NEW ARTEX 406 ELT'S AND GLIDER INSTALLATION

What are the issues and can they be overcome
with regard to installing either an ARTEX ME-406
with Whip Antenna or an ARTEX ME-406 with
Rod Antenna.

I have an ASW-27 WITH a transponder mounted
on top of the fuselage and no tail tank or
tail battery.

Natuarally, I want the antenna internal or located
to create as little drag as possible. The fin
is kevlar.

Is the 'possible'?

Thanks.

Doug Whitehead (EDW)

212-879-3131

I've had long discussions with the technical folks at Artex and other ELT
Manufacturers. Gliders and airplanes with carbon fiber do create so
additional problems when it comes to antennas. It is not possible to hide an
antenna inside these structures and a suitable ground plane is required for
any 406 mhz ELT.(Artex manual states the ELT requires a ground plane (metal
aircraft surface is typical) or can be made from metal tape 1" wide in a
minimum of 24" radials. or from 22 AWG wire, so obviously the fin of a
glider isn't going to allow you to meet these requirements. The ELT
antenna's are also supposed to be mounted with a (up) vertical
orientation...
Also I note that you say you have a transponder antenna mounted vertically
on the top of the fuselage.........this is also not a proper installation
since transponder antennas are intended to be directed toward the ground
(radar receivers) and Carbon fuselages will block or even absorb signals
rather than reflect them away as a proper ground plane does.
There are some high performance antennas (you can easily spend more on some
antennas than the cost of even a 406 mhz ELT!) that are more compact than
the Whip antennas but this doesn't completely change the requirement for
ground planes or proper orientation.
the Artex ME406 installation and operation manual is available from a link
on my web page http://www.wingsandwheels.com/page13.htm. Please look there
and you too can contact Artex and speak with their technical people for
additional advice.
I hope this is helpful
best regards
Tim Mara

Wings & Wheels
www.wingsandwheels.com


"E. Douglas Whitehead" wrote in
message ...
What are the issues and can they be overcome
with regard to installing either an ARTEX ME-406
with Whip Antenna or an ARTEX ME-406 with
Rod Antenna.

I have an ASW-27 WITH a transponder mounted
on top of the fuselage and no tail tank or
tail battery.

Natuarally, I want the antenna internal or located
to create as little drag as possible. The fin
is kevlar.

Is the 'possible'?

Thanks.

Doug Whitehead (EDW)

212-879-3131

Tim Mara wrote:

Also I note that you say you have a transponder antenna mounted vertically
on the top of the fuselage.........this is also not a proper installation
since transponder antennas are intended to be directed toward the ground
(radar receivers) and Carbon fuselages will block or even absorb signals
rather than reflect them away as a proper ground plane does.


If there is a choice of being seen either from above, or from below,
I'll take above every time. I'd far rather be seen on the TCAS of an
airliner that is descending through cloud into me than be seen on a
controller's screen.

Has anyone actually measured the antenna patterns for top or bottom
mounted transponder antennas on a typical carbon glider? Is the
masking a real problem?


Andy

Andy wrote:
Tim Mara wrote:


Also I note that you say you have a transponder antenna mounted vertically
on the top of the fuselage.........this is also not a proper installation
since transponder antennas are intended to be directed toward the ground
(radar receivers) and Carbon fuselages will block or even absorb signals
rather than reflect them away as a proper ground plane does.

If there is a choice of being seen either from above, or from below,
I'll take above every time. I'd far rather be seen on the TCAS of an
airliner that is descending through cloud into me than be seen on a
controller's screen.

Of course, if the controller could see you, he'd direct the airliner
away from you before the TCAS system would!

Remember, metal airplanes have their transponder antenna mounted on the
bottom of the airplane, yet they are able to trigger a TCAS system. I
believe the important factor is the airliner is relatively close to you,
so it receives the transponder signal regardless of the antenna
location. The ground station is much farther away, and that is when a
bottom antenna location will work better.


Has anyone actually measured the antenna patterns for top or bottom
mounted transponder antennas on a typical carbon glider? Is the
masking a real problem?

I haven't heard of any, but Tom Knauff once reported his Duo Discus had
the antenna mounted behind the canopy, and performance seemed adequate.


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

what many keep failing to realize is that the Transponder is there so YOU
can be seen.......and so that ATC can see you and other traffic to try to
redirect them (VFR Traffic on a work load permitting basis!!) and provide
separation.....Transponders I am afraid can do more to relax the pilot into
an unsafe feeling of security that "big brother" is looking out for
you....this certainly is not the case....Though a transponder may offer you
some additional safety, you have to realize that unless you are in contact
with ATC there is no way for them to notify YOU that there is traffic as
well....not everyone will have a TCAS system (few Cezna 150's do that I know
of) and not every corporate or airliner is going to move to avoid you,
especially if ATC doesn't see you clearly and notify them that you are
"somewhere" up there also... If you fly where there is a possibility of
airliners you should then monitor the ATC frequency and even notify them
that you are there and on the frequency..they too will want to see you on
their screen as well.
Tim
Wings & Wheels
www.wingsandwheels.com

"Andy" wrote in message
oups.com...

Tim Mara wrote:

Also I note that you say you have a transponder antenna mounted
vertically
on the top of the fuselage.........this is also not a proper installation
since transponder antennas are intended to be directed toward the ground
(radar receivers) and Carbon fuselages will block or even absorb signals
rather than reflect them away as a proper ground plane does.


If there is a choice of being seen either from above, or from below,
I'll take above every time. I'd far rather be seen on the TCAS of an
airliner that is descending through cloud into me than be seen on a
controller's screen.

Has anyone actually measured the antenna patterns for top or bottom
mounted transponder antennas on a typical carbon glider? Is the
masking a real problem?


Andy

I would be a bit worried about the xponder antenna frying my brain - thus I
like it under my bum with a circular 5 1/2 inch circular ground plain (if
glass glider) so nothing gets into my body except the bottom part of my
legs and they do not matter. Xponders put out a lot of power!!
That all
Ian McPhee (skype macca304)
Box 657
Byron Bay NSW 2481 Australia
Tel +61(0)2 66847642 mob +61(0)428847642
ianmcphee AT aapt.net.au
ww.mrsoaring.com


"Tim Mara" wrote in message
...
what many keep failing to realize is that the Transponder is there so YOU
can be seen.......and so that ATC can see you and other traffic to try to
redirect them (VFR Traffic on a work load permitting basis!!) and provide
separation.....Transponders I am afraid can do more to relax the pilot
into an unsafe feeling of security that "big brother" is looking out for
you....this certainly is not the case....Though a transponder may offer
you some additional safety, you have to realize that unless you are in
contact with ATC there is no way for them to notify YOU that there is
traffic as well....not everyone will have a TCAS system (few Cezna 150's
do that I know of) and not every corporate or airliner is going to move to
avoid you, especially if ATC doesn't see you clearly and notify them that
you are "somewhere" up there also... If you fly where there is a
possibility of airliners you should then monitor the ATC frequency and
even notify them that you are there and on the frequency..they too will
want to see you on their screen as well.
Tim
Wings & Wheels
www.wingsandwheels.com

"Andy" wrote in message
oups.com...

Tim Mara wrote:

Also I note that you say you have a transponder antenna mounted
vertically
on the top of the fuselage.........this is also not a proper
installation
since transponder antennas are intended to be directed toward the ground
(radar receivers) and Carbon fuselages will block or even absorb signals
rather than reflect them away as a proper ground plane does.


If there is a choice of being seen either from above, or from below,
I'll take above every time. I'd far rather be seen on the TCAS of an
airliner that is descending through cloud into me than be seen on a
controller's screen.

Has anyone actually measured the antenna patterns for top or bottom
mounted transponder antennas on a typical carbon glider? Is the
masking a real problem?


Andy

Ian McPhee wrote:
I would be a bit worried about the xponder antenna frying my brain - thus I
like it under my bum with a circular 5 1/2 inch circular ground plain (if
glass glider) so nothing gets into my body except the bottom part of my
legs and they do not matter. Xponders put out a lot of power!!

Not that much on average, really. Each pulse is high power, but the
average is only a 100 milliwatts or so, except in the very busiest
airspace, where it could be a couple watts. When I wrote my transponder
articles for Soaring a couple years ago, I couldn't find any hard
information about health effects (or any information, really). Still, I
prefer to mount my antenna much as you do (mine is just behind the gear
doors), and the carbon fuselage of my glider blocks most of it.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

Ian McPhee wrote:
I would be a bit worried about the xponder antenna frying my brain - thus I
like it under my bum...

Ian, I have this worrying image in my head - if the antenna is under
your bum and you make a gear-up landing, where does it go ?
Oh Dear...
See ya, Dave