Message-ID: <002e01ca95d1$cbde56d0$0301a8c0@your91hoehfy9g>
From: "mal hamilton" <g3kevmal@talktalk.net>
To: <rsgb_lf_group@blacksheep.org>
References: <000a01ca9530$c4ee97a0$0401a8c0@xphd97xgq27nyf><004901ca953b$6e896e70$8d01a8c0@JAYDELL> <20100114214523.i1xor1rdk0ccogkg@webmail6.kuleuven.be>
Date: Fri, 15 Jan 2010 10:59:23 -0000
MIME-Version: 1.0
Subject: Re: LF: Re: 1/2 wave 500
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


Rik, Jim & co
Tnx ur observations.
It seems there is not much advantage dipole v 1/4 wave inv L. My soil is
good therefore the 1/4 wave is probably better plus the low angle and
radiation resistance seems about the same at the 100 ft height.
One other approach would be to use open wire feeder and use it as part of
the dipole legs, there could be an advantage with the first 100ft being
vertical on each leg, matched at the bottom for 50 ohms.Maybe get some
cancellation !!!!!
Open wire say 12 inches separation.

73 mal/g3kev

----- Original Message -----
From: "Rik Strobbe" <Rik.Strobbe@fys.kuleuven.be>
To: <rsgb_lf_group@blacksheep.org>
Sent: Thursday, January 14, 2010 8:45 PM
Subject: Re: LF: Re: 1/2 wave 500


Jay, Mal,

I think that a "low" dipole is only meaningfull above poor soil.
At 20 ft (6m) above a perfect ground the radiation resistance would be
only 0.25 Ohm.
But in contradiction to a short vertical the dipole would work better
over poor soil.
At 100ft a dipole would have a radiation resistance of about 6 Ohm
(over perfect ground.
But even at this height it will radiate at very high angles (as Mal
suggests), so probably good for Europe but poor for DX.

73, Rik  ON7YD - OR7T

Quoting "jrusgrove@comcast.net" <jrusgrove@comcast.net>:

> Mal
>
> I worked WD2XSH/35 in South Dakota a couple weekends ago and heard
> him a couple times since. Here's
> his e mail to me on his setup. Think it should read one leg N/S and
> the other is E/W. Note that it
> is at 20 feet! Appears to work.
>
> Jay W1VD  WD2XNS  WE2XGR/2
>
> ____________
>
> Jay,
>
> I have an ICOM 706MKIIG feeding aqn attenuator which feeds a
> transverter from 7.2 MHz to 500 KHz.
> The transverter is feeding a solid state amp.  I am running about 10
>  - 15 watts ERP.  The antenna is
> a half wave dipole on 500 KHz about 20 feet above the ground in a
> N/S and E/W configuration. one leg
> is N/S and the other is N/S.
>
> I am listening on a ICOM 756PROII and a HyGain Hytower.
>
> 73
>
> Jim
>
> WD2XSH/35  K0HW
>
> ----- Original Message -----
> From: mal hamilton
> To: rsgb
> Sent: Thursday, January 14, 2010 10:45 AM
> Subject: LF: 1/2 wave 500
>
>
> Hi
> Has anyone in the USA tried a 1/2 wave dipole on 500 K/cs? inv V
> design, at a modest height around
> 100 ft.
> de mal/g3kev
>
>
>