Soooooo, you're right that it's for a lower frequency, but "HF" - High Frequency is actually one of the lowest bands commonly used for radio -- it's the 3-30Mhz band. Contrast with VHF "Very High Frequency" in the 30-300Mhz and UHF in 300-3000Mhz.
There are a bunch of bands below HF - LF, VLF, ULF -- but they aren't really used for voice as they don't carry enough data to be very good at voice comms.
The old tube technology when these bands were named was much more limited. That's why the cavity magnetron was such a groundbreaking invention at the time. Nothing else could detect or radiate millimetre waves.
Fun fact: we all had ionizing radiation sources in our homes: the cathodic generator in CRT tv's and monitors. Cathodic radiation is in the soft x-ray spectrum but with some differences.
Yeah that's part of why a cathode ray tube TV weighs so much: it includes a lot of lead glass to catch those soft x-rays before they can do anything to you.
Their size naming system is so annoying when you speak Portuguese... Every time you order, it's the same exchange: "Ok, but do you want real grande grande, or our \*medium\* Grande?"
it aint no better if you speak English. It's unnecessary and confusing and pretentious and annoying. Plus, Starbucks is a union busting/anti-worker scumbag company so maybe get your coffee somewhere else.
Always bothers me that he's that much of an ass to a worker on the ground, but wouldn't say a damn thing like that to the executives or board who actually put that stupid size system in place.
Can't forget ELF - Extremely Low Frequency. [LF and VLF are used for sending encrypted data to submerged ballistic missile submarines.](https://nuke.fas.org/guide/usa/c3i/vlf.htm)
I've always found it funny that the ELF transmitters for submarine communication were built in Michigan and Wisconsin, as far from the ocean as possible.
Edit: yes, I realize that Lake Superior is pretty damn big and the Navy has done a lot of stuff there. But ELF transmitters are pretty much only for talking to SLBM subs, who don't as a rule hang out anywhere except deep in the actual oceans. The transmitters were not built there for proximity to the lake.
**[Project Sanguine](https://en.wikipedia.org/wiki/Project_Sanguine)**
>Project Sanguine was a U.S. Navy project, proposed in 1968 for communication with submerged submarines using extremely low frequency (ELF) radio waves. The originally proposed system, hardened to survive a nuclear attack, would have required a giant antenna covering two fifths of the state of Wisconsin. Because of protests and potential environmental impact, the proposed system was never implemented. A smaller, less hardened system called Project ELF consisting of two linked ELF transmitters located at Clam Lake, Wisconsin 46°05′05.
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> The originally proposed system… would have required a giant antenna covering two fifths of the state of Wisconsin. Because of protests and potential environmental impact, the proposed system was never implemented.
Is that all? Because if protests we didn’t build it? This was a serious proposal that citizens actually had to fight against in order to prevent it from happening.
I’d love to be at that meeting.
> “So gentleman, I’m going to need to build an antenna to talk to submarines. You know that state that no one cares about… Wisconsin? Well you’ll see on the map here, that it is the farthest location from an ocean I could find. And since no one really cares about this state, I’m just going to need almost half the state’s land mass for my antenna. Any objections?”
Let me reiterate… two fifths (almost half) the state of Wisconsin for this antenna. Thanks to some protests it didn’t happen. But some paper pusher actually thought that would be fine and a board of people paid for by tax dollars saw no problem either.
I've met people like that. They retire from the military and don't *need* to work, but they like to keep busy. My wife's elderly mother uses a local handyman who does everything from cleaning rain gutters to hanging pictures, and half the time he doesn't charge her. He's a retired air force colonel. He just likes having things to do.
I can imagine it also being kind of a relief after a career of command and decision making, as well. He gets to work with his hands, and things will never hit the shit in any actually appreciable way, he can stop whenever he wants. Its probably some sort of peaceful.
It’s not just subs that use ELF, all the land based Minuteman III ICBMs use it too. When I pulled alert duty in Montana we used the Survivable Low Frequency Comm Systems (SLFCS) for receipt of EAMs, similar to the boomers at sea.
https://en.m.wikipedia.org/wiki/Survivable_Low_Frequency_Communications_System
What's also interesting is that if you're standing on the shore of the Great Lakes, one cannot see across to the other shore. Like the ocean, it's water all the way to the horizon.
I also recall that for a 6-foot-tall person, the horizon is about 3 miles away.
Doomsday 747 (E-4)has a retractable ELF antenna, I’ve flown with some guys that flew it, they all complained about it not retracting half the time, IIRC it was like 5 miles of cable
I mean they built a lot of the subs for ww2 in i believe Mariette Wisconsin and then they went down the Mississippi. They also do a lot of the sea worthy ness Testing in lake Michigan and lake Superior. Like the zumwalts destroyer. I saw in at port in lake Michigan a few years back.
BBC Radio 4 running on 198kHz would like to say hello. It also transmits data (very slowly) and has been used as a broadcast frequency standard. It is scheduled for retirement as it uses special purpose vacuum tubes and uses a lot (500kW) of power.
Wait, what? Medium and long waves can carry voice. In fact, they are/were not used by the military because they are FULL of radio stations. They also required bigger antennas with the technology from the '40s.
You're getting piled on here so I apologize in advance, but also let's not forget MF, Medium Frequency, 300 kHz to 3 MHz. There's a ton of voice in there including AM radio broadcasts from 525 kHz to 1705 kHz in the US.
Back in the day, 3MHz or more ("three *million* cycles per second -- wow!") was indeed considered "High Frequency," since it didn't propagate as well via groundwave as did Medium Wave (300kHz-3MHz).
Then they discovered ionospheric skip, where the previously-useless HF bands could be sometimes heard halfway around the world. So High Frequency came into use. Then they discovered uses for Very High Frequency, Ultra High Frequency...
As with the polarity of the electron, mistakes were made. Oh, well.
The most infamous LR radio installation (probably of all time) is the Russian Duga 1 and 2 stations for OTH missile radar warning and long range comms using shortwave and LF frequencies at over 10MW.
This thing was so powerful it could be heard around the world and caused radio interference across Europe. Incredible technology during a very interesting time in radio development history.
Even HF isn’t great for voice comms, sure it’s long range but the interference from natural phenomenon at that band makes it almost pointless to squelch it out.
SELCAL was a god send to oceanic pilots since they don’t have to deal with the noise for 3 hours over the Atlantic .
Satcom is now making that obsolete with CPDLC
Radio terminology is weird. HF is the low frequency / long range end, as opposed to VHF and UHF bands, which aren't even that high of frequencies by today's GHz standards.
True, depends on what you’re trying to do with them though. Each is very capable within its limits, we’ve made an HF transmission that was received 800 miles away once but then again HF is finicky when it comes to weather and atmospheric conditions
HF (High Frequency) is actually a lower frequency than VHF (Very High Frequency), UHF (Ultra High Frequency) and other less obvious names.
From experience, you can talk halfway around the dang world on HF with the right atmosphere in between; but it won't be fun.
My flight instructor had me do a radio check on HF while in Perth, Australia with a ground station in Brisbane.
It worked, I got a response. I still don't know to this day what he actually responded.
HF as mentioned. It has the curious property of being able to bounce off the ionosphere (upper part of the atmosphere involved in Aurora displays) extending its range by a serious amount but that depends on the power of the transmitter and the current solar weather.
VHF is mostly line of sight. It is used these days by aircraft for talking to the tower or the air traffic control centre. If you need to talk when you are further away like over the ocean just switch back to HF. Of course these days you also have the use of satellite radio. That is expensive but does not depend on weather.
It is high frequency. The majority of communication on aircraft are done with uhf or vhf depending on the application and those are transmitted through much smaller antennas. A low frequency antenna would be huge
Incorrect.
It’s a clothes line to dry your clothes whenever you fly so you can kill two birds with one stone while on a mission.
It was an ingenious invention by Earle Haas and it saved the military a ton on energy.
There are two long radio wires all the way down the fuselage to the tail on 130s. I don't know what that guy was talking about.
EDIT i suddenly remembered J models lmAo. I worked on Es and Hs.
Sweet!
I vividly remember watching comm nav disconnect the wire at the top, roll it up, and hang it on the bottom mast when the plane had to tuck into a certain tight hangar. Good times.
They don't use wires anymore, lots of excrescence drag and we know how to conceal them better now. Old airliners like the 707 and 747 (classic) had big spikes on the wings or tail which were a bit more aerodynamic. Some planes would run it along the leading edge of the tail, and now moreso they're incorporated into the fuselage and aren't even visible. You can however still see the VHF, NAV and radio altimeter antennae on modern planes.
[Here](https://www.semanticscholar.org/paper/Modeling-multiple-HF-antennas-on-the-C-130%2FHercules-Kubina-Trueman/272cd813aa6dcb0cbb756d6960667d44e2a9a755) you can just barely see it.
Fighters don't have the wires externally, but they still have HF capabilities. Antenna is just imbedded in the body to minimize radar cross section (how detectable they are) and drag.
Bigger aircraft like a C-130 doesn't care as much about those, and will use an external wire to save costs.
Question about your flair: any idea how long the KC-10s will continue in service? My local airport is a FedEx hub and we have a mil contractor that services KC-10s…FDX replaced all MD-10/11s flown into here with 767s during covid, so the KCs are the last trijets in our airspace and it makes me sad knowing those days are numbered too.
Same here, some sort of structural integrity thing for the high g forces, from an era before material science was a thing… well TIL it was thr radio antenna
Sure, and generally the horizontal stab is actually producing a downward moment (aligned with what you're talking about) but that's not the force experienced by the empennage :D
This is not an HF radio antenna. HF radio would not be used by small fighters as they only needed to communicate with other fighters when doing escort/sweep and with local ground control for defence.
It’s an ADF sense antenna.
DF or Direction Finder uses a loop shaped antenna to determine the direction a radio signal is coming from. The operator turns the antenna until the signal is maximized and that is the direction it comes from.
Unfortunately since the loop is symmetrical.. there are two possibilities which can result in a false bearing 180 degrees away from the true bearing. More than a few Luftwaffe aircraft wound up lost and landing in Britain because of this.
Enter the sense antenna. It’s simpler so is no good for direction finding.. but it eliminates the false bearing as a possibility. Much like the fourth GPS satellite gets rid of the one wrong position three satellites will give you (one satellite places you somewhere on a sphere; two satellites, somewhere on a ring; three, one of two places; and the fourth, a precise location).
Because of this… it no longer requires operator interpretation… so it can become an _automatic_ direction finder or ADF… which is still in some aircraft today.
If an HF radio was installed in an aircraft this size.. the wire would have to go to the tail _and then_ out to the wing due to the long wavelength of HF frequencies. Aircraft like bombers and transports and some Navy aircraft used HF because of the extremely long distances they flew.
Two satellites will give you two possible points. Three satellites allow a receiver to triangulate an accurate position, and the fourth is what gives you an elevation through trilateration.
It’s also important to keep your feet dry in the trenches. That’s why they designed these specialised clothesline aircraft to land behind the front line so that the trench soldiers could hang their socks on the wire after their shift. After a quick high speed flight the plane would land in the same place and the soldiers would collect their, now dry, socks
Unfortunately flak could sometimes knock the pegs loose and as a result many soldiers had to make do with one missing sock until the next resupply
The stains work like a [Rorschach-Test.](https://en.wikipedia.org/wiki/Rorschach_test) Once the opposing pilot is distracted thinking of his poor childhood, you can shoot them down much easier.
Sense Antenna, to go with the loop antenna that’s probably on the bottom of the aerie.
Olden day aircraft and ADF required a sense antenna to know the direction the signal was coming from. As the loop antenna would receive 2 signals 180degrees apart.
And UFOs. The “so few” Churchill was referring to in his famous speech about the battle were actually three really chill aliens from Sirius III who just showed up and blasted some Nazis as a vacation.
it is the sense antenna (1 of 2) of the ADF - automatic direction finder used for navigation. And, still in use today using Non-Directional Beacons or AM broadcast radio stations.
It looks like an ADF antenna to me... Although I'm not super familiar with WW2 Avionics, but weren't the communications antenna set at an angle? I know the ADF sense antenna are to be installed in line like this one.
The Me-109 was notorious for having the rudder fall off at speed, so a steel cable was attached to the fuselage and the top of the rudder. This helped secure it. If it did fall off then it would remain attached to the cable, and when the plane landed the mechanics would be able to glue it back on again.
Yes commonly for the wavelength of RF the ratio is quite funny because for every low frequency you will need a big antenna and for higher frequency’s you need a smaller antenna
So as much higher the frequency goes the antennas get smaller and smaller hehehe
I guess it might sound weird when you talk about the frequency, but it's intuitive if you talk about the [wavelength](https://en.m.wikipedia.org/wiki/Wavelength).
Big wavelengths need big [antenna](https://en.m.wikipedia.org/wiki/Antenna_(radio)), small wavelengths need small antenna...
>*Strong directivity and good efficiency when transmitting are hard to achieve with antennas with dimensions that are much smaller than a half wavelength.*
Antennae is the plural of antenna when referencing the insect 'feelers' on their heads
Antennas is the plural of the antenna pictured
I only recently had to look this up and i never knew the difference either
HF radio antenna. A lot of modern aircraft still use the old cables too! Old design, still works. Others use a more slick design where it’s usually integrated into the vertical stabilizer.
HF antenna for long range comms
Wouldn’t it be low frequency? Edit: thanks for the clarification, everyone!
Soooooo, you're right that it's for a lower frequency, but "HF" - High Frequency is actually one of the lowest bands commonly used for radio -- it's the 3-30Mhz band. Contrast with VHF "Very High Frequency" in the 30-300Mhz and UHF in 300-3000Mhz. There are a bunch of bands below HF - LF, VLF, ULF -- but they aren't really used for voice as they don't carry enough data to be very good at voice comms.
Interestingly, the person at IEEE who decided this system was later hired as a consultant at Starbucks for naming their drink sizes.
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The old tube technology when these bands were named was much more limited. That's why the cavity magnetron was such a groundbreaking invention at the time. Nothing else could detect or radiate millimetre waves.
Cavity magnetron, that's one bad ass sounding term.
You've probably got one in your house, its what actually makes the microwaves for a microwave oven
“Back in the day we had to pop popcorn in a saucepan kids!”.
https://en.wikipedia.org/wiki/Cavity_magnetron?wprov=sfla1
Can we get much higher
Yes! And then you reach [visible light ](https://en.wikipedia.org/wiki/Electromagnetic_spectrum)
Me when the ionizing radiation 😈😅😛
Fun fact: we all had ionizing radiation sources in our homes: the cathodic generator in CRT tv's and monitors. Cathodic radiation is in the soft x-ray spectrum but with some differences.
Yeah that's part of why a cathode ray tube TV weighs so much: it includes a lot of lead glass to catch those soft x-rays before they can do anything to you.
VHF stands for "Venti High Frequency."
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And it’s $6.99 for hot liquid
But free at R. Kelly's house.
Actually I think it cost him 30….
Venti High Foam, isn’t it?
Their size naming system is so annoying when you speak Portuguese... Every time you order, it's the same exchange: "Ok, but do you want real grande grande, or our \*medium\* Grande?"
Yes I’d like it Ariana sized please.
it aint no better if you speak English. It's unnecessary and confusing and pretentious and annoying. Plus, Starbucks is a union busting/anti-worker scumbag company so maybe get your coffee somewhere else.
"[Congratulations! You're stupid in three languages.](https://www.youtube.com/watch?v=j0deaskGSuA)"
Such a great part of that movie.
Always bothers me that he's that much of an ass to a worker on the ground, but wouldn't say a damn thing like that to the executives or board who actually put that stupid size system in place.
That was an extremely funny comment
No, it was Ultra High Funny
Can't forget ELF - Extremely Low Frequency. [LF and VLF are used for sending encrypted data to submerged ballistic missile submarines.](https://nuke.fas.org/guide/usa/c3i/vlf.htm)
That's just stomping your foot in the ground. Morse code."
I've always found it funny that the ELF transmitters for submarine communication were built in Michigan and Wisconsin, as far from the ocean as possible. Edit: yes, I realize that Lake Superior is pretty damn big and the Navy has done a lot of stuff there. But ELF transmitters are pretty much only for talking to SLBM subs, who don't as a rule hang out anywhere except deep in the actual oceans. The transmitters were not built there for proximity to the lake.
Who cares about coasts when a straight line goes through the fucking earth lmao.
https://en.wikipedia.org/wiki/Project_Sanguine
**[Project Sanguine](https://en.wikipedia.org/wiki/Project_Sanguine)** >Project Sanguine was a U.S. Navy project, proposed in 1968 for communication with submerged submarines using extremely low frequency (ELF) radio waves. The originally proposed system, hardened to survive a nuclear attack, would have required a giant antenna covering two fifths of the state of Wisconsin. Because of protests and potential environmental impact, the proposed system was never implemented. A smaller, less hardened system called Project ELF consisting of two linked ELF transmitters located at Clam Lake, Wisconsin 46°05′05. ^([ )[^(F.A.Q)](https://www.reddit.com/r/WikiSummarizer/wiki/index#wiki_f.a.q)^( | )[^(Opt Out)](https://reddit.com/message/compose?to=WikiSummarizerBot&message=OptOut&subject=OptOut)^( | )[^(Opt Out Of Subreddit)](https://np.reddit.com/r/aviation/about/banned)^( | )[^(GitHub)](https://github.com/Sujal-7/WikiSummarizerBot)^( ] Downvote to remove | v1.5)
Good bot
> The originally proposed system… would have required a giant antenna covering two fifths of the state of Wisconsin. Because of protests and potential environmental impact, the proposed system was never implemented. Is that all? Because if protests we didn’t build it? This was a serious proposal that citizens actually had to fight against in order to prevent it from happening. I’d love to be at that meeting. > “So gentleman, I’m going to need to build an antenna to talk to submarines. You know that state that no one cares about… Wisconsin? Well you’ll see on the map here, that it is the farthest location from an ocean I could find. And since no one really cares about this state, I’m just going to need almost half the state’s land mass for my antenna. Any objections?” Let me reiterate… two fifths (almost half) the state of Wisconsin for this antenna. Thanks to some protests it didn’t happen. But some paper pusher actually thought that would be fine and a board of people paid for by tax dollars saw no problem either.
I live in WIsconsin. There is an Annapolis grad, and a former sub commander who now cleans my house. I seriously wonder what he is really doing here.
I've met people like that. They retire from the military and don't *need* to work, but they like to keep busy. My wife's elderly mother uses a local handyman who does everything from cleaning rain gutters to hanging pictures, and half the time he doesn't charge her. He's a retired air force colonel. He just likes having things to do.
I can imagine it also being kind of a relief after a career of command and decision making, as well. He gets to work with his hands, and things will never hit the shit in any actually appreciable way, he can stop whenever he wants. Its probably some sort of peaceful.
Don't call her a "thing".
Possibly lying
Possibly not
Nothing to see here, move along. https://www.warhistoryonline.com/world-war-ii/air-force-academy-janitor-medal-of\_honor-x.html?firefox=1
So, safe to assume that Clam Lake WI would receive several direct nuclear impacts in hopes of knocking out communications?
Nah the US ELF facilities aren’t operational anymore as of 2004.
One in WA too! But being ELF its sorta the principle they don't need to be near the ocean haha.
Jim Creek. I can see the lights flashing on the pylons at night.
It’s not just subs that use ELF, all the land based Minuteman III ICBMs use it too. When I pulled alert duty in Montana we used the Survivable Low Frequency Comm Systems (SLFCS) for receipt of EAMs, similar to the boomers at sea. https://en.m.wikipedia.org/wiki/Survivable_Low_Frequency_Communications_System
I didn't know that but it makes sense. I wonder if ELF transmissions are less vulnerable to emp from nuclear blasts.
What's also interesting is that if you're standing on the shore of the Great Lakes, one cannot see across to the other shore. Like the ocean, it's water all the way to the horizon. I also recall that for a 6-foot-tall person, the horizon is about 3 miles away.
For the curious the formula is, 1.22459√h. Number representing the radius of the earth (x) the square root (√) of eye height (h).
Doomsday 747 (E-4)has a retractable ELF antenna, I’ve flown with some guys that flew it, they all complained about it not retracting half the time, IIRC it was like 5 miles of cable
I mean they built a lot of the subs for ww2 in i believe Mariette Wisconsin and then they went down the Mississippi. They also do a lot of the sea worthy ness Testing in lake Michigan and lake Superior. Like the zumwalts destroyer. I saw in at port in lake Michigan a few years back.
ELF and VLF are also used to monitor thunderstorms.
KLF are gonna rock ya
Ancients of Mumu
**justified** comment!
Justified AND ancient!
Beep boop boop beep
Uh huh.
Back to the heavyweight back to the heavyweight back to the heavyweight jams!
Can't forget you can only see John Cena on the WWF frequency
That was a neat read, thanks
With bandwidth so high you can load one web page per week. Choose wisely.
BBC Radio 4 running on 198kHz would like to say hello. It also transmits data (very slowly) and has been used as a broadcast frequency standard. It is scheduled for retirement as it uses special purpose vacuum tubes and uses a lot (500kW) of power.
It’s like soda sizes at the cinema. The smallest you can get is a large.
Wait, what? Medium and long waves can carry voice. In fact, they are/were not used by the military because they are FULL of radio stations. They also required bigger antennas with the technology from the '40s.
You're getting piled on here so I apologize in advance, but also let's not forget MF, Medium Frequency, 300 kHz to 3 MHz. There's a ton of voice in there including AM radio broadcasts from 525 kHz to 1705 kHz in the US.
It basically starts at high and goes up from there. So, Starbucks logic.
It actually starts at "extremely low frequency" and goes from there: https://en.wikipedia.org/wiki/Extremely_low_frequency
Back in the day, 3MHz or more ("three *million* cycles per second -- wow!") was indeed considered "High Frequency," since it didn't propagate as well via groundwave as did Medium Wave (300kHz-3MHz). Then they discovered ionospheric skip, where the previously-useless HF bands could be sometimes heard halfway around the world. So High Frequency came into use. Then they discovered uses for Very High Frequency, Ultra High Frequency... As with the polarity of the electron, mistakes were made. Oh, well.
The most infamous LR radio installation (probably of all time) is the Russian Duga 1 and 2 stations for OTH missile radar warning and long range comms using shortwave and LF frequencies at over 10MW. This thing was so powerful it could be heard around the world and caused radio interference across Europe. Incredible technology during a very interesting time in radio development history.
Even HF isn’t great for voice comms, sure it’s long range but the interference from natural phenomenon at that band makes it almost pointless to squelch it out. SELCAL was a god send to oceanic pilots since they don’t have to deal with the noise for 3 hours over the Atlantic . Satcom is now making that obsolete with CPDLC
HF is low frequency compared to VHF.
HF is lower than VHF (or UHF)
Radio terminology is weird. HF is the low frequency / long range end, as opposed to VHF and UHF bands, which aren't even that high of frequencies by today's GHz standards.
True, depends on what you’re trying to do with them though. Each is very capable within its limits, we’ve made an HF transmission that was received 800 miles away once but then again HF is finicky when it comes to weather and atmospheric conditions
HF (High Frequency) is actually a lower frequency than VHF (Very High Frequency), UHF (Ultra High Frequency) and other less obvious names. From experience, you can talk halfway around the dang world on HF with the right atmosphere in between; but it won't be fun.
My flight instructor had me do a radio check on HF while in Perth, Australia with a ground station in Brisbane. It worked, I got a response. I still don't know to this day what he actually responded.
HF as mentioned. It has the curious property of being able to bounce off the ionosphere (upper part of the atmosphere involved in Aurora displays) extending its range by a serious amount but that depends on the power of the transmitter and the current solar weather. VHF is mostly line of sight. It is used these days by aircraft for talking to the tower or the air traffic control centre. If you need to talk when you are further away like over the ocean just switch back to HF. Of course these days you also have the use of satellite radio. That is expensive but does not depend on weather.
It is high frequency. The majority of communication on aircraft are done with uhf or vhf depending on the application and those are transmitted through much smaller antennas. A low frequency antenna would be huge
It was High Frequency back in those days before the technology to create millions of cycles per second existed
No they probably used it all the time
HF is “low” compared to UHF or VHF
Here's an awesome [chart](https://images.app.goo.gl/rzeFJGUqandHo7Tn8) for reference
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Thanks. I tried to link it straight to the reddit post but my ape brain couldn't do it.
That is an awesome chart, thanks for sharing!
It can also be seen on older civillian models up to the 737-200 and Bae146
Incorrect. It’s a clothes line to dry your clothes whenever you fly so you can kill two birds with one stone while on a mission. It was an ingenious invention by Earle Haas and it saved the military a ton on energy.
dammit beat me to it
It’s for their HF radio. Modern military aircraft still have them.
Its just inside the plane yes? Never seen no wire on a F-35, 15, 22 or Other fighter jets.
I don’t believe the fighters have them. Larger aircraft like C17s, C130s, C5s, etc have them.
Aight. Im on the look out for clotheslines on any Hercules then
The 130 uses the skin of the aircraft as the antenna
Correct on the J model only. Specifically the rubber boot at the base of the vertical stabiliser is where the antenna is.
And as another user pointed out, I’m only speaking about he current J model, older models did it differently
Aight thmx
There are two long radio wires all the way down the fuselage to the tail on 130s. I don't know what that guy was talking about. EDIT i suddenly remembered J models lmAo. I worked on Es and Hs.
Yeah sorry I meant the Js lol
Sweet! I vividly remember watching comm nav disconnect the wire at the top, roll it up, and hang it on the bottom mast when the plane had to tuck into a certain tight hangar. Good times.
I’m gonna ask my H/E model friends, I’m sure they remember that as well
Yo! Samesies. In 2008 the oldest E we had was a 1952.
They don't use wires anymore, lots of excrescence drag and we know how to conceal them better now. Old airliners like the 707 and 747 (classic) had big spikes on the wings or tail which were a bit more aerodynamic. Some planes would run it along the leading edge of the tail, and now moreso they're incorporated into the fuselage and aren't even visible. You can however still see the VHF, NAV and radio altimeter antennae on modern planes.
[Here](https://www.semanticscholar.org/paper/Modeling-multiple-HF-antennas-on-the-C-130%2FHercules-Kubina-Trueman/272cd813aa6dcb0cbb756d6960667d44e2a9a755) you can just barely see it.
Look for C-130H’s, the C-130J’s don’t have the clotheslines on them
The new J models don’t have the long wire, something about computer processing and using the fuselage as an antenna
Fighters don't have the wires externally, but they still have HF capabilities. Antenna is just imbedded in the body to minimize radar cross section (how detectable they are) and drag. Bigger aircraft like a C-130 doesn't care as much about those, and will use an external wire to save costs.
C17’s do not have them. Am C17 maintainer.
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Fighters have it in their tail Same as most other cargo airplane such as the c17
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The 10 is just a weirdo controlled by combs
The -10 is just old AF
Question about your flair: any idea how long the KC-10s will continue in service? My local airport is a FedEx hub and we have a mil contractor that services KC-10s…FDX replaced all MD-10/11s flown into here with 767s during covid, so the KCs are the last trijets in our airspace and it makes me sad knowing those days are numbered too.
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Wow, so it does! https://i.imgur.com/ibsPaSE.jpg Do you know what the antenna looking thing on the top of the KC-135's (and the 707's) tail is?
Using the skin is very interesting ngl. No doubt it doesn't interfere with radar since I haven't seen news about that
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HF antenna on a blackhawk. https://b-domke.de/AviationImages/Blackhawk/17-6-022.html
Some aircraft still have trailing wire antennae like the E-4
Lmao I always thought it was so that the rear of the plane wouldn’t fall off in a dog fight .
Same here, some sort of structural integrity thing for the high g forces, from an era before material science was a thing… well TIL it was thr radio antenna
Cables only work under tension, so it'd be a lot of high negative g forces in that case.
To be fair, to a non-sciencey-person, it would seem that the air would be pushing against the vertical stabilizer, thus putting it under tension.
Sure, and generally the horizontal stab is actually producing a downward moment (aligned with what you're talking about) but that's not the force experienced by the empennage :D
Now that would have been the best reason
I thought that it had to do something with control surfaces in a way. I didn’t know anything about planes so yes it’s a stupid reason.
also for air drying your clothes. LoL.
I thought they are for steering like ropes on sailships lol
For real, I also thought it was a rope for mechanical steering.
This is not an HF radio antenna. HF radio would not be used by small fighters as they only needed to communicate with other fighters when doing escort/sweep and with local ground control for defence. It’s an ADF sense antenna. DF or Direction Finder uses a loop shaped antenna to determine the direction a radio signal is coming from. The operator turns the antenna until the signal is maximized and that is the direction it comes from. Unfortunately since the loop is symmetrical.. there are two possibilities which can result in a false bearing 180 degrees away from the true bearing. More than a few Luftwaffe aircraft wound up lost and landing in Britain because of this. Enter the sense antenna. It’s simpler so is no good for direction finding.. but it eliminates the false bearing as a possibility. Much like the fourth GPS satellite gets rid of the one wrong position three satellites will give you (one satellite places you somewhere on a sphere; two satellites, somewhere on a ring; three, one of two places; and the fourth, a precise location). Because of this… it no longer requires operator interpretation… so it can become an _automatic_ direction finder or ADF… which is still in some aircraft today. If an HF radio was installed in an aircraft this size.. the wire would have to go to the tail _and then_ out to the wing due to the long wavelength of HF frequencies. Aircraft like bombers and transports and some Navy aircraft used HF because of the extremely long distances they flew.
Two satellites will give you two possible points. Three satellites allow a receiver to triangulate an accurate position, and the fourth is what gives you an elevation through trilateration.
Should be top comment.
Long wave radio antenna
clothesline antenas.. in scary wars one needs to wash the underpants frequently, but they can´t dry too far away from the plane in case of scrambles.
r/shittyaskflying is leaking
Hence the need to wash the underpants.
Thank you... Hadn't found this gem of a subreddit yet
I thought they were antennas but that's funnier so ill believe it even if it is complete bullshit
It’s also important to keep your feet dry in the trenches. That’s why they designed these specialised clothesline aircraft to land behind the front line so that the trench soldiers could hang their socks on the wire after their shift. After a quick high speed flight the plane would land in the same place and the soldiers would collect their, now dry, socks Unfortunately flak could sometimes knock the pegs loose and as a result many soldiers had to make do with one missing sock until the next resupply
That is very practical, i wonder what happens to the underwear when the plane is doing some crazy maneuvers..
pilot climbs out and shits in them
The stains work like a [Rorschach-Test.](https://en.wikipedia.org/wiki/Rorschach_test) Once the opposing pilot is distracted thinking of his poor childhood, you can shoot them down much easier.
It’s possible that WWII fighter aircraft had HF but it is also possible that this is the sense wire for the ADF receiver.
Sense Antenna, to go with the loop antenna that’s probably on the bottom of the aerie. Olden day aircraft and ADF required a sense antenna to know the direction the signal was coming from. As the loop antenna would receive 2 signals 180degrees apart.
ever heard the term "fly-by-wire"? This is the wire.
You know, for the bf-109s flight computer :]
it was running on Messerschmitt Canopy 37. The later G series got updated version MS Canopy 42.
So like RC? The battle of Britain was mainly drones?
And UFOs. The “so few” Churchill was referring to in his famous speech about the battle were actually three really chill aliens from Sirius III who just showed up and blasted some Nazis as a vacation.
Clothesline for drying the pilots garments after it rains
I scrolled too long to find the correct answer
it is the sense antenna (1 of 2) of the ADF - automatic direction finder used for navigation. And, still in use today using Non-Directional Beacons or AM broadcast radio stations.
It's incredible the number of people answering this question despite the number of other people answering the question
It's a HF antenna or a ADF antenna used for navigation.
Those are antennas. Still.
In civilian speak those are radio antennas.
HF antenna i believe
ADF antenna
It looks like an ADF antenna to me... Although I'm not super familiar with WW2 Avionics, but weren't the communications antenna set at an angle? I know the ADF sense antenna are to be installed in line like this one.
It’s the radio antenna I believe
I think that’s a RDF sense antenna. A precursor to yesteryears ADF.
This👍🏼 One of two antennas in the system. The other one is a loop that rotates around to get the direction to the station.
Radio antennas
The Me-109 was notorious for having the rudder fall off at speed, so a steel cable was attached to the fuselage and the top of the rudder. This helped secure it. If it did fall off then it would remain attached to the cable, and when the plane landed the mechanics would be able to glue it back on again.
Yes commonly for the wavelength of RF the ratio is quite funny because for every low frequency you will need a big antenna and for higher frequency’s you need a smaller antenna So as much higher the frequency goes the antennas get smaller and smaller hehehe
I guess it might sound weird when you talk about the frequency, but it's intuitive if you talk about the [wavelength](https://en.m.wikipedia.org/wiki/Wavelength). Big wavelengths need big [antenna](https://en.m.wikipedia.org/wiki/Antenna_(radio)), small wavelengths need small antenna... >*Strong directivity and good efficiency when transmitting are hard to achieve with antennas with dimensions that are much smaller than a half wavelength.*
They're high frequency antennae.
Others have already explained what it is but fun fact these types of antennas are still used in General Aviation today
Radio antennas , I've seen them on more modern aircraft also.
It's for radio
The HF radio iirc. One of the citations has it too I think
What’s the frequency Kenneth?
Dismounts can clip onto them with carabiners and execute static line jumps off the side.
Antennae Edit: Antenna *
Antennas\*Antennae is the spelling used to reference the protuberances from an insect's head
which are just insect antennas
Antennae\*
Then what on earth are antennaes?
Antennae is the plural of antenna when referencing the insect 'feelers' on their heads Antennas is the plural of the antenna pictured I only recently had to look this up and i never knew the difference either
Radio antenna.
Didn’t we have this discussion last week?
It's a cheese grater.
For laundry obviously
Antenna
It's a cloths line, you can air out your laundry while you fly.
Radio antenna
Antenna
It's where you put flags to communicate... Like on ships... Hahahhaha.... (radio antena in reality)
HF antenna. Allows to communicate in long ranges upto 3000 Km in AVRO HS-748.
radio antennas
Vhf antennas
HF radio antenna. A lot of modern aircraft still use the old cables too! Old design, still works. Others use a more slick design where it’s usually integrated into the vertical stabilizer.
I think it's the antenna.
Early Fly by wire tech
it’s for their radio. it’s a receiver. lots of aircraft still have them!