X-GM-THRID: 1243583819375807210 X-Gmail-Labels: rsgb lf Delivered-To: daveyxm@gmail.com Received: by 10.70.87.11 with SMTP id k11cs199949wxb; Thu, 2 Aug 2007 10:35:13 -0700 (PDT) Received: by 10.66.249.8 with SMTP id w8mr2268225ugh.1186076112806; Thu, 02 Aug 2007 10:35:12 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id h1si2208793nfh.2007.08.02.10.35.09; Thu, 02 Aug 2007 10:35:12 -0700 (PDT) Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1IGeUd-0007of-T0 for rs_out_1@blacksheep.org; Thu, 02 Aug 2007 18:29:47 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1IGeUd-0007oW-1j for rsgb_lf_group@blacksheep.org; Thu, 02 Aug 2007 18:29:47 +0100 Received: from mk-filter-2-a-1.mail.uk.tiscali.com ([212.74.100.53]) by relay2.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1IGeUY-00024M-F3 for rsgb_lf_group@blacksheep.org; Thu, 02 Aug 2007 18:29:46 +0100 X-Trace: 11832023-mk-filter-2.mail.uk.tiscali.com-B2C-$THROTTLED-DYNAMIC-CUSTOMER-DYNAMIC-IP X-SBRS: -3.0 X-RemoteIP: 88.110.140.64 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AnA9ADuxsUZYboxARmdsb2JhbACCaYQHgTsMhVIBAQE1AQ Received: from 88-110-140-64.dynamic.dsl.as9105.com (HELO oem17oeylz9on8) ([88.110.140.64]) by smtp.tiscali.co.uk with SMTP; 02 Aug 2007 18:28:56 +0100 Message-ID: <00b501c7d52a$b1feff90$6400a8c0@oem17oeylz9on8> From: "Paul Tomlinson" To: References: <005001c7d3fe$e4786d80$6400a8c0@oem17oeylz9on8> <001901c7d42b$e6fbeaa0$86048351@w4o8m9> <00a001c7d43c$f4180690$0a7ee150@o> <1IGMYh-02648G0@fwd31.t-online.de> <003001c7d4d1$fcaf0390$db3a383e@Tom> <000201c7d4e6$2cabc650$9e75e150@o> Date: Thu, 2 Aug 2007 18:29:34 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Re: Re: newbie help Content-Type: multipart/alternative; boundary="----=_NextPart_000_00B2_01C7D533.136DA670" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.6 required=5.0 tests=FROM_ENDS_IN_NUMS, FROM_HAS_MIXED_NUMS,HTML_20_30,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 Status: O X-Status: X-Keywords: X-UID: 2681 This is a multi-part message in MIME format. ------=_NextPart_000_00B2_01C7D533.136DA670 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable lol ----- Original Message -----=20 From: GW3UEP=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, August 02, 2007 10:17 AM Subject: Re: LF: Re: Re: newbie help I discharge it thru' the xyl first. Rog. ----- Original Message -----=20 From: Tom Boucher=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, August 02, 2007 7:54 AM Subject: Re: LF: Re: Re: newbie help Good point Ha-Jo. When using my antenna impedance analyser, I always = leave a=20 50 ohm load in parallel with the antenna, using a BNC T-piece. Only = when the=20 antenna is connected do I remove the 50 ohm terminator, that way = hopefully=20 any static on the antenna is discharged through it. 73 Tom G3OLB ----- Original Message -----=20 From: To: Sent: Wednesday, August 01, 2007 11:20 PM Subject: Re: LF: Re: Re: newbie help > Dear all, > > I have heard of a case that a german LF amateur had ruined his > capacitance meter because of a static loading on the aerial! > > Therefore I have always preferred to measure aerial capacitance by > checking the detuning effect of the aerial to a tuned circuit. The = coil > of this circuit will always ground the aerial for dc. > > HW? > > 73 Ha-Jo, DJ1ZB > > > "John GM4SLV" schrieb: >> >> Rog, >> >> That's an interesting idea - I've never thought of trying a digital = Cap >> meter. I must try it on the new antenna - and compare it to my = homebrew >> RF bridge, calculations and - more telling - to the valuse of L I >> eventually need to resonate it. >> >> >> John GM4SLV >> >> >> On Wed, 1 Aug 2007, GW3UEP wrote: >> >> > Re ant cap: you can use a DMM [Rapid 328] to gnd - I use 1000pF = across >> > its terminals to decouple RF for a stable reading. Simply = subtract its >> > value. 73, Rog. >> > >> > ----- Original Message -----=20 >> > From: James Moritz >> > To: rsgb_lf_group@blacksheep.org >> > Sent: Wednesday, August 01, 2007 12:05 PM >> > Subject: LF: Re: newbie help >> > >> > >> > Dear Paul, >> > >> > In a nutshell: >> > >> > - You can tune up more or less any bit of wire for reasonable = results >> > on 500kHz. For best results, make it as high up as possible, and >> > secondarily as long as possible. An HF long wire, or dipole with >> > feeders strapped would be fine. >> > >> > -Work out the capacitance of the wire (see formulas on ON7YD's >> > antennas pages). and calculate the inductance for resonance = around >> > 502.5kHz. For most HF-sized wire antennas, this will be of the = order >> > of 100s of uH. The resulting coil is >> >> >> > >=20 -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG Free Edition.=20 Version: 7.5.476 / Virus Database: 269.11.2/931 - Release Date: = 01/08/2007 16:53 ------=_NextPart_000_00B2_01C7D533.136DA670 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
lol
----- Original Message -----
From:=20 GW3UEP
Sent: Thursday, August 02, 2007 = 10:17=20 AM
Subject: Re: LF: Re: Re: newbie = help

I discharge it thru' the xyl=20 first.
Rog.
----- Original Message -----=20
From: Tom=20 Boucher
Sent: Thursday, August 02, 2007 7:54 AM
Subject: Re: LF: Re: Re: newbie help

Good point Ha-Jo. When using my antenna impedance = analyser, I=20 always leave a
50 ohm load in parallel with the antenna, using a = BNC=20 T-piece. Only when the
antenna is connected do I remove the 50 ohm = terminator, that way hopefully
any static on the antenna is = discharged=20 through it.

73
Tom G3OLB

----- Original Message ----- =
From: <hajo.brandt.dj1zb@t-online.= de>
To:=20 <rsgb_lf_group@blacksheep.org= >
Sent:=20 Wednesday, August 01, 2007 11:20 PM
Subject: Re: LF: Re: Re: newbie = help


> Dear all,
>
> I have heard of a case = that a=20 german LF amateur had ruined his
> capacitance meter because of = a static=20 loading on the aerial!
>
> Therefore I have always = preferred to=20 measure aerial capacitance by
> checking the detuning effect of = the=20 aerial to a tuned circuit. The coil
> of this circuit will = always ground=20 the aerial for dc.
>
> HW?
>
> 73 Ha-Jo,=20 DJ1ZB
>
>
> "John GM4SLV" <gm4slv@sighthound.demon.co.= uk>=20 schrieb:
>>
>> Rog,
>>
>> That's = an=20 interesting idea - I've never thought of trying a digital = Cap
>>=20 meter. I must try it on the new antenna - and compare it to my=20 homebrew
>> RF bridge, calculations and - more telling - to = the=20 valuse of L I
>> eventually need to resonate=20 it.
>>
>>
>> John=20 GM4SLV
>>
>>
>> On Wed, 1 Aug 2007, GW3UEP=20 wrote:
>>
>> > Re ant cap: you can use a DMM = [Rapid 328]=20 to gnd - I use 1000pF across
>> > its terminals to = decouple RF for=20 a stable reading. Simply subtract its
>> > value. 73,=20 Rog.
>> >
>> > ----- Original Message -----=20
>> > From: James Moritz
>> > To: rsgb_lf_group@blacksheep.org=
>>=20 > Sent: Wednesday, August 01, 2007 12:05 PM
>> > = Subject: LF:=20 Re: newbie help
>> >
>> >
>> > = Dear=20 Paul,
>> >
>> > In a nutshell:
>>=20 >
>> > - You can tune up more or less any bit of wire = for=20 reasonable results
>> > on 500kHz. For best results, make = it as=20 high up as possible, and
>> > secondarily as long as = possible. An=20 HF long wire, or dipole with
>> > feeders strapped would = be=20 fine.
>> >
>> > -Work out the capacitance of = the wire=20 (see formulas on ON7YD's
>> > antennas pages). and = calculate the=20 inductance for resonance around
>> > 502.5kHz. For most = HF-sized=20 wire antennas, this will be of the order
>> > of 100s of = uH. The=20 resulting coil is
>>
>>
>>
>
> =

No virus found in this incoming message.
Checked by AVG Free = Edition.
Version: 7.5.476 / Virus Database: 269.11.2/931 - Release = Date:=20 01/08/2007 16:53
------=_NextPart_000_00B2_01C7D533.136DA670--