---------------------------------------------------------- Avionics-List Digest Archive --- Total Messages Posted Fri 06/04/04: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:45 AM - Transmit Noise (John Kenealy) 2. 11:40 AM - Re: Transmit Noise (Bruce Boyes) 3. 03:49 PM - Re: Transmit Noise (Doug McNutt) 4. 04:25 PM - Re: Transmit Noise (frequent flyer) ________________________________ Message 1 _____________________________________ Time: 10:45:53 AM PST US From: "John Kenealy" Subject: Avionics-List: Transmit Noise --> Avionics-List message posted by: "John Kenealy" The tower at my home airport, KBMG often tells me Im "Garbled & unreadable " I hear a tone in my headset when I transmit.(not feedback). The other day when I was calling for landing clearence I cut the power(throtled back) and they could understand me. When I am on the ground in taxi they have no problem either. When the engine is off there is also no problem. I bought an alternator filter and will install it soon. Any other sugestions? It is starting to be really irritating after a beautiful flight to have to deal with the negativity from the tower and the frustration of the noise. I have a Narco MK 12D NAV/COM with GS.This only hapens during Transmit. Is there a beter way to ground the radio? I have replaced the PTT switch twice and still no diff. Changed headsets no diff. HELP ! Thanks J T Kenealy Get Your FREE FlashMail Address now at http://www.flashmail.com It's Free, Easy, & Fun !!! ________________________________ Message 2 _____________________________________ Time: 11:40:08 AM PST US From: Bruce Boyes Subject: Re: Avionics-List: Transmit Noise --> Avionics-List message posted by: Bruce Boyes At 11:10 AM 6/4/2004 -0700, John Kenealy wrote: >--> Avionics-List message posted by: "John Kenealy" > > >The tower at my home airport, KBMG often tells me Im "Garbled & >unreadable " My wife often tells me the same thing. The problem doesn't seem to exist when communicating with other men. >I hear a tone in my headset when I transmit.(not feedback). I have the same problem, even when not wearing the headset. It's really annoying at times, and frequently makes routine conversation difficult. After some study, we have determined that this variable tone is in fact emanating from our two children (ages 2 and 6). I have not found a solution for either problem. Please advise if you do. Best of luck, Bruce ________________________________ Message 3 _____________________________________ Time: 03:49:03 PM PST US From: Doug McNutt Subject: Re: Avionics-List: Transmit Noise --> Avionics-List message posted by: Doug McNutt At 11:10 -0700 6/4/04, John Kenealy wrote: >--> Avionics-List message posted by: "John Kenealy" >I hear a tone in my headset when I transmit.(not feedback). Have a look at your alternator diodes. The three phase full wave rectifier will typically produce an AC ripple of 6 X 400 =2400 Hz which is fairly easy to filter, With one of six diodes failed the alternator will still work but will produce ripple at 400 Hz which will change with engine speed. 440 Hz is one of the ways the A above middle C is tuned on a piano. Is that the tome you hear? A portable oscilloscope on the aircraft power bus should show six equal peaks but will clearly show one or two bigger than the others if there is a bad diode. -- --> There are 10 kinds of people: those who understand binary, and those who don't <-- ________________________________ Message 4 _____________________________________ Time: 04:25:42 PM PST US From: frequent flyer Subject: Re: Avionics-List: Transmit Noise --> Avionics-List message posted by: frequent flyer --- Doug McNutt wrote: > --> Avionics-List message posted by: Doug McNutt > > --> There are 10 kinds of people: those who > understand binary, and those who don't <-- And base 8 is just like base 10 provided you are missing two fingers. ;<) Jack do not archive __________________________________ http://messenger.yahoo.com/