Skip to main content

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).

Filter by
Sorted by
Tagged with
1 vote
1 answer
206 views

Why and how can TCAS and SSR transponder work at the received frequency of each other?

The TCAS sends interrogation pulses at 1030 MHz and receives replies at 1090 MHz. And the transponder replies interrogations at 1030 MHz receiving at 1090 MHz. There could be interference between them,...
Galaxx's user avatar
  • 43
2 votes
0 answers
49 views

ADS-B for satellite Tx in Canada

Can simple rod transponder antennas be used to satisfy the Canadian requirements for a top antenna to communicate with ADS-B satellites? (eg. RAMI AV-22)
prhutson's user avatar
1 vote
1 answer
429 views

Could a Cessna Caravan be outfitted with Wi-Fi?

From what I understand, both ATG and satellite Wi-Fi require substantially large antennas to send and receive signals in large commercial airplanes. Could a system like this be outfitted on a Cessna ...
Charles Nicholson's user avatar
5 votes
3 answers
2k views

Why should the optimum position of GPS Antenna be close to aircraft's CG?

In CAE OAA Book11-Radio Navigation Chapter-18 Page-318, under GPS Error, "The optimum position for the antenna is on top of the fuselage close to the aircraft's centre of gravity". In the ...
Krishna Kanth's user avatar
0 votes
1 answer
998 views

Why do planes use wire HF antennas instead of smaller ones used by airliners?

why do some planes have wire Hf antennas if smaller hub antennas are more aerodynamic? like on the Boeing 787? Why do some modern aircraft like the c130 still have them?
Boeing787's user avatar
  • 6,454
15 votes
1 answer
559 views

What is the round tube mounted on the roof just behind the windshield of a PC-6?

If you look at the below image: (image source: Wikimedia Commons) There are three "antennas" mounted on the forward portion of the cabin roof. The two rear, wing-shaped ones probably are ...
TheEagle's user avatar
  • 1,394
9 votes
1 answer
2k views

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?
Oussama SDR's user avatar
0 votes
0 answers
127 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 ...
Boeing787's user avatar
  • 6,454
7 votes
1 answer
2k views

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?...
Konrad's user avatar
  • 2,025
3 votes
2 answers
8k views

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 ...
aneagleaerial's user avatar
7 votes
2 answers
1k views

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?
Jeff's user avatar
  • 71
3 votes
2 answers
381 views

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
zaki's user avatar
  • 33
5 votes
2 answers
3k views

What are these "winglets" on the roof of the 737?

I circled the parts on the fuselage in red.
Justin's user avatar
  • 79
1 vote
1 answer
2k views

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.
Anik Bhowmick's user avatar
1 vote
0 answers
460 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.
Charlie Echo's user avatar
3 votes
0 answers
145 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 ...
Peter's user avatar
  • 219
2 votes
1 answer
275 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 ...
John Wright Stanly's user avatar
5 votes
1 answer
5k views

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.
Romeo_4808N's user avatar
  • 73.8k
2 votes
1 answer
2k views

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 ...
AirCraft Lover's user avatar
1 vote
2 answers
292 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 ...
AirCraft Lover's user avatar
3 votes
1 answer
408 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 ...
dalearn's user avatar
  • 2,263
4 votes
1 answer
147 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.
William Taft's user avatar
1 vote
2 answers
2k 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 ...
jwzumwalt's user avatar
  • 11.5k
4 votes
4 answers
2k views

What are the radio characteristics of communications between tower and aircraft?

What type of antenna are used today for tower-aircraft comms? Are they directional or omni-directional? What's the range of data rate (in kbps) that these antennas can provide? Also, is there any ...
Teodorism's user avatar
  • 455
1 vote
1 answer
470 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 ...
Rumi's user avatar
  • 179
7 votes
1 answer
7k views

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
Andrea Ghilardi's user avatar
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 ...
TomMcW's user avatar
  • 28.6k