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Re: Optimizing Small Untuned Loop Antennas

VE7VXO All Messages By This Member #16871 开云体育 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 - the code could be tweaked to output a varactor voltage for an rx only antenna rather than drive a stepper motor if desired) and you have the advantage of a small and efficient antenna but the ability to work around its narrow band nature. ? With the excess gain that modern receivers have at HF especially the low end where compact antennas are attractive, the AGC action will still reveal signals that may be of interest outside the resonant envelope of the tuned antenna.? Click on the area of interest and presto the antenna follows you there.? Or take the old school approach of slowly tuning up the band while the antenna follows. If you are panadapter obsessed and must have a broadband antenna which can cover the entire HF spectrum, by definition (Chu-Wheeler) it must be lossy and reactive.? What does it mean then to "optimize" it??? In my opinion a compact efficient and therefore narrowband antenna which is frequency agile is an awesomized antenna. On 2022-10-26 4:25 p.m., Richard \(Rick\) Karlquist \(N6RK\) wrote: toggle quoted message Show quoted text 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 On 2022-10-26 16:19, Everett N4CY via groups.io wrote: 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 ? On Oct 26, 2022, at 6:07 PM, VE7VXO <jstreet@...> wrote: 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. ? On 2022-10-26 02:03 PM, Richard \(Rick\) Karlquist \(N6RK\) wrote: 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 from simply using a tuned loop? On n6rk.com you can find my article on building tuned loops. Many people have duplicated this design. --- Rick Karlquist N6RK

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#16871

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