I want to block RF from possibly feeding back into a 12 volt DC power supply. What is the best material for this available in a small toroid? Will a one-turn winding be sufficient? Thanks in advance
Ferrite 31 mix seems to be a good one for chokes. Raj -- Rajiv Dewan, N2RD n2rd@arrl.net FN13fc _______________________________________________ See: http://www.mscomputer.com for "Self Supporting Tow
Yes, good suggestion, Raj. I just made some measurements on a 2.4 inch O.D. type 31 Fair-Rite Products core that K9YC sent me. 7 turns on this core will give you >1000 ohms choking impedance from 1.8
Hi all, I am always interested in toroid comments. I have been successfully cleaning up a lot of my long-standing RFI problems with them. My question. Ignoring the economics, as I have both types ava
question. Ignoring the the results of There is a good bit on nonsense circulating about this, like adding a few beads of some type at the end of a string of other beads when building a balun. I gues
with two different materials, you've basically got two inductors/chokes in series. You'd have to evaluate them separately at the various frequencies and sum the contributions at each frequency. For i
Specifically what kind of RFI are you cleaning up. RFI effecting a stereo, TV, or a phone in your house or in your a neighbors? What bands where you TX'ing on and how much power. Thanks, XD _________
Yes, BUT: it is the COMPLEX SUM of their impedances that will result. A ferrite choke is basically a parallel RLC resonance having very low Q. At resonance (the peak of the Z curve) it will look resi
I happened to speak with a customer service representative at Fair-Rite just a couple of hours before seeing W4EF's posting (above), and as of late this afternoon (3/22) there were NO type 31 toroids
the SB-200. fixed inductors a closely I'm sorry, I was speaking of the series-resonant point. That's the frequency where a section of the choke has extreme voltages and the choke acts like back-to-b
TV, or a phone in your house or in your a neighbors? What bands where you TX'ing on and how much power. Dave, I am not sure who you addressed this question to, but here are some examples of what I us
Thanks to all who offered help. Seems mix 31 is the hands down favorite. The only thing I can find on the 'net are beads offered by DX Engineering. I suppose using beads rather than toroids will bloc
antenna two antenna analyzer measured some toroids be inserted Insertion loss was also acceptable so I am looking Keith, If you are only switching two ports to a common 500 MHz should be easy. In al
You are probably right. This project originally had one pair of SO239's and one relay. Then I upgraded it to a second port. Each pair and relay is on its own small PC board with separate DC supply w