Most Reliable Communication Means, Emergency

Posted by: ireckon

Most Reliable Communication Means, Emergency - 10/19/11 03:32 AM

Some will say it's POTS. I did a quick search on Google and found this:

Quote:
With respect to communications, the [9/11 Commission Report] concludes:”Almost all aspects of communications continue to be problematic, from initial notification to tactical operations. Cellular telephones were of little value….Radio channels were initially oversaturated….Pagers seemed to be the most reliable means of notification when available and used...”

- 9/11 Commission Report. Chapter 9, p. 315.

http://aquis.aquiscommunications.com/products/wireless-messaging.html
(no affiliation)

Pagers!
Posted by: MarkO

Re: Most Reliable Communication Means, Emergency - 10/19/11 03:49 AM

........ and what network(s) are pager messages sent through ??
Posted by: ireckon

Re: Most Reliable Communication Means, Emergency - 10/19/11 04:05 AM

I can see how pagers can be the most reliable means of communication for the average person walking around away from home. A pager is easy to EDC and the battery lasts for months, not days or hours. A pager takes a cell phone's most reliable communication means (text/email/SMS) and specializes in those departments in a device that is more rugged than a cell phone. A pager has no congestion issues. It just needs a quick burst of connectivity. Of course, the recipient needs to be communicating with text/email/SMS.

On the mountains I snowboard, I think I'll try communicating with pagers. Walkie Talkies are usually worthless.
Posted by: Am_Fear_Liath_Mor

Re: Most Reliable Communication Means, Emergency - 10/19/11 04:13 AM



Quote:
Most Reliable Communication Means, Emergency


I wouldn't put to much emphasis on that specific report, especially considering the military comms systems that are avialable, from GPS broadcast communications through to C3I JT terminals to dedicated Internet infrastructure.

For the rest of us POTs is probably the most reliable.

http://www.youtube.com/watch?v=f8lVXQfPXRw
Posted by: MarkO

Re: Most Reliable Communication Means, Emergency - 10/19/11 04:13 AM

Well, I've beaten the ever loving $%^& out of my work cell phone for the past 18mos and it still works. It's a phone/nextel direct-connect/accepts txts/accepts txt emails device. I carried a work pager for 9 years and broke more than my fair share of them.

I still have to ask how does a pager receive a short msg in the event of an emergency when my phone apparently will not. Bear in mind I no longer have a pager as its functions were folded into the single phone / nextel device.
Posted by: ireckon

Re: Most Reliable Communication Means, Emergency - 10/19/11 04:15 AM

I could plan on using for POTS for home only. For everywhere else, there has got to be other planning.

Regarding the idea that cell phones being able to do whatever a pager can do, I beg to differ. I expect my cell phone to last for no more than 24-hours at the most. A pager can last much longer. That may not seem like a big deal right now when we're warm and safe, but it could be a big deal in a large-scale disaster when you're out there.
Posted by: Am_Fear_Liath_Mor

Re: Most Reliable Communication Means, Emergency - 10/19/11 04:52 AM

Quote:
Regarding the idea that cell phones being able to do whatever a pager can do, I beg to differ. I expect my cell phone to last for no more than 24-hours at the most. A pager can last much longer. That may not seem like a big deal right now when we're warm and safe, but it could be a big deal in a large-scale disaster when you're out there.


Your cellular phone battery probably wouldn't be an issue. It would probably outlast the battery at the POTS exchange/cellular tower from the POTs telephone/cellular phone sending you the page message assuming a wide area power outage. Turning off/on every 30min etc to pick up SMS texts will greatly increase the life of the cell phone for 1-2 weeks.
Posted by: bws48

Re: Most Reliable Communication Means, Emergency - 10/19/11 12:00 PM

Originally Posted By: Am_Fear_Liath_Mor
Quote:
Regarding the idea that cell phones being able to do whatever a pager can do, I beg to differ. I expect my cell phone to last for no more than 24-hours at the most. A pager can last much longer. That may not seem like a big deal right now when we're warm and safe, but it could be a big deal in a large-scale disaster when you're out there.


Your cellular phone battery probably wouldn't be an issue. It would probably outlast the battery at the POTS exchange/cellular tower from the POTs telephone/cellular phone sending you the page message assuming a wide area power outage. Turning off/on every 30min etc to pick up SMS texts will greatly increase the life of the cell phone for 1-2 weeks.


This was a lesson learned for me from our last hurricane. A falling tree took out the power. No problem, my generator kicked in. After a number of hours, I lost POTS, DSL (internet) and cell phone (no signal).

I later found that nearby there is a small, unattended building that contains various phone switching and DSL equipment; our community is serviced by this mini-facility. It has battery power back up. When the batteries there died, there went my POTS, DSL and cellphone. I am not sure why the cell phone went out, but I am guessing that there was signal switching equipment in that building that routed the calls going to and from the actual tower (located some distance away).

This small building was thus a single critical node for 3 communications mediums, all dependent on the same local power and battery backup. The phone company got in, set up a 5KW portable generator and got all 3 back at the same time and (mostly) kept it up with this generator until the power came back.

A lot of our planning on back-ups make the (unstated) assumption that they are independent systems. I wonder how many of these shared single node failure points there are, and how we can find them. I am still trying to figure a way around this failure node.
Posted by: Arney

Re: Most Reliable Communication Means, Emergency - 10/19/11 12:42 PM

Originally Posted By: ireckon
Pagers!

As a historical point, that's interesting. But I don't think that's a very practical suggestion going forward.

I was a big fan of pagers and kept using a numeric pager as my main personal mobile point of contact while I lived in NYC long after most of my friends got mobile phones, but let's not forget the era when 9/11 happened. Even I had switched to a mobile phone when 9/11 happened.

Mobile networks weren't quite as well built out at that point and therefore had fewer towers and less overall capacity. Text messaging was still a rarity back then. I used Voicestream (which later became T-Mobile), which was the only GSM carrier and could do SMS natively. Europeans were already texting like crazy back then on their mobile phones but not Americans.

I don't recall if the analog, TDMA, and CDMA carriers like AT&T and Sprint could even do text messaging back then. Two-way pagers were popular, especially with the youth market. Oh, and Nextel was still big back then, and push-to-talk was all the rage among a mostly blue collar set.

There was also still a large pager transmitting network in place at that time. Many of those companies are gone now and I'm sure many of those transmitters are also gone. Motorola doesn't even make pagers anymore.

So, times have changed. I'm afraid that the pager infrastructure is not as robust as it once was. I did appreciate that a pager signal would reach me even when I would be in the bowels of old concrete and steel NYC skyscrapers while everyone with a mobile phone could not get a signal at all on their cell phones.
Posted by: Am_Fear_Liath_Mor

Re: Most Reliable Communication Means, Emergency - 10/19/11 03:21 PM


Here is my current setup for communications;



A VOIP phone (standard POTS phone) works over a Vigor 2100 Wireless VOIP cable router to a Cisco 2100 cable modem (cheapest 10Mb/s connection service). If the cable service goes down I could replace the Cisco 2100 with an ancient USR8000 + D-link DFM-56OE 56k modem for dial up connection (assuming that POTS service is still avialable). I will have to experiment to see if I can get a shared wireless 56K connection (typically 40Kb/s) and a working VOIP phone connection over dial up connection.

Going back to the year 2000/2001 this was my portable 2G email/SMS/WAP setup. Most of the paging network in the UK was shut down around 2004/6 in the UK.



What is interesting is that Palm at the time also produced a dial up modem attachment, which allowed dial connection over POTS, which is something even the iPhone 4S doesn't have available today.

http://www.amazon.com/Palm-10401U-PalmOn...0669&sr=1-1

So if all the networks go down (POTS, GSM, 3G etc) then I will have to just rely on getting information via Short Wave, DAB FM, DVB-T and DVB-S.
Posted by: ireckon

Re: Most Reliable Communication Means, Emergency - 10/19/11 03:38 PM

I had that same Palm for a long time, a great device.

As for POTS, I'd like to highlight what you've already said. You have a POTS phone pictured, but it's VOIP service (not POTS service). You did mention you could dial-up on a POTS service, but do you keep your POTS service active? I don't. The monthly fee is too much for my budget. I'll take the risk. By the way, if my cable service stays up, then that means I (probably) have Internet on my computer, along with VOIP.

What I don't see in your pic is a battery backup (which you probably have). As you know, that phone system does not work without power. My battery backup has kept my VOIP system running flawlessly during power outages.
Posted by: Pete

Re: Most Reliable Communication Means, Emergency - 10/19/11 05:11 PM

In a major emergency ... cell phones out, cables cut, repeaters down, internet down. A LOT of citizens are going to be feeling very uncomfortable in that situation. Suddenly our "wired-in" world is completely gone.

One important aspect ... is just to have a few simple emergency messaging procedures. I just went thru this with my 8-year old in L.A. In a major disaster, if the kids at school need to leave the schoolyard for some reason, she knows to take an index card out of her backpack, write a simple message about where people are going, and pin it to the wire netting fence near the main gate. Same thing goes for our family - we have a few designated spots to pin messages in our local neighborhood. Just hand written notes.

The best backups are usually simple ideas.

Pete2
Posted by: Am_Fear_Liath_Mor

Re: Most Reliable Communication Means, Emergency - 10/19/11 05:54 PM

Quote:
In a major emergency ... cell phones out, cables cut, repeaters down, internet down. A LOT of citizens are going to be feeling very uncomfortable in that situation. Suddenly our "wired-in" world is completely gone.


They should learn to chill out a little. Chances are even when the emergency is over, folks won't really get to the bottom of what really happened anyway in a major emergency so attempting/wishing/praying they knew what was happening in real time is all rather pointless. Yesterdays news is just todays fish and chip wrapping paper (well it used to be before the health and safety crowd deemed it unsafe wink ).

All this 'wired in' culture just means greater panic for the public when they lose their means of electronic communication. I've heard enough panic down the end of a phone when their Internet connection goes down, but they seem to calm down a little when you ask them what they would have done 10-15 years ago. Just get them to go down to the pub like they did in the past. All this Internet nonsense is just leading to a nation of stressed out moaning faced idiots, who can't even tie their own shoe laces without having to look it up on Google.


Posted by: Arney

Re: Most Reliable Communication Means, Emergency - 10/19/11 06:13 PM

Originally Posted By: Pete
I just went thru this with my 8-year old in L.A....write a simple message about where people are going, and pin it to the wire netting fence near the main gate.

That's a great plan. (Do kids still write on paper nowadays? wink )

Another option that bypasses the whole communications thing is just tell people that chances are you won't be able to get in touch. If a major quake strikes, everyone wants to know instantly if other people are OK.

I just tell certain loved ones that depending on what time it happens and how much damage there might be, if there is every a major quake, it will probably be tomorrow by the time I walk home from work so don't worry if you don't hear from me for a while. Easier said than done, but at least they know that's my plan.
Posted by: ireckon

Re: Most Reliable Communication Means, Emergency - 10/19/11 06:16 PM

Below is my simple, inexpensive, reliable radio for staying connected. It's only incoming communication AM/FM. I have fancier devices, but I'll put my money on this device being near me and working when it matters.


http://www.radioshack.com/product/index.jsp?productId=3705831
(no affiliation)
Posted by: Mark_R

Re: Most Reliable Communication Means, Emergency - 10/19/11 06:27 PM

Originally Posted By: Arney
Originally Posted By: ireckon
Pagers!

As a historical point, that's interesting. But I don't think that's a very practical suggestion going forward.

I was a big fan of pagers and kept using a numeric pager as my main personal mobile point of contact while I lived in NYC long after most of my friends got mobile phones, but let's not forget the era when 9/11 happened. Even I had switched to a mobile phone when 9/11 happened.

Mobile networks weren't quite as well built out at that point and therefore had fewer towers and less overall capacity. Text messaging was still a rarity back then. I used Voicestream (which later became T-Mobile), which was the only GSM carrier and could do SMS natively. Europeans were already texting like crazy back then on their mobile phones but not Americans.

I don't recall if the analog, TDMA, and CDMA carriers like AT&T and Sprint could even do text messaging back then. Two-way pagers were popular, especially with the youth market. Oh, and Nextel was still big back then, and push-to-talk was all the rage among a mostly blue collar set.

There was also still a large pager transmitting network in place at that time. Many of those companies are gone now and I'm sure many of those transmitters are also gone. Motorola doesn't even make pagers anymore.

So, times have changed. I'm afraid that the pager infrastructure is not as robust as it once was. I did appreciate that a pager signal would reach me even when I would be in the bowels of old concrete and steel NYC skyscrapers while everyone with a mobile phone could not get a signal at all on their cell phones.


My experiences were similiar to yours. I stayed with the pager and phone card as long as possible. But, three consecutive providers closed shop without telling me (I was buying a year's services in one lump transaction). When most of the pay phones were removed, I was left with no choice but to switch to cell phones.

Pagers may be out, but SMS has proven reliable during the wildfires in 2007 and the blackout last month. You couldn't talk to someone, but you could get a text through. Battery life on my cell phone is 4-7 days depending on use and if I leave it on at night.

AFLM, Will your setup continue to work with no power? During last months power outages, cordless phone, or anything requiring power from the grid, stopped working.

EDIT: Ireckon, I've got something similiar with ear buds for reduced power consumtion. It's the best choice for situation updates as the emergency radio stations have to stay up.
Posted by: Am_Fear_Liath_Mor

Re: Most Reliable Communication Means, Emergency - 10/19/11 06:44 PM


Quote:
AFLM, Will your setup continue to work with no power? During last months power outages, cordless phone, or anything requiring power from the grid, stopped working.



The SLA battery in the Belkin UPS should be able to power the Router and Modem for about 5-6 hrs continuously. It would be relatively easy to rig up a 30W solar panel/Portable 40Ahr 12V SLA battery/charge controller and a programmable DC-DC power regulator, which is kept in the same room to power a Hi-Fi.

http://forums.equipped.org/ubbthreads.php?ubb=showflat&Number=175102

Internet access would be available using an Archos media player.

If this all fails then its time to go down the pub. whistle
Posted by: Mark_R

Re: Most Reliable Communication Means, Emergency - 10/19/11 06:50 PM

Originally Posted By: Am_Fear_Liath_Mor


If this all fails then its time to go down the pub. whistle




Drinking warm beer on Hadrian's wall? whistle
Posted by: Am_Fear_Liath_Mor

Re: Most Reliable Communication Means, Emergency - 10/19/11 07:04 PM


Quote:
You have a POTS phone pictured, but it's VOIP service (not POTS service). You did mention you could dial-up on a POTS service, but do you keep your POTS service active? I don't.


Yes I keep the POTS service for around $18/month. The basic broadband service (Virgin Media) is for 10Mb/s @ $18/month (100Mb/s is available @ approx $50/month but this is a little more than I need) although I should perhaps get the free Broadband service from the telecoms company I work for as they have recently upgraded to BT infinity in my area, which is a fibre service at around 30Mb/s.
Posted by: MDinana

Re: Most Reliable Communication Means, Emergency - 10/19/11 07:24 PM

Originally Posted By: ireckon
I can see how pagers can be the most reliable means of communication for the average person walking around away from home. A pager is easy to EDC and the battery lasts for months, not days or hours. A pager takes a cell phone's most reliable communication means (text/email/SMS) and specializes in those departments in a device that is more rugged than a cell phone. A pager has no congestion issues. It just needs a quick burst of connectivity. Of course, the recipient needs to be communicating with text/email/SMS.

On the mountains I snowboard, I think I'll try communicating with pagers. Walkie Talkies are usually worthless.

Depends how busy you are. As an intern, I was going through batteries every 2-3 weeks. I was extremely tempted to put that little piece of ... plastic ... on a clay pigeon launcher on the last day of intern year and blast away with some #7 birdshot.

I assume the report is talking about 2-way pagers? Otherwise, access to internet/text/phone service to actually send a page is the rate-limiting step.

Yes, I realize someone already pointed this out.
Posted by: Eugene

Re: Most Reliable Communication Means, Emergency - 10/19/11 07:28 PM

I had a two way pager through work, it would eat an Alkaline battery a week. I took one of my old NiMH's from 1999 (1650mAH) and it would go two weeks. They replaced the pagers with blackberry's a couple years ago because the blackberry service was the same cost and we can get our e-mail and calendar and such as well.

Does anyone remember a few years ago when one of the communication satellites used for pagers went out of orbit and a bunch of doctor's lost service, it was big news then.
Posted by: Am_Fear_Liath_Mor

Re: Most Reliable Communication Means, Emergency - 10/19/11 07:47 PM

Quote:

Drinking warm beer on Hadrian's wall? whistle


If you want to go back in time (at least 30 years) to have a warm pint then Sinatras in Dundee is the place to go.

If you want to feel really old then the Social is the place to go... wink
Posted by: MartinFocazio

Re: Most Reliable Communication Means, Emergency - 10/20/11 05:45 PM

What ever happened to ham radio? I used to use it...don't even own any gear now...would love a pure digital pager/sms like network for robust short comms.
Posted by: Arney

Re: Most Reliable Communication Means, Emergency - 10/20/11 07:25 PM

Originally Posted By: MartinFocazio
What ever happened to ham radio? I used to use it...don't even own any gear now...would love a pure digital pager/sms like network for robust short comms.

Way too expensive for me to buy "just to have," but the Motorola DTR series seems like it can provide pretty secure, robust, digital voice and SMS for point-to-point comms (if that's how you're defining "short comms").

Tri-square also makes some ISM band two-way radios, but I hear they're junk.

Since the OP is talking about the 9/11 Commission results, didn't they also recommend that we establish a civilian Signal Corps ASAP made up of Amateur Radio folks? Hmmm, another decent suggestion gone by the wayside.
Posted by: sotto

Re: Most Reliable Communication Means, Emergency - 10/21/11 05:04 PM

For some reason, I'm having a problem in the "reliable" department right now, and it's a good lesson/reminder for all you folks interested in Emergency Comms.

I acquired 3 brand-new and name-brand FM transceivers in the last year to use specifically for emergency SHTF communications. They have been used very little, and the batteries have been judiciously and sensibly kept charged. 99% of the time, they sit handily on a table in my den turned off and ready to be grabbed at a moment's notice.

First one of them, and then another of a different manufacture, failed to receive at all. They transmit fine, but won't receive anything. Within a few days of their inexplicably crapping out, they had both been checked and found to be functioning perfectly.

So, a reminder of a couple lessons:

1. Two is one, and one is none.
2. And just because it's working perfectly today, doesn't mean it will work worth poo tomorrow.
Posted by: Arney

Re: Most Reliable Communication Means, Emergency - 10/21/11 05:34 PM

Originally Posted By: sotto
For some reason, I'm having a problem in the "reliable" department right now...just because it's working perfectly today, doesn't mean it will work worth poo tomorrow...

"I was just thinking the same thing," says the old codger, as he mixes up a glass of Metamucil... wink
Posted by: Eugene

Re: Most Reliable Communication Means, Emergency - 10/21/11 08:23 PM

Did a test a week or so ago myself, my handheld CB could no longer get a signal past the next street so no chance of getting the .5 mile to my work. I need to figure out if I just got the antenna mixed up with my scanner or if the transmit is bad.
Posted by: chaosmagnet

Re: Most Reliable Communication Means, Emergency - 10/21/11 09:22 PM

Originally Posted By: MartinFocazio
What ever happened to ham radio? I used to use it...don't even own any gear now...would love a pure digital pager/sms like network for robust short comms.


Take a look at PSK31. With the right antenna you can easily get over 1000 miles of DX with five watts on a battery pack.
Posted by: CANOEDOGS

Re: Most Reliable Communication Means, Emergency - 10/22/11 04:15 AM

SW sounds good at first,i have a old Hallicrafters that i use to listen in with,but i could see the waves so jammed up in a real nation wide emergency that you would never be able to get thru unless you had a huge rig and kept at it day and night.for local stuff like a earth quake or storm SW could be useful.it takes skill to use SW,you can't just turn it on and start shouting "CQ__CQ!!!..and who knows the quality of the info you might pick up...
Posted by: KG2V

Re: Most Reliable Communication Means, Emergency - 10/22/11 04:54 AM

The hams are still here, and there were some rave articles RE Joplin etc

If you're a pager user in the Baltimore to Boston area, the odds are pretty good I know the guy who owns your pager company/parger site. He's hoping it lasts long enough for him to retire - He is shutting down sites all the time, the main users left are, believe it or not, hospitals

Last time I saw him, he was talking about his shutting of a site in Northeast NJ. He said "It just didn't pay anymore" - basically he had a situation where he had ONE subscriber in the covered area, almost NO transients. The MD in question wasn't happy he was losing service, but the why my friend explained it to him "Tower and radio rack rent for the antenna that cover your home cost me in the 4 figures/month, I charge you, what 20-30/month (or whatever it is - I didn't get the exact amounts) - I can't afford to keep the tower up for just you
Posted by: adam2

Re: Most Reliable Communication Means, Emergency - 10/22/11 09:57 AM

Some years ago, terrorists attacked the London public transport system.
As a consequence there was no effective cellphone service over most of London.
Power was out in places, but only very close to the explosions, there was no general or widespread outage. (I suspect either blast damage to utility equipment, or local flooding from water pipes broken by the blast)
This put my then employers to substantial inconvienience as their business was spread over a number of buildings and heavily reliant on messengers with cellphones.
Many staff were distressed at not being able to contact friends , workmates or relatives.
It was most fortunate that I had about a mile of telephone cable by means of which land line phones could be used externally, simply throw the cable out of the window.
This was mainly for use of staff, but several police officers asked to use the phone, as the police radio system was overloaded.
Walkie talkies worked fine, but we only had 6, and only had means of charging them at one building.
When the immediate emergency was over, I extended my phone line into the local pub, in order to stay in touch as there was still no cellphone service.
Posted by: LesSnyder

Re: Most Reliable Communication Means, Emergency - 10/22/11 11:08 AM

an old touch tone phone, short section of cable to hook into a "borrowed" external phone box + an adapter for the cable to a couple of alligator clips for temp hookup

I get reliable 3mile service (typically more) out of a peaked CB with a good magnetic mount antenna (1:1 SWR) on SUV... receives NOAA WX 60mile to Ruskin, Fla
Posted by: unimogbert

Re: Most Reliable Communication Means, Emergency - 10/22/11 01:55 PM

Reliability is great. But it's more understandable if you specify more about the system.

Reliable over what distance? In what conditions? Connecting with who? For what purpose?

There are lots of answers to the original question in this thread but each of the answers assumes different scenarios. So they only make sense if you know what scenario is being assumed.

I'm a Reliability Eengineer by job title and a radio geek since vacuum tubes. But I don't have enough info to give my answer to the question. I'm surprised at how many have.
Posted by: chaosmagnet

Re: Most Reliable Communication Means, Emergency - 10/22/11 02:22 PM

Originally Posted By: CANOEDOGS
SW sounds good at first,i have a old Hallicrafters that i use to listen in with,but i could see the waves so jammed up in a real nation wide emergency that you would never be able to get thru unless you had a huge rig and kept at it day and night.for local stuff like a earth quake or storm SW could be useful.it takes skill to use SW,you can't just turn it on and start shouting "CQ__CQ!!!..and who knows the quality of the info you might pick up...


Well, the quality of the info you'd pick up couldn't be any worse than what passes for journalism these days.

Part of the skill of being a ham is knowing how to pass traffic in a controlled net.
Posted by: KG2V

Re: Most Reliable Communication Means, Emergency - 10/23/11 06:03 PM

Net Control, this is shelter 2 with priority Traffic, - kg2v
Posted by: MDinana

Re: Most Reliable Communication Means, Emergency - 10/23/11 11:16 PM

Originally Posted By: unimogbert
...

I'm a Reliability Eengineer by job title and a radio geek since vacuum tubes. But I don't have enough info to give my answer to the question. I'm surprised at how many have.

Silly man. Vacuums have bags or cannisters, not tubes. grin
Posted by: adam2

Re: Most Reliable Communication Means, Emergency - 10/24/11 06:42 AM

For the passing of simple pre arranged messages, rather than 2 way voice contact, dont forget such basics as colored flags or similar by day, and colored lamps at night.
In clear weather ranges of some miles are easily achieved.

This can be a usefull suplement to cellphones, walkie talkies, or ham radio if battery power is very short.
A simple pre-arranged code could save scarce battery power.

RED-------------turn on radio or phone ASAP and make contact
YELLOW----------radio/phone defective.
GREEN-----------All is well, no need to consume battery power.
BLUE------------Make contact briefly at 18-00 local time.

Or some other system as required by local conditions.

A coloured lamp need not be electric, oil lamps for railway purposes are still available and give a red, green or white light.
A single 5mm LED consumes less than 0.1 watt and can be seen for miles if correctly aligned.
A flag of course requires no power or fuel.
Posted by: KG2V

Re: Most Reliable Communication Means, Emergency - 10/24/11 10:33 PM

Originally Posted By: MDinana
Originally Posted By: unimogbert
...

I'm a Reliability Eengineer by job title and a radio geek since vacuum tubes. But I don't have enough info to give my answer to the question. I'm surprised at how many have.

Silly man. Vacuums have bags or cannisters, not tubes. grin


You of course realize that most RF AMps still use tubes, often ridiculously expensive tubes - Luckly my amp (used) had brand new tubes in it when I bought it - a matched set of 3 tubes would run me close to $1300
Posted by: MDinana

Re: Most Reliable Communication Means, Emergency - 10/24/11 11:19 PM

Originally Posted By: KG2V
Originally Posted By: MDinana
Originally Posted By: unimogbert
...

I'm a Reliability Eengineer by job title and a radio geek since vacuum tubes. But I don't have enough info to give my answer to the question. I'm surprised at how many have.

Silly man. Vacuums have bags or cannisters, not tubes. grin


You of course realize that most RF AMps still use tubes, often ridiculously expensive tubes - Luckly my amp (used) had brand new tubes in it when I bought it - a matched set of 3 tubes would run me close to $1300

No, I didn't actually.

My uncle and aunt are on again/off again HAM's. I never caught the bug.
Posted by: firefly99

Re: Most Reliable Communication Means, Emergency - 10/25/11 02:04 AM

When your house loss power, land line phone and mobile handset not operational. Your shouts for help is not heard by your nearest neighbour. In such a situation, a walkie talkie would be very helpful to get your message across to your neighbour.

But for walkie talkie to work in time of disaster. Some preparations is necessary.
Pre-disaster
- distribute walkie talkie units to your immediate neighbour

During disaster
- monitor the network for any request for assistance
- set a specific time to do touch base daily during disaster

Post-disaster
- assist with recovery process

Advantages of walkie talkie
- free
- limited range (enough range to reach your neighbour)

I did not mentioned CB because it can easily communicate with another party 50miles. But may have problem reaching your intended neighbour that is 1 or 2 miles away from you.
Posted by: ireckon

Re: Most Reliable Communication Means, Emergency - 10/25/11 04:04 AM

Originally Posted By: firefly99
When your house loss power, land line phone and mobile handset not operational.


During every power outage I've experienced, my land line phones and cable Internet phones have still worked. The cable Internet phones worked as long as I had a battery backup for the cable modem and VOIP device. I suspect if the power outage lasted for days, then the land line and cable would probably go out of service.
Posted by: LED

Re: Most Reliable Communication Means, Emergency - 10/25/11 05:37 AM

And don't forget to have a means of charging radio batteries, and/or a large stash of new alkalines.

I think CB's are a great idea. I use a Uniden/Little Wil combo for road trips.
Posted by: Eugene

Re: Most Reliable Communication Means, Emergency - 10/25/11 11:05 AM

Test your CB/FMRS radios though. I found that in my neighborhood none of them will transmit past the next street over. May be due to all the interference which might not be there in a power outage from wifi or it may be the 2 to 2.5 story houses close toegther just blocking the signal I don't know. I ordered a bigger antanna for the handheld.
Posted by: firefly99

Re: Most Reliable Communication Means, Emergency - 10/26/11 03:49 PM

For CB radio, due to the way the radio wave propagate. There is a blind zone. Hence the CB may link up with another CB unit 50 miles away. But cannot link up those CB within a 2 miles radius.

Most FMRS radio are low wattage unit, operating on UHF frequency. The low wattage reduce the operating range of the radio unit. Being UHF device, requires line of sight to connect. So if there is any trees or tall building, it will not be able to link up another unit further down the street.

So look for a walkie talkie unit that has at least 5 watt of power and operates on VHF frequency. Such an unit would be more effective within 2 ~5 miles range.
Posted by: chaosmagnet

Re: Most Reliable Communication Means, Emergency - 10/26/11 04:18 PM

The difference between VHF and UHF for range is pretty small, maybe 10% in the open using the same height, antenna gain, and wattage. Sometimes UHF has better penetration of buildings and trees.

All FRS and GMRS frequencies in the US are UHF. The FCC limits FRS output to 500 milliwatts, and radios must have fixed antennas to be type accepted. It's rare to get much more than a mile out of them, and less is common. GMRS can be significantly better due to higher wattage (1-5 commonly in handhelds, with a 50 W limit) and better antennas for many units.

While CB uses a much lower frequency, propagation can work locally if two stations have line of sight. Without line of sight, CB can propagate over the horizon by bouncing off the ionosphere, often producing a blind zone.
Posted by: Eugene

Re: Most Reliable Communication Means, Emergency - 10/26/11 04:30 PM

Originally Posted By: firefly99
For CB radio, due to the way the radio wave propagate. There is a blind zone. Hence the CB may link up with another CB unit 50 miles away. But cannot link up those CB within a 2 miles radius.

Most FMRS radio are low wattage unit, operating on UHF frequency. The low wattage reduce the operating range of the radio unit. Being UHF device, requires line of sight to connect. So if there is any trees or tall building, it will not be able to link up another unit further down the street.

So look for a walkie talkie unit that has at least 5 watt of power and operates on VHF frequency. Such an unit would be more effective within 2 ~5 miles range.


odd thing though is I've been able to use the handheld before when down in the city, I hadn't tested it since we moved. I'm hoping the better antanna will get me out, investig in different radios and licensing for them is a little out of budget for the moment.
Posted by: KG2V

Re: Most Reliable Communication Means, Emergency - 10/26/11 11:44 PM

Originally Posted By: firefly99
For CB radio, due to the way the radio wave propagate. There is a blind zone. Hence the CB may link up with another CB unit 50 miles away. But cannot link up those CB within a 2 miles radius.

Most FMRS radio are low wattage unit, operating on UHF frequency. The low wattage reduce the operating range of the radio unit. Being UHF device, requires line of sight to connect. So if there is any trees or tall building, it will not be able to link up another unit further down the street.

So look for a walkie talkie unit that has at least 5 watt of power and operates on VHF frequency. Such an unit would be more effective within 2 ~5 miles range.


Actually, it depends on your antennas - You can optimize your antenna system (and antennas are a system) for longer range communications (skip) or for short range comms

The issue you are talking about is often refered to as "the dreaded doughnut" - 2 Miles is usually NOT an issue, as you are within what is called 'ground wave' communications, then you have NOTHING just beyond that, and then you have signal again - so, in a doughnut pattern you have no comms

The way around this is with what is called a "Near Vertical Incidence System" - basically, you mount your antenna horizontally (or use a horizontal dipole) LOW to the ground - on a 40m or 80m it's typically in the range of 4-6 ft off the ground, and it tends to raise the 'take off angle' of you signal to near vertical, where your signal reflects off the ionosphere, and bounces back down - the exact OPPOSITE of what you want for working distant contacts, but perfect for close (in Ham terms, this becomes a 0-200 or so mile antenna system)

BTW, it is a BIG reason you actually WANT that nice 1/2 wave whip tied down like you see on Military vehicles - it's NOT only for clearance under things, but it actually makes the radio work BETTER in the doughnut - The military has thought about this
Posted by: firefly99

Re: Most Reliable Communication Means, Emergency - 10/27/11 04:06 PM

Originally Posted By: KG2V
The issue you are talking about is often refered to as "the dreaded doughnut" - 2 Miles is usually NOT an issue, as you are within what is called 'ground wave' communications, then you have NOTHING just beyond that, and then you have signal again - so, in a doughnut pattern you have no comms
"the dreaded doughnut" is a serious handicap in an emergency if you trying to contact another party that move beyond 2 miles into the black out zone.

Originally Posted By: KG2V
Actually, it depends on your antennas - You can optimize your antenna system (and antennas are a system) for longer range communications (skip) or for short range comms

The way around this is with what is called a "Near Vertical Incidence System" - basically, you mount your antenna horizontally (or use a horizontal dipole) LOW to the ground - on a 40m or 80m it's typically in the range of 4-6 ft off the ground, and it tends to raise the 'take off angle' of you signal to near vertical, where your signal reflects off the ionosphere, and bounces back down - the exact OPPOSITE of what you want for working distant contacts, but perfect for close (in Ham terms, this becomes a 0-200 or so mile antenna system)

BTW, it is a BIG reason you actually WANT that nice 1/2 wave whip tied down like you see on Military vehicles - it's NOT only for clearance under things, but it actually makes the radio work BETTER in the doughnut - The military has thought about this

Agreed, there are various things you can do to get the communication link working, if you are a ham or professional radio operator.

In an emergency, walkie talkie enable short range communication between neighbours. For most ordinary citizens, the walkie talkie is just another handset.
Posted by: LesSnyder

Re: Most Reliable Communication Means, Emergency - 10/27/11 05:09 PM

KG2V... thanks for the explaination of the near vertical incidence... I get 1:1 SWR, and good ground plane off the roof of my Explorer with the 1/4 wave magnetic mount CB antenna.. it is however tied down with a tarp bungee to get it in the garage, which probably accounts for the pretty consistent 2 to 3 mile mobile comms I get with interstate truckers

for anyone invesitgating a home CB for your local comms...a telescoping mast, 1/2 wave Shakespear Big Stick antenna..usually doesn't upset the neighbors... and be sure to include a good ground rod,... a 12v regulated power supply and a car transceiver will see if it works for you...
Posted by: sotto

Re: Most Reliable Communication Means, Emergency - 10/27/11 11:49 PM

If I may just amplify (sorry) on the donut issue (one of my fav hobbies BTW, eating them that is....no I'm not a Constable On Patrol), actually a great deal of the efficiency of a vertical "ground-plane" type of antenna is the "radiation resistance" factor. By efficiency, I mean the relative amount of transmitted signal radiated by the antenna, in other words, it's effective radio signal output.

Look at it this way. A vertical antenna a quarter wavelength long at the operating frequency, when one ground wire (called a radial) is attached to the shield (ground side) of the coaxial transmission line and laid on the round going away from the antenna, will provide approximately a 50 ohm load (actually more like 38 ohms or so), which is what most solid-state radio transmitters these days like to operate into. Now this will certainly radiate a signal. However, the radiation resistance of this arrangement is relatively high, certainly higher than if a whole bunch of radials (say 10 or so) are used, in which case the effective radiated signal from the 10 radial antenna will be substantially higher than the 1 radial antenna system. Not only that, but the one radial antenna will tend to be somewhat directional in the direction that the one radial is pointing. If 10 radials are laid out spoke-wise around the antenna, this will help make the antenna more omnidirectional. So, bottom line, if you're going to use a vertical antenna, try to use as many radials as comfortably possible arranged more or less equally around the antenna. This provides a similar ground "plane" to that which might be achieved by placing a short roof-mount antenna smack in the middle of the top of a big van.

Sorry, I was going to say that radiation resistance is pretty much directly dependent on the quality of the ground plane, being higher in the case of just one radial, and much closer to ideal with 10 or more wire radials or a flat metal rooftop all around the vertical antenna. So, in a nutshell, adding more radials within reason tends to bring down the radiation resistance and increases the effective radiated signal output from the vertical antenna.

Sorry if this has already been mentioned.
Posted by: KG2V

Re: Most Reliable Communication Means, Emergency - 10/28/11 10:52 PM

Yes, in ANY vertical antenna, the ground pain (body of the car, the radials you lay out on a ground mounted vertical, those parts of antennas you see sticking out parallel to the ground on rooftop antennas) are as much a part of the antenna, and are as needed as the vertical part of the vertical

Interestingly, as you start to put out more and more ground radials, your SWR will go up to a point, because a vertical doesn't have a natuaral resistance of 50 Ohms.

All this stuff is 'old hat' to hams who have studied it (not all have) It's PART of the reasons hams have been known to be able to get signals through, we tend to know the issues. Unfortunately, a lot of hams today haven't learned. Hams USED to even practice getting on organized nets for 'traffic handling' - basically how not to step on each other, and get a message through
Posted by: chaosmagnet

Re: Most Reliable Communication Means, Emergency - 10/29/11 10:54 AM

Originally Posted By: KG2V
All this stuff is 'old hat' to hams who have studied it (not all have) It's PART of the reasons hams have been known to be able to get signals through, we tend to know the issues. Unfortunately, a lot of hams today haven't learned. Hams USED to even practice getting on organized nets for 'traffic handling' - basically how not to step on each other, and get a message through


I know very little about antennas, unfortunately. But I do know a lot of hams who practice using organized nets. I think it's more common in the HF bands than VHF/UHF bands.
Posted by: sotto

Re: Most Reliable Communication Means, Emergency - 10/30/11 05:01 AM

I just want to add something to my earlier post in this thread (I think it was this thread--I'm old, OK?) regarding one of my FM handi-talkies that, after very little use, without warning quit receiving (transmitted OK). It was sent back in to Icom about 2 weeks ago and came back today completely fixed at no charge. So, score one point for the Icom company.
Posted by: KG2V

Re: Most Reliable Communication Means, Emergency - 10/31/11 11:01 PM

Originally Posted By: chaosmagnet

I know very little about antennas, unfortunately. But I do know a lot of hams who practice using organized nets. I think it's more common in the HF bands than VHF/UHF bands.


VHF/UHF nets are fairly common in larger cities, particularly for the ARES/RACES members - in NYC, it's on the 147.00 repeater on Monday nights (I have not checked-in to the net in a year+, but used to be a regular net control operator)