Mounting comm antenna on turtledeck center line.

[Rick524]

I'm about to start my Sonex scratch built turtledeck. I'd like to mount the comm antenna
on the centerline....ie, on the spline rivet line. Wonder if anyone has any ideas how to do
that before I start cutting metal?

Rick
Sonex 524

[radfordc]

The issue with mounting on the center line is that the aluminum sheets overlap along the center line and you have to make a shim to fit under the antenna base so that it sits level. What sort of antenna will you use. I originally used one of these: http://www.aircraftspruce.com/catalog/a ... 29_ant.php . Note the rather large base that it uses.

Later I changed to one of these: http://www.aircraftspruce.com/catalog/a ... ntenna.php . Much easier to install and works as well or better.

[sonex293]

I started off using a home-made antenna, and although it worked well I decided to install a bought antenna and I am extremely happy with the results. As you can tell from the picture below it is off center ever so slightly.

Old Antenna...


New Antenna, which can be bought now from MGL or the supplier Delta Pop Aviation...


On the Delta Pop antenna I put some closed cell foam to fill the void created by the turtledeck curvature.

--
Michael
Sonex N293SX

[Rick524]

I have a Dorne and Margolan C70-1/A antenna. I think the mounting holes are 1.5" from side to side. It wont sit flat on the turtledeck
but shouldnt have too much gap showing....nothing that a little fill wont fix.

http://www.aircraftspruce.com/catalog/a ... C70-1A.php

When I cut my trutledeck skins, I plan on leaving six inch square "tabs" on each skin, that will overlap each other when the skins are mated.
This will give more meat for the antenna to mount on, and add a little strength for where there are missing rivets under the antenna and where
the center C channel is notched out for the antenna connector.

Thats the plan..... :)

Rick
Sone 524

[Rick524]

Just an update on the antenna mounting. I have the turtledeck all riveted together complete with my overlapping tabs. It turned out the tabs only needed to be 3" each, which left me with a 6" square area for the antenna. The antenna ALMOST sits flat on the turtledeck. It came with a thin foam gasket that will fill the small gaps on the sides nicely.

Rick
Sonex 524

Turtledeck on it's side with comm ant mounted.

ant.jpg (21.91 KiB) Viewed 5148 times

Inside view of re-inforced C channel under antenna.

inside ant.jpg (53.91 KiB) Viewed 5148 times

[Mike53]

Just an update on the antenna mounting. I have the turtledeck all riveted together complete with my overlapping tabs. It turned out the tabs only needed to be 3" each, which left me with a 6" square area for the antenna. The antenna ALMOST sits flat on the turtledeck. It came with a thin foam gasket that will fill the small gaps on the sides nicely.
I took some pictures of it all, but dont know how to post them.

Rick
Sonex 524

Rick you will see edit in the upper right of your message .Click on it and then look in the lower left and you will see upload attachments.Click on that and find your file of pictures on your computer and attach them.You may have to reduce the size of the pictures and for that there has already been a couple posts probably in Discussions that you can go to if like me you didn't know how to do it.