X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [66.219.56.245] (HELO mail.qnsi.net) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3876903 for flyrotary@lancaironline.net; Tue, 06 Oct 2009 19:44:36 -0400 Received-SPF: none receiver=logan.com; client-ip=66.219.56.245; envelope-from=bhughes@qnsi.net Return-Receipt-To: "Bobby J. Hughes" Subject: RE: [FlyRotary] Re: Mystery Radio Noise MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01CA46E7.BECECBB6" Date: Tue, 6 Oct 2009 18:47:28 -0600 Disposition-Notification-To: "Bobby J. Hughes" Content-class: urn:content-classes:message Message-ID: <74120FDE88CAFE4DBDA8814BCE20A3F315EC94@qnsi-mail.qnsi.net> X-MimeOLE: Produced By Microsoft Exchange V6.5 X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: Mystery Radio Noise thread-index: AcpG5uEzVYRVxIRtR72U7KPhlM5gfwAAHiXg References: From: "Bobby J. Hughes" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01CA46E7.BECECBB6 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable I'll check that next flight. The noise is immediate on pitch down and stops immediately on naturalizing the elevator. Very strange.=20 =20 Bobby ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen Sent: Tuesday, October 06, 2009 6:37 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Mystery Radio Noise 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_001_01CA46E7.BECECBB6 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

I'll check that next flight. The noise is = immediate on pitch=20 down and stops immediately on naturalizing the elevator. Very strange.=20

Bobby

From: Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On Behalf Of Al=20 Gietzen
Sent: Tuesday, October 06, 2009 6:37 PM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] Re: Mystery Radio=20 Noise

It’s = hard to imagine=20 that it has anything to due with the exhaust since the spatial = relationship=20 between the exhaust and antenna does not change with aircraft=20 pitch.

You might = try=20 adjusting the squelch. I had a similar problem with noise when I = went=20 fast, or sometimes on climbout. Finally realized the sound level in the = cabin=20 was going higher and overcoming the squelch setting so I was hearing = cabin noise=20 on the sidetone from the mic. A small tweak on the squelch knob = made it go=20 away.

Al=20 G

-----Original=20 Message-----
From: = Rotary=20 motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bobby J. = Hughes
Sent: Tuesday, October 06, 2009 = 2:54=20 PM
To: Rotary motors = in=20 aircraft
Subject: = [FlyRotary]=20 Mystery Radio Noise

Got the plane back = together late=20 Sunday just in time for a few laps around the airport. Oil temps=20 showed major improvements with the larger inlets. Climbing at 100 = mph to=20 3000 ft, 7200 rpm on take off, reduced to 6500 rpm at 500 ft=20 agl.

Maintained 6500 rpm at 37" = MP for=20 several circuits. Oil temps went to 220F but started to come down when I = leveled=20 off. Water stay at 190F or below. OAT was 88F . My new "test" = ducts=20 do not seal as well as the first set so hopefully I still have room for=20 improvement.

While level at 3000 ft \ = ground=20 speed showing 145 knots I pitched the nose down and heard=20 a startling noise in my headset. Almost like wires shorting. = Leveled off=20 and noise stopped. Pitched up no change. Pitch down the noise returned. = I=20 decided it could not be wiring and repeated this several times. It also = happened=20 at slower speeds but I don't remember at what speed it stopped. It = doesn't=20 happen on the ground at full power run up. My guess is my new exhaust is = somehow=20 affecting the comm antenna when in a nose down attitude. The exhaust = ends about=20 1 ft in front and 1 ft to the side of the antenna. Any=20 ideas?

Bobby J = Hughes

RV-10 = SC=20 Renesis

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