Return-Path: Received: from mtain-mj01.r1000.mx.aol.com (mtain-mj01.r1000.mail.aol.com [172.21.164.85]) by air-me05.mail.aol.com (v129.4) with ESMTP id MAILINME052-8bb14d25da2e1d4; Thu, 06 Jan 2011 10:05:18 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mj01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 4215838000225; Thu, 6 Jan 2011 10:05:15 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ParO8-0008Av-CJ for rs_out_1@blacksheep.org; Thu, 06 Jan 2011 15:04:28 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ParO7-0008Am-P3 for rsgb_lf_group@blacksheep.org; Thu, 06 Jan 2011 15:04:27 +0000 Received: from mailout-de.gmx.net ([213.165.64.22] helo=mail.gmx.net) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1ParO5-0004c0-HQ for rsgb_lf_group@blacksheep.org; Thu, 06 Jan 2011 15:04:27 +0000 Received: (qmail invoked by alias); 06 Jan 2011 15:04:18 -0000 Received: from p5DD34A27.dip.t-dialin.net (EHLO Clemens04) [93.211.74.39] by mail.gmx.net (mp026) with SMTP; 06 Jan 2011 16:04:18 +0100 X-Authenticated: #17214767 X-Provags-ID: V01U2FsdGVkX1/+iRJL+ff+adZtGNNxFKRYdZc3Cn8R4OU44617Zf BSb3Tpc2X62EOX Message-ID: <01f801cbadb2$fde79e30$0201a8c0@Clemens04> From: "Clemens Paul" To: References: <3F10330D89BC46B2B0071A38A6E5EC09@PCFausto> <4D25ACDA.1090807@iup.uni-heidelberg.de> Date: Thu, 6 Jan 2011 16:04:10 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3664 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3664 X-Y-GMX-Trusted: 0 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_01F4_01CBADBB.5B0D29B0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,HTML_MESSAGE 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: 3039400c89a24d25da2b7f76 X-AOL-IP: 195.171.43.25 ------=_NextPart_000_01F4_01CBADBB.5B0D29B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Do you know,at least roughly,the complex feeding impedance at the point where the line (ladder od coax) is attached to the variom= eter? Then we could calculate the losses for coax and ladder line. I expect something far away from 50 Ohm and therefore would strongly favour ladder line because of much lower line losses. As Rik says there is not much impedance transformation by the line. 73 Clemens DL4RAJ ----- Original Message -----=20 From: Fausto Coletti To: rsgb_lf_group@blacksheep.org Sent: Thursday, January 06, 2011 2:19 PM Subject: Re: LF: Vertical antenna and connection line Thanks you Rik and Stefan for answer, of course I connect one wire of the ladder line at the ground just= under the antenna and the=20 same wire to the "cold" end of the variometer, the other wire frome the antenna and the "hot" end of the variometer= . I have think to cross the wall of the house through two copper tubes= connectef to ground then=20 pass the two wire at the center of the tubes. Another idea would to be use two coax cable with center conductor as= parallel line and the=20 shields grounded. Yesterday i have finished the tx converter, i have used a very stabl= e OCXO (0.05 PPM) at 6.4=20 MHz (i had this), anHPF505 mixer and two transistor amplifier stage for driving a TDA2= 030. I have obtained about=20 5 Watt of RF at the output of the low pass filter and a decent harmonic suppressi= on. With this i want to=20 drive a linear amplifier with four IRFP540 (G0MRF schematic). I hope to obtain 250-300 Watts= but for CW operation i=20 think to build a Kilowatt class D amplifier. For ground quality question i have no measurement data at the moment= . I live in the country and around i have only cultivated land for sev= eral hundreds of meters, i=20 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=20 more buried radials, 15 to 35 meter long as 160 m ground plane (the 25 meter tower), you can see the photo at= QRZ.com. the shack is in=20 the corner of the house close to my car. 73 Fausto IK4NMF ----- Original Message -----=20 From: Stefan Sch=E4fer To: rsgb_lf_group@blacksheep.org 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 groun= d and the "cold" end of=20 the main coil. Otherwise you'll have several kV in the shack and lower= the radiation resistance=20 strongly! Instead of ladder line you could use coax cable as well, alt= hough it has much more C=20 per meter. You even can add a galvanic decoupled primary winding on the coil= and feed the RF through a=20 coax cable such as RG213. Then you can fine tune the system (e.g. for= QSY within the band) in=20 the shack, at a lower impedance! Do you already have some data like the ground resistance and/or yo= ur planned TX power? :-) 73, Stefan Am 06.01.2011 12:28, schrieb Fausto Coletti: Hello, A question for RF expert: you think that i can connect a Marconi antenna and relative goun= d system to the variometer=20 with a high impedance ladder line? This because i need to have all the tuning equipment indoor and= the tower that support the=20 vertical part of the antenna is about at 20 meters to the home. Thanks in advance for answer Fausto IK4NMF ----------------------------------------------------------------------= ------ Nessun virus nel messaggio. Controllato da AVG - www.avg.com Versione: 10.0.1191 / Database dei virus: 1435/3362 - Data di rila= scio: 05/01/2011 ------=_NextPart_000_01F4_01CBADBB.5B0D29B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Do you know,at least roughly,the comp= lex feeding=20 impedance 
at the point where the line (ladder= od coax) is=20 attached to the variometer?
Then we could calculate the losses fo= r coax and=20 ladder line.
I expect something far away from= 50 Ohm and=20 therefore
would strongly favour ladder line bec= ause of much=20 lower line losses.
As Rik says there is not much impedan= ce=20 transformation by the line.
 
73
Clemens
DL4RAJ
 
----- Original Message -----
Sent: Thursday, January 06,= 2011 2:19=20 PM
Subject: Re: LF: Vertical ant= enna and=20 connection line

Thanks you Rik and Stefan for answe= r,=20
 
of course I connect one wire= of the ladder=20 line at the ground just under the antenna and the same wire to the= "cold" end=20 of the variometer,
the other wire frome the antenna an= d the "hot"=20 end of the variometer.
I have think to cross the wall of= the house=20 through two copper tubes connectef to ground then pass the two wire= =20
at the center of the tubes. =
Another idea would to be use two co= ax cable with=20 center conductor as parallel line and the shields grounded= .=20
Yesterday i have finished the tx co= nverter, i=20 have used a very stable OCXO (0.05 PPM) at 6.4 MHz (i had this)= ,=20
anHPF505 mixer and two transistor= amplifier stage=20 for driving a TDA2030. I have obtained about 5 Watt of RF
at the output of the low pass filte= r and a decent=20 harmonic suppression. With this i want to drive a linear amplif= ier=20
with four IRFP540 (G0MRF schematic)= . I hope to=20 obtain 250-300 Watts but for CW operation i think to build a Kilowat= t 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= have only=20 cultivated land for several hundreds of meters, i think that can hav= e a good=20 conductivity
The garden where i  have insta= lled the tower=20 is about 55 x 30 meters and I'm installing 120 or more buried radial= s, 15 to=20 35 meter long 
as 160 m ground plane (the 25 meter tower), you can see the= photo at QRZ.com.=20 the shack is in 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= antenna and=20 connection line

Fausto,

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

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

73,= =20 Stefan

Am 06.01.2011 12:28, schrieb Fausto Coletti:=20
Hello,
A question for RF expert:
you think that i can connect a= Marconi=20 antenna and relative gound system to the variometer with a&= nbsp;high=20 impedance ladder line?
This because i need to have all= =20 the tuning equipment indoor and the tower that support the= vertical=20 part
of the antenna is about at 20&n= bsp;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

------=_NextPart_000_01F4_01CBADBB.5B0D29B0--