Questions tagged [antenna]

Questions about antennae, the typically-long-and-thin things used by aircraft to send and/or receive radio signals (for communication and/or navigation and/or other things as well).

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Does ADS-B use its own antenna?

In the aircraft we have: ADS-B out/in using 1090ES A/C or Mode S transponder for SSR grounding interrogation. Does the ADS-B out use the same antenna as Mode S or does it use its own antenna?
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109 views

What is the string antenna on the back of this Cessna 172 for? [duplicate]

Okay, so this question was asked before. But I didn't get the answer I wanted. I read that its some sort of antenna. what is it, what does it do, and how does it work? Also, is it in anyway related to ...
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6 votes
1 answer
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Why does TCAS need 2 antennas?

Can someone explain why TCAS needs 2 antennas (one on the top of the fuselage and one on the bottom)? And why is the top one directional and the bottom one can be either omnidirectional or directional?...
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2 votes
2 answers
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What type of antenna is this?

I’m just getting more into airplanes and trying to do a project on antennas. This airplane example is a Piper PA-28-181 Archer II. I’ve labeled all the antennas, and I’ve noticed there’s a lot! I’m ...
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7 votes
2 answers
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What is that round antenna(?) on the bottom of a Piper Comanche?

Does anyone recognize this round object under the belly of a PA-24?
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2 votes
2 answers
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What is that wire connecting [duplicate]

What is that wire connecting the tail fin to the fuselage in beechcraft 1900 and so many other airplanes
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4 votes
2 answers
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What are these "winglets" on the roof of the 737?

I circled the parts on the fuselage in red.
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What are the names of the antennas which I have marked in this picture of a Boeing 737?

I have taken the picture from PMDG 737NGX Microsoft flight simulator X. I am really curious to know what this antennas are. These antennas are behind the nose gear.
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1 vote
0 answers
370 views

Can you identify these antenna/items on the belly of a Cessna 172? [duplicate]

Not sure what all these antenna are for. I have my checkride soon and want to make sure I can name everything that might be pointed out. Thank you.
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2 votes
0 answers
129 views

An-225 antenna layout

Does anyone have a good reference or information about the antenna layout on the An-225? Particularly interested whether the VOR antennas are up on the V-Stabs, or somewhere more creative. Thanks in ...
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2 votes
1 answer
140 views

Converting lat long & altitude into a line of sight target? [closed]

I want to design a long-range ADS-B receiver with a directional antenna (like a Yagi), but in order to maximize its range, I'll need to orient the antenna towards a target (plane) based on existing ...
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5 votes
1 answer
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Can you identify this antenna on a Cessna 172N?

Does anybody know what this antenna is used for? I suspect a glideslope antenna but I am not totally sure.
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2 votes
1 answer
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What is this "stick" on top of Cessna 152's wing, and how does it work? [duplicate]

What is this device? What is it for? Seems that some variants have only one, while some others have two. Added: As some have two, so what are they? The answers and comments have not explained which ...
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1 vote
2 answers
248 views

Why did this old Japan Nakajima J1N airplane use a Yagi rather than a parabolic antenna?

Picture source. As per my understanding, a Yagi antenna is a directional antenna with limited gain, which it broadcasts or receives the microwave signal to and from the front side. It can only ...
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2 votes
1 answer
264 views

How much extra drag does an external HF antenna incur?

As seen in the picture, some older planes have external HF antennas that run from the fuselage to the tail. Have any studies found the wire to be a significant source of drag or is the difference ...
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4 votes
1 answer
128 views

Is this a type of navigation aid?

I saw this contraption on the southeast corner of Eastern West Virginia Regional Airport, Martinsburg, WV (MRB). My first thought was this was some kind of NDB antenna but not sure.
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1 vote
2 answers
1k views

AWACS - what do these antennas do?

In a press release for a new Boeing "wingman" (BATS) drone being built in Australia, a closeup of this Australian AWACS flying in formation was provided. What would be some of the specific uses for ...
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2 votes
3 answers
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What are the radio characteristics of communications between tower and aircraft?

I have a few questions on the types of antenna used for tower-aircraft comms. What type of antennas are used today for tower-aircraft comms? Are they directional or omni-directional? What's the ...
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1 vote
1 answer
349 views

How the Log Periodic Dipole Antenna of Localiser help in varying modulation depth?

Here Albert Helfrick speaks about 40% modulation depth for each tone in a localiser radio signal. However latest manuals of ILS manufacturers and google source speaks about 20% modulation depth, not ...
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5 votes
1 answer
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Which antenna on an commercial airline airplane is used for the transponder (SSR)?

On the 767-200 image I see no SSR antenna, but since that TCAS uses the transponder I guess that are sharing the same antenna. Am I right ?]1
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12 votes
1 answer
5k views

How are antennas integrated into stealth aircraft?

In Hephaestus Aetnaean's answer to this question, it is mentioned that the F-117 had no radar detection equipment because at the time it was developed the designers had not figured out how to ...
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