Today's Message Index:
----------------------
1. 12:10 PM - Transponder ADSB Transponder Antenna (William Hunter)
2. 12:53 PM - Re: Transponder ADSB Transponder Antenna (William Hunter)
3. 01:03 PM - Ground Plane Question (William Hunter)
4. 01:04 PM - Re: Transponder ADSB Transponder Antenna (Rob Turk)
5. 01:14 PM - Re: Transponder ADSB Transponder Antenna (Tim Olson)
6. 01:22 PM - Re: Transponder ADSB Transponder Antenna (Peter Pengilly)
7. 02:03 PM - Transponder and ADS Antenna Mounting Location Questions For A Velocity (William Hunter)
8. 05:47 PM - Re: Ground Plane Question (user9253)
9. 06:02 PM - Re: Ground Plane Question (Charlie England)
10. 06:24 PM - Re: Transponder and ADS Antenna Mounting Location Questions For (user9253)
11. 06:29 PM - Re: Ground Plane Question (William Daniell)
12. 06:48 PM - Re: Ground Plane Question (Robert Borger)
13. 07:02 PM - Re: Ground Plane Question (user9253)
14. 07:04 PM - Re: Transponder ADSB Transponder Antenna (Kelly McMullen)
15. 09:57 PM - Re: Re: Transponder and ADS Antenna Mounting Location Questions For (William Hunter)
16. 10:00 PM - Infinity Aero Grip and Starter Switch (William Hunter)
17. 10:26 PM - Re: Infinity Aero Grip and Starter Switch (David Saylor)
18. 11:13 PM - Re: Ground Plane Question (Bill Maxwell)
Message 1
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| Subject: | Transponder ADSB Transponder Antenna |
Is it ok to install the ADS-B and transponder antenna in the same
location?
I have a composite aircraft and there is a ground plane installed on the
floorboard of the real plane and it already has the transponder antenna
located thereI would like to install the ADS-B antenna there.
..
Cheers!!!
Bill Hunter
Message 2
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| Subject: | Transponder ADSB Transponder Antenna |
Found the answerthe Dynon SkyView manual did not have any
reference in the transponder section however in the ADS-B section it has
the following:
The SV-ADSB-470 antenna should not be installed within 2 feet (24
inches) of the SVXPNDR-261/262 antenna.
..
Cheers!!!
Bill Hunter
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
William Hunter
Sent: Sunday, May 22, 2016 12:09 PM
Subject: AeroElectric-List: Transponder ADSB Transponder Antenna
Is it ok to install the ADS-B and transponder antenna in the same
location?
I have a composite aircraft and there is a ground plane installed on the
floorboard of the real plane and it already has the transponder antenna
located thereI would like to install the ADS-B antenna there.
..
Cheers!!!
Bill Hunter
Message 3
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| Subject: | Ground Plane Question |
I have a question about the =9CGround Plane=9D design and
the antenna mounting within that ground plane in a composite aircraft:
The SkyView manuals states =9CWhen a conventional aircraft
monopole antenna is used it relies on a ground plane for correct
behavior. For ideal performance the ground plane should be very large
compared to the wavelength of reception, which is 305 mm. In a metal
skinned aircraft this is usually easy to accomplish, but is more
difficult in a composite or fabric skinned aircraft. In these cases a
metallic ground plane should be fabricated and fitted under the antenna.
As the ground plane is made smaller, the actual dimensions of the ground
plane become more
critical, and small multiples of the wavelength should be avoided, as
should circles. Rectangles
or squares are much less likely to create a critical dimension that
resonates with the
transmissions. The smallest practical ground plane is a square around
130 mm per side; as the
size increases the performance may actually get worse, but will be
better by the time the
ground plane is 780 mm on each side. Anything much larger than that size
is unlikely to show
significant further improvement.
So I get that the metal foil/piece needs to be a square that is larger
than 130 MM X 130 MM however where should the antenna be mounted in that
square? At the edge, outside corner, or in the exact center? I would
think that the center would not be better than the edge or corner
because the wavelength
..
Cheers!!!
Bill Hunter
Message 4
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| Subject: | Re: Transponder ADSB Transponder Antenna |
Those antennas work on the same frequency. Having them right next to
eachother will at best overwhelm your ADS-B receiver, and worst case
damage it. Most ADS-B receivers have guidelines for minimum distance
between those antennas. I would take those guidelines at heart.
Rob
On 5/22/2016 9:08 PM, William Hunter wrote:
>
> Is it ok to install the ADS-B and transponder antenna in the same
> location?
>
> I have a composite aircraft and there is a ground plane installed on
> the floorboard of the real plane and it already has the transponder
> antenna located thereI would like to install the ADS-B antenna there.
>
> ..
>
> Cheers!!!
>
> Bill Hunter
>
Message 5
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| Subject: | Re: Transponder ADSB Transponder Antenna |
They need to be 5' apart in most cases.
Tim
> On May 22, 2016, at 2:08 PM, William Hunter <billhuntersemail@gmail.com> w
rote:
>
> Is it ok to install the ADS-B and transponder antenna in the same location
?
>
> I have a composite aircraft and there is a ground plane installed on the f
loorboard of the real plane and it already has the transponder antenna locat
ed thereI would like to install the ADS-B antenna there.
>
> ..
>
> Cheers!!!
>
> Bill Hunter
>
Message 6
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| Subject: | Re: Transponder ADSB Transponder Antenna |
Which frequency band will you be using?
On 22/05/2016 20:08, William Hunter wrote:
>
> Is it ok to install the ADS-B and transponder antenna in the same
> location?
>
> I have a composite aircraft and there is a ground plane installed on
> the floorboard of the real plane and it already has the transponder
> antenna located thereI would like to install the ADS-B antenna there.
>
> ..
>
> Cheers!!!
>
> Bill Hunter
>
Message 7
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| Subject: | Transponder and ADS Antenna Mounting Location Questions |
For A Velocity
Thanks the feedback on the other threads I startedI will
combine both questions here.
Does anybody have any advice on what I should do with respect to
mounting my transponder and ADS-B antennae?
I have a flying Velocity that I am doing a complete rewire because I am
installing a Dynon Skyview system. Since the airplane is already
completed I cannot get too creative with installing antennas in the
wings or wing tips and some of the installations so in some instances I
am stuck with what I got.
The airplane has existing antennae mounted in the wings for VHF NAV and
COM and it also has a single transponder monopole antenna mounted on the
copilot side aft floorboard (under the rear seat). This antenna is
mounted in a way that the antenna is mounted to the bottom of the
airplane (sticking strait down) and the connector end of the antenna
sticks up through the fuselage floor and it is mounted to the corner of
an egg shaped ground plane (why they used egg shape instead of
square/rectangle I do not knowperhaps a scrap piece of metal
was laying around). Attached is a PDF showing a picture.
I have installed a radio rack in the copilot side of the nose
compartment directly on top of the canard. I need to try to avoid
locating the antenna up front because on the pilot side of the nose
compartment is the ADHRS units and they have the magnetometer.
Any advice would be GREATLY APPRECIATED!!!
..
Cheers!!!
Bill Hunter
408-464-1902
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Tim
Olson
Sent: Sunday, May 22, 2016 1:03 PM
Subject: Re: AeroElectric-List: Transponder ADSB Transponder Antenna
They need to be 5' apart in most cases.
Tim
On May 22, 2016, at 2:08 PM, William Hunter <billhuntersemail@gmail.com
<mailto:billhuntersemail@gmail.com> > wrote:
Is it ok to install the ADS-B and transponder antenna in the same
location?
I have a composite aircraft and there is a ground plane installed on the
floorboard of the real plane and it already has the transponder antenna
located thereI would like to install the ADS-B antenna there.
..
Cheers!!!
Bill Hunter
Message 8
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| Subject: | Re: Ground Plane Question |
Mount the antenna in the center of the square. The numbers that I read on the
Dynon website are 120 mm and 700 mm, 120 being ideal. I could be wrong but do
not think that the size is going to make a whole lot of difference, practically
speaking. Sensitive test equipment might see a difference using different
sizes of ground planes, but will it make a difference to a radar receiver?
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=456475#456475
Message 9
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| Subject: | Re: Ground Plane Question |
On 5/22/2016 2:52 PM, William Hunter wrote:
>
> I have a question about the Ground Plane design and the antenna
> mounting within that ground plane in a composite aircraft:
>
> The SkyView manuals states When a conventional aircraft monopole
> antenna is used it relies on a ground plane for correct behavior. For
> ideal performance the ground plane should be very large compared to
> the wavelength of reception, which is 305 mm. In a metal skinned
> aircraft this is usually easy to accomplish, but is more difficult in
> a composite or fabric skinned aircraft. In these cases a metallic
> ground plane should be fabricated and fitted under the antenna.
>
> As the ground plane is made smaller, the actual dimensions of the
> ground plane become more
>
> critical, and small multiples of the wavelength should be avoided, as
> should circles. Rectangles
>
> or squares are much less likely to create a critical dimension that
> resonates with the
>
> transmissions. The smallest practical ground plane is a square around
> 130 mm per side; as the
>
> size increases the performance may actually get worse, but will be
> better by the time the
>
> ground plane is 780 mm on each side. Anything much larger than that
> size is unlikely to show
>
> significant further improvement.
>
> So I get that the metal foil/piece needs to be a square that is larger
> than 130 MM X 130 MM however where should the antenna be mounted in
> that square? At the edge, outside corner, or in the exact center? I
> would think that the center would not be better than the edge or
> corner because the wavelength
>
> ..
>
> Cheers!!!
>
> Bill Hunter
>
Hi Bill,
That text is a bit surprising to me; it's in conflict with stuff I've
read about 1/4 wave antennas and ground planes. There are surely HAM
operators on this list that can give you the formula for ground plane
size, but IIRC, it's approximately the same radius as the length of the
radiating element (antenna). If the ground plane 'legs' droop, it
changes their length slightly. The stuff I've read seems to say that
once you go beyond the "radius=element" size, there's not a lot of
benefit. Check out these images.
https://www.google.com/search?q=1/4+wave+ground+plane&espv=2&biw=1920&bih=993&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjDwL2u8O7MAhVW4mMKHQL4DlYQ_AUIBygC#imgrc=_
The only thing that makes sense to me is the 130x130 dimension, which
would yield roughly the average radius to match a 1/4 wave aircraft comm
antenna.
The antenna should be at the center of whatever you use for a ground
plane. To use some very non-physics terms, the ground plane 'mirrors'
the 1/4 wave antenna, making it think it's a 1/2 wave antenna. If the
antenna is way off-center, it will mess with the radiation pattern.
Meaning it will transmit stronger (farther) in one direction and weaker
in another.
Kitplanes Magazine has had several good articles recently about doing
just what you are trying to do. If you're not a subscriber, I'd suggest
you check it out. The current editor is a former NASA mission control
guy who's a homebuilding repeat offender, and the contributors are
getting more impressive almost every issue.
Charlie
Message 10
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| Subject: | Re: Transponder and ADS Antenna Mounting Location Questions |
For
Assuming that you are installing the SV-XPNDR-261, why not use the existing transponder
antenna? Since the original transponder worked OK with that egg shaped
ground plane, that reinforces my post that shape and size makes a theoretical
difference, but is not critical in real life.
The SV-ADSB-470 antenna is receive only. It will not affect the operation of
ADAHRS or Magnetometer. Keep the ADSB-470 antenna away from other transmitting
antennas, especially the transponder antenna.
The SV-ADSB-470 receives 978 only, not 1090. If you are out of range of an ADS-B
ground station (maybe in a traffic pattern), you will not see traffic transmitting
ADS-B out on 1090, i.e., other SkyView transponders. Dynon needs to
offer a dual band ADS-B receiver.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=456477#456477
Message 11
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| Subject: | Re: Ground Plane Question |
Cant you use a bob archer antenna. As i understand it these do not require
a ground plane
Will
On 22 May 2016 21:13, "Charlie England" <ceengland7@gmail.com> wrote:
> On 5/22/2016 2:52 PM, William Hunter wrote:
>
> I have a question about the =9CGround Plane=9D design and the
antenna mounting
> within that ground plane in a composite aircraft:
>
>
> The SkyView manuals states =9CWhen a conventional aircraft monopole
antenna
> is used it relies on a ground plane for correct behavior. For ideal
> performance the ground plane should be very large compared to the
> wavelength of reception, which is 305 mm. In a metal skinned aircraft thi
s
> is usually easy to accomplish, but is more difficult in a composite or
> fabric skinned aircraft. In these cases a metallic ground plane should be
> fabricated and fitted under the antenna.
>
>
> As the ground plane is made smaller, the actual dimensions of the ground
> plane become more
>
> critical, and small multiples of the wavelength should be avoided, as
> should circles. Rectangles
>
> or squares are much less likely to create a critical dimension that
> resonates with the
>
> transmissions. The smallest practical ground plane is a square around 130
> mm per side; as the
>
> size increases the performance may actually get worse, but will be better
> by the time the
>
> ground plane is 780 mm on each side. Anything much larger than that size
> is unlikely to show
>
> significant further improvement.
>
>
> So I get that the metal foil/piece needs to be a square that is larger
> than 130 MM X 130 MM however where should the antenna be mounted in that
> square? At the edge, outside corner, or in the exact center? I would
> think that the center would not be better than the edge or corner because
> the wavelength
>
> ..
>
>
> Cheers!!!
>
>
> Bill Hunter
>
>
> Hi Bill,
>
> That text is a bit surprising to me; it's in conflict with stuff I've rea
d
> about 1/4 wave antennas and ground planes. There are surely HAM operators
> on this list that can give you the formula for ground plane size, but IIR
C,
> it's approximately the same radius as the length of the radiating element
> (antenna). If the ground plane 'legs' droop, it changes their length
> slightly. The stuff I've read seems to say that once you go beyond the
> "radius=element" size, there's not a lot of benefit. Check out these im
ages.
>
>
> https://www.google.com/search?q=1/4+wave+ground+plane&espv=2&biw=19
20&bih=993&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjDwL2u8O7MAhVW4mM
KHQL4DlYQ_AUIBygC#imgrc=_
>
> The only thing that makes sense to me is the 130x130 dimension, which
> would yield roughly the average radius to match a 1/4 wave aircraft comm
> antenna.
>
> The antenna should be at the center of whatever you use for a ground
> plane. To use some very non-physics terms, the ground plane 'mirrors' the
> 1/4 wave antenna, making it think it's a 1/2 wave antenna. If the antenna
> is way off-center, it will mess with the radiation pattern. Meaning it wi
ll
> transmit stronger (farther) in one direction and weaker in another.
>
> Kitplanes Magazine has had several good articles recently about doing jus
t
> what you are trying to do. If you're not a subscriber, I'd suggest you
> check it out. The current editor is a former NASA mission control guy who
's
> a homebuilding repeat offender, and the contributors are getting more
> impressive almost every issue.
>
> Charlie
>
Message 12
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| Subject: | Re: Ground Plane Question |
William,
I too was going to suggest the Bob Archer transponder antenna. It is a
full dipole requiring no ground plane and can be mounted inside your
composite (assuming it is fiberglas and not carbon fiber) fuselage at a
location of your choice. The only requirement is that it be mounted in
a vertical plane. I use it for my transponder antenna and it sure seems
to work well.
http://www.aircraftspruce.com/catalog/avpages/archer_antenna5.php
<http://www.aircraftspruce.com/catalog/avpages/archer_antenna5.php>
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop (75 hrs).
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger@mac.com
On May 22, 2016, at 8:28 PM, William Daniell
<wdaniell.longport@gmail.com> wrote:
Cant you use a bob archer antenna. As i understand it these do not
require a ground plane
Will
Message 13
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| Subject: | Re: Ground Plane Question |
I agree with Charlie.
And the ADS-B receiver antenna can be mounted in any convenient place away from
the transponder antenna. How about inside of that center tunnel? It can even
be pointed up. Garmin's GDL 39 is designed to sit on the dash pointed up.
This one does not even have a ground plane.
http://tinyurl.com/120-ADS-B
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=456481#456481
Message 14
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| Subject: | Re: Transponder ADSB Transponder Antenna |
The Dynon ADS-B transponder is 1090-ES. The receiver is 978.
On 5/22/2016 1:21 PM, Peter Pengilly wrote:
> Which frequency band will you be using?
>
>
> On 22/05/2016 20:08, William Hunter wrote:
>>
>> Is it ok to install the ADS-B and transponder antenna in the same
>> location?
>>
>>
>>
>> I have a composite aircraft and there is a ground plane installed on
>> the floorboard of the real plane and it already has the transponder
>> antenna located thereI would like to install the ADS-B antenna there.
>>
>>
>>
>> ..
>>
>>
>>
>> Cheers!!!
>>
>>
>>
>> Bill Hunter
>>
>>
>>
>
Message 15
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| Subject: | Re: Transponder and ADS Antenna Mounting Location |
Questions For
Joe,
This is really valuable information. Sounds like you know your stuff so if
I could kindly pick a bit more of your brain
I am running the SV-XPNDR-260 and it is supposed to be the higher-powered
transponder that dynon offers I'm running the dynon ADDB receiver for
traffic.
The ideal location for convenience of installation would be to install the
monopole antenna directly underneath the Canard. If I installed it like I
am thinking then the monopole antenna would be sticking down from the
Cunard and since the Canard is mounted up high in the nose cone of the
airplane the antenna would not be sticking out below the bottom of the
airplane assuming there's no carbon graphite in that section of the
airplane and assuming there's no paint that has some kind of chromate based
material then my question is would the antenna be able to still receive the
ground-based signals?
To add to my confusion I will also be running a Garmin gtn - 650 and it is
supposed to be able to receive ADS-B signals. . Should I purchase an
additional monopole antenna for that unit as well or should I just run with
the dynon unit?
Subject is way out of my league so any help from you or some of the other
sharp guys on this forum would be greatly helpful!
THANKS AGAIN FOR YOUR HELP!!!
Bill Hunter
On May 22, 2016 6:30 PM, "user9253" <fransew@gmail.com> wrote:
Assuming that you are installing the SV-XPNDR-261, why not use the existing
transponder antenna? Since the original transponder worked OK with that
egg shaped ground plane, that reinforces my post that shape and size makes
a theoretical difference, but is not critical in real life.
The SV-ADSB-470 antenna is receive only. It will not affect the
operation of ADAHRS or Magnetometer. Keep the ADSB-470 antenna away from
other transmitting antennas, especially the transponder antenna.
The SV-ADSB-470 receives 978 only, not 1090. If you are out of range of
an ADS-B ground station (maybe in a traffic pattern), you will not see
traffic transmitting ADS-B out on 1090, i.e., other SkyView transponders.
Dynon needs to offer a dual band ADS-B receiver.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=456477#456477
Message 16
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| Subject: | Infinity Aero Grip and Starter Switch |
The other big wiring project I have is to connect the starter wire to the
momentary contact switch is at the base of the infinity grip.
Someone said that I should use a diode and somebody else said that I should
incorporate a relay into the system however the manufacturer said that the
switch he uses is sufficient for a starter circuit.
Has anybody run sort of arrangement?
I have a Lycoming IO - 540 engine with a skytec starter motor.
THANKS AGAIN!!!
Bill Hunter
Message 17
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| Subject: | Re: Infinity Aero Grip and Starter Switch |
I work next door to a radio shop and since I have an experiental I hear all
the experimental gripes. Recently they were doing radio work on an RV. The
builder put a starter switch on the stick. It was unmarked and they
inadvertently pushed it, with nearly disastrous results. Sorry I don't mean
to change subjects but please make sure it's well marked and obvious--ya
never know who's gonna push what buttons.
Good news is I think they're more careful now ;-)
-Dave
On Sunday, May 22, 2016, William Hunter <billhuntersemail@gmail.com> wrote:
> The other big wiring project I have is to connect the starter wire to the
> momentary contact switch is at the base of the infinity grip.
>
> Someone said that I should use a diode and somebody else said that I
> should incorporate a relay into the system however the manufacturer said
> that the switch he uses is sufficient for a starter circuit.
>
> Has anybody run sort of arrangement?
>
> I have a Lycoming IO - 540 engine with a skytec starter motor.
>
> THANKS AGAIN!!!
>
> Bill Hunter
>
Message 18
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| Subject: | Re: Ground Plane Question |
As a 40-year ham, I endorse Charlie's comments. I can add that placing
the vertical radiator off centre will distort the antenna's radiation
pattern, favouring the ground plane's longest dimension. Not exactly
what you want for best all-round performance, so best place it in the
centre. Drooping the ground plane's legs below horizontal will slightly
increas the antenna's feed point impedance. I find a 30 degree "droop"
gives close to the desired 50 ohms.
I also concur with Charlie's comments about the increasing quality of
"kitplanes" magazine.
Bill
On 23/05/2016 11:03 AM, Charlie England wrote:
> On 5/22/2016 2:52 PM, William Hunter wrote:
>>
>> I have a question about the Ground Plane design and the antenna
>> mounting within that ground plane in a composite aircraft:
>>
>> The SkyView manuals states When a conventional aircraft monopole
>> antenna is used it relies on a ground plane for correct behavior. For
>> ideal performance the ground plane should be very large compared to
>> the wavelength of reception, which is 305 mm. In a metal skinned
>> aircraft this is usually easy to accomplish, but is more difficult in
>> a composite or fabric skinned aircraft. In these cases a metallic
>> ground plane should be fabricated and fitted under the antenna.
>>
>> As the ground plane is made smaller, the actual dimensions of the
>> ground plane become more
>>
>> critical, and small multiples of the wavelength should be avoided, as
>> should circles. Rectangles
>>
>> or squares are much less likely to create a critical dimension that
>> resonates with the
>>
>> transmissions. The smallest practical ground plane is a square around
>> 130 mm per side; as the
>>
>> size increases the performance may actually get worse, but will be
>> better by the time the
>>
>> ground plane is 780 mm on each side. Anything much larger than that
>> size is unlikely to show
>>
>> significant further improvement.
>>
>> So I get that the metal foil/piece needs to be a square that is
>> larger than 130 MM X 130 MM however where should the antenna be
>> mounted in that square? At the edge, outside corner, or in the exact
>> center? I would think that the center would not be better than the
>> edge or corner because the wavelength
>>
>> ..
>>
>> Cheers!!!
>>
>> Bill Hunter
>>
> Hi Bill,
>
> That text is a bit surprising to me; it's in conflict with stuff I've
> read about 1/4 wave antennas and ground planes. There are surely HAM
> operators on this list that can give you the formula for ground plane
> size, but IIRC, it's approximately the same radius as the length of
> the radiating element (antenna). If the ground plane 'legs' droop, it
> changes their length slightly. The stuff I've read seems to say that
> once you go beyond the "radius=element" size, there's not a lot of
> benefit. Check out these images.
>
> https://www.google.com/search?q=1/4+wave+ground+plane&espv=2&biw=1920&bih=993&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjDwL2u8O7MAhVW4mMKHQL4DlYQ_AUIBygC#imgrc=_
>
> The only thing that makes sense to me is the 130x130 dimension, which
> would yield roughly the average radius to match a 1/4 wave aircraft
> comm antenna.
>
> The antenna should be at the center of whatever you use for a ground
> plane. To use some very non-physics terms, the ground plane 'mirrors'
> the 1/4 wave antenna, making it think it's a 1/2 wave antenna. If the
> antenna is way off-center, it will mess with the radiation pattern.
> Meaning it will transmit stronger (farther) in one direction and
> weaker in another.
>
> Kitplanes Magazine has had several good articles recently about doing
> just what you are trying to do. If you're not a subscriber, I'd
> suggest you check it out. The current editor is a former NASA mission
> control guy who's a homebuilding repeat offender, and the contributors
> are getting more impressive almost every issue.
>
> Charlie
>
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