Topband: Twin Lead Marconi Antenna

[Ross Primrose]

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.”