ASW27 Trasponder Antenna Installation Inside Fuselage.

I've been looking into ways to secure coax
inside the tailboom. My current avenue of
investigation is using magnetic receptive
rubber sheet.

Wrap a strip of sheet around the coax with
appropriate (suggestions welcome)
adhesive and use magnet on exterior of
tailboom to clamp at appropriate locations
well clear of elevator pushrod.

Times Microwave has a coax cable and
attenuation calculator:

http://www.timesmicrowave.com/calculat
or/?
productId=38&frequency=1090&runLength
=26&mode=calculate#form

Extra coax length is necessitated by tilt up
instrument panel.

I'd also like to to put a PowerFLARM
dipole in the fin, but that would have to be
at least a foot from the xpdr antenna.

The battery box is not big enough for both;
so may need an opening in the box to
achieve enough separation. Once in use
for antenna(s), likely the box would no
longer be available for ballast.

If the front of the nose cone, would work
for an L2 antenna, the problem would be
much simplified.

Any interference with the comm coax
and/or antenna would mess things up.

On Friday, March 4, 2016 at 8:30:10 PM UTC-5, George Haeh wrote:
I've been looking into ways to secure coax
inside the tailboom. My current avenue of
investigation is using magnetic receptive
rubber sheet.

Wrap a strip of sheet around the coax with
appropriate (suggestions welcome)
adhesive and use magnet on exterior of
tailboom to clamp at appropriate locations
well clear of elevator pushrod.

Times Microwave has a coax cable and
attenuation calculator:

http://www.timesmicrowave.com/calculat
or/?
productId=38&frequency=1090&runLength
=26&mode=calculate#form

Extra coax length is necessitated by tilt up
instrument panel.

I'd also like to to put a PowerFLARM
dipole in the fin, but that would have to be
at least a foot from the xpdr antenna.

The battery box is not big enough for both;
so may need an opening in the box to
achieve enough separation. Once in use
for antenna(s), likely the box would no
longer be available for ballast.

If the front of the nose cone, would work
for an L2 antenna, the problem would be
much simplified.

Any interference with the comm coax
and/or antenna would mess things up.

George, I am afraid the coax cable losses for Flarm antenna would be too high if you run it from the tail of your glider to the instrument panel. Flarm is a very low power unit and the cable length is very important. Also if the horizontal stab is carbon that would not work very well either.

On Sunday, February 28, 2016 at 5:46:46 AM UTC-8, wrote:
On Sunday, February 28, 2016 at 7:15:13 AM UTC-5, Paul Birkett wrote:
Hello, my intention is to fit a Transponder Antenna within my ASW27. I was

wondering does anyone know where on the ASW27 Fuselage is not Carbon
or Aramid(conductive) construction, which would allow internal fitting of
an
antenna such as a Dolba BD1, Dolba BD2, FUNKE DP1090-5 or similar?
Schleicher TM/TN 13 "installation of a PCB-transponder antenna in the
vertical tail" doesn't give a drawing/photo/diagram and I have
requested
additional information from Zulu-Glasstek. If I were to install antenna
within
the vertical stabilizer (Dolba BD1), the coax cable length would be
considerable (6 to 7 metre) and routing-security could be an issue, using
Carlisle ECS P/N 311501 coax cable. However, if the nose (tip area) of the

fuselage was manufactured from GRP as maybe used on other carbon fibre
Schleicher fuselages, then I would endeavour to install antenna within this

area? I have 95% dismissed TM/TN 12, installation of external antenna
alongside undercarriage due to it being ugly and prone to damage. Any
information gladly received. Best regards Paul.

We have installed the antenna, before TN 12 came out, on the bottom behind the gear. This requires and external ground plane of aluminum formed to match the fuselage contour. It looks better than the TN install and is about 5 times the work. All later ones were done to TN 12.
Nose does not meet required criteria.
FWIW
UH

UH can the ground plane be inside the fuselage and if not why?

Richard

On Sunday, February 28, 2016 at 11:20:40 AM UTC-5, Richard wrote:
On Sunday, February 28, 2016 at 5:46:46 AM UTC-8, wrote:
On Sunday, February 28, 2016 at 7:15:13 AM UTC-5, Paul Birkett wrote:
Hello, my intention is to fit a Transponder Antenna within my ASW27. I was

wondering does anyone know where on the ASW27 Fuselage is not Carbon
or Aramid(conductive) construction, which would allow internal fitting of
an
antenna such as a Dolba BD1, Dolba BD2, FUNKE DP1090-5 or similar?
Schleicher TM/TN 13 "installation of a PCB-transponder antenna in the
vertical tail" doesn't give a drawing/photo/diagram and I have
requested
additional information from Zulu-Glasstek. If I were to install antenna
within
the vertical stabilizer (Dolba BD1), the coax cable length would be
considerable (6 to 7 metre) and routing-security could be an issue, using
Carlisle ECS P/N 311501 coax cable. However, if the nose (tip area) of the

fuselage was manufactured from GRP as maybe used on other carbon fibre
Schleicher fuselages, then I would endeavour to install antenna within this

area? I have 95% dismissed TM/TN 12, installation of external antenna
alongside undercarriage due to it being ugly and prone to damage. Any
information gladly received. Best regards Paul.

We have installed the antenna, before TN 12 came out, on the bottom behind the gear. This requires and external ground plane of aluminum formed to match the fuselage contour. It looks better than the TN install and is about 5 times the work. All later ones were done to TN 12.
Nose does not meet required criteria.
FWIW
UH

UH can the ground plane be inside the fuselage and if not why?

Richard

Carbon fuselage so it will be more effective on the outside.
UH

My LAK-17a has a carbon fuselage. I installed a blade antenna aft of
the gear doors, at about the 5-o'clock position with a ground plane
inside the fuselage. Transponder checks show well over 200 watts
transmitted. I've got a Trig TT22.

On 2/28/2016 9:23 AM, wrote:
On Sunday, February 28, 2016 at 11:20:40 AM UTC-5, Richard wrote:
On Sunday, February 28, 2016 at 5:46:46 AM UTC-8, wrote:
On Sunday, February 28, 2016 at 7:15:13 AM UTC-5, Paul Birkett wrote:
Hello, my intention is to fit a Transponder Antenna within my ASW27. I was

wondering does anyone know where on the ASW27 Fuselage is not Carbon
or Aramid(conductive) construction, which would allow internal fitting of
an
antenna such as a Dolba BD1, Dolba BD2, FUNKE DP1090-5 or similar?
Schleicher TM/TN 13 "installation of a PCB-transponder antenna in the
vertical tail" doesn't give a drawing/photo/diagram and I have
requested
additional information from Zulu-Glasstek. If I were to install antenna
within
the vertical stabilizer (Dolba BD1), the coax cable length would be
considerable (6 to 7 metre) and routing-security could be an issue, using
Carlisle ECS P/N 311501 coax cable. However, if the nose (tip area) of the

fuselage was manufactured from GRP as maybe used on other carbon fibre
Schleicher fuselages, then I would endeavour to install antenna within this

area? I have 95% dismissed TM/TN 12, installation of external antenna
alongside undercarriage due to it being ugly and prone to damage. Any
information gladly received. Best regards Paul.
We have installed the antenna, before TN 12 came out, on the bottom behind the gear. This requires and external ground plane of aluminum formed to match the fuselage contour. It looks better than the TN install and is about 5 times the work. All later ones were done to TN 12.
Nose does not meet required criteria.
FWIW
UH
UH can the ground plane be inside the fuselage and if not why?

Richard
Carbon fuselage so it will be more effective on the outside.
UH

--
Dan, 5J

On Sunday, February 28, 2016 at 4:15:13 AM UTC-8, Paul Birkett wrote:
Hello, my intention is to fit a Transponder Antenna within my ASW27. I was

wondering does anyone know where on the ASW27 Fuselage is not Carbon
or Aramid(conductive) construction, which would allow internal fitting of
an
antenna such as a Dolba BD1, Dolba BD2, FUNKE DP1090-5 or similar?
Schleicher TM/TN 13 "installation of a PCB-transponder antenna in the
vertical tail" doesn't give a drawing/photo/diagram and I have
requested
additional information from Zulu-Glasstek. If I were to install antenna
within
the vertical stabilizer (Dolba BD1), the coax cable length would be
considerable (6 to 7 metre) and routing-security could be an issue, using
Carlisle ECS P/N 311501 coax cable. However, if the nose (tip area) of the

fuselage was manufactured from GRP as maybe used on other carbon fibre
Schleicher fuselages, then I would endeavour to install antenna within this

area? I have 95% dismissed TM/TN 12, installation of external antenna
alongside undercarriage due to it being ugly and prone to damage. Any
information gladly received. Best regards Paul.

You can often determine what is carbon vs. kevlar or white glass by shining a strong light through it. Carbon is opaque, gel coat/glass less so. On a 26 which has a very similar fuselage, I installed a dipole inside of the nose ahead of the rudder pedals. It tests fine from all angles, and return is reported good from many contacts in the air. No drag, no possibility of breaking it off ground handling. There are some who considered this a heretical install, so you will have to decide for yourself.

Originally Posted by Paul Birkett

Hello, my intention is to fit a Transponder Antenna within my ASW27. I was

wondering does anyone know where on the ASW27 Fuselage is not Carbon
or Aramid(conductive) construction, which would allow internal fitting of
an
antenna such as a Dolba BD1, Dolba BD2, FUNKE DP1090-5 or similar?
Schleicher TM/TN 13 “installation of a PCB-transponder antenna in the
vertical tail� doesn’t give a drawing/photo/diagram and I have
requested
additional information from Zulu-Glasstek. If I were to install antenna
within
the vertical stabilizer (Dolba BD1), the coax cable length would be
considerable (6 to 7 metre) and routing-security could be an issue, using
Carlisle ECS P/N 311501 coax cable. However, if the nose (tip area) of the

fuselage was manufactured from GRP as maybe used on other carbon fibre
Schleicher fuselages, then I would endeavour to install antenna within this

area? I have 95% dismissed TM/TN 12, installation of external antenna
alongside undercarriage due to it being ugly and prone to damage. Any
information gladly received. Best regards Paul.

Hi

I have a friend who installed his transponder aerial in the rear of the stbd gear door on his 27. It was recessed and attached to the inner skin of the door so it didn't protrude much and was well clear of the ground in the event of a wheel up and lifted up out of the way when the gear was down.

Quite an elegant solution I thought. I can get pictures to post here next time I'm at the field if anyone is interested

:-) Colin