X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 30 Dec 2010 20:09:13 -0500 Message-ID: X-Original-Return-Path: Received: from relay16.smp.mweb.co.za ([196.28.80.36] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTPS id 4659191 for lml@lancaironline.net; Thu, 30 Dec 2010 16:51:36 -0500 Received-SPF: none receiver=logan.com; client-ip=196.28.80.36; envelope-from=rossl@mweb.co.za Received: from 41-135-45-221.dsl.mweb.co.za ([41.135.45.221] helo=[192.168.2.6]) by relay16.smp.mweb.co.za with esmtp (Exim 4.72) id 1PYQOY-000PJl-4e for ; Thu, 30 Dec 2010 23:50:57 +0200 User-Agent: Microsoft-Entourage/12.23.0.091001 X-Original-Date: Thu, 30 Dec 2010 23:50:49 +0200 Subject: Re: [LML] P-STATc? From: Ross Leighton X-Original-To: Lancair List X-Original-Message-ID: Thread-Topic: [LML] P-STATc? Thread-Index: Acuoa57WRYcPF8NXpkS6+gFva+oDPQ== In-Reply-To: Mime-version: 1.0 Content-type: multipart/alternative; boundary="B_3376597850_39487519" > This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. --B_3376597850_39487519 Content-type: text/plain; charset="ISO-8859-1" Content-transfer-encoding: quoted-printable Dennis The loss of the GPS signal is as regular as clockwork. Sometimes as the aircraft lifts off the ground it=B9s gone. Initially I thought it was the gea= r pump but sometimes it goes well after gear up. I have considered that I use a 28v system but MGL assures me that its equipment can take the voltage. Nonetheless I tried a voltage converter to 14v and still the GPS signal was lost. Then I smoothed out the input voltage using a capacitor in an attempt to eliminate voltage spikes. Still lost the signal. Nothing else seems to be affected within the EFIS or the other avionics, which only adds to the mystery. Thus, I am led to the idea of P-STAT. Is there perhaps a momentary electrical discharge into the system that disrupts the GPS. If so why only the one GPS and why none of the other equipment? The Tru Trak AP is rock solid using the secondary GPS; the comms are rock solid; as is the transponder. BTW in answer to another list member, all ground connections have been checked and are good. All very frustrating. Ross=20 On 2010/12/30 4:21 AM, "Dennis Johnson" wrote: > Hi Ross, > =20 > There are many, many Legacies flying without P-static problems disabling = their > avionics. Before I went to a lot of trouble electrically bonding parts o= f the > airframe, I'd try to determine how your Legacy is different from the othe= rs. > And I'd make sure all the electrical grounds are solidly connected. > =20 > Do you have any indication that P-static is a frequent problem in your > airplane? Is anything except the GPS function of your MGL Voyager affect= ed? > I once picked up enough static charge that what little hair I have on my = head > stood straight up, towards the charged canopy. It didn't cause a problem= with > any of the avionics, though. > =20 > Dennis > =20 > =20 >=20 --B_3376597850_39487519 Content-type: text/html; charset="ISO-8859-1" Content-transfer-encoding: quoted-printable Re: [LML] P-STATc? Dennis

The loss of the GPS signal is as regular as clockwork. Sometimes as the air= craft lifts off the ground it’s gone. Initially I thought it was the g= ear pump but sometimes it goes well after gear up. I have considered that I = use a 28v system but MGL assures me that its equipment can take the voltage.= Nonetheless I tried a voltage converter to 14v and still the GPS signal was= lost. Then I smoothed out the input voltage using a capacitor in an attempt= to eliminate voltage spikes. Still lost the signal.

Nothing else seems to be affected within the EFIS or the  other avioni= cs, which only adds to the mystery.

Thus, I am led to the idea of P-STAT. Is there perhaps a momentary electric= al discharge into the system that disrupts the GPS. If so why only the one G= PS and why none of the other equipment? The Tru Trak AP is rock solid using = the secondary GPS; the comms are rock solid; as is the transponder.

BTW in answer to another list member, all ground connections have been chec= ked and are good.

All very frustrating.

Ross


On 2010/12/30 4:21 AM, "Dennis Johnson" <pinetownd@volcano.net> wrote:

H= i Ross,
 
There are many, many Legacies flying without P-static problems disabling th= eir avionics.  Before I went to a lot of trouble electrically bonding p= arts of the airframe, I'd try to determine how your Legacy is different from= the others.  And I'd make sure all the electrical grounds are solidly = connected.  
 
Do you have any indication that P-static is a frequent problem in your airp= lane?  Is anything except the GPS function of your MGL Voyager affected= ?  I once picked up enough static charge that what little hair I have o= n my head stood straight up, towards the charged canopy.  It didn't cau= se a problem with any of the avionics, though.
 
Dennis
 
 

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