Interesting link and a reason to use AM

[w3kmp]

http://www.catastrophenetwork.org/?page_id=446

[W4EWH]

http://www.catastrophenetwork.org/?page_id=446

Here's a paragraph from the splash page:

Amateur Radio Stations using the Standardized Prepper frequencies of 3.818, 7.242, and 14.242 MHz transmit pertinent information in AM (Amplitude Modulation) mode rather than SSB (Single Sideband) mode so that those with less expensive shortwave receivers that do not receive SSB can still gather pertinent prepper information from the Amateur “Ham” Radio community.

... which leads me to ask if getting through to someone who has only a shortware receiver is such a good idea. I'm not a "prepper", so I'll throw out a few thoughts, just to start a discussion, but I'm not any sort of expert in this stuff.

• Most hand-held shortwave radios tune in 5KHz increments, so odd frequencies such as these won't be heard very well.
• Anyone who seeks out the source of the AM transmission will be looking for something:
  • Food
  • Medicine
  • Shelter
  
  ... after all, people don't go looking for strangers when they already have what they need, unless they're looking to get more of it, and either way I'm not so sure that asking for uninvited guests would be a great idea during a disaster.
  
• Hams, or anyone else, wouldn't be allowed to broadcast anything that contradicts what the government wants people to hear in the wake of a disaster. The first "visitor" that someone broadcasting to the public could expect to receive would be a cop with wire cutters in his hand.

Of course, that's just the start of the list, but I invite comments. As much as I'm tempted to poke holes in this plan, there's a serious side to my post, too. The question is really "How do we convince hams who are in the prepper community that ARES is a better idea"?

FWIW.

73,

Bill, W1AC

[WA3VJB]

I picked around that website and found it curious that there is no licensed radio hobbyist named among the pages of discussion.  Even the "about" and "contact" pages are anonymous.  I wonder who is behind the group that developed the "plan."  No individual names on that text document either.

There is a different "home page" that has some names and activity reports and it gives a flavor of what they're trying to accomplish.

http://www.taprn.com/

I found it in the text document. Also,  there was another,  broader recommendation in there about the use of AM (not frequency specific)

The communication of critical information using the AM mode is encouraged on the standard 80, 40, and 20 meter voice frequencies at the top of each hour so that those who do not have SSB capable receivers may obtain pertinent information using the AM mode.

But that wording could create more confusion than clarity.  Does it mean "standard voice frequencies" where AM is customarily found?  Or just anywhere in the phone bands?

And if serious about employing the mode, why is there no discussion about suitable transceiver adjustments, and a reference to the AM Community at large?  I didn't check all the station registrations on the map they provide for signups, but maybe there are a few AMers among them.

AM and "emergency communications" were put in the same context a few years ago in a regulatory proceeding.

When the FCC and other federal agencies were deliberating whether to grant any allocations on 60 meters to the Amateur Service,  part of the ARRL's push was to say the band would provide better propagation during hurricane communications.

Then we started hearing about mode restrictions and channelization, and I was among those who filed comments with the FCC suggesting AM should be included among permitted modes because of its potential benefit to the SWL / monitoring community hoping to obtain information.

That didn't happen, but neither did 60 meters for hurricane nets.

[Opcom]

As far as 'unwanted guests' from the public homing in on the transmission, those with receivers that only pick up AM tend to live at a technology/knowledge level where they probably do not have the ability to direction-find. When they try to go mobile and their 60 FT long wire is no longer present, it my become even more difficult.

The 6M people that live in DFW are likely to cause me more trouble than SWLs.

[Steve - K4HX]

Are you saying the preppers are unprepared?

[Pete, WA2CWA]

Gee, I wonder if they have "jump teams" too.

[KA0HCP]

Are you saying the preppers are unprepared?

When we speak of logic, reason, rationality.  Yes.

[KA3EKH]

Use that link and go to their home page, there big prep deal for radio is CB channel 4.
Couple years back one of the broadcast companies I do work for was involved in a big government deal, don’t recall if it was FEMA or what at the time but think the whole thing fell thru for us. The idea was that the government would build a fuel storage facility for thirty days of operation at one of our AM transmitter sites along with placing a container or type of sealed building that would contain a AM broadcast transmitter generator and satellite reception equipment and in the event of an emergency and our existing facilities were destroyed or disabled the sealed building would be opened and put on the air. Got to figure that the emergency would have to have been something like an EMP event being all this would have been useless without the survival of the towers, phaseor network and ground system and the sealed building had no electrical connections to the outside world except for fiber. My limited understanding was that many of these same packages had already been deployed and our station was to be included in a future round of budgeting but beyond the first couple site visits and communications nothing else happened.  Between government plans for disasters and commercial capabilities would speculate that if we were ever in an event where the government, commercial telecommunications and broadcast were nonexistent any network of a couple surviving Ham operators  would be pointless or useless, regardless of there mode of operations. But that’s just my opinion.
Additional thought, was a speculation that the government must have EMP proof warehouses full of crank up AM radios to be used after this proposed event, if not what would people use to listen to these radio stations?

[KB2WIG]

"Additional thought, was a speculation that the government must have EMP proof warehouses full of crank up AM radios to be used after this proposed event, if not what would people use to listen to these radio stations? "

"They" can't ballance the budget; watt makes you think that "they" would think this through ? ??

klc

[WA3VJB]

... along with placing a container or type of sealed building that would contain a AM broadcast transmitter generator and satellite reception equipment and in the event of an emergency and our existing facilities were destroyed or disabled the sealed building would be opened and put on the air.

//
.. any network of a couple surviving Ham operators  would be pointless or useless, regardless of there mode of operations. But that’s just my opinion.

I dunno, man, we had a great time testing something like that.

http://amwindow.org/pix/htm/ktrkhut.htm

[kb3ouk]

Additional thought, was a speculation that the government must have EMP proof warehouses full of crank up AM radios to be used after this proposed event, if not what would people use to listen to these radio stations?

Single tube regenerative sets using a bunch of 9V batteries in series for the B+. 

(Which when you think about it, actually does make sense)

[W4EWH]

"Additional thought, was a speculation that the government must have EMP proof warehouses full of crank up AM radios to be used after this proposed event, if not what would people use to listen to these radio stations? "

I thought EMP fried everything with electronic components, anywhere within the blast, whether turned on or not. Is that correct?

Bill, W1AC

[W4NEQ]

In any case, having watched the "doomsday preppers" television show, it appears that the "prepper experts" consistently recommend getting a ham license.
I'm sure that some of these folks are smart and rational, but there seems to be plenty that aren't, and they are headed our way.

Chris

Are you saying the preppers are unprepared?

When we speak of logic, reason, rationality.  Yes.

[Pete, WA2CWA]

"Additional thought, was a speculation that the government must have EMP proof warehouses full of crank up AM radios to be used after this proposed event, if not what would people use to listen to these radio stations? "

I thought EMP fried everything with electronic components, anywhere within the blast, whether turned on or not. Is that correct?

Bill, W1AC

Probably at least everything that has a "PN" junction in it.

[KA0HCP]

I thought EMP fried everything with electronic components, anywhere within the blast, whether turned on or not. Is that correct?

Bill, W1AC

No, certainly not.  It all depends on the charge Voltage, induced delivered to the component(s).  Range, altitude, tonnage, surface area available to induce a voltage, device shielding, device surge/grounding arrangements.  All these come into play.

Detonating a nuke, per se, does not mean there will be widespread EMP damage, nor necessarily wide spread EMP!   Low altitude nukes, below 15 miles altitude, will have only nearby effects.  Closer to the surface EMP is limited to line of sight and hampered by earth losses!

The doomsday continental effects can only achieved by detonating nukes of 1 megaton or more, in a moderately sized window centered at 30 miles altitude (180,000 ft).  Note you can't do that with a suitcase nuke in a Cessna or Learjet!

There is a lot more hoopla than facts on the internet about EMP.  A radio sitting on closet shelf will not necessarily suffer any damage.   EMP is not some magic-destructo force that can somehow target all electronics.

Both the Navy (Empress II) and USAF (Trestle) closed their full size EMP testing facilities in the early 90's.  There isn't a pressing need for continued research in EMP.  Obviously there is confidence the understanding of EMP theory, modern components  and modern system design principles.  

In Summary:  EMP is NOT a bogeyman.

[kb3ouk]

And most of us probably have at least one all tube receiver (I think I have 8 of them at least) laying around, and tubes are EMP-proof naturally.

[W4EWH]

And most of us probably have at least one all tube receiver (I think I have 8 of them at least) laying around, and tubes are EMP-proof naturally.

That's another thing that I don't understand: why are tubes immune?

I thought that EMP did damage because it induced voltage differences between nearby components that is sufficient to arc-over caps. Wouldn't even boatanchor rigs be damanged?

Bill, W1AC

[WB2EMS]

That's another thing that I don't understand: why are tubes immune?

As I understand it, the EMP pulse can produce voltage gradients of 100KV per meter or more. The issues that semiconductors have is that even though their thickness is very small, their hold off voltage before puncturing is so low that even if they are 1/1000 meter thick, they have 100 volts across them and can only handle 20 before failing. So most semiconductors exposed to the field will be damaged immediately.

Tubes have much larger structures, and can even handle an arc over momentarily and not suffer permanent damage like a semiconductor. Now other components around the tube like caps or coils or resistors might fail under the stress - but none of them are as inherently fragile to voltage gradients as semiconductors.

I remember an old ARRL article on the subject that said if a tube rig were disconnected from the AC mains and antennas, that it would have a fair chance of surviving. I think the main risk would be the voltage induced in the power cord and propagated into the rig.

I gather the best way to protect gear from damage from an EMP event is to isolate it in a faraday cage. I wonder how many hams have any gear sequestered away in some fashion to survive an EMP event?