Using airliner antenna as a scanner antenna for airband?

[AZ645]

I have obtained an old airline fin VHF antenna, was wondering if anyone has used as a receiving antenna and whether they would work decently?

 

[byndhlptom]

Aircraft antenna

Should work Ok, but....

The are designed to use with a ground plane (think lots of aluminum skin).

You probably don't need all the mounting screws (3-4 should be plenty in a non aircraft use)

You might need an adapter at the antenna (depends on what your coax has)

$.02

 

[737mech]

Airplane Antennas

I've done it, they work if you have a plate under them as mentioned above. Rule of thumb the plate needs to be larger than the antenna if it tipped over on it's side. As a matter of fact I'm using a sensor systems l-band for ADS-B tracking. A long time ago there was posts about the very cool AT-256A/ARC. As noted you may need adaptors for the coax connector depending on what you have. VHF will be good, don't expect much out of band from those. Worth the try and fun project.

 

[kb3isq]

Why not just get a discone. When you go to an airport you see a lot of discones.

 

[JamesPrine]

Use a decent ground plane and the proper coax adapters, and settle in in your listening post at 30,000 feet...should offer excellent reception <g>.

 

[KB7MIB]

Years ago, I saw a Chevy Suburban pull into the Phoenix HRO parking lot sporting several aircraft style blade antennas.
I don't know how well they worked for whatever radios they were connected to, but it's been done mobile, at least.

John
Peoria, AZ

 

[AZ645]

Thanks, I actually have a discone and that is my antenna of choice. just have had this VHF airplane antenna sitting around in my junk box for a few years and figured I'd make use of it.

 

[AZ645]

Thanks, I'll have to check what the connection is on the end, if I recall correctly it was BNC.

 

[majoco]

Most of those fin type antennas are a simple quarter wave ground plane - the element is probably shortened with a loading coil on a piece of printed circuit board. "N" sockets are the usual standard. There is no need for any great sensitivity - once the aircraft gets over say 5000ft then signal strength is no problem. The ground stations tend to be around 25watts and so do the larger aircraft with Collins gear, small turboprops may be 12watts with the King Air/Bendix equipment. I can hear aircraft descending into Rotorua from home, a distance of about 180 miles on a discone into a BCT8. Probably a better antenna if you can get one is the localiser antenna commonly called a 'ramshorn' which was mounted over the cockpit on the centreline, like this one on one of our Calibration aircraft. We checked for minimum signal levels from ground stations and they had to be more than 10uV in the stated coverage areas - we used an Ailtech NM-37/57A field intensity meter which I just happen to have at home - found on our local auction site for NZ$120!

 

[KB7MIB]

That looks like one of those boomerang shaped TV antennas that were marketed for mobile use.

And the OP said the blade/fin antenna he has had been sitting in his junk box, and he wants to make use of it.

John
Peoria, AZ

 

[nanZor]

Some aircraft use slot antennas - you may want to try one of those just for kicks if you have some spare metal surfaces sitting around.

John Portune, W6NBC has a nice article on how to make one out of a used sat-dish, although he had to bend the dipole slot element. Cut for 2 meters, it could easily be lengthened just a little for vhf airband:

http://w6nbc.com/articles/20xx-dishslot.pdf

Basically everything is backwards. The horizontal slot is vertically polarized. A low impedance feedpoint is near the ends, not in the middle. And of course the empty slot.

Just in case you have some spare aluminum sheet in the junkbox lying around.....

 

[DaveNF2G]

Railroad antennas are similar and they work well at ground level.