Installing an ELT antenna.

Any advice out there re the preferred location for an ELT antenna in a
Ventus 2 ? With a Carbon fiber fuselage its not obvious to me the best
place to install the antenna ( Ameriking supplied - about 20 inches
long ) The factory suggests "under the canopy" , but to me I can't see
how to do that easily . All suggestions welcome .

Ron Clarke (ZA)

I'm investigating the same problem for a Discus 2. The problem with
the lower location is it's very subject to damage. I am leaning
towards a "shark fin" installation on top of the fuselage just behind
the wings. A local Nimbus 3 has just had one installed there.

Mike

Options are limited if you don't want an external antenna. If the area over
the spars is fiberglass, you could use the "Bob Archer Sportcraft" folded
dipole, which is flexible and can be mounted to the inside of curved
surfaces. Dimensions are 12" X 26.5", mod SA-006, from Chief Aircraft $82.50
US.

You might be able to find a home for this antenna somewhere else, like under
the glareshield, if there's room.

One could also make their own dipole antenna by separating the inner
conductor and outer shield, then extending same in opposite directions (or
alternately soldering the coax conductors to two strips of copper foil or
wires). The total length of the antenna, both sides, for 121.5 Mhz, would be
about 3ft.10-1/4in. or 1.174 M.

Since response to 121.5 MHz ELTs is scheduled to end in 3 years, I purchase
a 406 MHz PLB w/ built in GPS for $500 USD ($550 before rebate - - which I
haven't received yet!). This unit must be tripped manually, is registered to
me, and can attach to parachute harness etc.

good luck

bumper

wrote in message
oups.com...
Any advice out there re the preferred location for an ELT antenna in a
Ventus 2 ? With a Carbon fiber fuselage its not obvious to me the best
place to install the antenna ( Ameriking supplied - about 20 inches
long ) The factory suggests "under the canopy" , but to me I can't see
how to do that easily . All suggestions welcome .

Ron Clarke (ZA)

I also have one of the new PLBs on my parachute harness but understand that
it does not satisfy the US Competition requirement for an ELT in 2006 since
it is not "g" activated.

Bob Kibby "2BK"





Since response to 121.5 MHz ELTs is scheduled to end in 3 years, I
purchase a 406 MHz PLB w/ built in GPS for $500 USD ($550 before
rebate - - which I haven't received yet!). This unit must be tripped
manually, is registered to me, and can attach to parachute harness etc.

good luck

bumper

Oops. I mixed up two replies. My transponder antenna is the current
problem. My ELT antenna is a rubber duckie mounted at the rear of the
canopy rail. Probably the quickest and cheapest solution.

"Mike the Strike" wrote in message
ups.com...
Oops. I mixed up two replies. My transponder antenna is the current
problem. My ELT antenna is a rubber duckie mounted at the rear of the
canopy rail. Probably the quickest and cheapest solution.


Oh, okay. Transponder antenna it is, then.

I know that some have mounted their transponder antenna up forward of, or on
the glareshield. I'm not comfortable with this due to RF exposure concerns.
Also, since it is arguably more important to give ATC a good view of your
antenna, the bottom of the aircraft is the optimal location.

If the ship fuselage is glass, an aluminum plate, for a ground plane and
mount can be installed within the fuselage. DG shows examples of this on
their website. However, if the ship is carbon, then the antenna will
probably have to go on the outside. My ASH26E has it just aft of the left
gear door. It's the little stub monopole antenna (costs 35 to 45 bucks US)
you see everywhere. Mounted on carbon, it needs no additional ground plane,
but if one desired, some copper or aluminum foil or sheet could be placed
inside.

This location, while not immune from trailer hits, is relatively easy to
avoid, at least on the 26E. In the case of a gear-up, which isn't on my
remaining short list of things to do, unlike a blade, it won't try to
protect itself by destroying a chunk of fuselage.

all the best,

bumper

Hi Ron,

Some of the replies to your post on r.a.s. mentioned short stub antennas and
spade antennas. They are designed for use with a transponder which use very
different frequencies than an ELT.

The ELT you purchased will transmit on 121.5 MHz and 243 MHz.

I see that Wings and Wheels offers a small rubber ducky antenna he
http://www.wingsandwheels.com/page14.htm I don't have any idea whether that
solution would be acceptable to the FAA or how the transmit output would be
affected, but it is a simple solution. I can't say that I recommend it, but
I don't know what else to suggest. The disclaimer note on Tim's web site
is, "note: this may not be suitable for installations that require
certification,
but ELT's are not required in sailplanes and can use this for an added
safety feature."

Good Soaring,

Paul Remde
Cumulus Soaring, Inc.
http://www.cumulus-soaring.com




wrote in message
oups.com...
Any advice out there re the preferred location for an ELT antenna in a
Ventus 2 ? With a Carbon fiber fuselage its not obvious to me the best
place to install the antenna ( Ameriking supplied - about 20 inches
long ) The factory suggests "under the canopy" , but to me I can't see
how to do that easily . All suggestions welcome .

Ron Clarke (ZA)

bumper wrote:
This location, while not immune from trailer hits, is relatively easy to
avoid, at least on the 26E. In the case of a gear-up, which isn't on my
remaining short list of things to do, unlike a blade, it won't try to
protect itself by destroying a chunk of fuselage.

A blade can be mounted on the lower fuselage such that it is not
vulnerable to gear-ups or trailer hits. If it is possible to reach far
enough back in the fuselage, it can be mounted on the center line where
the fuselage curves upwards toward the tailboom. Otherwise, it can be
mounted behind the gear well, offset from the center line just enough
that it does not extend below the lowest part of the fuselage.

Marc

T o d d P a t t i s t wrote:
Tim's note is correct - you can't use a rubber ducky type
antenna for a certified ELT installation, but if you don't
have to have an ELT under the FAR's, you can use any antenna
you want. The other option is a center fed dipole tape
antenna. I know Tim sells those too.

I think it is fairly clear that for a glider with an experimental
certificate, you can pretty much install an ELT any way you want, and
likely get away with signing it off yourself (as a non-A&P). I think it
is also fairly clear that an ELT installation in a type certified glider
will require at least an A&P (and possibly IA) sign off, but probably
does not require a 337. The question in my mind, however, is whether
the typical A&P (or IA) would be willing to sign off an ELT installation
in a certified glider, that makes use of uncertified components (like a
rubber ducky). Any A&Ps out there willing to comment?

Marc

Hi,

Beyond whether it is OK to do - it is also important to consider whether it
will work well when needed. The rubber duck antenna is for 118 to 136 MHz
while the ELT that Ron asked about transmits on both 121.5 and 243.0 MHz
simultaneously. It is important to use an antenna that will transmit on
those frequencies well in an emergency.

Please don't get me wrong, I am not trying to knock Tim. His advice on the
web page is very good and he does have many nice antenna options. It is
clear to me that Tim knows more about antennas than I do. I am trying to
help Ron find a good solution for the AmeriKing AK-450 ELT that he purchased
from me.

Some other sailplane owners must have done this before... I look forward to
some good feedback from the many sharp glider pilots.

Good Soaring,

Paul Remde

"Marc Ramsey" wrote in message
...
T o d d P a t t i s t wrote:
Tim's note is correct - you can't use a rubber ducky type
antenna for a certified ELT installation, but if you don't
have to have an ELT under the FAR's, you can use any antenna
you want. The other option is a center fed dipole tape
antenna. I know Tim sells those too.

I think it is fairly clear that for a glider with an experimental
certificate, you can pretty much install an ELT any way you want, and
likely get away with signing it off yourself (as a non-A&P). I think it
is also fairly clear that an ELT installation in a type certified glider
will require at least an A&P (and possibly IA) sign off, but probably does
not require a 337. The question in my mind, however, is whether the
typical A&P (or IA) would be willing to sign off an ELT installation in a
certified glider, that makes use of uncertified components (like a rubber
ducky). Any A&Ps out there willing to comment?

Marc