++++++++++++++++++ See also RFI From Computer ++++++++++++++++++ Date: Wed, 20 Nov 2002 23:12:57 -0800 From: "John, KI6WX" Subject: Re: [Elecraft] OT - Toroids for Stereo RFI? To: Elecraft Mailing List Hi; For blocking HF into cables, you want the highest mu ferrite material you can get. I often use #73 material for this purpose, but there are higher mu ferrites available. As for size, you have two choices. You can buy a big toroid and wind a number of turns on it, or you can buy one that just barely fits over the wire (this sometimes requires removing connectors). If you do the second, you do want a tight fit around the wire. Also, some manufacturers make split ferrites which can be clamped around the cables using the plastic housing that contains the ferrite material. These work great when you don't want to remove the connector when sliding the ferrite over the cable. -John KI6WX > Greetings: -- snip -- > > So, what are the best toroids (size and mix identifier) for winding audio > input cables, speaker wires and AC power cords onto, how many turns and > where's the best place to get em? > > Tnx and 73, > John, K7JG. ++++++++++++++ From: "Bob - AG5Q" To: "JAKidz" , Subject: Re: [Elecraft] OT - Toroids for Stereo RFI? Date: Thu, 21 Nov 2002 07:54:41 -0600 This site has some good info on RFI suppression: http://www.fair-rite.com/ 73, Bob - AG5Q +++++++++++++++ Subject: Re: [Elecraft] OT - Toroids for Stereo RFI? To: elecraft at mailman.qth.net Date: Thu, 21 Nov 2002 17:48:18 +0000 (GMT) From: ehramm at dk3uz.shnet.org (Edmund H. Ramm) John, KI6WX writes: > For blocking HF into cables, you want the highest mu ferrite material you > can get. I often use #73 material for this purpose, but there are higher > mu ferrites available. > [...] I prefer ferrite rods (5-6"long) as used im medium wave AM radios. Not only are they less expensive than toroids, I also don't have to remove and re-fit connectors, regardless of their size. Two Panduit straps will fix the cable to the rod, often a third one can be used to hold the rod's far end near the equipment's back plane. Also useful in the shack for keeping line noise away from the K2. Ha! On-topic agn. 73, Eddi ._._. -- email: dk3uz AT darc DOT de - AMPRNET: dk3uz at db0hht.ampr.org +++++++++++++++ To: elecraft at mailman.qth.net Date: Thu, 21 Nov 2002 20:14:05 -0500 Subject: Re: [Elecraft] OT - Toroids for Stereo RFI? From: Michael E Dobson They also sell an RFI kit at a reasonable price along with a variety of beads, toroids, and split beads at reasonable prices. Another good place for the larger split ferrites is Nebraska Surplus Sales. 73, Mike WA3KYY On Thu, 21 Nov 2002 07:54:41 -0600 "Bob - AG5Q" writes: > This site has some good info on RFI suppression: > http://www.fair-rite.com/ > > 73, > Bob - AG5Q ++++++++++++++++ Date: Thu, 5 Dec 2002 09:12:56 -0500 (EST) From: k4wtf at ENTERZONE.NET To: "Wallace, Andy" Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] QRP, DX ops, RFI, K2/100 On Thu, 5 Dec 2002, Wallace, Andy wrote: > a challenge to anyone who lives in any kind of populated area. Right now > I am trying to track down a wandering signal which is 5 kHz wide and > appears on 40 and 30m here -- fairly regular on 10.112. It's nothing > in my place. It wanders up and down at random, sounding like a swooshing > wind through an opening. Does not sound like light dimmers or switching > supplies or like anything I'd heard before. Andy, That sounds JUST like the RFI I traced down to a PC. You may want to start there with your tracking. 73 de John - K4WTF ++++++++++++