X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao106.cox.net ([68.230.241.40] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3876906 for flyrotary@lancaironline.net; Tue, 06 Oct 2009 19:37:37 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.40; envelope-from=alventures@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao106.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20091006233659.RSQL21192.fed1rmmtao106.cox.net@fed1rmimpo01.cox.net> for ; Tue, 6 Oct 2009 19:36:59 -0400 Received: from BigAl ([72.192.133.78]) by fed1rmimpo01.cox.net with bizsmtp id pbcz1c00R1hf1Cg03bcziW; Tue, 06 Oct 2009 19:36:59 -0400 X-VR-Score: 0.00 X-Authority-Analysis: v=1.0 c=1 a=Ia-xEzejAAAA:8 a=BjsXAJ13YUGhwfLOChIA:9 a=MwgbLVD4OqxfqzBfBrd9U4Dn_I8A:4 a=EzXvWhQp4_cA:10 a=7GhHdPs5BdZNWVxeSgYA:7 a=w98rB70ht99dQu_9Tv5CGnLzSSoA:4 X-CM-Score: 0.00 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Mystery Radio Noise Date: Tue, 6 Oct 2009 16:37:16 -0800 Message-ID: <5C5EE0EBD5FE428484A92C2A6CEFECE9@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0031_01CA46A3.44134E90" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6838 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 In-reply-to: Thread-Index: AcpGzxW3vB0o1t9xRQOwnHQqIpgiRAAFmVMg Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_0031_01CA46A3.44134E90 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable It's hard to imagine that it has anything to due with the exhaust since = the spatial relationship between the exhaust and antenna does not change = with aircraft pitch. =20 You might try adjusting the squelch. I had a similar problem with noise when I went fast, or sometimes on climbout. Finally realized the sound = level in the cabin was going higher and overcoming the squelch setting so I = was hearing cabin noise on the sidetone from the mic. A small tweak on the squelch knob made it go away. =20 Al G =20 -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes Sent: Tuesday, October 06, 2009 2:54 PM To: Rotary motors in aircraft Subject: [FlyRotary] Mystery Radio Noise =20 Got the plane back together late Sunday just in time for a few laps = around the airport. Oil temps showed major improvements with the larger inlets. Climbing at 100 mph to 3000 ft, 7200 rpm on take off, reduced to 6500 = rpm at 500 ft agl. Maintained 6500 rpm at 37" MP for several circuits. Oil temps went to = 220F but started to come down when I leveled off. Water stay at 190F or = below. OAT was 88F . My new "test" ducts do not seal as well as the first set = so hopefully I still have room for improvement.=20 =20 While level at 3000 ft \ ground speed showing 145 knots I pitched the = nose down and heard a startling noise in my headset. Almost like wires = shorting. Leveled off and noise stopped. Pitched up no change. Pitch down the = noise returned. I decided it could not be wiring and repeated this several = times. It also happened at slower speeds but I don't remember at what speed it stopped. It doesn't happen on the ground at full power run up. My guess = is my new exhaust is somehow affecting the comm antenna when in a nose down attitude. The exhaust ends about 1 ft in front and 1 ft to the side of = the antenna. Any ideas? =20 Bobby J Hughes RV-10 SC Renesis =20 ------=_NextPart_000_0031_01CA46A3.44134E90 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

It’s hard to imagine that = it has anything to due with the exhaust since the spatial relationship between = the exhaust and antenna does not change with aircraft = pitch.

 

You might try adjusting the = squelch.  I had a similar problem with noise when I went fast, or sometimes on = climbout. Finally realized the sound level in the cabin was going higher and overcoming = the squelch setting so I was hearing cabin noise on the sidetone from the = mic.  A small tweak on the squelch knob made it go away.

 

Al G

 

-----Original = Message-----
From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. Hughes
Sent: Tuesday, October = 06, 2009 2:54 PM
To: Rotary motors in = aircraft
Subject: [FlyRotary] = Mystery Radio Noise

 

Got the plane back together = late Sunday just in time for a few laps around the airport. Oil temps showed major improvements with the larger inlets. Climbing at 100 = mph to 3000 ft, 7200 rpm on take off, reduced to 6500 rpm at 500 ft = agl.

Maintained 6500 rpm at = 37" MP for several circuits. Oil temps went to 220F but started to come down = when I leveled off. Water stay at 190F or below. OAT was 88F . My new "test"  ducts do not seal as well as the first = set so hopefully I still have room for improvement.

 

While level at 3000 ft \ = ground speed showing 145 knots I pitched the nose down and heard a startling noise in my headset. Almost like wires shorting. = Leveled off and noise stopped. Pitched up no change. Pitch down the noise returned. = I decided it could not be wiring and repeated this several times. It also happened = at slower speeds but I don't remember at what speed it stopped. It doesn't = happen on the ground at full power run up. My guess is my new exhaust is = somehow affecting the comm antenna when in a nose down attitude. The exhaust = ends about 1 ft in front and 1 ft to the side of the antenna. Any = ideas?

 

Bobby J = Hughes

RV-10 SC = Renesis

 

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