New breed of transponder antennas

Hello all,

I see a new type of transponder antennas on the market, for example the
Filser DP1090-5:
http://glider-equipment.nl/catalog/p...a-dp10905-p-63
These seem almost too good to be true; Low cost & complexity, easy
installation inside (non-carbon) fuselages..
Does anyone have experience with these antennas. Performance? Compatibility
with transponder models commonly used in gliders? Examples of EASA approved
installations?

Thanks,
Lars Peder (who finds that more and more of the airspace around him becomes
class C :-( )

this is really nothing new, it's a simple dipole antenna and these we have had for a number of years already for less $ than even this one
see http://wingsandwheels.com/antenna_vh...s_mobile_e.htm L2 Transponder antenna
$99.00
Antennas, even the conventional transponder antennas can be used internally in FIBERGLASS gliders and aircraft but not in those made of metal or carbon fiber just the same as these dipole types.....Dipole antennas simply have to be matched like any antenna to the frequency by length and the dipole antenna is essentially twice as long as a 1/4 wave antenna since one lead is essentially the ground plane ...... these antennas also should be mounted vertically, not just lying down like the picture shows and should not be next to other antennas, cables or metals posts or structures.....then they will work pretty much "as good" as conventional antenna types.
tim
Please visit the Wings & Wheels website at www.wingsandwheels.com

"Lars Peder Hansen" wrote in message k...
Hello all,

I see a new type of transponder antennas on the market, for example the
Filser DP1090-5:
http://glider-equipment.nl/catalog/p...a-dp10905-p-63
These seem almost too good to be true; Low cost & complexity, easy
installation inside (non-carbon) fuselages..
Does anyone have experience with these antennas. Performance? Compatibility
with transponder models commonly used in gliders? Examples of EASA approved
installations?

Thanks,
Lars Peder (who finds that more and more of the airspace around him becomes
class C :-( )



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Am 06.02.2012 19:35, Lars Peder Hansen wrote:
Hello all,

I see a new type of transponder antennas on the market, for example the
Filser DP1090-5:
http://glider-equipment.nl/catalog/p...a-dp10905-p-63
These seem almost too good to be true; Low cost& complexity, easy
installation inside (non-carbon) fuselages..
Does anyone have experience with these antennas. Performance? Compatibility
with transponder models commonly used in gliders? Examples of EASA approved
installations?

Thanks,
Lars Peder (who finds that more and more of the airspace around him becomes
class C :-( )


Lars,

this antenna seems to be recommended for ballons and airplanes that have
a non-shielding structure. Filser ((the supplier of the antenna) has an
info document with recommendations for their different antennas.
Unfortunaltely the document seems to be available only in German :

http://www.funkwerk-avionics.com/cms...nneneinbau.pdf

For gliders they recommend their TransFelx model which is also covered
in the document.

If you need help with the translation, feel free to contact me.

--
Peter Scholz
ASW24 JE

On Feb 6, 10:35*am, "Lars Peder Hansen"
wrote:

That is just a simple dipole antenna; you can make a nice one for
about six dollars worth of parts. If you are good at scrounging, it's
possible to get it in under a dollar.

Thanks, Bob K.

I looked at something similar but, alas, my fuselage is carbon. So I
installed a blade on the underside just aft of the gear doors


"Lars Peder Hansen" wrote in message
k...
Hello all,

I see a new type of transponder antennas on the market, for example the
Filser DP1090-5:
http://glider-equipment.nl/catalog/p...a-dp10905-p-63
These seem almost too good to be true; Low cost & complexity, easy
installation inside (non-carbon) fuselages..
Does anyone have experience with these antennas. Performance?
Compatibility with transponder models commonly used in gliders? Examples
of EASA approved installations?

Thanks,
Lars Peder (who finds that more and more of the airspace around him
becomes class C :-( )

I have had an L2 in my LS8-18 for over 10 years. It works fantastic
and is mounted just using velcro.

On Feb 6, 10:25*pm, guy wrote:
I have had an L2 in my LS8-18 for over 10 years. *It works fantastic
and is mounted just using velcro.

Where do you have it mounted?

Thanks,

WD

On Monday, February 6, 2012 1:35:23 PM UTC-5, Lars Peder Hansen wrote:
... These seem almost too good to be true; Low cost & complexity, easy
installation inside (non-carbon) fuselages..

Well, you will get two answers to this question:

(1) Great ! No problem !

(2) Antennas don't work so well next to big conductive chunks.
The vertical stabilizer is filled with radio antenna, elevator
pushrod (and sometimes mechanism + balance weight), mass balance
on leading edge of rudder. So, we will not install this antenna
in the fin, and we do not believe it can be approved and/or
work properly. Also antenna should be on bottom for good
reception by ground stations (no blanking by carbon aircraft).

Personally I have a fin transponder antenna on the bottom
of my (carbon) fuselage with an approved installation...

Hope that helps,
Best Regards, Dave "YO electric" (NOT an antenna expert)

Bob K makes a very good point about scrounging.

Many years ago when I was building a Quickie Q2, I built comm and nav
antennae using sticky backed quarter inch wide (IIRC) copper foil. Simply
cut to length, peel, and stick in the proper configuration. Solder on coax
center and shield (being careful of heat), use baluns near the antenna. Lay
glass over top of the antenna.


"Dave Nadler" wrote in message
news:1140599.3749.1328627575416.JavaMail.geo-discussion-forums@vbcj7...
On Monday, February 6, 2012 1:35:23 PM UTC-5, Lars Peder Hansen wrote:
... These seem almost too good to be true; Low cost & complexity, easy
installation inside (non-carbon) fuselages..

Well, you will get two answers to this question:

(1) Great ! No problem !

(2) Antennas don't work so well next to big conductive chunks.
The vertical stabilizer is filled with radio antenna, elevator
pushrod (and sometimes mechanism + balance weight), mass balance
on leading edge of rudder. So, we will not install this antenna
in the fin, and we do not believe it can be approved and/or
work properly. Also antenna should be on bottom for good
reception by ground stations (no blanking by carbon aircraft).

Personally I have a fin transponder antenna on the bottom
of my (carbon) fuselage with an approved installation...

Hope that helps,
Best Regards, Dave "YO electric" (NOT an antenna expert)