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Flat Earth Theory / Re: HF Radio Signals, Propagation and DX.
« on: May 04, 2022, 02:37:46 PM »
Never did get an answer on this.
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2
Flat Earth Theory / Re: HF Radio Signals, Propagation and DX.
« on: December 24, 2019, 08:36:38 AM »In this instance though, would have made a big old differenceVery true. But my point about how incorrect it is to say the atmosphere is not transparent to radio signals still stands.
Indeed. Transparent to smaller wavelengths that can pass through it, reflective (on times) to those low enough to bounce off it.
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Flat Earth Theory / Re: HF Radio Signals, Propagation and DX.
« on: December 24, 2019, 08:35:45 AM »A good internet search will show you that the atmosphere is not transparent to radio waves.Well that all depends on the wavelength in use. If you look above, i posted a picture from the good old internet which explains it a bit.
Bouncing a signal of the ionosphere/dome will be easier than line of sight since the atmosphere is only a thin layer which decreases in density rapidly as altitude increases.
Im actually sat here now listening on 7mhz... quite a few stations coming in this evening
It will affect all wavelengths to varying degrees - higher frequecy more interference .Atmosphere hinders 7mhz signals - that's classed as a HF wave . That good old picture needs the bottom line straightening - the dome bits ok though ho ho. The sun's interference on radio signals is a good indicator of electrical interference of the local sun imo. Enjoy your listening to the signals reflecting from the dome .
Interesting. Doesn't explain it though.
If the earth was flat... my "aim at the horizon" signal would ALWAYS get there. That wouldn't hit any "dome", or "atmosphere", just direct line of sight, no?
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Flat Earth Theory / Re: HF Radio Signals, Propagation and DX.
« on: December 23, 2019, 11:24:13 AM »What's a factor of 100 between friends? That'll teach me to do arithmetic in my headA good internet search will show you that the atmosphere is not transparent to radio waves.This is not true. A better internet search will show you that the atmosphere is transparent to wavelengths from about 3cm to about 10m. Which covers a lot of radio frequencies. The OP was talking about 7mHz - that is a wavelength of around 43cm. The atmosphere is transparent to that wavelength.
Not quite.
7Mhz is approx 40meters.
Haha true
In this instance though, would have made a big old difference
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Flat Earth Theory / Re: HF Radio Signals, Propagation and DX.
« on: December 22, 2019, 09:16:56 PM »A good internet search will show you that the atmosphere is not transparent to radio waves.Well that all depends on the wavelength in use. If you look above, i posted a picture from the good old internet which explains it a bit.
Bouncing a signal of the ionosphere/dome will be easier than line of sight since the atmosphere is only a thin layer which decreases in density rapidly as altitude increases.
Im actually sat here now listening on 7mhz... quite a few stations coming in this evening
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Flat Earth Theory / Re: HF Radio Signals, Propagation and DX.
« on: December 22, 2019, 09:14:01 PM »A good internet search will show you that the atmosphere is not transparent to radio waves.This is not true. A better internet search will show you that the atmosphere is transparent to wavelengths from about 3cm to about 10m. Which covers a lot of radio frequencies. The OP was talking about 7mHz - that is a wavelength of around 43cm. The atmosphere is transparent to that wavelength.
Not quite.
7Mhz is approx 40meters.
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Flat Earth Theory / Re: HF Radio Signals, Propagation and DX.
« on: December 20, 2019, 02:21:22 PM »
Little bump, in-case anyone wants to discuss
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Flat Earth Theory / Re: HF Radio Signals, Propagation and DX.
« on: April 19, 2019, 07:01:58 AM »
Hey JCM, thanks for the reply.
So, my thoughts are :
1. I don't see why on a FE the bounce would make more sense? On a FE you wouldnt need to, you could aim your signal at the "horizon" and your away, no need for angle of attack at all.
2. Bouncing around the globe is based on the fact the layers within the atmosphere are also round, and thats where the bouncing occurs. (Read : "https://www.sws.bom.gov.au/Educational/5/2/2 ),
3. Bouncing generally only affects HF and below. Satellite signals are generally in the GHZ range and require line of sight to work. 1575.42 MHz for GPS for example. Those signals, if sent from the ground would simply penetrate straight into space.
So here's another example of how we know this happens. When working modes like FT8 on HF, i'm in the UK and my signal was being received in Australia, and Iran, all sorts. But people in Scotland cant hear me. Neither can those in London, and the signal passes directly over them (in the F or E regions of the atmosphere, not at ground level). Hence the curve
Cheers!
Kev
Edit : So here's a quick propagation report based on stations receiving my signal this morning.
Signals again received in Australia... but shot directly over everyone else?
So, my thoughts are :
1. I don't see why on a FE the bounce would make more sense? On a FE you wouldnt need to, you could aim your signal at the "horizon" and your away, no need for angle of attack at all.
2. Bouncing around the globe is based on the fact the layers within the atmosphere are also round, and thats where the bouncing occurs. (Read : "https://www.sws.bom.gov.au/Educational/5/2/2 ),
3. Bouncing generally only affects HF and below. Satellite signals are generally in the GHZ range and require line of sight to work. 1575.42 MHz for GPS for example. Those signals, if sent from the ground would simply penetrate straight into space.
So here's another example of how we know this happens. When working modes like FT8 on HF, i'm in the UK and my signal was being received in Australia, and Iran, all sorts. But people in Scotland cant hear me. Neither can those in London, and the signal passes directly over them (in the F or E regions of the atmosphere, not at ground level). Hence the curve
Cheers!
Kev
Edit : So here's a quick propagation report based on stations receiving my signal this morning.
Signals again received in Australia... but shot directly over everyone else?
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Flat Earth Theory / Re: HF Radio Signals, Propagation and DX.
« on: April 17, 2019, 08:44:18 AM »
Did a bit more FT8 last night, chasing the shadow (certain bands work better in the evening)... still hard to think how this would happen in the FE world.
Some good contacts from the UK down to Australia, Portugal, all on low power
Some good contacts from the UK down to Australia, Portugal, all on low power
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Flat Earth Theory / HF Radio Signals, Propagation and DX.
« on: April 15, 2019, 11:16:21 AM »
Morning all
Have had a few spare hours this weekend so have been performing some HF Radio experiments, mostly looking at time of day propagation however this lead me into thinking... How would the FE guys explain what i'm seeing here. In the RE model its pretty straight forward.
So to set the picture, 7.074mhz is the frequency in use, using a mode called FT8. What FT8 is, in a nutshell, is a Data mode where radio transceivers controlled by PC's (doesnt need to be connected to the internet) exchange information back and forth, signal strength, location, etc. This can then be seen using a website called PSK Reporter (https://pskreporter.info).
So anyway, the question. At the moment, the HF "bands" are pretty flat, meaning comms are difficult due to the sun spot cycle. We are at flat bottom at the moment, causing Ionospheric "lulls" (Can read about it here : https://www.electronics-notes.com/articles/antennas-propagation/ionospheric/hf-propagation-basics.php if interested). What this means is, to best of my understanding, the ionosphere isn't reflecting HF frequencies well.
So - my observations. Using FT8 this weekend I can see my signal being picked up, mostly around Europe. Nothing local, nothing much further. I can put this down to the fact that, as the earth is a globe, my signal cannot "bend" and relies on reflection back down to earth. If the earth was indeed flat, I would not require any bouncing of signals as such? The only thing in the way would be mountains, buildings etc but being on a high ASL myself, this would help. But what REALLY adds the heat to the fire with this one, is all of a sudden, boom, i can be heard in the states, Russia, Antarctica, etc due to changes in the atmosphere. And then... as quickly as it comes,,, it goes.
Anyone else have any thoughts or experiences themselves? Happy to go further into FT8 if anyone is interested, or provide some times / my callsign for anyone wanting to see how the propagation works on PSK Reporter.
Kev
Have had a few spare hours this weekend so have been performing some HF Radio experiments, mostly looking at time of day propagation however this lead me into thinking... How would the FE guys explain what i'm seeing here. In the RE model its pretty straight forward.
So to set the picture, 7.074mhz is the frequency in use, using a mode called FT8. What FT8 is, in a nutshell, is a Data mode where radio transceivers controlled by PC's (doesnt need to be connected to the internet) exchange information back and forth, signal strength, location, etc. This can then be seen using a website called PSK Reporter (https://pskreporter.info).
So anyway, the question. At the moment, the HF "bands" are pretty flat, meaning comms are difficult due to the sun spot cycle. We are at flat bottom at the moment, causing Ionospheric "lulls" (Can read about it here : https://www.electronics-notes.com/articles/antennas-propagation/ionospheric/hf-propagation-basics.php if interested). What this means is, to best of my understanding, the ionosphere isn't reflecting HF frequencies well.
So - my observations. Using FT8 this weekend I can see my signal being picked up, mostly around Europe. Nothing local, nothing much further. I can put this down to the fact that, as the earth is a globe, my signal cannot "bend" and relies on reflection back down to earth. If the earth was indeed flat, I would not require any bouncing of signals as such? The only thing in the way would be mountains, buildings etc but being on a high ASL myself, this would help. But what REALLY adds the heat to the fire with this one, is all of a sudden, boom, i can be heard in the states, Russia, Antarctica, etc due to changes in the atmosphere. And then... as quickly as it comes,,, it goes.
Anyone else have any thoughts or experiences themselves? Happy to go further into FT8 if anyone is interested, or provide some times / my callsign for anyone wanting to see how the propagation works on PSK Reporter.
Kev
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Flat Earth Theory / Re: Observation of the ISS
« on: April 19, 2018, 12:39:51 PM »
So ill add my 2p in here. Im a licenced Amateur radio operator (not that you even need to be to do this but it helps) and quite often follow what the ISS guys are doing.
For those of you interested, the Downlink frequency is 145.800MHz FM.
If you can tune into that frequency, you can often either hear the astronauts speaking down to earth (they run scheduled sessions with schools and the like) or receive some SSTV if they are broadcasting that.
Its simple enough to do, seen as it uses VHF frequencies and there obviously is nothing in the way when they are overhead but you do get doppler effect as they are going super speed... and also they are only contactable for a few mins until they fly over the horizon.
Here's a bit of SSTV i received from them this week : https://www.instagram.com/p/BhfU4_ahfjXB5RaOiWjrz8smffJXiKwhvRmmhs0/?taken-by=kevamiga
Its not perfect but its OK. I think its 9600 baud so that image takes around 50 seconds to be transmitted, so given you only have a few minutes the timing needs to be spot on.
Im not sure how anyone could really suggest that :
a. The ISS isn't circling a globe seen as literally people around the globe sent reports of it which are timed
b. If the earth was flat, and there was an ISS up there but it was all fakery and the like, a VHF signal would not disappear over the horizon. Granted it could be faked using directional antennas and the like but why? That would take massive amounts of effort to co-ordinate and i mean, NASA would just not allow it right?
c. If it was space junk or whatever... it can communicate 2-way with schools hahaha
Pretty simple stuff really.
For those of you interested, the Downlink frequency is 145.800MHz FM.
If you can tune into that frequency, you can often either hear the astronauts speaking down to earth (they run scheduled sessions with schools and the like) or receive some SSTV if they are broadcasting that.
Its simple enough to do, seen as it uses VHF frequencies and there obviously is nothing in the way when they are overhead but you do get doppler effect as they are going super speed... and also they are only contactable for a few mins until they fly over the horizon.
Here's a bit of SSTV i received from them this week : https://www.instagram.com/p/BhfU4_ahfjXB5RaOiWjrz8smffJXiKwhvRmmhs0/?taken-by=kevamiga
Its not perfect but its OK. I think its 9600 baud so that image takes around 50 seconds to be transmitted, so given you only have a few minutes the timing needs to be spot on.
Im not sure how anyone could really suggest that :
a. The ISS isn't circling a globe seen as literally people around the globe sent reports of it which are timed
b. If the earth was flat, and there was an ISS up there but it was all fakery and the like, a VHF signal would not disappear over the horizon. Granted it could be faked using directional antennas and the like but why? That would take massive amounts of effort to co-ordinate and i mean, NASA would just not allow it right?
c. If it was space junk or whatever... it can communicate 2-way with schools hahaha
Pretty simple stuff really.
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Flat Earth Theory / Re: Why doesn't satellite radio work between buildings?
« on: March 17, 2018, 08:42:08 PM »
Doesn't work because;
a. The signal is generally of a very high frequency. "Mobile phones operate at 800–900 and 1700–2100 MHz. Iridium Communications satellite phones use frequencies between 1616 and 1626.5 MHz to communicate with the satellites." Higher the frequency, the more line of sight it becomes, same with HF vs UHF/VHF. AM radio is MW, even lower than HF, and AM/FM is the lower portion of VHF radio.
b. The signal is coming from above, a Satellite.
But - you already knew that
a. The signal is generally of a very high frequency. "Mobile phones operate at 800–900 and 1700–2100 MHz. Iridium Communications satellite phones use frequencies between 1616 and 1626.5 MHz to communicate with the satellites." Higher the frequency, the more line of sight it becomes, same with HF vs UHF/VHF. AM radio is MW, even lower than HF, and AM/FM is the lower portion of VHF radio.
b. The signal is coming from above, a Satellite.
But - you already knew that
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Flat Earth Theory / Re: Why?
« on: March 17, 2018, 08:36:19 PM »
"Why would the world keep it a secret"
"They" couldn't even if they wanted to. There would be no point, financially or otherwise to make something like FE up.. its just a small group of people who are arguing the point.
I cant help thinking that, there's someone who started this whole FE thing who is now laughing at all of this, OR everyone who uses their eyes, sees the RE and post's here is being laughed at by the FE gang... one or the other is true, i'm just trying to figure out which
"They" couldn't even if they wanted to. There would be no point, financially or otherwise to make something like FE up.. its just a small group of people who are arguing the point.
I cant help thinking that, there's someone who started this whole FE thing who is now laughing at all of this, OR everyone who uses their eyes, sees the RE and post's here is being laughed at by the FE gang... one or the other is true, i'm just trying to figure out which
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Flat Earth Theory / Re: Hey Flat Earthers, Just wondering...
« on: March 02, 2018, 10:49:17 AM »
I guess it would be nice to give this a go.
http://www.antarcticaflights.com.au/
One day, ill win the lotto. Then offer to pay for some FE chaps to come with me on a flight, and put an end to this nonsense
http://www.antarcticaflights.com.au/
One day, ill win the lotto. Then offer to pay for some FE chaps to come with me on a flight, and put an end to this nonsense
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Flat Earth Theory / Re: Why is earth special?
« on: December 19, 2017, 05:29:55 PM »
I can maybe help
Which gets me to my next question, why is earth special? Why are other planets -or basicly every other object in the universe- spherical, but earth isn't? - It isn't, its a planet like any other, round, just so happens to have an atmosphere that supports life. Pretty lucky that!
3),How long are the "ice walls" that keep the water on earth? And why has no one ever reached the very end of them? - Simple answer, they don't exist.
Im sure someone will come and (try to) prove me wrong pretty quickly
Hope that helps!
Which gets me to my next question, why is earth special? Why are other planets -or basicly every other object in the universe- spherical, but earth isn't? - It isn't, its a planet like any other, round, just so happens to have an atmosphere that supports life. Pretty lucky that!
3),How long are the "ice walls" that keep the water on earth? And why has no one ever reached the very end of them? - Simple answer, they don't exist.
Im sure someone will come and (try to) prove me wrong pretty quickly
Hope that helps!
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Flat Earth Theory / Re: AM/FM Radio
« on: December 13, 2017, 05:45:30 PM »
Im glad we agree on one thing in that statement haha
Quote : Since you have no experience with radio comms in aircraft, then I guess you didn’t know that our equipment CAN NOT be switched from AM to FM or vice versa.
I never said that, you said : If the AM station sends an AM signal only, then there is no way for me to receive it with VHF equipment.
You can get VHF equipment that does AM, FM, USB, LSB, CW modes. Not in aircraft, no, im aware of the AM VHF Airband allocation.
Quote "None of this has anything to do with why the signals are blocked at much closer distances from the transmitter while on the ground vs in the air. "
It does, but i get what you mean.
Im glad we both agree we live on a round ball.
Quote : Since you have no experience with radio comms in aircraft, then I guess you didn’t know that our equipment CAN NOT be switched from AM to FM or vice versa.
I never said that, you said : If the AM station sends an AM signal only, then there is no way for me to receive it with VHF equipment.
You can get VHF equipment that does AM, FM, USB, LSB, CW modes. Not in aircraft, no, im aware of the AM VHF Airband allocation.
Quote "None of this has anything to do with why the signals are blocked at much closer distances from the transmitter while on the ground vs in the air. "
It does, but i get what you mean.
Im glad we both agree we live on a round ball.
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Flat Earth Theory / Re: AM/FM Radio
« on: December 12, 2017, 11:25:55 PM »
Ok so :
If the AM station sends an AM signal only, then there is no way for me to receive it with VHF equipment.
False.
Also your statement is riddled with errors, you need to read up a bit more about modulation types vs frequency.
I have no experience with radio comms from aircraft, but sure listening from ground based stations is just the reverse.
If you like, I’ll post a video of my uhf / vhf radio receiving in AM modulation mode, if that helps.
If the AM station sends an AM signal only, then there is no way for me to receive it with VHF equipment.
False.
Also your statement is riddled with errors, you need to read up a bit more about modulation types vs frequency.
I have no experience with radio comms from aircraft, but sure listening from ground based stations is just the reverse.
If you like, I’ll post a video of my uhf / vhf radio receiving in AM modulation mode, if that helps.
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Flat Earth Theory / Re: AM/FM Radio
« on: December 12, 2017, 06:47:42 PM »
Also, my aircraft can not dictate what type of signal the radio station sends.
Yes it can. All radio receivers have a detection stage. Your radio in the aircraft prob doesn’t have a switchable detection phase so will be AM only. This is why we have band plans. Pilots prob wouldn’t appreciate someone transmitting using SSB on their frequencies. Could be a disaster.
Yes it can. All radio receivers have a detection stage. Your radio in the aircraft prob doesn’t have a switchable detection phase so will be AM only. This is why we have band plans. Pilots prob wouldn’t appreciate someone transmitting using SSB on their frequencies. Could be a disaster.
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Flat Earth Theory / Re: AM/FM Radio
« on: December 12, 2017, 06:45:46 PM »
Ah sorry, yes I meant vhf not uhf, (frequency will be close though).
So, AM isn’t a band. AM is a modulation type. Your AM radio is probs using MF band, so less than 1mhz. 100 or so times bigger wavelength than your aircraft radio.
Don’t confuse band with modulation type. That’s why it travels so far, and isn’t affected by buildings and walls. Trust me, do the same with a 70cm signal and literally a wall can wipe it out. PMR radios are a good example.
So, AM isn’t a band. AM is a modulation type. Your AM radio is probs using MF band, so less than 1mhz. 100 or so times bigger wavelength than your aircraft radio.
Don’t confuse band with modulation type. That’s why it travels so far, and isn’t affected by buildings and walls. Trust me, do the same with a 70cm signal and literally a wall can wipe it out. PMR radios are a good example.
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Flat Earth Theory / Re: please explain this flight from sydney to johannesburg
« on: December 12, 2017, 04:08:55 PM »Why do travelers not see Asia (or stop there) in this flight from Sydney to Johannesburg. And is able to make this in one flight, even though the plane was not designed to make a flight like this on a flat earth.
here is the link to the direct flight: https://fly10.emirates.com/CAB/IBE/SearchAvailability.aspx?gclid=CjwKCAiA9rjRBRAeEiwA2SV4ZfSXltEF1Z-SiT1lBW-ESOcMEuL-A7ZwUNNi9NQwrspyb2pHqw4jhBoCuCcQAvD_BwE&gclsrc=aw.ds
On the flat earth: https://www.metabunk.org/attachments/flat-earth-sydney-to-johannesburg-jpg.15089/
On the round earth: https://www.metabunk.org/data/MetaMirrorCache/contrailscience.com_skitch_Google_Earth_20111211_141946.jpg
BTW: If you're going to argue that I haven't been on this flight so I don't know what I'm talking about, then have you seen the ice wall supposedly surrounding the earth?
Think you may have answered that question yourself