A while back I posted impedance vs frequency vs # of turns data for the Amidon FT-240-77 toroid (Fair-Rite Products P/N 5977003801). I have updated my website to include plots of the real (R) and ima
______ Good info, Mike This is close to what I see for 77 material in smaller size toroids and beads, with some variation in the frequency of peak impedance. Readers should not interpret the data as
Mike: When I compare your plots to those from Fair-Rite ( http://www.fair-rite.com/fr_catalog-14thed_rev3.pdf , page 173, Figure 4), the difference is quite notable. Fair-Rite shows that the impedanc
it I'll take a stab at it, Chuck. I've also measured a bunch of ferrite chokes, both single turn and multiple turns. It is VERY important to understand that these are not transformers, they are choke
Jim (and/or others): http://www.dellroy.com/W4EF's-Ham-Radio-Page/Ferrite_Data/Ferrite.htm Help me understand how this translates to a practical use at the feedpoint of a receiving antenna. I want t
1) Consider how the X component affects your particular installation. Would capacitive reactance cause a resonance at the frequency you are transmitting (or at another frequency that could be nearby
http://www.w8ji.com/common-mode_noise.htm You will probably never get the siolation you need with a choke of any form in the case of something like a Pennant/Flag. You need an isolated winding prima
I would revise that to say that chokes are most effective and most easily used if there is a low shunting impedance across the load. Yes, I would love to have a low shunt Z across the load, but I'm n
I just measured two cores of 77 material Jeff sent me. I wasn't in any hurry since Mike had posted data, but since I had the analyzer up and calibrated on the correct fixture today I ran them. Looks
Yes, different sizes of the same mix have different properties and some of the Amidon charts show that clearly with overlaid data so there's no surprise there. But that wasn't really intended to be m
If you look at the portion of the mu curves where u' is flat and much larger than u", that is where you expect the core to act like a high-mu low loss magnetic material. In that region the inductance