---------------------------------------------------------- Avionics-List Digest Archive --- Total Messages Posted Sun 04/13/08: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:57 PM - Questions on avionics (Rv9APlane) 2. 07:04 PM - Re: GARMIN GI-106A VS. MD200-306 CDI (Rv9APlane) 3. 07:30 PM - Re: Questions on avionics (Doug McNutt) 4. 07:46 PM - Re: Questions on avionics (Bruce Peters) ________________________________ Message 1 _____________________________________ Time: 05:57:43 PM PST US Subject: Avionics-List: Questions on avionics From: "Rv9APlane" Hi all, I have a couple of basic questions I don't understand well: 1. What does it mean to "cage" an attitude indicator? I've never flown a plane that has had this option but I see it on some I'm considering for my homebuilt. 2. I want a light IFR panel and have read some things about Mode S transponders. Is there any advantage to having one over a Mode C other than the TIS capability? 3. Is purchasing a separate encoder necessary? I was planning on putting a Blue Mountain EFIS One in my plane (please no negative comments as I'm already committed), a Garmin 430W with a GI-106A CDI, and a Garmin 327 transponder (pending the answer to number 2 above) in my plane. I see some avionics vendors packaging in a separate encoder but don't really understand why. Thanks for your help -------- Bruce Peters RV9A, Fuselage Bakersfield, CA Read this topic online here: http://forums.matronics.com/viewtopic.php?p=176633#176633 ________________________________ Message 2 _____________________________________ Time: 07:04:12 PM PST US Subject: Avionics-List: Re: GARMIN GI-106A VS. MD200-306 CDI From: "Rv9APlane" Hi OC, I am new to the list and saw this today. I am planning the same equipment , i.e., a 430W, SL30, and 106A. I am not familiar with the items you mentioned about switching back and forth. Can you point me to the catalog locations or suppliers with the correct items numbers? I'm pretty weak on the electrical stuff although I reading up on it now(Bob Nuckolls book). Thanks for your help. -------- Bruce Peters RV9A, Fuselage Bakersfield, CA Read this topic online here: http://forums.matronics.com/viewtopic.php?p=176650#176650 ________________________________ Message 3 _____________________________________ Time: 07:30:56 PM PST US From: Doug McNutt Subject: Re: Avionics-List: Questions on avionics At 17:53 -0700 4/13/08, Rv9APlane wrote: >1. What does it mean to "cage" an attitude indicator? I've never flown a plane that has had this option but I see it on some I'm considering for my homebuilt. Gyros come in gimbals that allow the rotor to stay in a plane (That's a term of geometry here.) while the airplane moves around it. When you cage a gyro you clamp the bearings in the gimbals so that the rotating wheel is held so that its axis turns with the airplane. You do it when you set a directional gyro and then release it. Older attitude indicators could be made to lie by exceeding the limits of their gimbals and the two axes would line up with each other and the gyro would lock up and "tumble". Caging it would keep it from tumbling but would also make it unusable for flight. >2. I want a light IFR panel and have read some things about Mode S transponders. Is there any advantage to having one over a Mode C other than the TIS capability? Mode ADS-B is coming. It's a political point but I'd not waste cash on mode -S when ADS-B may be required before you get much out of S. >3. Is purchasing a separate encoder necessary? I was planning on putting a Blue Mountain EFIS One in my plane (please no negative comments as I'm already committed), a Garmin 430W with a GI-106A CDI, and a Garmin 327 transponder (pending the answer to number 2 above) in my plane. I see some avionics vendors packaging in a separate encoder but don't really understand why. You need a barometric input for any of the transponder modes. GPS altitude won't cut it. So external or internal it has to be a pressure measuring device connected with a tube to the static system. -- --> From the U S of A, the only socialist country that refuses to admit it. <-- ________________________________ Message 4 _____________________________________ Time: 07:46:50 PM PST US From: "Bruce Peters" Subject: Re: Avionics-List: Questions on avionics Thanks Doug, I appreciate the help. On Sun, Apr 13, 2008 at 7:24 PM, Doug McNutt wrote: > > > > At 17:53 -0700 4/13/08, Rv9APlane wrote: > >1. What does it mean to "cage" an attitude indicator? I've never flown > a plane that has had this option but I see it on some I'm considering for my > homebuilt. > > Gyros come in gimbals that allow the rotor to stay in a plane (That's a > term of geometry here.) while the airplane moves around it. When you cage a > gyro you clamp the bearings in the gimbals so that the rotating wheel is > held so that its axis turns with the airplane. You do it when you set a > directional gyro and then release it. Older attitude indicators could be > made to lie by exceeding the limits of their gimbals and the two axes would > line up with each other and the gyro would lock up and "tumble". Caging it > would keep it from tumbling but would also make it unusable for flight. > > >2. I want a light IFR panel and have read some things about Mode S > transponders. Is there any advantage to having one over a Mode C other than > the TIS capability? > > Mode ADS-B is coming. It's a political point but I'd not waste cash on > mode -S when ADS-B may be required before you get much out of S. > > >3. Is purchasing a separate encoder necessary? I was planning on > putting a Blue Mountain EFIS One in my plane (please no negative comments as > I'm already committed), a Garmin 430W with a GI-106A CDI, and a Garmin 327 > transponder (pending the answer to number 2 above) in my plane. I see some > avionics vendors packaging in a separate encoder but don't really understand > why. > > You need a barometric input for any of the transponder modes. GPS altitude > won't cut it. So external or internal it has to be a pressure measuring > device connected with a tube to the static system. > > > -- > > --> From the U S of A, the only socialist country that refuses to admit > it. <-- > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message avionics-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Avionics-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/avionics-list Browse Digests http://www.matronics.com/digest/avionics-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.