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ASW27 Trasponder Antenna Installation Inside Fuselage.



 
 
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  #11  
Old February 29th 16, 03:30 AM
Ventus_a Ventus_a is offline
Senior Member
 
First recorded activity by AviationBanter: May 2010
Posts: 202
Default

Quote:
Originally Posted by Paul Birkett View Post
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
  #12  
Old February 29th 16, 03:58 AM posted to rec.aviation.soaring
jfitch
external usenet poster
 
Posts: 1,134
Default ASW27 Trasponder Antenna Installation Inside Fuselage.

On Sunday, February 28, 2016 at 10:11:18 AM UTC-8, wrote:
On Sunday, February 28, 2016 at 11:24:09 AM UTC-5, JS wrote:
If it's a "27", not a "27B" or "29", there is a place below the seat pan, under your left knee that a ground plane and stubby antenna can be mounted.
It tests fine at TXP certification, is relatively easy to install and connect, and is zero drag.
Jim


RF transmitting a foot and a half from the family jewels may not be optimum.
FWIW
UH


There's been plenty of tests on that in conjunction with the European personal transponder initiatives. All of my children have had no more that 4 eyes and 3 ears.....
  #13  
Old March 3rd 16, 08:39 AM posted to rec.aviation.soaring
Paul Birkett
external usenet poster
 
Posts: 7
Default ASW27 Trasponder Antenna Installation Inside Fuselage.

At 15:20 28 February 2016, John Cochrane wrote:
You can snake a coax cable back through the fuselage to an L2 antenna in
the tail battery box. Not easy or fun but possible. UH solution is

"easier"


John Cochrane

Hello John, many thanks for the information. Was the L2 antenna mounted
inside the battery box and doesn't the horizontal
stabilizer(carbon-Kevlar-
aramid) structure shadow the antenna? Also, did you have to "Fettle" the
vertical stab to enable coax routing?
Many thanks to all replies.
Best regards
Paul

  #14  
Old March 3rd 16, 09:28 AM posted to rec.aviation.soaring
Paul Birkett
external usenet poster
 
Posts: 7
Default ASW27 Trasponder Antenna Installation Inside Fuselage.

At 15:20 28 February 2016, John Cochrane wrote:
You can snake a coax cable back through the fuselage to an L2 antenna in
the tail battery box. Not easy or fun but possible. UH solution is

"easier"


John Cochrane

Hello John, many thanks for the information. Was the L2 antenna mounted
inside the battery box and doesn't the horizontal
stabilizer(carbon-Kevlar-
aramid) structure shadow the antenna? Also, did you have to "Fettle" the
vertical stab to enable coax routing?
Many thanks to all replies.
Best regards
Paul

  #15  
Old March 3rd 16, 12:07 PM posted to rec.aviation.soaring
Paul Birkett
external usenet poster
 
Posts: 7
Default ASW27 Trasponder Antenna Installation Inside Fuselage.

At 15:20 28 February 2016, John Cochrane wrote:
You can snake a coax cable back through the fuselage to an L2 antenna in
the tail battery box. Not easy or fun but possible. UH solution is

"easier"


John Cochrane

Hello John, many thanks for the information. Was the L2 antenna mounted
inside the battery box and doesn't the horizontal
stabilizer(carbon-Kevlar-
aramid) structure shadow the antenna? Also, did you have to "Fettle" the
vertical stab to enable coax routing?
Many thanks to all replies.
Best regards
Paul

  #16  
Old March 5th 16, 02:22 AM posted to rec.aviation.soaring
George Haeh
external usenet poster
 
Posts: 167
Default 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.

  #17  
Old March 5th 16, 02:13 PM posted to rec.aviation.soaring
Andrzej Kobus
external usenet poster
 
Posts: 585
Default ASW27 Trasponder Antenna Installation Inside Fuselage.

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.
  #18  
Old March 5th 16, 05:37 PM posted to rec.aviation.soaring
George Haeh
external usenet poster
 
Posts: 167
Default ASW27 Trasponder Antenna Installation Inside Fuselage.

LMR-300 would do the job for a price:

COAXIAL CABLE - ATTENUATION POWER
HANDLING CALCULATOR

Coaxial Cable Data
Product:
Frequency (MHz): 968
Run Length (Feet): 26
« Reset Calculate »

PRODUCT PERFORMANCE PARAMETERS
Attenuation: 6.3 db/100ft 20.6 db/100mtr
Average Power: 0.35 KW
Cable Vg: 85 %
Nominal Td: 1.2 nSec/ft 3.92 nSec/mtr
Capacitance: 23.9 pF/ft 78.4 pF/mtr
Typical Connector Loss: 0.06 dB/pair

CABLE ASSEMBLY PERFORMANCE
Cable Run Attenuation: 1.6 dB
Total Cable Assembly Loss: 1.9 dB
Cable Run Efficiency: 68.6 %
Cable Run Time Delay: 31.08 nSec


As far as RG 58 is concerned, forget it for
that length.

At 13:13 05 March 2016, Andrzej Kobus
wrote:
On Friday, March 4, 2016 at 8:30:10 PM

UTC-5, George Haeh wrote:
I've been looking into ways to secure

coax=20
inside the tailboom. My current avenue

of=20
investigation is using magnetic

receptive=20
rubber sheet.=20
=20
Wrap a strip of sheet around the coax

with=20
appropriate (suggestions welcome)=20
adhesive and use magnet on exterior

of=20
tailboom to clamp at appropriate

locations=20
well clear of elevator pushrod.=20
=20
Times Microwave has a coax cable

and=20
attenuation calculator:
=20

http://www.timesmicrowave.com/calculat
or/?

productId=3D38&frequency=3D1090&runL
ength
=3D26&mode=3Dcalculate#form
=20
Extra coax length is necessitated by tilt

up=20
instrument panel.=20
=20
I'd also like to to put a

PowerFLARM=20
dipole in the fin, but that would have to

be=20
at least a foot from the xpdr

antenna.=20
=20
The battery box is not big enough for

both; =20
so may need an opening in the box

to=20
achieve enough separation. Once in

use=20
for antenna(s), likely the box would

no=20
longer be available for ballast.=20
=20
If the front of the nose cone, would

work=20
for an L2 antenna, the problem would

be=20
much simplified.=20
=20
Any interference with the comm

coax=20
and/or antenna would mess things up.


George, I am afraid the coax cable losses

for Flarm antenna would be too
hi=
gh if you run it from the tail of your glider

to the instrument panel.
Flar=
m 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.


  #19  
Old March 5th 16, 07:29 PM posted to rec.aviation.soaring
Andrzej Kobus
external usenet poster
 
Posts: 585
Default ASW27 Trasponder Antenna Installation Inside Fuselage.

On Saturday, March 5, 2016 at 11:45:10 AM UTC-5, George Haeh wrote:
LMR-300 would do the job for a price:

COAXIAL CABLE - ATTENUATION POWER
HANDLING CALCULATOR

Coaxial Cable Data
Product:
Frequency (MHz): 968
Run Length (Feet): 26
Reset Calculate

PRODUCT PERFORMANCE PARAMETERS
Attenuation: 6.3 db/100ft 20.6 db/100mtr
Average Power: 0.35 KW
Cable Vg: 85 %
Nominal Td: 1.2 nSec/ft 3.92 nSec/mtr
Capacitance: 23.9 pF/ft 78.4 pF/mtr
Typical Connector Loss: 0.06 dB/pair

CABLE ASSEMBLY PERFORMANCE
Cable Run Attenuation: 1.6 dB
Total Cable Assembly Loss: 1.9 dB
Cable Run Efficiency: 68.6 %
Cable Run Time Delay: 31.08 nSec


As far as RG 58 is concerned, forget it for
that length.

At 13:13 05 March 2016, Andrzej Kobus
wrote:
On Friday, March 4, 2016 at 8:30:10 PM

UTC-5, George Haeh wrote:
I've been looking into ways to secure

coax=20
inside the tailboom. My current avenue

of=20
investigation is using magnetic

receptive=20
rubber sheet.=20
=20
Wrap a strip of sheet around the coax

with=20
appropriate (suggestions welcome)=20
adhesive and use magnet on exterior

of=20
tailboom to clamp at appropriate

locations=20
well clear of elevator pushrod.=20
=20
Times Microwave has a coax cable

and=20
attenuation calculator:
=20

http://www.timesmicrowave.com/calculat
or/?

productId=3D38&frequency=3D1090&runL
ength
=3D26&mode=3Dcalculate#form
=20
Extra coax length is necessitated by tilt

up=20
instrument panel.=20
=20
I'd also like to to put a

PowerFLARM=20
dipole in the fin, but that would have to

be=20
at least a foot from the xpdr

antenna.=20
=20
The battery box is not big enough for

both; =20
so may need an opening in the box

to=20
achieve enough separation. Once in

use=20
for antenna(s), likely the box would

no=20
longer be available for ballast.=20
=20
If the front of the nose cone, would

work=20
for an L2 antenna, the problem would

be=20
much simplified.=20
=20
Any interference with the comm

coax=20
and/or antenna would mess things up.


George, I am afraid the coax cable losses

for Flarm antenna would be too
hi=
gh if you run it from the tail of your glider

to the instrument panel.
Flar=
m 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.


George, transponder installations usually call for total loss not higher than 2 dB with a practical allowance for a connector of 0.25 dB on each end, leaving 1.5 dB for coax.
Your connector allowance is really low.

For example Schleicher uses Aircell 7 and total coax length and connectors are just about at max allowance for a Class 1 transponder.

I doubt that such loss will be tolerated by PF. I actually discussed this with Schleicher and I was told it will not work in practice.
  #20  
Old March 5th 16, 10:21 PM posted to rec.aviation.soaring
Darryl Ramm
external usenet poster
 
Posts: 2,403
Default ASW27 Trasponder Antenna Installation Inside Fuselage.

Yes to all that. Trig for example assumes 0.5dB connector losses (thats for the pair of connectors at the RF unit and another pair that joins to the coax to the antenna), but even that may be low vs. what what people will achieve assembling these connectors in practice. And you can get less lossy coax that LMR-300 if you really needed to.

You really don't want the PowerFLARM antenna that close to the Transponder antenna. And I'm not comfortable with a FLARM antenna being close below the RF opaque and reflective horizontal stabilizer. not sure if test flying a mock-up is an option or not but something I'd consider.

If you are installing a TRIG transponder mount the RF box somewhere other than the panel, ideally behind the cockpit area, so there is no coax flexing to the panel and the coax is shorter/straighter to the antenna location. For an ASW-27 the old-safe simple external antenna behind the gear doors with a short coax from a nearby TT-22 transponder would be my first (and last) choice. If ordering a new Schleicher from the factory, sure I might go for a tail hinge mounted transponder antenna.

I'm not sure why all the complex approach of vertical fin mounted transponder and FLARM antennas is needed in the first place. The transponder antenna behind the gear door works fantastically well, is really not a hassle unless you are stupidly careless.. and then it's easy to replace anyhow). People are getting good performance of FLARM antennas mounted in the cockpit area, including the nose cone area of ASW-27.


On Saturday, March 5, 2016 at 10:29:55 AM UTC-8, Andrzej Kobus wrote:
On Saturday, March 5, 2016 at 11:45:10 AM UTC-5, George Haeh wrote:
LMR-300 would do the job for a price:

COAXIAL CABLE - ATTENUATION POWER
HANDLING CALCULATOR

Coaxial Cable Data
Product:
Frequency (MHz): 968
Run Length (Feet): 26
Reset Calculate

PRODUCT PERFORMANCE PARAMETERS
Attenuation: 6.3 db/100ft 20.6 db/100mtr
Average Power: 0.35 KW
Cable Vg: 85 %
Nominal Td: 1.2 nSec/ft 3.92 nSec/mtr
Capacitance: 23.9 pF/ft 78.4 pF/mtr
Typical Connector Loss: 0.06 dB/pair

CABLE ASSEMBLY PERFORMANCE
Cable Run Attenuation: 1.6 dB
Total Cable Assembly Loss: 1.9 dB
Cable Run Efficiency: 68.6 %
Cable Run Time Delay: 31.08 nSec


As far as RG 58 is concerned, forget it for
that length.

At 13:13 05 March 2016, Andrzej Kobus
wrote:
On Friday, March 4, 2016 at 8:30:10 PM

UTC-5, George Haeh wrote:
I've been looking into ways to secure

coax=20
inside the tailboom. My current avenue

of=20
investigation is using magnetic

receptive=20
rubber sheet.=20
=20
Wrap a strip of sheet around the coax

with=20
appropriate (suggestions welcome)=20
adhesive and use magnet on exterior

of=20
tailboom to clamp at appropriate

locations=20
well clear of elevator pushrod.=20
=20
Times Microwave has a coax cable

and=20
attenuation calculator:
=20

http://www.timesmicrowave.com/calculat
or/?

productId=3D38&frequency=3D1090&runL
ength
=3D26&mode=3Dcalculate#form
=20
Extra coax length is necessitated by tilt

up=20
instrument panel.=20
=20
I'd also like to to put a

PowerFLARM=20
dipole in the fin, but that would have to

be=20
at least a foot from the xpdr

antenna.=20
=20
The battery box is not big enough for

both; =20
so may need an opening in the box

to=20
achieve enough separation. Once in

use=20
for antenna(s), likely the box would

no=20
longer be available for ballast.=20
=20
If the front of the nose cone, would

work=20
for an L2 antenna, the problem would

be=20
much simplified.=20
=20
Any interference with the comm

coax=20
and/or antenna would mess things up.

George, I am afraid the coax cable losses

for Flarm antenna would be too
hi=
gh if you run it from the tail of your glider

to the instrument panel.
Flar=
m 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.


George, transponder installations usually call for total loss not higher than 2 dB with a practical allowance for a connector of 0.25 dB on each end, leaving 1.5 dB for coax.
Your connector allowance is really low.

For example Schleicher uses Aircell 7 and total coax length and connectors are just about at max allowance for a Class 1 transponder.

I doubt that such loss will be tolerated by PF. I actually discussed this with Schleicher and I was told it will not work in practice.

 




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