Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 8E53038000082; Sun, 13 Jan 2013 11:31:57 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TuQSb-0000z6-Tb for rs_out_1@blacksheep.org; Sun, 13 Jan 2013 16:31:01 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TuQSb-0000yx-Cn for rsgb_lf_group@blacksheep.org; Sun, 13 Jan 2013 16:31:01 +0000 Received: from imr-db01.mx.aol.com ([205.188.91.95]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1TuQSZ-0001ca-7r for rsgb_lf_group@blacksheep.org; Sun, 13 Jan 2013 16:31:00 +0000 Received: from mtaout-da06.r1000.mx.aol.com (mtaout-da06.r1000.mx.aol.com [172.29.51.134]) by imr-db01.mx.aol.com (Outbound Mail Relay) with ESMTP id 47E6338000098 for ; Sun, 13 Jan 2013 11:30:37 -0500 (EST) Received: from Black (188-194-147-156-dynip.superkabel.de [188.194.147.156]) by mtaout-da06.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id AA69AE0000D5 for ; Sun, 13 Jan 2013 11:30:36 -0500 (EST) Message-ID: <4FFE5858E0A04326AC48E8B73E1D620F@Black> From: "Markus Vester" To: References: <50F1BC6E.9090405@iup.uni-heidelberg.de> <427C8E7C302341129739C903AAC04464@GaryAsus> <50F28C3F.3060405@xs4all.nl> <50F2D0A5.4070806@iup.uni-heidelberg.de> In-Reply-To: <50F2D0A5.4070806@iup.uni-heidelberg.de> Date: Sun, 13 Jan 2013 16:50:09 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6000.16480 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16669 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1358094637; bh=N/NeLvharxUGZrchOvv1VmGb7c9wzuy+5nzL91RqpkI=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=IJOP+FXZDy5AiXBHFzoIU/0vzRQ/XOO6xDgNTU3+T4NTl4AkzeB3JWVemghqhT2ED 6QBKSDTQgKEURh0aL4wyqfU/AqiIcwCgIicgw3KGu4rMSFmBTmoWf2Hc88gykYoJaC cXbzd/BDEYW2uabxXWvZH/uVrwvmv6TVuTte84yE= X-AOL-SCOLL-SCORE: 0:2:453053888:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Stefan, having the LF coil in parallel to the MF one will not increase the losses at MF. But the open switch will have to withstand a high voltage when operating LF, which is not trivial. I had played with a diplexer here, consisting of a loading coil which resonates the antenna at sqrt(f1*f2) ~ 255 kHz. From this point, there was an inductive low-pass branch for LF and a capacitive high-pass branch for MF. In addition, each branch was equipped with an extra parallel element to notch the other frequency. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [205.188.91.95 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: f45514038df04b1035abb1d5446da941 Subject: Re: LF: Re: MF variometer Content-Type: multipart/alternative; boundary="----=_NextPart_000_0031_01CDF1AE.0C299E30" 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-SCOLL-AUTHENTICATION: mtain-dk06.r1000.mx.aol.com ; domain : mx.aol.com DKIM : pass x-aol-sid: 3039ac1db40a50f2e17d5a31 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_0031_01CDF1AE.0C299E30 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable Hi Stefan, having the LF coil in parallel to the MF one will not increase the = losses at MF. But the open switch will have to withstand a high voltage = when operating LF, which is not trivial. I had played with a diplexer here, consisting of a loading coil which = resonates the antenna at sqrt(f1*f2) ~ 255 kHz. From this point, there = was an inductive low-pass branch for LF and a capacitive high-pass = branch for MF. In addition, each branch was equipped with an extra = parallel element to notch the other frequency.=20 This worked ok at low powers. But the disadvantage was that it largely = increases the stored energy (loaded Q) at the MF frequency, with = associated narrow bandwidth and high voltages as on LF. Best 73, Markus (DF6NM) ----- Original Message -----=20 From: Stefan Sch=E4fer=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Sunday, January 13, 2013 4:20 PM Subject: Re: LF: Re: MF variometer Hi Albert and Gary, Yes, here it is the same. The detuning due to wet soil is higher than on = LF. Also the relative rise of the resistive losses are higher than on=20 LF. It can make up to 3 dB here. Now i think about a switch that allows to switch from LF to MF remotely. = The idea is that the LF coil remains connected to the antenna (i.e. is=20 not switched), only the MF coil would be switched in parallel. There=20 will be some reactive current through the LF coil when operating on MF=20 but it can be compensated and the losses will be low. I still did no=20 calculations. At least the MF voltages and currents are quite low=20 compared to LF... 73, Stefan/DK7FC Am 13.01.2013 11:28, schrieb Albert W: > Hello Stefan es Gary, > > The same here depending on weather conditions and of course frequency=20 > change, using a relative small variometer (DC-motor adjustable from=20 > the shack) in series with the fixed L. > > 73, Albert PA0A > > > > > ------=_NextPart_000_0031_01CDF1AE.0C299E30 Content-Type: text/html; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable
Hi Stefan,
 
having the LF coil in parallel to = the MF one=20 will not increase the losses at MF. But the open switch will have to = withstand a=20 high voltage when operating LF, which is not trivial.
 
I had played with a diplexer = here,=20 consisting of a loading coil which resonates the antenna=20 at sqrt(f1*f2) ~ 255 kHz. From this point, there was an=20 inductive low-pass branch for LF and a capacitive high-pass = branch for=20 MF. In addition, each branch was equipped with an extra parallel=20 element to notch the other frequency.
 
This worked ok at low powers. But=20 the disadvantage was=20 that it largely increases the stored energy (loaded Q) at the = MF=20 frequency, with associated narrow bandwidth and high voltages as on = LF.
 
Best 73,
Markus (DF6NM)
 
 
----- Original Message -----=20
From: Stefan = Sch=E4fer
Sent: Sunday, January 13, 2013 4:20 PM
Subject: Re: LF: Re: MF variometer

Hi=20 Albert and Gary,

Yes, here it is the same. The detuning due to = wet soil=20 is higher than on
LF. Also the relative rise of the resistive losses = are=20 higher than on
LF. It can make up to 3 dB here.

Now i think = about a=20 switch that allows to switch from LF to MF remotely.
The idea is = that the LF=20 coil remains connected to the antenna (i.e. is
not switched), only = the MF=20 coil would be switched in parallel. There
will be some reactive = current=20 through the LF coil when operating on MF
but it can be compensated = and the=20 losses will be low. I still did no
calculations. At least the MF = voltages=20 and currents are quite low
compared to LF...

73,=20 Stefan/DK7FC

Am 13.01.2013 11:28, schrieb Albert W:
> Hello = Stefan=20 es Gary,
>
> The same here depending on weather conditions = and of=20 course frequency
> change, using a relative small variometer = (DC-motor=20 adjustable from
> the shack) in series with the fixed = L.
>
>=20 73, Albert = PA0A
>
>
>
>
>

------=_NextPart_000_0031_01CDF1AE.0C299E30--