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Re: [TowerTalk] Metal roof

To: <>
Subject: Re: [TowerTalk] Metal roof
From: "David Jordan" <>
Date: Fri, 5 Aug 2011 18:13:22 -0400
List-post: <">>
Our court house has a copper metal roof (flat).  Hustler Vertical antennas 
require an added $45. shunt coil (16 turns) to couple the low impedance to 
52ohm coax.  The Hustler vertical trap antennas are not designed to operate 
over a perfect or very good ground radial system.  I guess there are more 
poor to fair radial systems out there then good ones. So those of us with 
good ones have to pay an extra $50 BUCKS...     GO FIGURE!  BUXCOMM sells 
OCF antennas and they offer their antenna in three options, all for the same 
price. So, you tell them the wire is going to be up over 50ft you get one 
type of balun... if it close to the earth you get a different one or if it 
is going to be over a roof of a building yet a third type, but they don't 
screw you because of your choice, geez DX Engineering, hahaha

----- Original Message ----- 
From: "Jim Lux" <>
To: <>
Sent: Friday, August 05, 2011 3:40 PM
Subject: Re: [TowerTalk] Metal roof

> On 8/5/11 11:44 AM, Pete Smith wrote:
>> Without any direct experience, other than a trap vertical on a 20 x 40
>> metal roof made up of 4x8 metal sheets, I'd say a vertical would work
>> fine, but anything else nearby could be adversely affected.  I also
>> wonder, at least in theory, if you wouldn't risk imperfect electrical
>> connections between shingles becoming harmonic-generating diodes, in the
>> presence of a strong RF field.
> But... what about all the harmonic generating diodes from the chicken
> wire under the stucco, or the woven mesh of a chain link fence.
> I think the harmonics & diodes thing pops up more in situations where
> you have multiple transmitters in a single location, generating spurs
> that get into receivers at that same location.
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