Varieze Transponder Antenna Position

[Hercpilot]

For those of you who are using a blade-type transponder antenna, where are you mounting the antenna? My aircraft is setup for NACA cooling. I was wandering if the antenna would affect airflow through the scoop if I positioned the antenna just prior to start of the scoop.

 

Justin

[Drew Swenson]

Putting things in the scoop will adversely effect the cooling.

I have the normal "stick with a ball" antenna mounted to an appropriately sized groundplane---and the whole thing is mounted in the nose of my Cozy (interior sidewall----completely internal----works great----nothing hanging in the breeze). If you have a long nose, it should not be a problem.

[Hercpilot]

Thanks Drew! So when you say "appropriately sized" what does that mean for the ball and stick type antennas?

 

Justin

[TMann]

Thanks Drew! So when you say "appropriately sized" what does that mean for the ball and stick type antennas?

 

Justin

See page 3 of :

http://www.cozybuilders.org/ref_info/RST_82704.pdf

[Hercpilot]

Thanks T Mann! Exactly what I needed!

 

Justin

[epicez]

This helped me too, however, if you put the antennae under the pilot leg rest, where do you run the cable from the top side of the exit hole (assuming under the leg) without kinking the cable? And, is there any other common places for installation/fabricate a bracket in the nose etc...?

[epicez]

Some of the confusion comes from the fact that you are supposed to orient the antenna down (I have the T.E.D., realizing now that a bolt would have sufficed)

 

But, why the downward orientation? There are many more installation options if I can mount it horizontally.

[longezdave]

But, why the downward orientation? There are many more installation options if I can mount it horizontally.

The ground based antennas, that your transponder antenna is going to communicate with, are vertically oriented. If you orient your antenna horizontally, you will loose (a ballpark of) about 20 db of signal. This will result in less range, but it will still work. I would not recommend going horizontal.