if it is good for a choke it can be used to feed a dipole ... not a real balun .. i know .. but a similar function ...
just wind one and measure with vna
if not superb to use on antenna they may be used to choke such things like telephone lines, printer or screen cables, rotor control lines .. whatever
so the only way for an unknown core is to just try them .. maybe wind a coil over them and measure it to compare with known mixes
dg9bfc sigi
Am 12.03.2023 um 00:23 schrieb N2MS:
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Bryan,
Those power supply ferrites are useful for low frequency power or choke applications but are not that useful for HF balun, unun or transformer applications. The unknown ferrites I find useful are those split ferrites placed on cables for RFI attenuation. Most are designed for VHF attenuation and are similar to the Fair-Rite 43 mix.
There is no standard color code. The colors are probably unique to the manufacturer.
Mike N2MS
On 03/11/2023 4:25 PM Bryan Curl <bc3910@...> wrote:
Thanks all. I just wasnt sure, for a thru cal where to place the Open Short and Load bits. Its pretty straight forward for using just S11 for reflected measurements.
Mike that's a great idea for identifying ferrites! I tore some out of an old PC power supply that were green, blue and black but have no idea what they are. Colors may or may not be an indication.
Thanks again everyone.
Bryan
