What would it take to bring communication down to just radio

[Bricona]

Hey I'm just wondering, there's a lot of ways people can communicate over the internet and over the phone, so what would it take so that humanity could only communicate via radio?

What places or satellites would people have to destroy? How would radio communication being the primary be possible?

[Evan the Diplomat]

Would never happen. A solar flare/EMP scenario would take down radios too. Don't forget that despite the cell phone boom, North America has heaps of landlines, so you would have to go around destroying a bunch to telephone exchanges too.

[CitizenZ]

All it would take is for the gov't to flip a switch and they can stop all commercial telecom. They can also jam the air waves, but they won't be able to jam completly everywhere. There would be large holes in large areas in certain bands that will still permit radio com across the way or around the world.

What would it take for them to do it? War. Real war.

[bonanacrom]

Power plants - that's why the government was so high alert at times. If the power stops we can't use the servers to do anything. The Northeast Blackout of 2003 cut off 45 million people in eight U.S. states. From what I remember the phone lines remained working but because everyone started using the phones they overloaded and cut circuits. Basically if all the power plants stopped all communication would stop working.

[whisk.e.rebellion]

What would it take to bring communication down to just radio

Prolonged power outage.

[bonanacrom]

Sure, cut to the quick.

[mattltm]

This is surprisingly easy on a small scale.

Most people these days no longer have a simple home phone. They have wireless ones, ones with built in answer phones and a lot of people I know don't have a home phone at all (they have a line for internet but no phone as they use their mobile). The new, all singing, all dancing home phones need power to work. They wont get a dial tone unless they are plugged it. Mobile phones need power at the base stations.

Small local power cut = no local communication.

Also worth pointing out is that most people who have radios at home run them from PSU's as I found out recently...

[Shok]

...Also worth pointing out is that most people who have radios at home run them from PSU's as I found out recently...

Most people aren't ZS either.

Shok

[ke4yqd]

A storm was all it took to drop the PSTN here in Omaha in 2007. We had a good storm, knocked down some trees, and power lines, and presto the PSTN soon followed. Not because of damage, because of congestion. For nearly 2 hours the phone system was so intermittent the police were forced to rely on their radios only, which screwed them up, as no one knew how to activate their tactical channels in their digital radios.

EMPs are an interesting thought, however I work in the communications industry and don’t think it will be as big a deal as everyone thinks. Days down at the most. I think I will have to cover EMPs and EMP hardening in a separate thread.

[Qasim]

Fiber optic cables (terrestrial and undersea- view attached link) http://www.telegeography.com/product-info/map_cable/index.php carry much more voice/data than satellites do. Cellular eventually needs to be sent over another medium (microwave, fiber, or satellite) for most calls.

Note that many countries, including the US, have multiple landing points for cable, so EMP/power outage/government interference/physical destruction would have to be widespread in order to totally cut off a country.

The telecommunications industry prides itself on reliability, so there is a lot of redundancy and resiliency built into the system.

In terms of what comms are most survivable, depends on what you are defending against. Radio can be jammed, but a PSTN line can be cut. Cell towers can run out of fuel in their back-up generators or be overwhelmed by call volume, etc.

-Q

[ke4yqd]

Here we go, EMPs... I hate to tell you this, but in large part, it's mostly a myth used to scare people...

Now I know I will be flamed for this, but guys, I’m a systems engineer for a military contract communications company. I work with this stuff. At the same time I’m an amateur radio operator to I try to keep my stuff just as safe as the next guy.

The biggest threat in the event of an EMP, is the charge that is amplified by long run, above ground cables. Power lines will most likely blow transformers, and substations, but not much else. Long runs into your house can almost be completely controlled by proper grounding and good surge protection...

Remember, the "waves" everyone worries about is the one generated at +100 miles AGL. While it is in the magnitude of 10s of millions of watts, the attenuation is still astronomical (get it, it's in space!!! haha); as the waves will have to pass on the already energized portion of the Ionosphere. At the same time it has to pass through the THICKEST LAYERS of the Ionosphere (F and E) which will cause more attenuation. Which means by the time it gets to the earth it is only at mV levels. Most of your average equipment that is stored indoors will survive. And modern EFI cars may not even be affected. Remember that for the most part, they are insulated, which means that the wave really has no place to go but across the surface of the ground plane (skin of the car).

I know everyone saw, and will quote the video from "Future Weapons". But that was a 100KV + discharge that only took effect in a short radius. This was a simulation of a ground burst; which as proven in the 40’s and 50’s, only affected electronics in a near field environment. Your biggest threat there won’t be the EMP. It will be the blast!

The threat to commercial communications will come, in large, from unprotected lines running into local switches, and distribution boxes, (the small green boxes on the corner). But even then, a good repair man could run through, find the errant circuits, and have it back up and running in estimated time = hours * number of units down in the worst case.

Your TV (hooked up to cables or outside antennas) may be in the biggest danger, as it runs for long distances, unprotected and often not sufficently or ungrounded. The wave will enter the reciever of the TV and probably spread through to ground...

Next, (sad to say) is your radio equipment. For low band antennas (we’ll say an 80m dipole) you have a run of 120 ft of wire, connected to 75 ft of coax running into the house where it connects to your very sensitive radio, and then to the ground. SO, UNHOOK THE ANTENNA WHEN YOU AREN’T USING THE RADIO. That is just good amateur practice right there.

Remember, don't stand in the shortest path!!!

[Maast]

And leave just radios? Not an (H)EMP, that'll cook most things with a chip and a few things with very small traces on the circuit boards, including radios. I have to strongly disagree with the previous poster, and yeah, I'm an engineer too: with high power military radar experience. The E1 component of a HEMP is a multiband radio pulse primarily in the 10 to 100mhz range (page 141 EMP comission report), the E3 component resembles a CME event. 10mhz full wave resonance is 98 feet, half is 49, quarter 24... etc and on down, basically anything metal will act as an antenna.

Now a CME event (super flare) that moves the Earths magnetic field lines around would do it, the field lines would induce large currents in the long telephone wires, it'd also take down the power lines but the event would happen slowly enough that most lightning arrestors and surge protectors would protect equipment, unlike a EMP which is essentially a square wave event.

So if you had a power source independent of the mains you could still broadcast.

[ke4yqd]

And leave just radios? Not an (H)EMP, that'll cook most things with a chip and a few things with very small traces on the circuit boards, including radios.

The E1 component of a HEMP is a multiband radio pulse primarily in the 10 to 100mhz range (page 141 EMP comission report), the E3 component resembles a CME event....essentially a square wave event.

Not sure why you said you would like to disagree with me. Nothing you said was in disagreement with what I said, and only one or two things disagreed with physics. Let me number it out for you.

1) At the end of my post I listed radios as some of the most vulnerable pieces of equipment. But said they are easily protected.

2) The effective radiated power decreases on the square root of the initial radiated blast by distance in waves. That's why at 7ghz you need A LOT of power to reach out 100nm to illuminate a target. So at 100MHz (easy because it's 3m long) and 100 watts; at 9m you will have 10 watts effective radiated power. At 15m (5x the distance) you will effectively have 1.2 watts on a from a 100 watt transmitter. This backs up what I said before about the attenuation of the wave being SUBSTANTIAL, agrees with physics, and agrees with your numbers Maast. I used simple numbers so anyone with a calculator can follow along. On the 10MHZ side it's the same numbers only with 10x the distance. Which is where long runs in any multiple of the harmonic of the wave can amplify the received wave, causing an increase of the received power. Like I said.

3) Most of us radio nerds like to be able to operate in the event of an emergency and keep battery arrays on chargers and generators in good condition just so we can supply our own power to our equipment. Matter of fact, my equipment doesn't directly touch any AC circuit. Batteries and maintainer in the basement...

4) At the last major CME (n Canananananada March 13, 1989) 6 million people lost electrical power for 9 or more hours. 9 hours is along line with MY time estimates of fixing things and not the end of world??? And while it may pose a problem in the VHF and above range, it's what we dream of for HF comms!!!

I think the misunderstanding is in the Maxwell Faraday principle "A changing magnetic field creates an electric field".
This is the principle that makes generators and electric guitar pickup work. Only in reverse. Instead of a moving wire in a static magnetic field, you have a magnetic field that is changing and oscillating at multiple frequencies. However the principle of near fields still applies. Move the wire away from the magnetic field and the voltage goes away. Not to 0. But a lot lower. Ground the wire and the V=0.

Here is what I will argue. Most of the worlds communications equipment is stored in boxes, made out of metal, to which the internal components are not grounded to, but carry their own ground. Seriously check out your neighborhood underground telephone wires and the boxes they use. The green square boxes on the corners of the street. It's almost like they want to protect their multi-BILLION investment in equipment. I.E. It sits in a Faraday cage. Faraday cages work by taking the wave along the SURFACE (that's where electrons flow, not through conductive metals, but on their surfaces) and passes it to ground without any inductive wave on the interior of the cage. Therefore no damage. Do these cages need be fine brass mesh? NO. A buried (underGROUND) component is just as safe. A simple ammo can will work as well. Or a metal shed. As long as the device being protected is not in contact with the surface, and has no radials protruding. Unpluged and Unhooked.

Furthermore the current communications systems employed in the US, is robust enough to to suffer minimal damages. Telephone runs that were wires going to PSTNs, are quickly being replaced with TCPIP systems running over optical fiber. And a fare portion of the remaining phone system is underground (key word for this dissertation, GROUND).

We all know power lines are floating over head. But does everyone here think there is no protection to the circuit when there is an opposing wave introduced? Transformers will pop in the event of an EMP. But do the substations not have ground fault relays (also stored in a large metal box) that cut off the instant a there is a large overload in the circuit?

I'm not saying nothing will happen. I agree that there will be significant losses in the world of technology. Probably set us back a good several months. But I think the claims of doom and gloom for every device with a IC, is about as real as global warming.

p.s. Square waves do not occur outside of circuits under any circumstance. Square waves have to be produced, and are usually associated with digital timing circuits, and RF. http://www.mathreference.com/la-xf-four,sqw.html taught me that.

Do your own math for near and far field attenuation. The numbers DO NOT ADD UP to total cataclysmic destruction. (a 100000000 watt burst = around 30 watts at 100MHz).

[TacAir]

Hhuummmm

I'll add this -

I worked for a major telecom company, we had more than one fiber optic system running from AK to Ore. All were DC powered - that is to say, power went down a long copper conductor - the full length of the cable.

Geomagnetic storms can induce a variable voltage on the system, if the voltage exceeded a very tight limit, the system shut down and the HVPS would 'ground' both ends of the system. The systems react within a very few milliseconds. The HAARP site is still monitored to provide an idea of the level of geomagnetic activity.

The Fairbanks to Anchorage power inter-tie routinely gets hit with so-called "auroral currents" (geomagnetic coupled eddy currents) on the order of magnitude measured in 100s of amps. The CB kick in and out, as designed, every little downtime.

My work included the investigation and reporting of all outages and providing Root Cause Anaylisis reports IAW FCC rules on these outages. I was also the DR manager for the company and attended the all utility / FEMA meetings covering just these things. No one in industry seemed concerned in the least. Vandalism was a much greater worry.

Could it be an issue? Maybe. But then, we could get hit with a massive space rock as well - I don't worry about either.....

[Bunsen]

2) The effective radiated power decreases on the square of the initial radiated blast in distance. A ham and a radar guy alike, should know this. That's why at 7ghz you need A LOT of power to reach out 100nm to illuminate a target. So at 100MHz (easy because it's 3m long) and 100 watts; at 9m you will have 10 watts effective radiated power. At 15m (5x the distance) you will effectively have 1.2 watts on a from a 100 watt transmitter. This backs up what I said before about the attenuation of the wave being SUBSTANTIAL, agrees with physics, and agrees with your numbers Maast. I used simple numbers so anyone with a calculator can follow along. On the 10MHZ side it's the same numbers only with 10x the distance. Which is where long runs in any multiple of the harmonic of the wave can amplify the received wave, causing an increase of the received power. Like I said.

There are a bunch of things wrong (mostly small, some big) with that post, most of which I'm not going to address just now. I'm going to take a minute, though, to correct a significant misconception implicit in that quote.

A nuclear EMP does not radiate from a point source, and therefore does not follow the usual far-field 1/r^2 law. The explosion itself is a point source, but the prompt gamma emissions from the blast don't turn into the E1 pulse until they hit sufficiently dense atmosphere and undergo Compton scattering. For large-ish bombs, those gamma rays turn the entire atmosphere, from directly under the bomb to the horizon, into a radio source. Since the distance from the source surface to ground is far smaller than the extent of that surface, the intensity at ground level is only negligibly smaller than the intensity in the source region.

Also, Faraday cages only shield their interiors from electromagnetic fields if they don't have wires running through holes. All that telecom equipment in the boxes has big, long wires leading out of the boxes (except for the fiber optic stuff, of course), which provide entry paths for all that RF energy. Since most of the last-mile (or last-hundred-feet at least) connections are still copper, that's a problem.

Being buried isn't absolute protection either -- look up some soil conductivity numbers, calculate the skin depth at 50 MHz or so, and think about what that means.

Okay, I guess I couldn't resist tackling a couple extra points. The upshot is that nuclear EMPs involve situations that normal ham/electrical engineering habits don't necessarily apply to, and you have to think very carefully about what's going on to get the physics right. Reading the most technical material you can find helps a lot.

[Maast]

Dammit, didnt want to get into yet another discussion of EMP, but I have to add a couple of things:

1. The EMP commision report states that the electric field strength will be 50,000v/meter AT GROUND LEVEL, depending on where you are in relation to the HEMP.

2. The shielding of an enclosure is directly proportional to how good a conductor the shielding is, which is why an aluminum box is decent EMI shielding, but a sheet steel metal steel box isnt.

Aluminum is a good conductor and steel is a crappy conductor. It has to do with the induced current generating a magnetic field that is of opposite polarity of the magnetic portion of the inbound electro-magnetic wave (and is then re-radiated thus effecively "bouncing" the signal.)

You can use steel as a shielding/reflecting material, but it has to be much thicker than aluminum of equal effectiveness to overcome the poor conduction characteristics of steel.
This is why you'll never see steel used as a radar reflector or microwave dish, unless its got a thin sheet of copper or aluminum.

[OttawaXJ]

I read this entire thread and now am left with more questions than answers.

I'm trying to figure out if CBs will still work after large solar flares big enough to cut out power or create mass hysteria.

At this point I'm thinking a solar flare taking out communications is far more likely than a war on or anywhere near Canadian soil so Im trying to figure out how to protect my and others CBs from such an event.

I saw all kinds of numbers and crazy math thats far above my level of understanding but couldn't understand any of it to be honest.

Edit: From rereading it would seem that an aluminum case would shield a CB radio, what about batteries and such? My vehicles would most likely be completely fried too right? So how would we power our CB if it still worked and everything outside of the small aluminum case fried. Or am I not understanding.

[TacAir]

I read this entire thread and now am left with more questions than answers.

I'm trying to figure out if CBs will still work after large solar flares big enough to cut out power or create mass hysteria.

At this point I'm thinking a solar flare taking out communications is far more likely than a war on or anywhere near Canadian soil so Im trying to figure out how to protect my and others CBs from such an event.

I saw all kinds of numbers and crazy math thats far above my level of understanding but couldn't understand any of it to be honest.

Edit: From rereading it would seem that an aluminum case would shield a CB radio, what about batteries and such? My vehicles would most likely be completely fried too right? So how would we power our CB if it still worked and everything outside of the small aluminum case fried. Or am I not understanding.

1) Do not leave the antenna conected to the rig, do not leave the power connected to the rig
2) Ground the antenna input
3) If you are really worried, wrap the rig in Al foil.
4) Take a deep breath and go have a cold Molson.
5) Don't sweat the truck/car/battery - if the EMP pulse was powerful enough to fry those protected modules, your house will be on fire....
6) See #4

[aa1pr]

Hey I'm just wondering, there's a lot of ways people can communicate over the internet and over the phone, so what would it take so that humanity could only communicate via radio?

What places or satellites would people have to destroy? How would radio communication being the primary be possible?

Sounds kind of grey area?

[RadioShooter]

WIth the reports coming out of Japan, it appears that a powerful earthquake and tsunami could bring communications down to just two way radio. The pictures show search and rescue personel with handhelds, so ham radio repeaters should still be in operation.

RS