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From: "Mike Dennison" <mike.dennison@ntlworld.com>
To: rsgb_lf_group@blacksheep.org
Date: Sat, 12 Aug 2006 17:04:45 +0100
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Subject: RE: LF: Re: antenna: how to get max. capacity
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You have the answer at the end of your e-mail. Multiple vertical 
wires are good for broadbanding, but provide additional capacitance 
to ground at a low height, thus reducing the effective height. 
Broadbanding may have been important in an efficient commercial 
station, but is unnecessary when ground resistances of 100+ohms make 
the antenna broad enough.

Mike, G3XDV
==========.

> I remember seeing a multi top wire LF antenna with multi wire vertical
> conductors somewhere & I found it in the 'Low Frequency Experimenters
> Handbook' in an article written by Peter G3LDO. He shows a 4 wire top
> with a 4 wire vertical feed & describes it as a 'Traditional T LF
> Antenna'. What I am curious about is that if it is detremental to have
> this multi wire vertical arrangement as you stated, why has Peter
> shown it in his article? I have an Admiralty book 'Handbook of
> Wireless Telegraphy' (1938) which shows the same type of T antenna
> with a multi wire vertical section.  I have also seen articles
> elsewhere (maybe on internet) regarding multi wire verticals & tops
> were the wires are in a  circular arrangement/format & are presented
> as 'Cage Antennas & Cage Dipoles' although I believe to increase
> bandwidth.
> 
> The reason I am interested is that I have thought about a similar
> arrangement because of my small garden area like Dick.
> 
> Comments invited please.
> 
> Gary - G4WGT.
> 
> 
> 
> -----Original Message-----
> From: owner-rsgb_lf_group@blacksheep.org
> [mailto:owner-rsgb_lf_group@blacksheep.org]On Behalf Of Rik Strobbe
> Sent: 11 August 2006 22:10 To: rsgb_lf_group@blacksheep.org Subject:
> Re: LF: Re: antenna: how to get max. capacity
> 
> 
> Quoting captbrian <captbrian@ukonline.co.uk>:
> 
> > Make the vertical of three parallel conductors , each to the centre
> > of
> each
> > top wire
> 
> Using multiple vertical wires will increase the antenna capacitance
> but also decrease the radiation resistance. I guess that a thing you
> don't want.
> 
> 73, Rik  ON7YD - OR7T
> 
> 
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>