Return-Path: Received: from mtain-dc06.r1000.mx.aol.com (mtain-dc06.r1000.mx.aol.com [172.29.64.134]) by air-mc03.mail.aol.com (v127_r1.1) with ESMTP id MAILINMC032-a8dc4b991db6235; Thu, 11 Mar 2010 11:43:34 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dc06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 7F5AA38000385; Thu, 11 Mar 2010 11:43:30 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NplSN-0007sv-Rv for rs_out_1@blacksheep.org; Thu, 11 Mar 2010 16:41:55 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NplSN-0007sm-Cx for rsgb_lf_group@blacksheep.org; Thu, 11 Mar 2010 16:41:55 +0000 Received: from out1.ip07ir2.opaltelecom.net ([62.24.128.243]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NplSL-00055g-GA for rsgb_lf_group@blacksheep.org; Thu, 11 Mar 2010 16:41:55 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AmsFAGKsmEtcGOJj/2dsb2JhbACMRAOOGmUOvgWEewQ X-IronPort-AV: E=Sophos;i="4.49,621,1262563200"; d="scan'208,217";a="442640699" Received: from unknown (HELO xphd97xgq27nyf) ([92.24.226.99]) by out1.ip07ir2.opaltelecom.net with SMTP; 11 Mar 2010 16:41:46 +0000 Message-ID: <000a01cac139$b9d5e5a0$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: "rsgb" Date: Thu, 11 Mar 2010 16:41:40 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 1.2 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,SUBJ_ALL_CAPS=1.166 Subject: LF: DREAM 9 ANTENNA Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01CAC139.B96D11B0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.0 required=5.0 tests=HTML_20_30,HTML_MESSAGE, SUBJ_ALL_CAPS autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G x-aol-sid: 3039ac1d40864b991db24f33 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_0007_01CAC139.B96D11B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Probably an inv L or T antenna as high as possible for TX is the best= solution for 9 kcs. Base load the antenna with the necessary inductan= ce for resonance and if necessary add another small inductor in series= to ground and adjust with taps up from ground to get a 1 : 1 match wi= th the coax feed from the TX, readjust the main inductor to maintain= resonance if necessary. This system has never failed me on 73, 137 and 500 kcs and this would= be my approach on 9 kcs. RX is a different matter and there are a variety of antennas suitable.= =20 I can RX the Alpha signals around 12 kcs at good strength using my 500= kcs 1/4 wave inv L and weaker on the 40m loop both antennas not reson= ated for 9 kcs. Obviously if resonated the signals would be very strong with these ant= ennas.=20 9 kcs is a lot easier to get going than the other LF/MF bands because= there is an abundance of LF generators and high power audio amplifier= s about, I would suggest modifying a audio amp output to 50 ohms with a suitabl= e transformer then use existing station equipment for monitoring and= measuring. Suggested approach for making a large inductor to resonate antenna. Get several slotted laundry baskets size diam 600mm, height about the= same, stiff plastic material. Wind some wire on a few and connect in= series with antenna and check for resonance, then add baskets as nece= ssary to resonate at desired frequency These baskets fit into one anot= her and look tidy.=20 Use the largest diam wire possible to achieve the desired inductance.= If using a vy small inv L with lots of Henries required then go for= the water butt coil former. Do not forget some earth radials and rods. I could probably manage about 4 inv L antennas in parallel, 500 kcs si= ze, loaded against ground and would hope the signal would travel some= hundreds of miles. If only I had the time. de mal/g3kev =20 =20 ------=_NextPart_000_0007_01CAC139.B96D11B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Probably an inv L or T antenna as hig= h as possible=20 for TX  is the best solution for 9 kcs. Base load the antenna wit= h the=20 necessary inductance for resonance and if necessary add another= small=20 inductor in series to ground and adjust with taps up from ground= to get a 1=20 : 1 match with the coax feed from the TX,  readjust the main indu= ctor to=20 maintain resonance if necessary.
This system has never failed me on 73= , 137 and 500=20 kcs and this would be my approach on 9 kcs.
RX is a different matter and there ar= e a variety of=20 antennas suitable.
I can RX the Alpha signals around 12= kcs at good=20 strength using my 500 kcs 1/4 wave inv L and weaker on the 40m loop bo= th=20 antennas not resonated for 9 kcs.
Obviously if resonated the signals wo= uld be very=20 strong with these antennas.
9 kcs is a lot easier to get going th= an the other=20 LF/MF bands because there is an abundance of LF generators and hi= gh=20 power audio amplifiers about,
I would suggest modifying a audio amp= output to 50=20 ohms with a suitable transformer then use existing station equipment= for=20 monitoring and measuring.
Suggested approach for making a large= inductor to=20 resonate antenna.
Get several slotted laundry baskets= size diam=20 600mm, height about the same, stiff plastic material. Wind some wire= on a few=20 and connect in series with antenna and check for resonance, then add= baskets as=20 necessary to resonate at desired frequency These baskets fit into one= another=20 and look tidy.
Use the largest diam wire possib= le to achieve=20 the desired inductance. If using a vy small inv L with lots of Henries= required=20 then go for the water butt coil former.
Do not forget some earth radials and= =20 rods.
I could probably manage about 4 inv= L antennas in=20 parallel, 500 kcs size, loaded against ground and would hope the= signal=20 would travel some hundreds of miles.
If only I had the time.
de mal/g3kev
 
 
 
 
 
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