Return-Path: Received: from mtain-mp09.r1000.mx.aol.com (mtain-mp09.r1000.mx.aol.com [172.29.193.77]) by air-db10.mail.aol.com (v129.4) with ESMTP id MAILINDB101-85fc4d25c1a9128; Thu, 06 Jan 2011 08:20:41 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mp09.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1C2303800048C; Thu, 6 Jan 2011 08:20:39 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Papkk-0007Fo-20 for rs_out_1@blacksheep.org; Thu, 06 Jan 2011 13:19:42 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Papkj-0007Ff-GK for rsgb_lf_group@blacksheep.org; Thu, 06 Jan 2011 13:19:41 +0000 Received: from smtp209.alice.it ([82.57.200.105]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Papkh-0003oR-Fu for rsgb_lf_group@blacksheep.org; Thu, 06 Jan 2011 13:19:41 +0000 Received: from PCFausto (79.23.51.72) by smtp209.alice.it (8.5.124.08) id 4C1A27590E747A4D for rsgb_lf_group@blacksheep.org; Thu, 6 Jan 2011 14:19:33 +0100 Message-ID: From: "Fausto Coletti" To: References: <3F10330D89BC46B2B0071A38A6E5EC09@PCFausto> <4D25ACDA.1090807@iup.uni-heidelberg.de> In-Reply-To: <4D25ACDA.1090807@iup.uni-heidelberg.de> Date: Thu, 6 Jan 2011 14:19:32 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18197 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18263 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Vertical antenna and connection line Content-Type: multipart/alternative; boundary="----=_NextPart_000_005D_01CBADAC.BC980290" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_20_30,HTML_MESSAGE, MISSING_OUTLOOK_NAME 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: 3039ac1dc14d4d25c1a72dd1 X-AOL-IP: 195.171.43.25 ------=_NextPart_000_005D_01CBADAC.BC980290 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks you Rik and Stefan for answer,=20 of course I connect one wire of the ladder line at the ground just und= er the antenna and the same wire to the "cold" end of the variometer,= =20 the other wire frome the antenna and the "hot" end of the variometer.= =20 I have think to cross the wall of the house through two copper tubes= connectef to ground then pass the two wire=20 at the center of the tubes.=20 Another idea would to be use two coax cable with center conductor as= parallel line and the shields grounded.=20 Yesterday i have finished the tx converter, i have used a very stable= OCXO (0.05 PPM) at 6.4 MHz (i had this),=20 anHPF505 mixer and two transistor amplifier stage for driving a TDA203= 0. I have obtained about 5 Watt of RF=20 at the output of the low pass filter and a decent harmonic suppression= . With this i want to drive a linear amplifier=20 with four IRFP540 (G0MRF schematic). I hope to obtain 250-300 Watts bu= t for CW operation i think to build a Kilowatt class D amplifier.=20 For ground quality question i have no measurement data at the moment.= =20 I live in the country and around i have only cultivated land for sever= al hundreds of meters, i think that can have a good conductivity The garden where i have installed the tower is about 55 x 30 meters= and I'm installing 120 or more buried radials, 15 to 35 meter long=20 as 160 m ground plane (the 25 meter tower), you can see the photo at= QRZ.com. the shack is in the corner of the house close to my car.=20 73 Fausto IK4NMF ----- Original Message -----=20 From: Stefan Sch=E4fer=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, January 06, 2011 12:51 PM Subject: Re: LF: Vertical antenna and connection line Fausto, You can do that but you should place the ladder line between ground= and the "cold" end of the main coil. Otherwise you'll have several kV= in the shack and lower the radiation resistance strongly! Instead of= ladder line you could use coax cable as well, although it has much mo= re C per meter.=20 You even can add a galvanic decoupled primary winding on the coil an= d feed the RF through a coax cable such as RG213. Then you can fine tu= ne the system (e.g. for QSY within the band) in the shack, at a lower= impedance! Do you already have some data like the ground resistance and/or your= planned TX power? :-) 73, Stefan Am 06.01.2011 12:28, schrieb Fausto Coletti:=20 Hello,=20 A question for RF expert:=20 you think that i can connect a Marconi antenna and relative gound= system to the variometer with a high impedance ladder line?=20 This because i need to have all the tuning equipment indoor and th= e tower that support the vertical part=20 of the antenna is about at 20 meters to the home.=20 Thanks in advance for answer=20 Fausto IK4NMF ----------------------------------------------------------------------= -------- Nessun virus nel messaggio. Controllato da AVG - www.avg.com Versione: 10.0.1191 / Database dei virus: 1435/3362 - Data di rilasc= io: 05/01/2011 ------=_NextPart_000_005D_01CBADAC.BC980290 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks you Rik and Stefan for answer,=
 
of course I connect one wire of= the ladder=20 line at the ground just under the antenna and the same wire to the "co= ld" end of=20 the variometer,
the other wire frome the antenna and= the "hot" end=20 of the variometer.
I have think to cross the wall of the= house through=20 two copper tubes connectef to ground then pass the two wire
at the center of the tubes.
Another idea would to be use two coax= cable with=20 center conductor as parallel line and the shields grounded.= =20
Yesterday i have finished the tx conv= erter, i have=20 used a very stable OCXO (0.05 PPM) at 6.4 MHz (i had this),
anHPF505 mixer and two transistor amp= lifier stage=20 for driving a TDA2030. I have obtained about 5 Watt of RF
at the output of the low pass filter= and a decent=20 harmonic suppression. With this i want to drive a linear amplifie= r=20
with four IRFP540 (G0MRF schematic).= I hope to=20 obtain 250-300 Watts but for CW operation i think to build a Kilowatt= class D=20 amplifier.
For ground quality question i have no= measurement=20 data at the moment.
I live in the country and around i ha= ve only=20 cultivated land for several hundreds of meters, i think that can have= a good=20 conductivity
The garden where i  have install= ed the tower=20 is about 55 x 30 meters and I'm installing 120 or more buried radials,= 15 to 35=20 meter long 
as 160 m ground=20 plane (the 25 meter tower), you can see the photo at QRZ.com. the shac= k is in=20 the corner of the house close to my car.
 
73 Fausto IK4NMF
----- Original Message -----
Sent: Thursday, January 06,= 2011 12:51=20 PM
Subject: Re: LF: Vertical ant= enna and=20 connection line

Fausto,

You can do that but you should place= the ladder=20 line between ground and the "cold" end of the main coil. Otherwise= you'll have=20 several kV in the shack and lower the radiation resistance strongly!= Instead=20 of ladder line you could use coax cable as well, although it has muc= h more C=20 per meter.
You even can add a galvanic decoupled primary winding= on the=20 coil and feed the RF through a coax cable such as RG213. Then you ca= n fine=20 tune the system (e.g. for QSY within the band) in the shack, at a lo= wer=20 impedance!

Do you already have some data like the ground resi= stance=20 and/or your planned TX power? :-)

73, Stefan

Am 06.01.= 2011=20 12:28, schrieb Fausto Coletti:=20
Hello,
A question for RF expert: =
you think that i can connect a Ma= rconi antenna=20 and relative gound system to the variometer with a high= impedance=20 ladder line?
This because i need to have all= the tuning=20 equipment indoor and the tower that support the vertical part
of the antenna is about at 20&nbs= p;meters to=20 the home.
 
Thanks in advance for answer
 
Fausto IK4NMF

Nessun virus nel= =20 messaggio.
Controllato da AVG - www.avg.com
Versione: 10.0.1191 / Database=20 dei virus: 1435/3362 - Data di rilascio:=20 05/01/2011

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