Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mc04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 52B9C38000089; Thu, 11 Aug 2011 11:42:50 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QrXO6-0001Hv-UA for rs_out_1@blacksheep.org; Thu, 11 Aug 2011 16:41:38 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QrXO6-0001Hm-Br for rsgb_lf_group@blacksheep.org; Thu, 11 Aug 2011 16:41:38 +0100 Received: from out1.ip09ir2.opaltelecom.net ([62.24.128.245]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QrXO4-0004Hl-Pi for rsgb_lf_group@blacksheep.org; Thu, 11 Aug 2011 16:41:38 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AlIBAO33Q05cHY8S/2dsb2JhbABBgk2RMQOEAA+POXiBOwUBAQUIAQEDSQIcEAEBAwUCAQMRBAEBCiUUAQQaBgwKCAYKCQoBAgIBAQqHVrxPhkcEglGEX5VRhn0 X-IronPort-AV: E=Sophos;i="4.67,357,1309734000"; d="scan'208,217";a="487154470" Received: from host-92-29-143-18.as13285.net (HELO xphd97xgq27nyf) ([92.29.143.18]) by out1.ip09ir2.opaltelecom.net with SMTP; 11 Aug 2011 16:41:30 +0100 Message-ID: <001501cc583d$1d6fd760$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <4E418609.6020500@iup.uni-heidelberg.de> <67A6F7BF45BF4A0193A3DCB53000A283@PcMinto> <008401cc56ce$2f1fb2c0$0401a8c0@xphd97xgq27nyf> <12C475F3F4C84B818461753F2E8A60A6@PcMinto> <4E41AECB.90808@iup.uni-heidelberg.de> <8D68749D37B94275855FDBA46A3F6C97@PcMinto> <4E427DFB.50801@iup.uni-heidelberg.de> <1313064500.49233.YahooMailNeo@web111905.mail.gq1.yahoo.com> <4E43CF0A.8020207@iup.uni-heidelberg.de> <1313071415.43423.YahooMailNeo@web111903.mail.gq1.yahoo.com> Date: Thu, 11 Aug 2011 16:41:19 +0100 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: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Re: HB9ASB... Content-Type: multipart/alternative; boundary="----=_NextPart_000_0012_01CC5845.7EFB06F0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=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 x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:477400128:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d604c4e43f87a59f5 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_0012_01CC5845.7EFB06F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Daniele I would expect to Receive virtually no signal using an optical cable, = because one of the dipole elements would be missing and you would only = have the small probe element doing all the work and capturing little or = no signal. The probe element has to be tuned against something and if = you take away the coax feed cable the only thing left is the small cct = board that might act as the second element but this again is so small = that signal pickup would be very low ie very little signal capture area. This type of antenna does not sound attractive to me. I have a commercial LF ships probe type antenna about 1 metre long as = one element and a wire hanging down as the Second element, the assembly = has a preamplifier and coax feed to the RX. mal/g3kev ----- Original Message -----=20 From: Daniele Tincani=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, August 11, 2011 3:03 PM Subject: Re: LF: Re: HB9ASB... Yes I'm sure it works. BTW, I work in the optical networks area of a = well-known (swedish) company of telecom equipments, so I really trust = optical comms ;-) The interesting thing would be to compare in a very quiet location an = active, optically-coupled E-probe, with very short copper leads, just = for the battery; and another identical E-probe, installed at the same = height, on a similar pole, etc. with "conventional" feeder through a = coax cable. Just to see what changes. I mean, if the cable actually is an integral part of such an antenna = ("the cable is the real antenna", as I read sometimes in comments about = the MiniWhip), I would expect a significant improvement from using a = coax rather than fiber. It would be necessary to find a very quiet = location for such test, to prevent local hum from giving an obvious = advantage to the fiber solution. Regards D. From: Stefan Sch=E4fer To: rsgb_lf_group@blacksheep.org Sent: Thursday, August 11, 2011 2:46 PM Subject: Re: LF: Re: HB9ASB... Hello Roelof, Daniele, LF, Yes, it works. Before i started with the VLF stuff in February 2010 i did tests with = LF active antennas, battery supplied, and signal transfer by fiber optic = cables. Actually it worked well with a single BF862 with the TX LED in = the drain-to-plus stage and a 9V battery. This was an interesting = alternative. But later i started with the LF grabber and so it becomes inpractical = since i don't want to replace a battery all the time and thought a solar = module might be covered by snow in winther and so on... Nice stuff to experiment. Anyway you have to be in a quiet location = but noise transfer on a coax screen was history... It also worked on a = multi turn loop which i used in France last year... 73, Stefan/DK7FC Am 11.08.2011 14:33, schrieb Roelof Bakker: > Hello Daniele, >=20 > I have the parts on hands, but house restoration has prevented tests = so far. > I will report in due time. >=20 > However Stefan has used an optical link with a 30 cm active whip. > So, it certainly will work. >=20 > 73, > Roelof ------=_NextPart_000_0012_01CC5845.7EFB06F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Daniele
I would expect to Receive virtually no signal = using an=20 optical cable, because one of the dipole elements would be missing and = you would=20 only have the small probe element doing all the work and capturing = little or no=20 signal. The probe element has to be tuned against something and if you = take away=20 the coax feed cable the only thing left is the small cct board that = might act as=20 the second element but this again is so small that signal pickup would = be very=20 low ie very little signal capture area.
This type of antenna does not sound = attractive to=20 me.
 
 
I have a commercial LF ships probe type = antenna about=20 1 metre long as one element and a wire hanging down as the Second = element, the=20 assembly has a preamplifier and coax feed to the RX.
 
mal/g3kev
 
 
----- Original Message -----
From:=20 Daniele Tincani
Sent: Thursday, August 11, 2011 = 3:03=20 PM
Subject: Re: LF: Re: = HB9ASB...

Yes I'm sure it = works. BTW,=20 I work in the optical networks area of a well-known (swedish) = company of=20 telecom equipments, so I really trust optical = comms ;-)
The interesting = thing would=20 be to compare in a very quiet location an active,=20 optically-coupled E-probe, with very short copper leads, just for = the=20 battery; and another identical E-probe, installed at the same height, = on a=20 similar pole, etc. with "conventional" feeder through a coax cable. = Just to=20 see what changes.
I mean, if the = cable=20 actually is an integral part of such an antenna ("the cable is the = real=20 antenna", as I read sometimes in comments about the MiniWhip), I would = expect=20 a significant improvement from using a coax rather than fiber. = It would=20 be necessary to find a very quiet location for such test, to = prevent=20 local hum from giving an obvious advantage to the fiber solution.
Regards
D.
 

From:=20 Stefan Sch=E4fer = <Stefan.Schaefer@iup.uni-heidelberg.de>
To:=20 rsgb_lf_group@blacksheep.org
Sent: Thursday, August 11, 2011 = 2:46=20 PM
Subject: Re: LF: = Re:=20 HB9ASB...

Hello Roelof, Daniele, LF,

Yes, it=20 works.
Before i started with the VLF stuff in February 2010 i did = tests=20 with LF active antennas, battery supplied, and signal transfer by = fiber optic=20 cables. Actually it worked well with a single BF862 with the TX LED in = the=20 drain-to-plus stage and a 9V battery. This was an interesting=20 alternative.

But later i started with the LF grabber and so it = becomes=20 inpractical since i don't want to replace a battery all the time and = thought a=20 solar module might be covered by snow in winther and so = on...

Nice=20 stuff to experiment. Anyway you have to be in a quiet location but = noise=20 transfer on a coax screen was history... It also worked on a multi = turn loop=20 which i used in France last year...

73, = Stefan/DK7FC


Am=20 11.08.2011 14:33, schrieb Roelof Bakker:
> Hello = Daniele,
>=20
> I have the parts on hands, but house restoration has = prevented tests=20 so far.
> I will report in due time.
>
> However = Stefan has=20 used an optical link with a 30 cm active whip.
> So, it = certainly will=20 work.
>
> 73,
>=20 Roelof



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