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Re: [TowerTalk] Topband: 160 meter elevated vertical

Subject: Re: [TowerTalk] Topband: 160 meter elevated vertical
From: Jim Lux <>
Date: Sat, 20 Oct 2012 08:56:46 -0700
List-post: <">>
On 10/20/12 8:47 AM, wrote:
Along with that line of thinking...using RG58 on a 4 inch core.  About  how
many turns?  My thinking is around 25 or so.

why not 4 or 5 turns on a 2.4" ferrite/powdered metal core? 4" PVC core is a foot per turn, 25 turns is 25 feet of coax (which I grant you probably already have), but say it's 0.25/ft. that's 5-6 bucks worth of coax against a $5 ferrite core, which will be more broadband, higher choking impedance, physically smaller, etc. Air core chokes don't have a lot of resistive impedance: you're depending on their inductive reactance, and that's subject to cancellation from parasitic C, etc.

You'd have to check K9YCs writeup to see what an appropriate material for the core would be. #31 is the sort of general go-to material for ham band use, but there might be something better for lower frequencies.


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