Radio question

[AsheForeth]

I have a plot idea set in some sort of radio or other electronic installation, maybe for rebroadcasting, in a remote location. Is it at all plausible that there might be some sort of a rebroadcasting or relay station: 1. In a very remote location and 2. Having a minimal human staff? Thank you.

 

[alohadave]

I have a plot idea set in some sort of radio or other electronic installation, maybe for rebroadcasting, in a remote location. Is it at all plausible that there might be some sort of a rebroadcasting or relay station: 1. In a very remote location and 2. Having a minimal human staff? Thank you.

Radio relay stations are often located in remote areas to amplify and rebroadcast radio signals. They are typically unmanned, and computer controlled these days, but you could have a manned station if it works for your plot.

 

[Writer61]

Yes
Especially in fiction

 

[TheLobster]

In this day and age, with ubiquitous satellite coverage, it seems unlikely. But even decades ago you didn’t need a dense network of radio transmitters to achieve acceptable coverage. A single mast can literally cover an entire continent; there was one near Warsaw, that collapsed in early 90s, that could transmit radio waves all the way across the Atlantic.

However, this doesn’t mean the idea wouldn’t work in fiction, since most readers would be unlikely to know technical details about radio wave propagation, and a remote station sounds just plausible enough to be accepted.

 

[KittyOfSteele]

Yes, and it has been done in real life before. In fact, pirate radios were pretty much the podcasts of an era where there was no way to listen to a podcast, and some pirate radios are just one person. The reach of those stations varied.

Mechanics of radio are hazy at this moment, but it all depends on the waves. Radio signals operate through two modulations: frequency, and amplitude. That's where you get those nice FM and AM. Like AC and DC, both are quite different, but remembering from what the radio people told me, AM signals go up and down, so they have far more reach than FM signals, which can be interrupted by a building or a mountain. I don't think that's how it actually works, but AM signals can reach for an entire country, whereas FM signals are more localized in either small communities, cities, or even states or provinces. FM radios can reach an entire country, however, the radios that I've seen that are one station operate almost under a franchise model, where their frequency changes depending on the location, but their schedule is the same.

Don't quote me on this; do your own research. But, in short, yes, it has been done in real life, and I do have a character in my universe who operates a pirate radio station that broadcasts to at least five cities.

 

[ElectricBlue]

I have a plot idea set in some sort of radio or other electronic installation, maybe for rebroadcasting, in a remote location. Is it at all plausible that there might be some sort of a rebroadcasting or relay station: 1. In a very remote location and

Yes

2. Having a minimal human staff? Thank you.

and Yes.

Especially in a large and underpopulated country, like Australia, there are many transmission stations, these days mostly automated. At the back end of nowhere: ideal for an alien invasion, disposal of the bodies, or illicit sex.

 

[AsheForeth]

Thank you, all. VMA!

 

[Britva415]

I have a plot idea set in some sort of radio or other electronic installation, maybe for rebroadcasting, in a remote location. Is it at all plausible that there might be some sort of a rebroadcasting or relay station: 1. In a very remote location and 2. Having a minimal human staff? Thank you.

Follow the money.

What is the nature and purpose of the radio signal? Is it a commercial broadcast? Amateur? A military one? Are there any people in this remote location to receive the rebroadcast? Are there enough of them for it to be financially or pragmatically worth it to the broadcaster to invest in rebroadcasting to them?

As long as you can justify the existence of it, you can justify the unmanned automation of it.

It's more likely that it would have no human staff rather than minimal human staff. Again, depending on what kind, why it's there, who funds it, etc.

 

[AsheForeth]

Yes

and Yes.

Especially in a large and underpopulated country, like Australia, there are many transmission stations, these days mostly automated. At the back end of nowhere: ideal for an alien invasion, disposal of the bodies, or illicit sex.

'Transmission stations' - as in the electrical grid? That might work.

 

[KittyOfSteele]

At the back end of nowhere: ideal for an alien invasion, disposal of the bodies, or illicit sex.

By experience I can confirm this. Two ways of communications are king whenever all mass comm systems fail: radio, and pigeons.

 

[ElectricBlue]

'Transmission stations' - as in the electrical grid? That might work.

Transmission stations for radio, is what I meant - we talk about transmitter or transmission towers. Here in Oz, for the power grid, we'd typically refer to sub-stations.

 

[MrPixel]

A popular (technical) format for broadcast radio and TV in isolated locations are what is known as "transponders". They simply transmit the content received on the "main" broadcast frequency and repeat the content on a different frequency. They are are typically unstaffed.

I used to be in a related business. Staffed transponders would be very unusual. It would have to be a location where access would be too difficult for normal maintenance and be a critical need to service the distant population. As highlighted above, satellite service has more or less replaced transponders, but I'm sure there are a few around where leasing a satellite subchannel might be too expensive to justify for the broadcaster.

 

[ronde]

In this day and age, with ubiquitous satellite coverage, it seems unlikely. But even decades ago you didn’t need a dense network of radio transmitters to achieve acceptable coverage. A single mast can literally cover an entire continent; there was one near Warsaw, that collapsed in early 90s, that could transmit radio waves all the way across the Atlantic.

However, this doesn’t mean the idea wouldn’t work in fiction, since most readers would be unlikely to know technical details about radio wave propagation, and a remote station sounds just plausible enough to be accepted.

The need for a repeater is determined by the type of broadcast. Amplitude modulated (AM) radio signals follow the curve of the earth and have a maximum range of about 75 miles. You'd need a repeater station to reach farther than that. The signal can also be masked by mountains or lost in deep valleys, and there used to be repeater stations to improve reception.

Frequency modulated radio signals (FM) only need one antenna because the signals will bounce off the ionosphere. The ionosphere acts like a repeater station. That's how Ham radio operators are able to talk to operators on the other side of the globe using only one antenna.

 

[MrPixel]

The need for a repeater is determined by the type of broadcast. Amplitude modulated (AM) radio signals follow the curve of the earth and have a maximum range of about 75 miles. You'd need a repeater station to reach farther than that. The signal can also be masked by mountains or lost in deep valleys, and there used to be repeater stations to improve reception.

Frequency modulated radio signals (FM) only need one antenna because the signals will bounce off the ionosphere. The ionosphere acts like a repeater station. That's how Ham radio operators are able to talk to operators on the other side of the globe using only one antenna.

Uh... no. Been a ham for 35 years, and was in the 2-way radio business before that.

"Propagation" is what you describe, and how that propagation occurs is dependent on frequency, not the broadcast mode. It just happens that AM and SSB (single sideband) are predominate at lower frequencies (<50 MHz) and FM is the most popular mode above, aircraft communications between 108 and 118 MHz a notable exception, with AM.

Since the OP is asking about broadcast radio, transponders are FM, in the US from 87-108 MHz. TV transponders exist or existed; I've been too far away from the business for too long to know if the transition from the analog mixed-mode FM/SSB to digital brought transponders along with them. Ionospheric propagation is an exotic conditional mode and is not going to be used for broadcast; any such propagation of a broadcast signal is going to be dumb luck.

 

[Duleigh]

The need for a repeater is determined by the type of broadcast. Amplitude modulated (AM) radio signals follow the curve of the earth and have a maximum range of about 75 miles. You'd need a repeater station to reach farther than that. The signal can also be masked by mountains or lost in deep valleys, and there used to be repeater stations to improve reception.

Frequency modulated radio signals (FM) only need one antenna because the signals will bounce off the ionosphere. The ionosphere acts like a repeater station. That's how Ham radio operators are able to talk to operators on the other side of the globe using only one antenna.

I've been a licensed radio operator since 1994, my first call sign was HL9LVT operating in Gunson Korea. I was operating with AGA8KU transmitting telephone calls via AM radio on 6.996 Mhz AM through a 13-element Log Periodic antenna on an 85-foot mast pointing NNE to take the great circle route to AFC6RI in San Diego. That's quite a haul but it was AM at 1kilowatt, we estimate it bounced off the E layer of the Ionosphere about 5 times to reach across "the pond." We also reached the Space Shuttle that same year on 146.520 Mhz at 50 watts, FM straight up on a vertically polarized mobile mag mount antenna using the officer's dormatory as the ground plane.

Mr. Pixel is right, you got everything backwards. It's AM that bounces (or follows a ground wave) FM VHF and UHF burns right through all levels of the atmosphere and has repeaters everywhere. The entire state of Florida is wired together on SARnet, a statewide series of linked repeaters intended for use in emergencies. I can sit in Jacksonville and chat with Miami and Pensacola using a low power handheld FM radio.

Don't get me started on DMR

 

[Britva415]

the OP is asking about broadcast radio

If what you mean is "FM commercial broadcast radio," I'm not sure that's clear at all. I asked, and they haven't clarified.

Is there something technical about the word "broadcast" that limits it to the sense you referred to? It did seem like you were presuming the FM commercial band.

 

[ronde]

I've been a licensed radio operator since 1994, my first call sign was HL9LVT operating in Gunson Korea. I was operating with AGA8KU transmitting telephone calls via AM radio on 6.996 Mhz AM through a 13-element Log Periodic antenna on an 85-foot mast pointing NNE to take the great circle route to AFC6RI in San Diego. That's quite a haul but it was AM at 1kilowatt, we estimate it bounced off the E layer of the Ionosphere about 5 times to reach across "the pond." We also reached the Space Shuttle that same year on 146.520 Mhz at 50 watts, FM straight up on a vertically polarized mobile mag mount antenna using the officer's dormatory as the ground plane.

Mr. Pixel is right, you got everything backwards. It's AM that bounces (or follows a ground wave) FM VHF and UHF burns right through all levels of the atmosphere and has repeaters everywhere. The entire state of Florida is wired together on SARnet, a statewide series of linked repeaters intended for use in emergencies. I can sit in Jacksonville and chat with Miami and Pensacola using a low power handheld FM radio.

Don't get me started on DMR

I stand corrected.

 

[Duleigh]

If what you mean is "FM commercial broadcast radio," I'm not sure that's clear at all. I asked, and they haven't clarified.

Is there something technical about the word "broadcast" that limits it to the sense you referred to? It did seem like you were presuming the FM commercial band.

First of all, do you know the difference between Broadcast and Transmit?

 

[Britva415]

First of all, do you know the difference between Broadcast and Transmit?

No, please do tell.

Has it got to do with directionality?

 

[Duleigh]

Broadcast and Transmit are two different licenses and two different ways of using radio. They can use the same antenna, same transmitter, the same amplifier. Broadcast means you're sending a signal to anyone who wants to listen. When you said "Commercial Broadcaster" that means someone who is licensed to send out a signal to everyone and receive pay for it. When I worked for the Military Affiliate Radio System I was transmitting, which means to send a signal to one individual station. I would call "AFC6RI this is AGA8KU with traffic." Transmitting is 1 to 1. You can call "CQ" looking for someone to talk to, but once they respond it's a 1 to 1 conversation FOR FREE. I patched a lot of phone calls over the radio, if someone came by and gave us a case of beer for patching him through to mom, we could lose our license.

Directionality is a very complex operation. Short Wave radio stations broadcasting AM on High Frequency will use antennas that generally aim toward their target audience. Antennas have lobes depending on their type, altitude, and power pumped into them. My High Frequency radio is very low powered (QRP) with a straight wire antenna that is stretched south to north. That gives me lobes that extend east to west. I can chat with Texas from Florida with no problem at 5 watts when the atmospheric conditions are right. FM on VHF is more like a laser A directional antenna will be built on a horizontal boom and have three vertical elements. The center vertical is the driven element, it's the one connected to the radio. The element behind it is the reflector which catches incoming signals and reflects them onto the driven element, and the element in front of it is the director, which directs outgoing signals. This is a very simple Yagi antenna, and to be honest, it's mostly used to direct your signal to a high-powered repeater station.

 

[Britva415]

Broadcast and Transmit are two different licenses and two different ways of using radio. They can use the same antenna, same transmitter, the same amplifier. Broadcast means you're sending a signal to anyone who wants to listen. When you said "Commercial Broadcaster" that means someone who is licensed to send out a signal to everyone and receive pay for it. When I worked for the Military Affiliate Radio System I was transmitting, which means to send a signal to one individual station. I would call "AFC6RI this is AGA8KU with traffic." Transmitting is 1 to 1. You can call "CQ" looking for someone to talk to, but once they respond it's a 1 to 1 conversation FOR FREE. I patched a lot of phone calls over the radio, if someone came by and gave us a case of beer for patching him through to mom, we could lose our license.

Directionality is a very complex operation. Short Wave radio stations broadcasting AM on High Frequency will use antennas that generally aim toward their target audience. Antennas have lobes depending on their type, altitude, and power pumped into them. My High Frequency radio is very low powered (QRP) with a straight wire antenna that is stretched south to north. That gives me lobes that extend east to west. I can chat with Texas from Florida with no problem at 5 watts when the atmospheric conditions are right. FM on VHF is more like a laser A directional antenna will be built on a horizontal boom and have three vertical elements. The center vertical is the driven element, it's the one connected to the radio. The element behind it is the reflector which catches incoming signals and reflects them onto the driven element, and the element in front of it is the director, which directs outgoing signals. This is a very simple Yagi antenna, and to be honest, it's mostly used to direct your signal to a high-powered repeater station.

I see why the distinction is important.

However: Without OP's clarification, I'm not sure they're using "broadcast" in the limited sense you are, and I'm not sure whether they had a regular old FM radio station in mind or some totally different application.

In plain language, even if an operator's intention is to transmit a message to a particular recipient, they're still broadcasting to everyone else who has the equipment to pick it up. This could be spies, the general public, other parties who are authorized if not necessarily intended to receive, etc.

I always kind of thought of "broadcast" referring to the signal but "transmit" referring to the message (the content of the signal). Thanks for the nuance.

 

[HelenL]

Since the type of installation doesn't matter, what about a radio telescope?

 

[Five_Inch_Heels]

Go in a different direction ....

An intelligence listening outpost. High tech, highly secret.

No Such Agency operates them, or used to.

Or even go SciFi like TNG's 'Who Watches The Watchers'