---------------------------------------------------------- Avionics-List Digest Archive --- Total Messages Posted Thu 06/12/14: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:21 AM - Direction Indicator Needs (Summary) (Owen Baker) 2. 11:51 AM - Re: Direction Indicator Needs (Summary) (Ken) ________________________________ Message 1 _____________________________________ Time: 10:21:54 AM PST US From: "Owen Baker " Subject: Avionics-List: Direction Indicator Needs (Summary) 6/12/2014 Hello Aeroelectric and Avionics Listers, On this subject back on 6/10/2014 I wrote: =9CI know that there are many technically smart people on these lists and I would like to enlist your assistance. Picture this situation: There are hundreds (maybe thousands) of EAB (Experimental Amateur Built) IFR capable aircraft flying around with vacuum driven mechanical spinning mass gyroscopic attitude and directional indicators. A large percentage of these builders and pilots would like to (or need to) replace those indicators with something electronic (other than expensive electrical motor driven mechanical spinning mass gyroscopic) in nature and remove the entire vacuum system from their EAB.=9D and =9CHow about it experts (and entrepreneurs) are my desires hopeless and unrealistic?=9D I want to now post what I have learned / concluded and express my gratitude to the several people who responded: 1) The two best choices for replacing my previous vacuum driven attitude gyro: a) The Sandia SAI 340 Quattro. See here: http://www.sandia.aero/?q=node/80 b) The Dynon EFIS-D6. See here: http://www.dynonavionics.com/docs/D6_intro.html 2) The best choice for replacing my previous vacuum driven directional gyro: The MGL Avionics Velocity Singles Horizon / Compass. See here: http://www.mglavionics.com/html/velocity_singles.html Many thanks again for all that posted help and I would be willing to discuss my choices if desired. OC 'O C' Baker says "The best investment you can make is the effort to gather and understand information." ________________________________ Message 2 _____________________________________ Time: 11:51:37 AM PST US From: Ken Subject: Re: Avionics-List: Direction Indicator Needs (Summary) There is also the Trutrak gemini ADI series for a drop in 3" replacement with gps track (not magnetic heading). These are rate sensing gyros so they are a bit different than spinning gyro's. If you hold a pitch attitude and there is an altitude change they function well. However with no corresponding altitude change they gradually return to displaying nose level. Not really a problem but if I decelerate very very slowly I can get the nose quite high while the display still reads a level flight attitude. Accordingly the gemini flashes an airpseed warning when the speed gets low. Similarly if you maintain a turn for a long time, the display will gradually indicate wings level unless it has heading or track information such as from a gps. I would not expect the $500. MGL magnetic sensor and display to be a satisfactory replacement for a directional gyro. I've never flown it but the description says it won't be accurate during any turn unless you upgrade to the substantially more expensive AHRS. I was surprised to learn that in my location at 45*N lattitude, the magnetic vector is tilted about 70 degrees below the horizon which makes attitude info pretty much essential to simulate a gyro compass. While it's as heavy as the removed vacuum pump, I've been running a $25. junk table 28volt T&B for quite some time powered with a $5. dc-dc converter on my 12 volt electrical system. Nothing like the noise from a spinning gyro to remind me that the master is still on. Ken On 12/06/2014 1:21 PM, Owen Baker wrote: > 6/12/2014 > Hello Aeroelectric and Avionics Listers, On this subject back on > 6/10/2014 I wrote: > I know that there are many technically smart people on these lists and > I would like to enlist your assistance. > Picture this situation: There are hundreds (maybe thousands) of EAB > (Experimental Amateur Built) IFR capable aircraft flying around with > vacuum driven mechanical spinning mass gyroscopic attitude and > directional indicators. A large percentage of these builders and pilots > would like to (or need to) replace those indicators with something > electronic (other than expensive electrical motor driven mechanical > spinning mass gyroscopic) in nature and remove the entire vacuum system > from their EAB. > and > How about it experts (and entrepreneurs) are my desires hopeless and > unrealistic? > I want to now post what I have learned / concluded and express my > gratitude to the several people who responded: > 1) The two best choices for replacing my previous vacuum driven attitude > gyro: > a) The Sandia SAI 340 Quattro. See here: > http://www.sandia.aero/?q=node/80 > b) The Dynon EFIS-D6. See here: > http://www.dynonavionics.com/docs/D6_intro.html > 2) The best choice for replacing my previous vacuum driven directional gyro: > The MGL Avionics Velocity Singles Horizon / Compass. See here: > http://www.mglavionics.com/html/velocity_singles.html > Many thanks again for all that posted help and I would be willing to > discuss my choices if desired. > OC > 'O C' Baker says "The best investment you can make is the effort to > gather and understand information." > > * > ------------------------------------------------------------------------------------- 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.