X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 16 Feb 2006 01:25:53 -0500 Message-ID: X-Original-Return-Path: Received: from [24.93.47.40] (HELO ms-smtp-01-eri0.texas.rr.com) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 986769 for lml@lancaironline.net; Wed, 15 Feb 2006 19:10:38 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.93.47.40; envelope-from=toucan@Satx.rr.com Received: from VAIO (cpe-24-243-1-103.satx.res.rr.com [24.243.1.103]) by ms-smtp-01-eri0.texas.rr.com (8.13.4/8.13.4) with SMTP id k1G09qEZ017063 for ; Wed, 15 Feb 2006 18:09:53 -0600 (CST) X-Original-Message-ID: <006601c6328d$4944a1d0$6701f318@VAIO> From: "James Cameron" X-Original-To: "Lancair Mailing List" Subject: Antenna switch; ground planes X-Original-Date: Wed, 15 Feb 2006 18:09:41 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0063_01C6325A.FE309500" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0063_01C6325A.FE309500 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I used Bob Archer's antenna switch on my last Legacy, and it worked = fine. You couldn't tell you had only one antenna for two COM's. The = only down side is that you do indeed have one more possible point of = failure in your COM system, which violates the KISS principle. As for ground planes, I made a star pattern ground plane for my = XPNDR antenna with thin copper sheet (think hobby shop), but didn't do = anything for the MKR or COM antennas (normal Comant types). They worked = fine, which says to me that the conductance of the carbon fiber skin at = radio frequences is sufficient, and that any other ground plane is = superfluous. BTW, I've had techies at various companies swear to me that their = "hockey puck" type antennas for GPS, XM radio, etc., absolutely will not = work without being place on at least 2.567 square feet of metal, = blahdidiblah, . . . I've put several in airplanes and other places = without any ground plane at all and they work perfectly. Go figure. Jim Cameron Boerne, TX (RFLEG (Really Fast Legacy) in progress!) ------=_NextPart_000_0063_01C6325A.FE309500 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
   I used Bob Archer's antenna switch on = my last=20 Legacy, and it worked fine.  You couldn't tell you had only one = antenna for=20 two COM's.  The only down side is that you do indeed have one more = possible=20 point of failure in your COM system, which violates the KISS=20 principle.
 
    As for ground planes, I made a = star pattern=20 ground plane for my XPNDR antenna with thin copper sheet (think hobby = shop), but=20 didn't do anything for the MKR or COM antennas (normal Comant = types).  They=20 worked fine, which says to me that the conductance of the carbon fiber = skin=20 at radio frequences is sufficient, and that any other ground plane = is=20 superfluous.
 
    BTW, I've had techies at various = companies=20 swear to me that their "hockey puck" type antennas for GPS, XM radio, = etc.,=20 absolutely will not work without being place on at least 2.567 square = feet of=20 metal, blahdidiblah, . . .   I've put several in airplanes and = other=20 places without any ground plane at all and they work perfectly.  Go = figure.
 
Jim Cameron
Boerne, TX
 
(RFLEG (Really Fast Legacy) in = progress!)
 
 
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