X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 26 Apr 2014 13:28:52 -0400 Message-ID: X-Original-Return-Path: Received: from qmta10.westchester.pa.mail.comcast.net ([76.96.62.17] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTP id 6848020 for lml@lancaironline.net; Sat, 26 Apr 2014 12:03:58 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.62.17; envelope-from=jmorgan1023@comcast.net Received: from omta18.westchester.pa.mail.comcast.net ([76.96.62.90]) by qmta10.westchester.pa.mail.comcast.net with comcast id ufKj1n0021wpRvQ5Ag3Rcc; Sat, 26 Apr 2014 16:03:25 +0000 Received: from [192.168.1.107] ([24.11.157.196]) by omta18.westchester.pa.mail.comcast.net with comcast id ug3Q1n00H4EXR5U3eg3RnT; Sat, 26 Apr 2014 16:03:25 +0000 From: Jack Morgan Mime-Version: 1.0 (Apple Message framework v1283) Content-Type: multipart/alternative; boundary="Apple-Mail=_690C27EE-0CD0-437E-8DB3-643B60F9286D" Subject: Noise filter X-Original-Date: Sat, 26 Apr 2014 12:03:24 -0400 In-Reply-To: X-Original-To: Lancair Mailing List References: X-Original-Message-Id: X-Mailer: Apple Mail (2.1283) --Apple-Mail=_690C27EE-0CD0-437E-8DB3-643B60F9286D Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 Hi Shane, Zac at Trutrak suggests using a DGFC37MF from L-com. The cost is $35. I = had an occasional gyro upset in the AP. The filter seems to have helped = so far. Never was able to associate the upset occurrence with anything=85.= just happened occasionally. The AP is teamed up with a G900x which has = no issues. Jack Morgan On Apr 26, 2014, at 6:01 AM, Lancair Mailing List wrote: > From: Steve Richard > Subject: RE: [LML] G3X Fuel probe interference > Date: April 25, 2014 4:45:17 PM EDT > To: lml@lancaironline.net >=20 >=20 > I had a similar problem with the Grand Rapids EIS 6000 engine monitor = and TruTrak autopilot. I found someone with much, much more electronics = knowledge than me to put an oscilloscope on various wires. We found = that during transmission an alternating current (very low) was =91riding=92= on the DC power line into the EIS. We found other issues with the fuel = probes, EGT=92s and the autopilot, but I can=92t remember exactly what = they were. > =20 > We solved (to the annoyance level) the problems by installing a = filtered connector on the EIS and the autopilot:=20 > > Catalog: = http://www.digikey.com/Web%20Export/Supplier%20Content/AmphenolCommercial_= 664/PDF/Amp_CP_FILTERD-CONN_CAT.pdf?redirected=3D1 > =20 > We used a FCC17-B25AD-250, only because that=92s what he had in his = bin. It worked fairly well. I=92m sure if we would have done more work = we could have eliminated the problem, but it was very time consuming. = The only time I have a problem now is transmitting on the higher = frequencies, >135.00 on one radio. It only affects the EGT=92s by 5-10 = degrees inflight. Of course, it is much worse just sitting in the = hangar. > =20 > I am sure this problem has something to do with routing. I used = RG-400 everywhere, but inevitably wires get next to each other. I did = not shield everything. I only shielded in accordance with the manuals. = Neither TruTrak or Grand Rapids recommended shielding. At the same = time, none of my RV friends have these kinds of problems, so an all = fiberglass airplane may make it much more difficult to eliminate all the = RF problems.=20 > =20 > Steve > =20 > =20 > From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of = Shane > Sent: Friday, April 25, 2014 10:53 AM > To: lml@lancaironline.net > Subject: [LML] G3X Fuel probe interference > =20 > Hello all, > =20 > We have installed a G3X dual screen system in a Lancair ES and have a = strange occurrence happening. > =20 > The system uses the standard EI capacitance probes and fuel level = indication is very accurate. What is happening is when we key the mike = to transmit, after a few seconds the fuel indication drops to zero. = After we stop transmitting the level returns to normal. We have used = shielded wiring, antenna coax is routed down the opposite side of the = fuselage from the probe wiring, all the LRU=92s in the G3X system are = centrally grounded along with everything else in the system. We have = tried everything we can think of as far as trying to isolate and shield = all the different components, but nothing works. The rest of the system = works perfectly. > =20 > Any ideas? >=20 --Apple-Mail=_690C27EE-0CD0-437E-8DB3-643B60F9286D Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 Hi = Shane,

Zac at Trutrak suggests using a DGFC37MF from = L-com. The cost is $35. I had an occasional gyro upset in the AP. The = filter seems to have helped so far. Never was able to associate the = upset occurrence with anything=85. just happened occasionally. The AP is = teamed up with a G900x which has no = issues.

Jack Morgan

On = Apr 26, 2014, at 6:01 AM, Lancair Mailing List wrote:

To: 
I had a similar problem with the = Grand Rapids EIS 6000 engine monitor and TruTrak autopilot.  I = found someone with much, much more electronics knowledge than me to put = an oscilloscope on various wires.  We found that during = transmission an alternating current (very low) was =91riding=92 on the = DC power line into the EIS.  We found other issues with the fuel = probes, EGT=92s and the autopilot, but I can=92t remember exactly what = they were.
We = solved (to the annoyance level) the problems by installing a filtered = connector on the EIS and the = autopilot: 

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