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If you don't have a VNA you can also use an antenna analyser.

At my last workplace we had a pile of scrap electronics that was sent for disposal at regular intervals. I must have recovered many hundred ferrites with moulded plastic covering from various

Hi, The mini ring core calculator program enables parameters, of ferrite and iron powered cores, to be determined. https://qsl.net/v15/DL5SWB-Software.htm Regards, Edgar Moonah, Tasmania.

Because a person is curious? Best reason i know of. Some of my better learning comes from starting with variations to existing designs. 73, kevin kc6pob

Still, even if your budget is very close to zero, don't be discouraged and keep experimenting and learning. Loop antennas are one area where you can make something usable from pieces of junk. 73,

Tom We are saying the same thing.. Simon

Not really, Simon. The problem with unknown cores is that you could compound the problem rather than helping solve it. I'm gradually adding to all my cheap Chinese ferrites with genuine Fair-Rite

Hi Nice idea, but why? when said proper cores are widely available and cheap?(If in Europe or USA.) with known cores you know the outcome.. Reinventing the wheel?? However can see the point if

Made a transformer using 2 VGA cable cores, 4 turns of twisted pair from an Ethernet Cat5 cable. Did a sweep with NanoVNA. Primary connected to port 1, secondary to port 2. -3dB bandwidth is 0.15MHz

And besides..who uses a magloop ( or other narrow bandwidth antenna) for rx in a competition? One uses active rx loops/ beverage/ short verticals etc ( on low bands) and then tunes mag loop to

That’s not really true I have no problems as long as on one band.. ie 160m. one still can see the activity perfectly well.. its just not linear across the display. I have just 2.5khz useable

Another downside to high-Q antennas is the effect on waterfall displays.? They're OK for digimodes that operate in narrow bands but not helpful in SSB contests. Keith? M0KIL.

Hi Ed & Bob, A high Q antenna can act as a pre-selector / band pass filter, which may help prevent overload from other strong stations on nearby frequencies, but this is less of a problem than it

I made a NCPL with this kind of balun. Works very well.

Pretty cool way of making a binocular core toroid! Not sure of the loss factor but these ferrites need to be lossy to reduce, if not kill, EMI/RFI on the cable. it is definitely an experiment worth

Not sure how well they perform but Tak Tenna has a beam version of flat spirals. They use the antenna frame to hold the windings in place as well as a reasonably stiff wire. I assume the last part as

My post refers to _/tuned/__//_ (inductance-capacitance) circuits.? Properly constructed, a spiral loop will have a bandwidth (-6 db) of just a few kHz at lower SW frequencies.? The Q is extremely

Remember that flat spiral antennas are very wide band ant that means low Q which equals more QRM/QRN. Narrow band means High Q and low noise.

https://swling.com/blog/2020/04/hack-a-broken-vga-cable-to-make-a-binocular-ferrite-cores-for-your-ncpl-antenna/ -- Jim, KA6TPR

I have been using _/spiral /_loops exclusively for reception of LW, MW, and SW many years.? I understand, despite their low radiation resistance, loops have become quite popular for transmission