Re: ADSB In - Classic Cozy 3 Antenna Placement Experience

Del Schier

Hi Richard,  You may not be aware of the S53MV annular slot transponder antenna for composite aircraft. It is easy and cheap to make and works with no holes in the airplane; just set it on the floor.  It has the advantage that it has about 6 dB gain over a ¼ wave rod or ½ wave dipole giving approximately four times the signal strength. 


Note that the original designer told me his design may not work at 978 MHz for ADS-B UAT and it didn’t.  I scaled the antenna, see attached, so that it was optimized for 978.  If you are going to use it with a 1090 ES ADS-B or Mode C transponder you should use the drawings from the designer, no my attached drawing. 


There are at least a dozen people using these in their canards and to my knowledge they are all working well, provided they were made accurately (+- 1/16”).  One guy sent me one to test that he had almost ½” errors and that one did not work. 


Del Schier

Cozy IV N197DL

Cannon Creek Airpark 15FL




From: <> On Behalf Of Richard Sessions
Sent: Sunday, June 21, 2020 11:40 PM
Subject: [Canard Zone] ADSB In - Classic Cozy 3 Antenna Placement Experience



I know there has been a lot of discussion on the ADSB-In antenna placements a few months back, but curious to see what people are getting good results with in
a Classic Cozy 3 now that there has been a little more time and likely more experience.

I know there was the slot antenna and others, but I am thinking a 13"ish square foil for the dipole under the left thigh support.  I know it is a projection and subject to ridicule, but pretty simple and not a lot of changes / structure in the back seat area.

I am hooking up to a Dynon HDX system in a panel upgrade and it is about the last thing I have when my newly repaired ADAHRs gets back (static port failure....).

Feel free to contact me off line as I am sure most feel we have done this to death.

Richard Sessions, Cozy 3 N9455 (William Chorley builder if anyone has anything on it)
Houston's Ellington Field (KEFD) - Go RAFE!
rtsessions@..., 281-467-2432 (leave a message with all the spam....)

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