Towertalk
[Top] [All Lists]

Re: [TowerTalk] Wireless Internet RFI

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Wireless Internet RFI
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Mon, 29 Jul 2013 23:39:24 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 7/29/2013 10:07 AM, Brian Sarkisian wrote:
Any help would be appreciated.

In addition to the advice that both W8JI and I have offered about switching power supplies, don't overlook radiation from, and reception by, the telephone line. This mechanism is greatly increased when the telephone cable utilizes parallel conductors rather than twisted pair, and is interference is considerably reduced when the the twisted pair has a very high twist ratio (more twists per inch) and a more uniform twist.

For more than a century, telegraph and telephone wiring VERY effectively used twisted pair to reject interference, but the bean counters took over, and local wiring now uses a lot of parallel wire cables (because they are cheaper). In ALL cases of interference involving telephone systems, one of the first moves should be to replace parallel wire cables with CAT5/6/7 cables, ALWAYS dedicating a pair per circuit. In CAT5/6/7 cables, Blue and Blue/White is a pair, Or and Or/Wh is a pair, and so on. Most of this wiring belongs to the telephone carrier, and it is THEIR RESPONSIBILITY to make this replacement.

Likewise, when ANY product is the cause (or victim) of RF interference, we should ALWAYS DEMAND that the vendor solve HIS problem, which is ALWAYS the result of poor engineering of domination of the manufacturing process by bean counters. Several years ago, I saw a post by W8JI that he had done exactly this to solve a DSL RFI issue.

When ANY baseband system receives RFI, or CAUSES RFI, it is defective, and should be returned for replacement or refund. As I learned in the civil rights movement 40 years ago, if you're not part of the solution, you're part of the problem.

73, Jim K9YC
Still working on solving the root cause of problems :)

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

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