X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Sat, 07 Oct 2006 11:45:47 -0400 Message-ID: X-Original-Return-Path: Received: from vms048pub.verizon.net ([206.46.252.48] verified) by logan.com (CommuniGate Pro SMTP 5.1c.5) with ESMTP id 1447410 for lml@lancaironline.net; Sat, 07 Oct 2006 01:24:13 -0400 Received: from jacky0da39824a ([71.111.129.224]) by vms048.mailsrvcs.net (Sun Java System Messaging Server 6.2-4.02 (built Sep 9 2005)) with ESMTPA id <0J6R006VV2Z8F7U9@vms048.mailsrvcs.net> for lml@lancaironline.net; Sat, 07 Oct 2006 00:23:35 -0500 (CDT) X-Original-Date: Fri, 06 Oct 2006 22:23:27 -0700 From: "Tom Gourley" Subject: Re: [LML] Weak Antenna X-Original-To: "Lancair Mailing List" Reply-to: "Tom Gourley" X-Original-Message-id: <002301c6e9d0$b86d5480$640610ac@jacky0da39824a> MIME-version: 1.0 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-Mailer: Microsoft Outlook Express 6.00.2900.2869 Content-type: multipart/alternative; boundary="----=_NextPart_000_0020_01C6E996.0B75E600" X-Priority: 3 X-MSMail-priority: Normal References: This is a multi-part message in MIME format. ------=_NextPart_000_0020_01C6E996.0B75E600 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Leon Smith wrote: "The SA-008 in the vert stab uses RG58 lead in coax, the other uses the = newer RG400. =20 The problem is the SA-008 in the vert stab produces a weak signal as = reported by the controllers. If I switch the antenna between com1 & = com2 the problem moves with the antenna." Leon, RG58 is not higher impedance than RG400; they are both 50 ohms. RG58 = has a little more loss than RG400, but unless you're running through 100 = feet or more it shouldn't make that much difference. However, if both = radios work well when connected to the SA-006 but both are reported as = sounding weak when connected to the SA-008 then it sounds like there is = a problem with the coax, the antenna, or the connection between the two. = If you can get someone to run a VSWR check on it you can tell if there = is an impedance mis-match problem, but it may not tell you if there is a = lossy connection somewhere. An antenna tip worth reading from Bob = Archer can be found at=20 http://www.express-builder.com/docs/tip1/index.html Tom Gourley ------=_NextPart_000_0020_01C6E996.0B75E600 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Leon Smith wrote:
 
"The SA-008 in the vert stab uses RG58 lead = in coax,=20 the other uses the newer RG400. 
 
The problem is the SA-008 in the vert stab = produces a weak=20 signal as reported by the controllers.  If I switch the = antenna=20 between com1 & com2 the problem moves with the = antenna."
 
Leon,
 
RG58 is not higher impedance than RG400; they = are both 50=20 ohms.  RG58 has a little more loss than RG400, but unless you're = running=20 through 100 feet or more it shouldn't make that much = difference. =20 However, if both radios work well when connected to the SA-006 but both = are=20 reported as sounding weak when connected to the SA-008 then it sounds = like there=20 is a problem with the coax, the antenna, or the connection between the=20 two.  If you can get someone to run a VSWR check on = it you=20 can tell if there is an impedance mis-match problem, but it = may not=20 tell you if there is a lossy connection somewhere.  An antenna tip = worth=20 reading from Bob Archer can be found at
 
Tom Gourley
 
------=_NextPart_000_0020_01C6E996.0B75E600--