refurbish old Narco antenna

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7524
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refurbish old Narco antenna

Post by 7524 »

Hello Gents,
I have the removed the headliner in my 140A in order to facilitate the ADS-B installation. While it's out I'm updating my ELT and considering refurbishing the old Narco comm antenna. While removing the antenna from the top of the fuselage seems straightforward, how to handle it after it's off is another story. There appear to be several machine screws holding the top of the antenna on and it is not apparent how it's put together. I can't seem to find any discussion on the web or youtube vids of the process so I thought I'd reach out to my fellow members.

Regards,
Ray
4004
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Re: refurbish old Narco antenna

Post by 4004 »

I think most will be confused as to which antenna you are talking about. A "comm" antenna, of that vintage, is generally just a single "rod" with a porcelain feed-thru base. The old Narco VOR antenna was a "flying V" on a mast with NARCO on the sides of the mast and IIRC it has a coaxial cable balun inside the mast.
So, I think a picture or better description may help the "gurus" understand your question. 2C
7524
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Re: refurbish old Narco antenna

Post by 7524 »

My apologies. It is the "flying V" with NARCO on both sides of the mast. I have pics, just need to figure out how to post them.

Ray
7524
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Re: refurbish old Narco antenna

Post by 7524 »

attempting to post a picture.
Narco Antenna.JPG
Narco Antenna.JPG (75.34 KiB) Viewed 3238 times
4004
Posts: 221
Joined: Tue May 01, 2018 7:00 am
Location: KFGU TN
Name: Edd
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Re: refurbish old Narco antenna

Post by 4004 »

Yes that is the antenna I described (obviously). I have one in my basement and I just refreshed looking at it. I would not recommend any further disassembly of the antenna - it's a passive device but with unique electrical properties. The two cable loops protruding thru the base are segments of the "balun" I mentioned. This is special configuration of coaxial cable that matches the antenna impedance to the input impedance of the receiver ensuring maximum sensitivity and directivity. Since it becomes a sealed item there is no "wear and tear" on the internals.

Recommend you just clean the exposed metal (paint and corrosion) and prime and paint. Just scotch brite the stainless steel rods (wings) but do not paint. The original NARCO lettering was black but most over the years were painted over due to erosion/corrosion reducing the sharpness of the characters - your call.

Hope this is the info you're looking for.

Edd

PS: When was the last time you tracked a VOR viz-a-viz a GPS. :)
7524
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Name: Ray P
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Re: refurbish old Narco antenna

Post by 7524 »

Thanks for the great info, Edd. I will proceed as you recommended. I've already decided to just retighten the machine screws on the top and no further disassembly.
Believe it or not, I don't have GPS in my plane. I have an efb which will show my a/c location via a bad elf. That being said, I do use my VOR for nav at times and I do ILS approaches (in VMC conditions).
Thanks again.

Ray
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