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CF & Transponders


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I'm looking at my Berkut drawings and they indicate that the transponder antenna protrudes through a hole in the landing brake.

 

I am wondering ........ if I were to make the landing brake out of carbon fiber (for the added strength and stiffness) and still have the transponder antenna protude through (with the ground plane behind the CF) as indicated in the Berkut drawings, world the carbon fiber cause me any heartache?

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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I don't see how it could keep from reducing your range. Is the Berkut speed brake made from CF?

 

My stock speed brake is holding up well. I did incorporate the changes as outlined in the CPs. Seems like you should just go stock, although strength and stiffness impovements are what the CP changes were intended to improve.

Dave Adams

Long EZ N83DT

Race 83

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I'm looking at my Berkut drawings and they indicate that the transponder antenna protrudes through a hole in the landing brake.

 

I am wondering ........ if I were to make the landing brake out of carbon fiber (for the added strength and stiffness) and still have the transponder antenna protude through (with the ground plane behind the CF) as indicated in the Berkut drawings, world the carbon fiber cause me any heartache?

 

If you like the concept of the transponder antenna out of the brake, why not use the carbon speed brake (if needed) as the ground plane, possibly with some aluminum foil behind it for the ground plane. The only thing that you have to engineer out is the bending/stoage of the cable as the brake deploys and retracts

I Canardly contain myself!

Rich :D

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I don't see how it could keep from reducing your range. Is the Berkut speed brake made from CF?

The Berkut landing brake came prefabricated and I do no know how it was constructed (layup schedule etc.) My nose strut cover is CF and I really like the way it came out and would like to do the same on the landing brake.

 

My stock speed brake is holding up well. I did incorporate the changes as outlined in the CPs. Seems like you should just go stock, although strength and stiffness impovements are what the CP changes were intended to improve.

Yes, that is what I'm going for here. I have some extra CF and I'm trying to build some small parts with it to gain some experience prior to building my wings. So far it has been a dream to work with. I really like it.

 

If you like the concept of the transponder antenna out of the brake, why not use the carbon speed brake (if needed) as the ground plane, possibly with some aluminum foil behind it for the ground plane. The only thing that you have to engineer out is the bending/stoage of the cable as the brake deploys and retracts

Sounds interesting but I think I'll stick with it projecting through vs. actually being part of a moving panel. I don't suspect that this arrangement would impare functionality.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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The Berkut landing brake came prefabricated and I do no know how it was constructed (layup schedule etc.) My nose strut cover is CF and I really like the way it came out and would like to do the same on the landing brake.

 

Yes, that is what I'm going for here. I have some extra CF and I'm trying to build some small parts with it to gain some experience prior to building my wings. So far it has been a dream to work with. I really like it.

 

 

Sounds interesting but I think I'll stick with it projecting through vs. actually being part of a moving panel. I don't suspect that this arrangement would impare functionality.

is your fuselage carbon? if so you will need it to protrude out the bottom as the radar station is going to see the signal from an angle that is mostly horizontal . any carbon between you and the station in a horizontal plane will block the signal. with carbon wings even a slight bank with a low wing in the antenna line of sight to the station will block the signal.

Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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is your fuselage carbon?

 

No

if so you will need it to protrude out the bottom as the radar station is going to see the signal from an angle that is mostly horizontal .

 

Yes, as stated, the berkut design has the antenna protrude through an oblong hole (.5" x 1.0") through the landing brake.

any carbon between you and the station in a horizontal plane will block the signal. with carbon wings even a slight bank with a low wing in the antenna line of sight to the station will block the signal.

More so than aluminum?

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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No

 

Yes, as stated, the berkut design has the antenna protrude through an oblong hole (.5" x 1.0") through the landing brake.

 

More so than aluminum?

Yes, one of the things that dave is doing with his berkut is antenna testing for government contractors. It seems that the carbon structure of guided weapons hung under carbon aircraft causes a problem with the guidance signals

if the fuselage is glass then the best place for the antenna is in the nose. you can use a foil tape dipole and save some weight and antenna wire. no antenna sticking out at all. mine is in the nose on the right side just in front of the canard and has always worked. also the radiation just under your butt is not a good idea

Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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Yes, one of the things that dave is doing with his berkut is antenna testing for government contractors. It seems that the carbon structure of guided weapons hung under carbon aircraft causes a problem with the guidance signals

That makes me rather curious as to why Dave chose to configure it that way on the Berkut.

 

if the fuselage is glass then the best place for the antenna is in the nose. you can use a foil tape dipole and save some weight and antenna wire. no antenna sticking out at all. mine is in the nose on the right side just in front of the canard and has always worked.

My nose sticks out to fs -19.0 so I have plenty of room to put it there. It sounds like that is the best solution.

 

also the radiation just under your butt is not a good idea

Well ...... it's not sitting in your crotch but I know what you mean (being an ex-radarman in the USN.) It still begs the question as to why the design had it that way.

 

Does Dave have any kids? :D

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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I have met all transpnder test requirements (FAA and CASA) with the ADVANCED AIRCRAFT ELECTRONICS HIGH GAIN ANTENNA SYSTEMS P/N L2 mounted inside the strake without a groundplane. I would venture to say you could place this small antenna elsewhere in a Berkut where you do not have carbon shielding the antenna (e.g. base of winglet).

Cheers,

 

Wayne Blackler

IO-360 Long EZ

VH-WEZ (N360WZ)

Melbourne, AUSTRALIA

http://v2.ez.org/feature/F0411-1/F0411-1.htm

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Thanks Wayne. I'm familiar with that line of antenna. That's actually the direction I was leaning. I'm sure I'll have enough room in the nose.

thats the one I had at first and had problem at certain angles replaced it with the homemade foil tape one and the problem went away. the foil tape cost about 1/100 of the fancy one. TMann I thought you where making your own antennas. the transponder one is only 1/16" thick and about 8" long

Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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My buddy had the same hi-gain antenna in the right strake of his Long-EZ. ATC complained alot. They usually lost us any time we were turning with our bodies between the antenna and ground station. The problem worsened when travel stuff was put into the strakes. Everyone's mileage varies I guess.

Wayne Hicks

Cozy IV Plans #678

http://www.ez.org/pages/waynehicks

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TMann I thought you where making your own antennas.

A little of both. My Nav antenna (one) in the canard is foil.

I'll have a high gain in one winglet and a foil in the other for the COM.

 

The jury is still out on the transponder.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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A little of both. My Nav antenna (one) in the canard is foil.

I'll have a high gain in one winglet and a foil in the other for the COM.

 

The jury is still out on the transponder.

what people don't realize is that the name high gain is just advertising. the antenna you built is a "quote" high gain antenna the guts are the same. its a simple dipole antenna inside the fancy black packaging. I have heard from many that say their home built one works better.

Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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I have heard from many that say their home built one works better.

....hence the reason I intend to put one high gain antenna in one winglet and a homebuilt foil antenna in the opposite winglet. That way I'll be able to have both a backup as well as a viable testbed to compare the performance.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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