From: Rik Strobbe <Rik.Strobbe@fys.kuleuven.be>
To: "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>
Date: Wed, 28 Apr 2010 17:03:06 +0200
Thread-Topic: Re: Antenna Article
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JB, Alan,

if I recall well this feeding method was tried on 136kHz with success by=
 some Dutch hams activating a windmill (PI4OSS ?).

73, Rik  ON7YD - OR7T
________________________________________
Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.or=
g] namens Alan Melia [alan.melia@btinternet.com]
Verzonden: woensdag 28 april 2010 16:48
Aan: rsgb_lf_group@blacksheep.org
Onderwerp: LF: Re: Antenna Article

Hi JB there is something similar to this I believe in Rick's ON7YD's web
tutorial on LF antennas.
http://www.strobbe.eu/on7yd/136ant/    look at section 2.12

Is this a case of feeding at an elevated tapping point to get a better
impedance.....very short antennas are very low in impedance at
160........you may find this doesnt work at LF  (136 - 180) due to the muc=
h
higher ground losses.....interesting experiment though.

Alan G3NYK

----- Original Message -----
From: "John Bruce McCreath" <weazle@hurontel.on.ca>
To: "& UK) and MedFer bands Discussion of the Lowfer (US European"
<lowfer@mailman.qth.net>
Cc: <rsgb_lf_group@blacksheep.org>
Sent: Wednesday, April 28, 2010 1:35 PM
Subject: LF: Antenna Article



Hello LFers & Lowfers,

Volume 7 of the ARRL Antenna Compendium has an interesting article by John=
,
VE2CV, on  an electrically small
antenna for 160 meters.   He mentions how a virtual inductance can be
created at the top of a tower by means
of "insulating a suitable conductor inside the tower and shorting it to th=
e
tower at some judicious length away
from the end."   The top loading wires are attached to the top of this
conductor which extends above the top
of the tower by some distance.

Has anyone here tried this very interesting approach?   I don't recall
hearing or reading of this method  of putting
an inductor at the top of a vertical section of a top loaded LF antenna.
Being more of a mechanical nature rather
than the usual elevated coil, its losses may be less.   I might give it a
try myself just to check it out.


73, J.B., VE3EAR

LowFER Beacon "EAR"
188.830 kHz. QRSS30