Repairing Transponder Antenna

[skippydiesel]

My blade type transponder antenna has suffer a mishap. A wombat (due to space limitations can only have been a wombat) has used the antenna as a convenient scratching post  In the process, neatly separated the composite blade from its base.

Blade filled with some sort of tough glassy looking material, with very thin antenna wire in centre.

Need to remove glassy material to replace wire antenna. 

Looks like an easy repair, however glassy material resists drilling.  Added pressure resulted in drill bit departing side of fin - not good.

Replacement, with same unit, north of $400, so well worth repairing.

Hoping that someone has been down this track before me and knows how to remove glassy material, without further damage to blade casing.

All constructive suggestions welcome😈

 

 

[Kiwi]

Not what you are asking, but.

[Kiwi]

I have one of these on my Rans S6S.

Seems to work well.

 

 

[skippydiesel]

5 minutes ago, Kiwi said:

Not what you are asking, but.

Thanks Kiwi - Way ahead of you. Just don't like scrapping things that may be repairable.😈

 

[skippydiesel]

18 minutes ago, Kiwi said:

I have one of these on my Rans S6S.

Seems to work well.

 

 

 They all work.

I had this Rod and Ball type on my last aircraft - poxy things don't put up with careless overenthusiastic aircraft cleaning.

After the second snap, made my own.

Easy to do.

BNC Type Connector bases  available from JayCar ( & others) for  $1-$8, depending on type selected.

Short length of copper wire (same length as original R & B). Some heat shrink. You have a functioning flexible  Transponder antenna.

Just not a "flash" looking as a Blade or R&B type.

😈

Edited yesterday at 12:04 AM by skippydiesel

[onetrack]

Skippy, forget trying to repair it. The material is Acrylonitrile styrene acrylate (ASA) and it is specifically designed to be bullet proof. As with potting mixes around electronic components, it is designed to be unrepairable.

 

These tough products resist every type of attack - including drilling, or even chemical dissolution. You will destroy the antenna, trying to repair it. Read about ASA's properties on its Wikipedia page. 

 

It certainly hurts having to replace a relatively expensive item that has suffered simple damage, and which appears at first glance to be repairable. But the deeper examination just shows repairability is not an option. Just bite the bullet.

 

I trust you've taken steps to prevent further investigative animal attacks. Rodents are also a major concern in this area.

 

https://www.ozpilot.com.au/product/harrys-hm109b-blade-antenna/

 

https://en.wikipedia.org/wiki/Acrylonitrile_styrene_acrylate

 

[skippydiesel]

Thanks Onetrack -

Expensive mistake;

About 12 months ago, I saw evidence of wombat using the underside of my Sonex as a "rubbing post". No damage, just mud a hair.

Errected an electric fence around aircraft. Did the job - no more nocturnal visits.

Having to rotate batteries, remove/ replace fence  "gate" was a pain- in- the- rectum.

After 12 months, I thought that the local wombat(s) had been trained to stay away from the Sonex but Nooooo!

Such is life.

😈

[BurnieM]

I understand wanting to repair but repaired antennas never work as well as a new one and some perform very poorly indeed.

 

[facthunter]

Electric Fences can be solar Powered with it's own small Battery. Most animals hate even a small electric shock. Nev

[skippydiesel]

5 hours ago, BurnieM said:

I understand wanting to repair but repaired antennas never work as well as a new one and some perform very poorly indeed.

 

Are you speaking from experince?

 

An antenna that is made or repaired, to the same dimensional, material & connection standards, as the original, will perform just as well.

 

😈

 

[BurnieM]

12 minutes ago, skippydiesel said:

Are you speaking from experince?

 

An antenna that is made or repaired, to the same dimensional, material & connection standards, as the original, will perform just as well.

😈

 

Yep.

Almost all antennas are made on automated line to close tolerances in temp and moisture controlled environments.

Save yourself a years troubleshooting why you have poor performance and just buy a new one.

 

Edited 12 hours ago by BurnieM

[skippydiesel]

10 hours ago, BurnieM said:

 

Yep.

Almost all antennas are made on automated line to close tolerances in temp and moisture controlled environments.

Save yourself a years troubleshooting why you have poor performance and just buy a new one.

 

Maaate!

 

I am a total electronics cluts but even I know that the basic components of most (meaning not all) aircraft antenna are ?

 

For your future reference:

• A metal rod/wire. Length adjusted to give the optimum performance for a given frequency band
• A coaxial cable connector, to facilitate a good electrical connection between rod & inner wire and the outer conductor (shielding) of the coax cable, from the transceiver
• Some sort of secure mounting system, that includes the ability to make a good earth return
• Other than some, usually non contributing to efficacy refinements (paint/cover/etc), that is it - couldn't be more simple.

Radio buffs & pilots have been making their own antenna, since radio was invented.

 

What you purchase from a supplier/manufacturer is the esthetic (sometimes more streamlined) version of the above.

 

😈

 

 

[BurnieM]

All correct.

You are not paying for the basic antenna, you are paying for a sealed unit designed to work at high speed/wind load and resist corrosion for a reasonable time period.

It comes down to the time you will spend 'repairing' it and the time you will use in future to troubleshoot predictable problems.

 

Me, I would rather just fly.

 

 

[onetrack]

Yeah, but it's not Wombat proof!

 

Skippy is working on devising a Wombat-proof one! 😄