On Sunday, December 29, 2019 at 6:48:52 PM UTC-8, 2G wrote:
On Saturday, December 28, 2019 at 6:43:02 PM UTC-8, Darryl Ramm wrote:
On Saturday, December 28, 2019 at 4:10:30 PM UTC-8, wrote:
"Pay attention to the proper ground plane installation with any of the standard external transponder 1/4 wave antenna. That is very important."
Can the ground Plane be inside a carbon fibre fuselage for an external blade type antenna ?
Dan

The ground plane you install would normally be inside the CF fuselage. And the antenna manufacture or glider manufacturer should provide instructions on how to do this properly. A part of the point of that aluminium plate or foil tape ground plane is to help with a good connection to the coax cable ground. In some cases you might scuff the inside of the fueslage to help make additional electrical connection to the carbon fibre weave. *Follow the directions your glider manufacturer provides.* A plate especially can also help provide a good solid surface for antenna lock washers to engage with. Clearly here the CF will act in part as a ground plane (even without a good direct electrical connection, but by backing it with a better conductor with good connection to the coax you are helping things along).

Not all transponder antennas need a ground plane:

https://wingsandwheels.com/avionics-...as/l2-aae.html

You are replying to a thread that clearly stated "with any of the standard external transponder 1/4 wave antenna." Are you adding value here?