Those odd ball ‘be-a-man’ posts brought up a subject concerning breaking down out on the hiway.
With all the emergency supplies I stock in each of my three trucks, the most important tool these days may very well be the cel-phone. I have not shopped yet, but thought I would put this out there for youall.
Is there a product one can use to receive a signal when your phone says ‘no service’ ? something to up the wattage or similar. ?
Case in point; My dad traveled the country in his van and had in it a ‘bag phone’ . A more powerful phone in it’s own right @ 5 watts. Why ? To get signal in many areas where you pocket cel-phone would not. ( we proved this out in practice .)
Knowing this can be the case ( signal strength -vs- phone power ) makes me wonder about those emergency situations where simply more power ( Tim the tool man Taylor ) would allow anyone to communicate.
Your cell phone’s power rating is related to TRANSMITTING. You also need to be concerned about RECIEVING the cell tower signals. This is a function of the antenna and the cell phone’s front end gain/sensitivity.
The bag phone could outperform old style analog cell phones because it had a much higher capacity power supply and a better, external antenna.
With the advent of digital cell phones, the power requirements went way down and the receiver sensitivity is way up in comparison. They are much more capable than the old analog phones.
That’s not to say that a signal booster wouldn’t help, especially in marginal areas. Some phone designs outperform others in these marginal areas. For example, I use an internal antenna phone and it works just fine in high signal strength areas. An extendable antenna or better yet, a roof mounted antenna would be best rather than relying on the phone alone. They make docking stations for autos along with external antennas. If you’re that concerned, this is where I would be looking to enhance your reception and transmitting capabilities.
My son had a cell phone from one company and there were places here in the midwest where he couldn’t get service. On the other hand, I have been able to go anyplace in the country with the cell phone I have and have been able to communicate. The cell phone service has become much more reliable. Ten years ago I was on the Amtrak train between Grand Junction, Colorado and Denver. I decided to try to place a call to my son who was near Chattanooga, Tennessee. The call went right through and we talked for at least half an hour.
In the wattages of cell phones, I’m not certain that more power will help you connect if there are no cell towers in the vicinity.
Maybe that external antenna idea might be the ticket.
Room-mate travels extensively to see family from the four corners & Navajo reservation to Phoenix. She can have reception in Window Rock, drive down the road to her dad’s and, bzzzzt, nuthin !
Making up a roadside service tool bag for her car got me to thinking that the most important emergency tool can be the phone, unless…
Look for a phone with an external antenna jack. A decent, roof=mounted external antenna will improve performance much more than increased power.
Are you aware that ANY serviceable cell-phone will make a 911 call. You don’t need an active account.
You can always purchase a sattelite phone then you are never out of contact,unless someone destroys the sattelite or you drop the phone in the toilet, there is always something that can go wrong.
Alas, not without a signal. 
I think TwinTurbo said it pretty well: The sensitivity of the receiver and the quality of the antenna are the most important factors. The transmitter in the phone is kind of important though, as the phone needs to announce its availability to the cell phone towers, and of course you want the person on the other end to be able to hear you or it’s going to be a pretty one-sided conversation. The days of analog phones are mostly gone. These days, phones mostly have a lower power digital transceiver. This enables good clarity, and features like texting and broadband internet, and improved battery life, but does sacrifice some range over the ancient bag phones that had the full legal output power, which I think was 3 watts. A modern hand-held cell phone has about an eighth of a watt max power I think.
What might be most important these days is having the roaming feature properly programmed and up to date, as well as having a multi-band phone. This way, if one network isn’t available, the phone can try another. For example, my phone will do CDMA and PCS. (Sprint) In the building where I work, I get a lousy signal from Verizon, but I can switch the phone to use “PCS only” and usually pick up a stronger signal. This also worked during a blackout when the tower near my home was apparently incapacitated. Alternatively, at my old job, I had a Sprint company phone that had miserable coverage out in the sticks, but I could use my personal phone and get a great signal.
If you really need to communicate anywhere, consider a satellite phone.
Check out the service areas for the various phones. Pick the one with service where you live or expect to drive. Then you don’t have to worry about being out of range.