Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: Horizontally polarised radiation

To: [email protected]
Subject: Re: LF: Horizontally polarised radiation
From: "captbrian" <[email protected]>
Date: Tue, 6 Jan 2004 19:15:35 -0000
References: <000201c3d2f3$c4fb5f40$61e4fc3e@l8p8y6> <[email protected]> <000001c3d009$acf7a620$c7e47f50@Smisan> <[email protected]> <000601c3d2c3$2bd34e70$b733f7c2@johnb5a82ea1a4> <[email protected]> <000201c3d2f3$c4fb5f40$61e4fc3e@l8p8y6> <[email protected]> <001401c3d45a$7fb4b400$55e4fc3e@l8p8y6>
Reply-to: [email protected]
Sender: <[email protected]>
The DDDR is simply a quarter-wave grounded vertical with its major part bent
over into a horizontal loop. The fact that it is looped back on itself is
intended to have some self-cancelling effect on the radiation from the
horizontal part. By design  most radiation is from the short vertical part
so radiation resistance is low and it has gamma matching for feeding from
50 ohm coax.

Nothing magic about it but its usual proportions for HF are still impossible
for amateur 136 . (how would one keep the loop up ? )

Bryan g3gvb


----- Original Message -----
From: "hamilton mal" <[email protected]>
To: <[email protected]>
Sent: 06 January 2004 13:25
Subject: Re: LF: Horizontally polarised radiation



 ----- Original Message -----
 From: Rik Strobbe
 To: [email protected]
 Sent: Tuesday, January 06, 2004 8:16 AM
 Subject: Re: LF: Horizontally polarised radiation


 Hello group,

 It is an "idée fixe" that a horizontal wire must radiate a horizontal
polarized EM-wave.
 A nice example of a mechanical horizontal construction that radiates a
vertical polarized signal is the DDRR antenna.
 So a large horizontal topload close to ground will in most cases improve
the antenna efficiency (reduce the loss resistance ... footprint theory) but
the radiated signal will be nevertheless mainly vertical polarized.

 73, Rik  ON7YD

 At 17:47 5/01/2004 +0100, you wrote:

 Rik
 I agree with your observations. Some are being misled by computer
modelling and antenna theory not applicable to the type of small LF antennas
used by radio amateurs.
 73 de Mal/G3KEV
















<Prev in Thread] Current Thread [Next in Thread>