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John, I forgot to mention in the final equation of AF Is indirectly included the aperture value of antenna through the antenna gain G because any antenna gain is dependent on its aperture value.

All, I see some of responders are confused about AF definition and variables that effect AF value. I did not call AF as a loss factor, only made my point about “mismatch factor” caused by

The antenna factor is strictly a function of the effective aperture of the antenna.? For a given power density the ratio of the free space impedance and the system impedance form a factor which is a

All, In recent years the use of a term called “Antenna Factor” in EMC and spectrum pollution work has become very important. There has been a great need for measuring field intensity and/or power

Already a thing, Rick.? The latest firmware for the KiwiSDR outputs a CAT string on /dev/tty/usb0 with its tuned frequency. Connect this to a tracking magloop tuner (a number of fine designs exist -

Yes, I thought the function of an antenna (part of it) is to act like a coupling device that transforms the feedpoint impedance to that of free space. Not that the antenna should have the impedance of

KISS is always the best approach. Everett N4CY

One could imagine a swept receiver (wouldn't have to be SDR) that was synchronized with a swept loop antenna to make a "Panadapter" display. Would that work for you? --- Rick Karlquist N6RK

Most of us these days are using SDR receivers and want to look at a wider piece of spectrum than the small amount you will see with a tuned loop. Are we going forward, or backwards? Everett N4CY

As a bonus you also get protection from out of band signals overloading the front end of your rx by virtue of the antenna acting as a narrow RF filter. Links: ------ [1]

You can get a lot more signal out of a given loop if you tune it. Also, you get 9 dB additional signal every time you double the diameter of the loop. Do you have some requirement that prevents you

"Mismatch factor from 377 ohms to 50 ohms providing that the impedance of your antenna is 50 ohms." Is this true? I'm not sure I buy this idea. Why should an antenna's radiation resistance match that

Hi Martin, I see Alan has responded to the second part of your question. I will respond to the first part regarding the antenna factor. In transmission path there are two chains - transmit antenna -

Alan, Best’s work was published in 2016 and I do not consider electrodynamics laws old fashioned. Technologies could be new and advanced but physics theories stay the same regardless how you would

Hi Martin, EZNEC exports a Source impedance, R and X, file, LastZ.txt. SimSmith can use LastZ.txt file for matching solutions. System gain, or loss, is a combined EZNEC and SimSmith. John KN5L

Raphael Dr Best's paper is a very old fashioned outline approach to receiving antennas because it uses matching using passive components which implies narrow band operation. It completely omits active

Hmmm, I've always assumed that the Antenna Factor included any mismatch loss, but you may well be correct in your comment. Another issue that has puzzled me is that, if you model an antenna with

Small correction to my e-mail: The definitions shall be corrected – mismatch loss factor is expressed for these equations ( its range of value 0 to 1 ). Mismatch loss will be defined as 10 log of

All, I am wondering whether those who spend a lot of time building and testing small loop antennas besides Owen Duffy's concept of SNR degradation? are familiar as well as with Steven R. Best's

Hi John, Would you share with our community how to break laws of electrodynamics and wave propagation nature to receive shortwave stations apart 6000 miles using indoor small loop antennas in USA