[Top] [All Lists]

Re: [TowerTalk] decoupling RF from control lines

To: "" <>
Subject: Re: [TowerTalk] decoupling RF from control lines
From: "Jim Brown" <>
Date: Tue, 16 Aug 2005 08:06:51 -0500
List-post: <>
On Tue, 16 Aug 2005 08:36:18 -0400, Pete Smith wrote:

>I'm thinking that an RF choke in series and bypass cap to 
>ground on each line would help.  

Pete -- take a look at the following link, which is an applications 
note I wrote for audio system RF suppression. The chokes described 
would work quite nicely to suppress common mode current on those 
cables. Simply use the data (curves) and guidelines to tell you how 
many turns to use for the frequencies where you are having problems.

Also look at the material in the link below on "the pin 1 problem." 

You might also need capacitors, but probably a lot smaller ones. 

Another point. Twisting can be just as important as shielding in 
rejecting interference. If you aren't already doing so, and if the 
right choke doesn't fix it, my next move would be to use cable that 
uses a twisted pair for each signal circuit. 

Jim K9YC


See:  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>