Matronics Email Lists :: View topic - Half wave copper foil dipole transponder antenna

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Half wave copper foil dipole transponder antenna

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

rnbraud

Joined: 20 Sep 2011
Posts: 2

Posted: Tue Aug 05, 2014 11:23 am Post subject: Half wave copper foil dipole transponder antenna

I hope this isn't a duplicate, but I was unable to find sufficient info on this topic in the archives. 



I have successfully built and tested several copper foil/tape comm antennas for my Cozy MkIV and would like to build a transponder antenna the same way.



Will the following work for a Mode S transponder:



1. Vertically oriented 1/2 wave dipole.

2. 1/2" copper tape with ferrites

3. Each leg 6.25" long



Thanks.

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

kjashton(at)vnet.net
Guest

Posted: Tue Aug 05, 2014 12:46 pm Post subject: Half wave copper foil dipole transponder antenna

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



The transponder is a little different than the other antennae.  The reference discusses it.  Keep the coax run short and put it on the bottom of the airplane.  Mine is under removable front seats.  You can make the antenna from an AN bolt but they are very cheap on ebay.

-kent



 	  Quote: 	
		   On Aug 5, 2014, at 3:23 PM, "rnbraud" <rnbraud(at)yahoo.com> wrote:

 

 

 

 I hope this isn't a duplicate, but I was unable to find sufficient info on this topic in the archives. 

 

 I have successfully built and tested several copper foil/tape comm antennas for my Cozy MkIV and would like to build a transponder antenna the same way.

 

 Will the following work for a Mode S transponder:

 

 1. Vertically oriented 1/2 wave dipole.

 2. 1/2" copper tape with ferrites

 3. Each leg 6.25" long

 

 Thanks.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=428048#428048

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

rnbraud

Joined: 20 Sep 2011
Posts: 2

Posted: Tue Aug 05, 2014 12:56 pm Post subject: Re: Half wave copper foil dipole transponder antenna

Hello Kent,



I am trying to avoid the antenna sticking out of the airplane. I see where Advanced Aircraft Electronics makes an "L2" transponder antenna which looks a lot like my other foil tape antennas.



I was hoping maybe I could make my own "L2" type of antenna with my leftover RST antenna kit.



Just want to confirm if it is feasible and if the leg lengths and vertical orientation is correct.



If this does not work, I will make my transponder antenna as you mentioned and place it either out at the end of the strake or right under the pilot seat protruding out of the fuselage.



Thanks.

 	  kjashton(at)vnet.net wrote: 	
		  See.  http://www.cozybuilders.org/ref_info/RST_82704.pdf



The transponder is a little different than the other antennae.  The reference discusses it.  Keep the coax run short and put it on the bottom of the airplane.  Mine is under removable front seats.  You can make the antenna from an AN bolt but they are very cheap on ebay.

-kent

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

kjashton(at)vnet.net
Guest

Posted: Tue Aug 05, 2014 1:41 pm Post subject: Half wave copper foil dipole transponder antenna

As I understand it, a ground plane made of copper foils will work as well as the solid ground plane.  And vertical orientation sounds right.  As for where to put it, just consider that folks who try to put them in the nose of a canard airplane or up front on the airplane often run into problems climbing out away from the radar station because the bodies of the crew (bags of salt-water) and the engine blank off line-of sight with the radar.

Quick:  When you are 30 miles from a station at 5000', the angle to the station from the horizon is ___.   

ANS: 1.57 degrees.  I doesn't take much nose up deck angle to hide the antenna.  Ask me how I know.

-Kent

On Aug 5, 2014, at 4:56 PM, rnbraud wrote:

 	  Quote: 	

 Hello Kent,

 I am trying to avoid the antenna sticking out of the airplane. I see where Advanced Aircraft Electronics makes an "L2" transponder antenna which looks a lot like my other foil tape antennas.

 I was hoping maybe I could make my own "L2" type of antenna with my leftover RST antenna kit.

 Just want to confirm if it is feasible and if the leg lengths and vertical orientation is correct.

 If this does not work, I will make my transponder antenna as you mentioned and place it either out at the end of the strake or right under the pilot seat protruding out of the fuselage.

 Thanks.

 kjashton(at)vnet.net wrote:

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

> 

> The transponder is a little different than the other antennae.  The reference discusses it.  Keep the coax run short and put it on the bottom of the airplane.  Mine is under removable front seats.  You can make the antenna from an AN bolt but they are very cheap on ebay.

> -kent

> 

> 

 Read this topic online here:

 http://forums.matronics.com/viewtopic.php?p=428053#428053

- The Matronics AeroElectric-List Email Forum -

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List

Display posts from previous:

	Matronics Email Lists Forum Index -> AeroElectric-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum