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Re: Topband: Twin Lead Marconi Antenna

Subject: Re: Topband: Twin Lead Marconi Antenna
From: Ross Primrose <>
Date: Mon, 15 Jun 2009 14:54:23 -0400
List-post: <">>
On 6/13/09 9:55 PM, Herb Schoenbohm wrote:
> Garry wrote:
> I do recall however that the theory that the ground losses were reduced by a 
> 4 to 1 base impedance multiplication factor has been disputed.

Citation? That's still the working theory in Low Band DXing.

> I always carried along some small 1/4 wave bell wire radials which terminated 
> at the rig ground.  The twin lead Marconi may improve on the rigs ability to 
> match the antenna with a built in tuner but you can raise the impedance by 
> making a single wire the antenna longer like 180 feet.  This antenna can be 
> generally brought to resonence by a series variable capacitor to remove the 
> inductive reactance it imposes.
> The twin lead is two close spaced for much bandwidth improvement and the 
> ground loses are a factor of the radial system. But for certain applications 
> it is a good antenna to consider.

> 73
> Herb, KV4FZ

Ground RESISTANCE is a factor of the radial system. Ground LOSSES are 
related to the ratio of ground resistance to radiation resistance.

Ross AJ4LL

FCC Section 97.313(a) “At all times, an amateur station must use the minimum 
transmitter power necessary to carry out the desired communications.”

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