Return-Path: Sender: "Marvin Kaye" To: lml@lancaironline.net Date: Wed, 26 Jan 2005 10:12:34 -0500 Message-ID: X-Original-Return-Path: Received: from imo-m19.mx.aol.com ([64.12.137.11] verified) by logan.com (CommuniGate Pro SMTP 4.2.8) with ESMTP id 622956 for lml@lancaironline.net; Wed, 26 Jan 2005 10:05:56 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.11; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m19.mx.aol.com (mail_out_v37_r3.8.) id q.d1.20f8b0cb (4410) for ; Wed, 26 Jan 2005 10:05:17 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Wed, 26 Jan 2005 10:05:16 EST Subject: Re: [LML] Re: antenna bonding-Lancair 320 X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1106751916" X-Mailer: 9.0 Security Edition for Windows sub 5000 -------------------------------1106751916 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 1/26/2005 7:05:45 A.M. Central Standard Time, 5zq@cox.net writes: Have people encountered antenna bonding problems and is their a simple fix for these "darn" plastic aeroplanes..:) Hello Gerard, I've got the following antennae installed internally in our 320 (no external antennae). VHF com 2 VHF nav 1 GPS 1 Mkr Bcn 1 TCAD 2 FM 1 XPONDR 1 TOTAL 9 We have had ZERO problems with any of our electronics in 900 hrs. (Thanks Bryant). All communication is clear and long ranging. I'm no electronic wiz but one suggestion I'd make is to check all of your grounding. All coax should be grounded only at one end. All grounding leads should run to a common ground bus bar and not to each other (no piggybacking). The ground bus bar itself should be connected to the negative battery terminal with substantial grounding strap type cable. My guess is that proper grounding will go a long way toward solving your radio problem. Good luck. Gerard, Yeah, what Bill said with a bit more info relative to the ART of fixing interference. 1. Fiberglass presents no problem with respect to an antenna's ability to see thru it - Carbon is a different story. In the LNC2/prepreg airplanes, the main spar caps (top and bottom) contain carbon and certain antennas may not work well buried in the wing outside the aileron bellcrank. These include DME, Transponder and, perhaps, TCAD. This may be true of other locations relative to the proximity of the main spar. 2. I have only one Comm antenna and use an "antenna switching" device for using the antenna with two comm radios. The comm antenna is in the vertical stabilizer. 3. Some antennae require a ground plane (transponder, ADF, etc). For example, my high-speed blade transponder antenna is located hanging outside of an outboard wing panel with the ground plane on the inside surface of the wing skin. 4. Use the more expensive, but less lossey RG400 antenna rather than the leak prone RG58 - especially for long runs. 5. Do not make sharp bends in antenna cable because, under vibration, the center lead can work its way thru the insulator and short against the shield. 6. Some ART: Currently, my comm uses leaky RG58 and for a long time I had problems with every temperature readout going crazy when the mike was keyed. The solution was to move the antenna switcher (thus the two 14" radio coaxs, the device and the antenna coax) about 8 inches away from the problem location - Voila, the problem went away. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Fair and Balanced Opinions at No Charge! There is an oxymoron in that, somewhere... -------------------------------1106751916 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 1/26/2005 7:05:45 A.M. Central Standard Time,=20 5zq@cox.net writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Have people encountered antenna bonding problem= s and=20 is their a simple fix for these "darn" plastic=20 aeroplanes..:)


Hello Gerard,
 
I've got the following antennae installed= =20 internally in our 320 (no external antennae).
 
    VHF com  &nb= sp;=20 2
    VHF=20 nav      1
   =20 GPS           1
    Mkr=20 Bcn      1
   =20 TCAD         2
    FM   =20         1
    XPONDR  &nbs= p;=20 1
 
TOTAL      =  =20 9
 
We have had ZERO problems with any of our= =20 electronics in 900 hrs. (Thanks Bryant).  All communication is clear=20= and=20 long ranging. I'm no electronic wiz but one suggestion I'd make is to chec= k=20 all of your grounding. All coax should be grounded only at one end. A= ll=20 grounding leads should run to a common ground bus bar and not to each othe= r=20 (no piggybacking). The ground bus bar itself should be connected to t= he=20 negative battery terminal with substantial grounding strap type=20 cable. 
 
My guess is that proper grounding will go= a long=20 way toward solving your radio problem. Good=20 luck.
Gerard,
 
Yeah, what Bill said with a bit more info relative to the ART of fixing= =20 interference.
 
1. Fiberglass presents no problem with respect to an antenna's abi= lity=20 to see thru it - Carbon is a different story.  In the LNC2/prepreg=20 airplanes, the main spar caps (top and bottom) contain carbon and certa= in=20 antennas may not work well buried in the wing outside the aileron=20 bellcrank.  These include DME, Transponder and, perhaps, TCAD.  Th= is=20 may be true of other locations relative to the proximity of the main spar.
 
2. I have only one Comm antenna and use an "antenna switching" device f= or=20 using the antenna with two comm radios.  The comm antenna is in the=20 vertical stabilizer.
 
3. Some antennae require a ground plane (transponder, ADF, etc). =20= For=20 example, my high-speed blade transponder antenna is located hanging outside=20= of=20 an outboard wing panel with the ground plane on the inside surface of t= he=20 wing skin.
 
4. Use the more expensive, but less lossey RG400 antenna rather than th= e=20 leak prone RG58 - especially for long runs.
 
5. Do not make sharp bends in antenna cable because, under vibration, t= he=20 center lead can work its way thru the insulator and short against the=20 shield.
 
6.  Some ART:  Currently, my comm uses  leaky RG58 and f= or a=20 long time I had problems with every temperature readout going crazy when the= =20 mike was keyed.  The solution was to move the antenna switcher (thus th= e=20 two 14" radio coaxs, the device and the antenna coax) about 8 inches away fr= om=20 the problem location - Voila, the problem went away.
 
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)

Fai= r=20 and Balanced Opinions at No Charge!
There is an oxymoron in that,=20 somewhere...

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