Today's Message Index:
----------------------
1. 07:10 AM - Re: ADS-B Ground Plane Question (Charles Brame)
2. 07:32 AM - Re: ADS-B Ground Plane Question (user9253)
3. 11:13 AM - Re: Re: ADS-B Ground Plane Question (n1dw)
4. 01:48 PM - Re: ADS-B Ground Plane Question (markfw)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: ADS-B Ground Plane Question |
Time: 03:15:12 PM PST US
Subject: AeroElectric-List: ADS-B Ground Plane Question
From: "markfw" <markwheelermd@icloud.com
<mailto:markwheelermd@icloud.com>>
Mark,
Mark,
I mounted my uAvionix echoUAT ADS-B antenna on the belly of my RV-6A and
just aft of the firewall. It is located less than 30 inches horizontally
from the transponder antenna. Works like a charm.
Charlie Brame
RV-6A, N11CB
San Antonio
=94=94=94=94=94=94=94=94
=94=94=94=94=94=94=94=94
=94=94=94=94=94
I will be mounting a uAvionix echoUAT ADS-B antenna on the belly pan of
my cub.
The vendor says to keep it 1 meter from my transponder antenna, which is
mounted
14" forward of the leading edge of my belly pan.
The pan itself is an isosceles triangle with a 15" base and a length of
32". The
pointy part of the pan is oriented facing aft.
Thus I have to place my Rami blade antenna toward the narrow (aft) part
of the
belly pan to stay 1 meter away from the transponder antenna.
My problem is that at the location that is sufficiently far from the
transponder
antenna the belly pan has narrowed so that it does not provide the 5"
diameter
circular ground plane that is apparently required.
SO (after all that), my question is whether the ground plane is only the
part of
of the belly pan that is immediately adjacent to the antenna, or is it
the whole
belly pan?
A related question is whether I can "cheat" the antenna forward a few
inches? Since
antenna radiated power varies inversely with the square of the distance
does
that imply that I could move the antenna 6' - 8" closer to the
transponder
antenna without a significant problem?
I am just trying to establish what my boundary conditions are with
respect to the
antenna location.
Thanks.
Mark
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495455#495455
<http://forums.matronics.com/viewtopic.php?p=495455#495455>
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: ADS-B Ground Plane Question |
I would cheat, but only 3 or 4 inches. Move the antenna forward so that the
two antennas are about 36 inches apart. The ground plane does not have
to be a perfect circle. If the ground plane extends the correct distance in 3
equally spaced directions (120 degrees), that is good enough.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495457#495457
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: ADS-B Ground Plane Question |
Charlie,
I recently installed a vertical monopole antenna on the belly of my
Glastar (haven=99t had a chance to test it yet). The instructions
for the antenna specifically said NOT to use a circular ground plane
(apparently it can set up some interference with the antenna function)
and suggested using a rectangular shape to reduce the interference
possibility. The 5=9D dimension is a minimum, twice as large is
more effective, but the benefits beyond that diminishes quickly.
In your situation, with the antenna very near the apex, the ground plane
would probably act more like a foil ground with two foil ribbons both
facing forward (essentially along the edges of your triangle.
Doesn=99t sound like a good arrangement to me.
I used a 10=9D square of .020 aluminum for my ground plane. Could
you possibly do the same? Either mounting the ground plane aft of your
triangle, or near the apex if that option is not practical?
Doug Windhorn
From: owner-aeroelectric-list-server@matronics.com
<owner-aeroelectric-list-server@matronics.com> On Behalf Of Charles
Brame
Sent: Saturday, March 28, 2020 7:10 AM
Subject: AeroElectric-List: Re: ADS-B Ground Plane Question
Time: 03:15:12 PM PST US
Subject: AeroElectric-List: ADS-B Ground Plane Question
From: "markfw" < <mailto:markwheelermd@icloud.com>
markwheelermd@icloud.com>
Mark,
Mark,
I mounted my uAvionix echoUAT ADS-B antenna on the belly of my RV-6A and
just aft of the firewall. It is located less than 30 inches horizontally
from the transponder antenna. Works like a charm.
Charlie Brame
RV-6A, N11CB
San Antonio
=94=94=94=94=94=94=94=94
=94=94=94=94=94=94=94=94
=94=94=94=94=94
I will be mounting a uAvionix echoUAT ADS-B antenna on the belly pan of
my cub.
The vendor says to keep it 1 meter from my transponder antenna, which is
mounted
14" forward of the leading edge of my belly pan.
The pan itself is an isosceles triangle with a 15" base and a length of
32". The
pointy part of the pan is oriented facing aft.
Thus I have to place my Rami blade antenna toward the narrow (aft) part
of the
belly pan to stay 1 meter away from the transponder antenna.
My problem is that at the location that is sufficiently far from the
transponder
antenna the belly pan has narrowed so that it does not provide the 5"
diameter
circular ground plane that is apparently required.
SO (after all that), my question is whether the ground plane is only the
part of
of the belly pan that is immediately adjacent to the antenna, or is it
the whole
belly pan?
A related question is whether I can "cheat" the antenna forward a few
inches? Since
antenna radiated power varies inversely with the square of the distance
does
that imply that I could move the antenna 6' - 8" closer to the
transponder
antenna without a significant problem?
I am just trying to establish what my boundary conditions are with
respect to the
antenna location.
Thanks.
Mark
Read this topic online here:
<http://forums.matronics.com/viewtopic.php?p=495455#495455>
http://forums.matronics.com/viewtopic.php?p=495455#495455
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: ADS-B Ground Plane Question |
Thanks everyone for your replies.
It seems that the consensus is that I need to be far enough forward to have 5"
of belly pan on each side of the antenna, which for me would be about 32". And,
for at least one person, that distance worked.
This helps me establish the boundary conditions that I was looking for.
Mark
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=495459#495459
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|