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Antennas Spotted On Helicopters
Antennas Spotted On Helicopters
https://www.ultralifecorporation.com/EC ... om-antenna
Looks like a simple loop turnstile to me. Nothing fancy. Look at the frequency range and reach your own conclusions.
Looks like a simple loop turnstile to me. Nothing fancy. Look at the frequency range and reach your own conclusions.
"I had a job for a while as an announcer at WWV but I finally quit, because I couldn't stand the hours."
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Re: Antennas Spotted On Helicopters
Looks like it's made out of cardboard.
I started out with nothing and I still have most of it.
Re: Antennas Spotted On Helicopters
Where was the helicopter and what was it doing?
Re: Antennas Spotted On Helicopters
It appears to me to be an antenna that is polarized in all directions.
Re: Antennas Spotted On Helicopters
Read the data sheet. The antenna under discussion is an aircraft antenna for 243 to 318-MHz. It has right-hand circular polarization and a gain of 6 dBiC (decibels referenced to a circularly polarized, theoretical isotropic radiator).
The antenna is designated as a SATCOM antenna, which I presume means military satellite communication.
The antenna is designated as a SATCOM antenna, which I presume means military satellite communication.
Re: Antennas Spotted On Helicopters
Of what material is it constructed?
I started out with nothing and I still have most of it.
Re: Antennas Spotted On Helicopters
So where does the gain come from? You can't call it passive antenna gain if its amplified. Is each blade some kind of multi turn inductor loop? If so, maybe a good plan for a gain radio receiving antenna.
"I had a job for a while as an announcer at WWV but I finally quit, because I couldn't stand the hours."
-Author Unknown
-Author Unknown
Re: Antennas Spotted On Helicopters
I came across a link to this item about curious helicopter flights over Los Angeles, most likely military, possibly conducting training exercises.
There is frequent mention and photo highlights of the "egg-beater" or "O Wing" type UHF satellite communications (SATCOM) antenna on the tail booms of these Bell 407 helicopters, as well as some identification of the many other antennas deployed about the aircraft.
Posted as on-topic for technical interest. Please, no conspiracy theory followups, at least on this forum!
There is frequent mention and photo highlights of the "egg-beater" or "O Wing" type UHF satellite communications (SATCOM) antenna on the tail booms of these Bell 407 helicopters, as well as some identification of the many other antennas deployed about the aircraft.
Posted as on-topic for technical interest. Please, no conspiracy theory followups, at least on this forum!
Re: Antennas Spotted On Helicopters
Was the antenna on the top or bottom of the helicopter?
EDIT: (after I read the link Solarmax posted)
Is this the same antenna the OP observed?
I worked on a project a while ago where we instrumented a small aircraft (Cessna 210) and flew over areas to detect RF signals. We had two GPS antennas on the top to give us good positioning info, and some antennas on the bottom and back of the aircraft to sense the frequencies we were looking for. None of our antennas had an appearance of the one in the photo above but I could see an antenna like that used for either GPS, satcomms or satdata to keep them connected while they are on their mission - whatever that might be.
EDIT: (after I read the link Solarmax posted)
Is this the same antenna the OP observed?
I worked on a project a while ago where we instrumented a small aircraft (Cessna 210) and flew over areas to detect RF signals. We had two GPS antennas on the top to give us good positioning info, and some antennas on the bottom and back of the aircraft to sense the frequencies we were looking for. None of our antennas had an appearance of the one in the photo above but I could see an antenna like that used for either GPS, satcomms or satdata to keep them connected while they are on their mission - whatever that might be.
Re: Antennas Spotted On Helicopters
It's easy to illustrate with a vertical antenna. The goal of gain , here, is to increase signals toward the horizon where receivers are listening,
A quarter wave has a wide launch angle of signal density from nearly straight up, to down to the horizon. Consider it 0 dB or no gain as a reference.
A halfwave has a narrower launch window with less upward and more power radiated toward the horizon, consider this as 3 dB gain.
A 5/8 wave antena has the maximum power radiated toward the horizon, and less at higher angles, of any continuous vertical radiator and is considered to be 6 dB gain over the reference QW vertical.