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kelson73 wrote:The CI 2480-200 isn't on the approved antenna list anyway. I believe the factory uses DM C63/1A which is 2.0:1 for comm #1 on top of the fuselage. I'm confused on the VOR wording. VOR doesn't use this antenna but the horizontally polarized one inside the stabilizer on the DA40 and is of course receive only.

Any reasonable person would be confused! I'm not sure how my brain glitched but I was typing this while participating in a teleconference (note to self) and I was thinking about the cluster of COMM frequencies toward the lower end versus the substantially unused upper end. Of course, ATC uses the full range (in theory) but in my part of the country, ATC seems to be using mostly the lower end. Other than AWOS, I seldom wander above 129.0. Twenty-one mHz (118-137) is a pretty wide range for this kind of antenna. I would guess that the VSWR at the extremes is pretty high. I know one antenna manufacturer that optimizes VSWR around 122.00 mHz rather than the 127.5 center. Since 99% of my tansmitting is 122.7, 122.8 & 122.9 I have tuned the quarter wave ground plane I installed on top of my hangar to peak at 122.8. Sorry for the confusion!

I had the combo antenna installed. It is GPS/COM/NAV.

Replaces old top NAV/COM. From a structural standpoint they fill the small screw holes (three screw pattern) and drill 4 new for the new antenna. Apparently the little screw holes are allowed whereas no new 'big' whole needed. My shop is a FAA repair station so they do everything by the book. Woodland Aviation, Davis, CA.

And a much prettier antennae than factory. Gonna have a similar style replace the now ugly bottom nav/com at annual this month.

FYI also planning to replace backups with L3 ESI 500 with synthetic vision.

I also believe the antenna I used (cobham) is what is specified in 345R STC from Garmin - but may be wrong on that.

FWIW, my DA40 has WAAS, so I am planning to wait until at least next year. Diamond Canada takes ownership of the DA40 type certificate from Austria RSN(tm). Hopefully they will release new firmware supporting the non-WAAS GTX345R.

Maybe eventually we will even have an upgrade path to the NXi.

Chris

I'm considering waiting until December 2019 to look into this, in the hope that there will be a clear solution to the problem by then. Seems like a mess right now. DA40, G1000, non WAAS, XM Weather, TAS600.