---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Tue 03/31/15: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:27 PM - Engine noise in Radio and Headset (Hugh McKay) 2. 06:41 PM - Re: Engine noise in Radio and Headset (Larry Edson) ________________________________ Message 1 _____________________________________ Time: 01:27:00 PM PST US From: "Hugh McKay" Subject: RotaxEngines-List: Engine noise in Radio and Headset I have an Allegro 2000 E-LSA with a Rotax 912 UL engine using the standard Rotax Voltage regulator. After 600 +/- hours I am getting a lot of =9Cnoise=9D in my head sets when I use the radio push-to-talk transmit button. The radio is an ICOM IC-A200 VHF Transceiver using a Comant CI 121 VHF Antenna. When using the P-T button to transmit I can actually hear the engine rpm, especially at low rpms. At higher rpms the noise is not as bad but it is still there as noise. The voltage regulator is wired per the Rotax engine wiring diagram with the addition of two 10,000 Mf capacitors in parallel. Can anyone give me advice as to how to eliminate this =9Cnoise=9D? Hugh G. McKay III, P.E. Fellow, L.M. ASCE Senior Consultant Worldwide Engineering Inc. 4090 North NC Hwy. 16 Denver, NC 28037 Ph. 704-661-8271 Fax 704-483-5466 email hgmckay@bellsouth.net Allegro 2000 E-LSA N661WW Rotax 912 UL 689 hours ________________________________ Message 2 _____________________________________ Time: 06:41:52 PM PST US Subject: Re: RotaxEngines-List: Engine noise in Radio and Headset From: Larry Edson Hugh, I would check the noise canceling capacitors. They do fail with exposure to heat and humidity and they are not hard to check. The following document will help you to understand the various failure modes of the different types of capacitors. http://www.electrocube.com/electrocube/assets/File/documentation-files/capac itor-documents/electrocube-tech-bulletin-why-capacitors-fail.pdf Good luck, Larry Edson N4362C Sent from my iPad > On Mar 31, 2015, at 4:26 PM, Hugh McKay wrote: > > I have an Allegro 2000 E-LSA with a Rotax 912 UL engine using the standard Rotax Voltage regulator. After 600 +/- hours I am getting a lot of =9C noise=9D in my head sets when I use the radio push-to-talk transmit bu tton. The radio is an ICOM IC-A200 VHF Transceiver using a Comant CI 121 VHF Antenna. When using the P-T button to transmit I can actually hear the engi ne rpm, especially at low rpms. At higher rpms the noise is not as bad but i t is still there as noise. The voltage regulator is wired per the Rotax engi ne wiring diagram with the addition of two 10,000 Mf capacitors in parallel. > > Can anyone give me advice as to how to eliminate this =9Cnoise =9D? > > Hugh G. McKay III, P.E. Fellow, L.M. ASCE > Senior Consultant > Worldwide Engineering Inc. > 4090 North NC Hwy. 16 > Denver, NC 28037 > > Ph. 704-661-8271 > Fax 704-483-5466 > email hgmckay@bellsouth.net > Allegro 2000 E-LSA N661WW > Rotax 912 UL 689 hours > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rotaxengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RotaxEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rotaxengines-list Browse Digests http://www.matronics.com/digest/rotaxengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.