[Lowfer] FW: TOP-HAT; how long is not useful anymore ??

[Bill Ashlock]

From: ashlockw at hotmail.com
To: evp at pacbell.net
Subject: RE: [Lowfer] TOP-HAT; how long is not useful anymore ??
Date: Wed, 19 Aug 2009 20:46:00 -0400



All tophatters,
 
Another point to be considered is the proximity of tall lossy objects within, maybe, 50ft of the edge of the top hat - mainly trees. Therefore one can actually reduce the transmitting efficiency of an antenna by increasing the size of the top hat. Another point to be considered in attempting to measure the benefits of larger top hats (via antenna current measurements) is that it is difficult to separate the "tree effect" from the effect of a poor grounding system.
 
Bill
 
> Date: Wed, 19 Aug 2009 16:07:03 -0700
> From: evp at pacbell.net
> To: lowfer at mailman.qth.net
> Subject: Re: [Lowfer] TOP-HAT; how long is not useful anymore ??
> 
> It all depends on your ground circuit resistance. If it's low 
> enough you could get considerable improvement If it's high enough won't 
> make any difference.
> 
> Ed
> 
> Andy - KU4XR wrote:
> 
> >Hey everyone:
> >
> >Hope summer is going well for everyone. I'm planning to play
> >around with my lowFER ant. and try to raise its' efficiency
> >for this winter season. Concerning Top-Hats; does the law of
> >diminishing returns come into play ?? Is there any need to 
> >go longer than 50' for the tophat wires ?? I've read the
> >" more wires is better " part; but regarding length; does
> >the rule of " Doubling " the size of the Top-Hat length
> >have an effect on overall ant. efficiency ??
> >
> >At the moment, I'm using 20' of Top-Hat wire length, in a 
> >semi-circle pattern with a circumference wire tieing the 
> >9 wires in the Top-Hat together. I can easily go 200' in 
> >length with a single " T " type Top-Hat. Other wires could
> >be added in different directions, at various lengths.
> >
> >The overall question is; Will a Super Size Top-Hat result 
> >in a noticable enough improvement to warrant the effort ??
> >
> >
> >
> >Andy - KU4XR - EM75xr - Friendsville, TN.
> >LOWfer Beacon " XR " @ 184.322 KHz ( QRSS-60 )
> >Coordinates: N: 35* 43' 54" - W: 84* 3' 16"
> >http://www.myspace.com/beaconxr
> >
> 
> 
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