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Re: [TowerTalk] Antenna Stubs

Subject: Re: [TowerTalk] Antenna Stubs
From: Jim Brown <>
Date: Sun, 14 Aug 2011 09:14:56 -0700
List-post: <">>
On 8/1/2011 8:42 PM, Tom Osborne wrote:
> I'll be using some RG-6
> for the stubs as I have about 600 feet of it.  I know it's not as good as
> bigger coax, but it's what I have on hand.


For several reasons, RG6 is a lousy choice for stubs in 50 ohm systems. 
The fundamental problem is that stubs work by shorting out the undesired 
signal.That requires very low resistance of both center conductor and 
shield. RG6 has relatively high resistance both because it is 75 ohms, 
and because the conductors are smaller.  IMO, your project is not worth 
doing unless you do it with an RG8 that has big copper center conductor 
and a robust copper shield.

To throw some numbers at it, stubs made with the best coax can achieve 
25-30dB attenuation, depending on frequency range, while those you're 
planning might be good for 12 dB at best.

73, Jim K9YC

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