[RFI] Snap on split beads; coax high-pass filter recommendations

Jon Ogden Jon Ogden <jono@enteract.com>
Fri, 03 Dec 1999 09:04:42 -0600

on 12/2/99 19:31, Charles T Johnston at ctj92@primenet.com wrote:

>> The material though in the split ferrites and so forth that you can buy from
>> Radio Shack are not type 43.  They are designed more for attenuating VHF
>> energy which would probably make them type 61 or 68 material.
> I had great success eliminating TVI in my home ( on a cable TV system) by
> placing 2 of the Radio Shack snap-on ferrites at the RG59 coax input to the
> TV.  Prior to that I was unable to run 15M or 17M without very noticeable TVI.
> Where did you get the specs on the Radio Shack ferrites?

I am almost certain the material in the Radio Shack ferrites is not type 43.
It probably works well for you because 15 and 17 meters are high enough in
frequency for material 61 or 68.  I also had a long talk with Earl at Amidon
about ferrite materials and Radio Shacks product in particular.  He said it
certainly would help but that it was not type 43 and that a type 43 ferrite
would do an even better job.

It depends on how much attenuation you really need.  When I run 1.5 KW with
my beam, I had to put large core ferrites on all of my speakers leads an in
multiple places on my TV coax leads (at input and output of cable box and
input of TV).  I really needed a lot of attenuation.  A snap on beam on my
coax would not have done the trick!



The Second Amendment is NOT about duck hunting!

Jon Ogden


"A life lived in fear is a life half lived."

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