output device, but more generally will such as to maximise the available output power subject to keeping the output stage within the safe operating area, and avoid clipping, whilst, in conjunction with any safety measures, tolerating a significant divergence from the nominal 50 ohms.
Exactly right.
Re: position of capacitor: A capacitor in the shack can act like an inductor, at the antenna.
This is totally dependent on the match of the antenna to the transmission line, the impedance of the line, and its length. The person asking the question needs to open the ARRL Handbook and/or Antenna Book and study transmission lines.
Also all of these things are only strictly true for a completely pure sine wave.
I think you may be confusing modulation, which is often complex, with RF, which IS essentially sinusoidal, minus distortion components, which are quite small by the time they get through the output network to the transmission line.
73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
