# Road sign -'Turn Off Two-Way Radios and Cellular Telephones'? **URL:** \ **Category:** Factual Questions\ **Created:** [August 26, 2013, 1:07am UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166 "2013-08-26T01:07:13Z")\ **Posts on this page:** 12\ **Page:** 2
**Author:** ![Si\_Amigo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/si_amigo/32/2877_2.png) [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)\ **Post date:** [August 27, 2013, 3:03pm UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/21 "2013-08-27T15:03:29Z")
> [@UncleFred](#): > > You may be on to something here. Cell phones are limited to about 3 Watts transmit power. > > However, CB sets can be 5 watts. And truckers have been known to boost the output of their CB’s in order to increase their range. Illegal? Yes. Hard to stop them if they are not doing it continuously. ---
**Author:** ![drew870mitchell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drew870mitchell/32/3946_2.png) [@drew870mitchell](https://boards.straightdope.com/u/drew870mitchell)\ **Post date:** [August 27, 2013, 3:34pm UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/22 "2013-08-27T15:34:13Z")
> [@leahcim](#): > > There were similar issues at the Dominion Radio Astronomy Observatory. In addition, gasoline-powered vehicles were not allowed within a certain range because of the emissions from their spark plugs (diesel was OK), and the on-site staff couldn’t have a microwave in the kitchen. Likewise with Green Bank, which is nestled in the [United States National Radio Quiet Zone](https://en.wikipedia.org/wiki/Radio_Quiet_Zone), a square a little over a hundred miles on each side whose only allowed transmitters are low-power radio stations, CB, and emergency responders. IIRC when we toured it cell phones and digital cameras were forbidden. ---
**Author:** ![Smapti](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smapti/32/17938_2.png) [@Smapti](https://boards.straightdope.com/u/Smapti)\ **Post date:** [August 27, 2013, 6:37pm UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/23 "2013-08-27T18:37:30Z")
> [@drew870mitchell](#): > > Likewise with Green Bank, which is nestled in the [United States National Radio Quiet Zone](https://en.wikipedia.org/wiki/Radio_Quiet_Zone), a square a little over a hundred miles on each side whose only allowed transmitters are low-power radio stations, CB, and emergency responders. IIRC when we toured it cell phones and digital cameras were forbidden. Based on the pages linked to from that page, over 100,000 civilians live in that area, and much of the University of Virginia is located within it. How does that work out - are there really that many people prohibited by federal law from having cell phones or having access to over-the-air TV and radio? Is that _constitutional?_ Not trying to start an argument - just curious. ---
**Author:** ![butler1850](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@butler1850](https://boards.straightdope.com/u/butler1850)\ **Post date:** [August 27, 2013, 8:11pm UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/24 "2013-08-27T20:11:09Z")
> [@UncleFred](#): > > This article > > [http://www.arrl.org/files/file/Get%20on%20the%20Air/Choosing%20a%20Ham%20Radio.pdf](http://www.arrl.org/files/file/Get%20on%20the%20Air/Choosing%20a%20Ham%20Radio.pdf) > > says mobile ham radios can be in the 10-50W range. > > (I have no idea how old the article is…) Probably a fair statement for a stock radio setup, but one can add amplifiers legally if you’re authorized to use an amateur radio in the first place. I think up to 1000W ERP (Effective Radiated Power. Output x gain = ERP) But the guideline is to use the least power needed to make the contact… It’s been a while since I’ve been active, and there may be restrictions on some bands/modes as to power output that make the above statement void. ---
**Author:** ![Absolute](https://avatars.discourse-cdn.com/v4/letter/a/b2d939/32.png) [@Absolute](https://boards.straightdope.com/u/Absolute)\ **Post date:** [August 27, 2013, 8:43pm UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/25 "2013-08-27T20:43:17Z")
Most modern mobile ham radio transceivers will run at 100W by default out of the box. The legal limit for almost all amateur bands is 1500W. ---
**Author:** ![DataX](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@DataX](https://boards.straightdope.com/u/DataX)\ **Post date:** [August 27, 2013, 9:09pm UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/26 "2013-08-27T21:09:21Z")
> [@Smapti](#): > > Based on the pages linked to from that page, over 100,000 civilians live in that area, and much of the University of Virginia is located within it. How does that work out - are there really that many people prohibited by federal law from having cell phones or having access to over-the-air TV and radio? Is that _constitutional?_ > > Not trying to start an argument - just curious. I have been through the quiet zone several times - including spending the night in a motel/hotel there (on the outer part - but still within the lat/long). This is the first I’ve heard of it. I remember it was stormy when I stayed the night - and the direct tv was going in and out. Cell Service sucked, but was there. I don’t remember seeing any signs or anything else related to this. If there was a sign about turning cell phone off - I would have assumed it was for demolitions - and probably wouldn’t have remembered it. I would have remembered anything about entering a “quiet zone” though. ---
**Author:** ![drew870mitchell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drew870mitchell/32/3946_2.png) [@drew870mitchell](https://boards.straightdope.com/u/drew870mitchell)\ **Post date:** [August 27, 2013, 9:51pm UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/27 "2013-08-27T21:51:57Z")
> [@Smapti](#): > > Based on the pages linked to from that page, over 100,000 civilians live in that area, and much of the University of Virginia is located within it. How does that work out - are there really that many people prohibited by federal law from having cell phones or having access to over-the-air TV and radio? Is that _constitutional?_ > > Not trying to start an argument - just curious. I flubbed that explanation hard, let me try to dig my way out. AFAIK the University of Virginia is _not_ within the RQZ. The consumer electronics ban was for the actual grounds of the Green Bank Telescope, i.e. as a visitor, not the entire RQZ. [This Wired article](http://www.wired.com/wired/archive/12.02/quiet_pr.html) describes it better than I could. Note that they replaced a faulty electric blanket that was generating interference a couple miles from the telescope. They’re detecting astronomical radio waves a thousand times weaker than a typical cell phone’s output. The method of investigation would be impossible without minimizing human-generated interference. As far as the regulatory side goes, nobody’s prohibited from owning a cell phone on their own property anywhere, but there’s no (or very few) cell towers in the area, so they’d be mostly useless. The radio spectrum is only usable if there’s some scheme of coordination for transmitters so that distinct channels can exist and transmitters not interfere to hell, so if you’re over a certain power, your device has to be licensed by the FCC. I’m completely unaware of whether the constitutional authority of the FCC has ever been challenged. ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [August 28, 2013, 1:11am UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/28 "2013-08-28T01:11:46Z")
I worked a while in an electronic repair shop when I got out of high school. Three or four times a year we’d get someone in wanting to know if we could boost the output on their mobile or base station CB setup. We always refused, but the owner told me it would have been absurdly easy to do. That was back in the 80’s so I don’t know how the tech has evolved to know how easy it would be with a current model. ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [August 28, 2013, 1:58am UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/29 "2013-08-28T01:58:39Z")
On Range Road at Fort Dix there used to be a sign telling people to turn off their radios at a particular range. I assume at the time they used it for demo. The sign is long gone. The military has not used electrical detonation for a very long time. ---
**Author:** ![Darth\_Panda](https://avatars.discourse-cdn.com/v4/letter/d/ee7513/32.png) [@Darth\_Panda](https://boards.straightdope.com/u/Darth_Panda)\ **Post date:** [August 28, 2013, 2:05am UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/30 "2013-08-28T02:05:34Z")
> [@Smapti](#): > > How does that work out - are there really that many people prohibited by federal law from having cell phones or having access to over-the-air TV and radio? Is that _constitutional?_ No idea how it works out logistically, but I can say that I don’t see any constitutional issue here. Which article or amendment do you think it violates? eta: also not looking for an argument, but curious if you had something particular in mind. If not, then I’ll just go with my blanket statement “no problem I can see.” Remember, there’s nothing unconstitutional about laws that are stupid, pointless, burdensome, annoying, or outright counter-productive (or any combination thereof), unless they actually violate a specific provision of the Constitution (or an interpretation thereof). ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [August 28, 2013, 5:53am UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/31 "2013-08-28T05:53:41Z")
> [@Loach](#): > > On Range Road at Fort Dix there used to be a sign telling people to turn off their radios at a particular range. I assume at the time they used it for demo. The sign is long gone. The military has not used electrical detonation for a very long time. Still taught at some places and used though shock tube is the current preferred system for the combat engineers and EOD. My son-in-law at Ft. Leonard Wood told me they just phased out electrical training last year there for the combat engineers. McAlester Army Ammo Plant does 36 demolition pits per day (approx. 350 lbs of HE per pit counting items to be detonated and donor material), 5 to 6 days a week, year around using electric. The demolition range school there at MCAAP teaches all three methods - non-electric (time fuse), shock tube, and electric methods. Electric is controllable and considerably cheaper than the shock tube systems for large scale demolition operations. Crane AAP and Hawthorne AAP and many other locations still do it electrically. Any range that uses or teaches has gates/lights/signs warning of electrical transmission dangers. The storage areas are posted and prohibitions against radios and cellphones are in the area Standard Operating Procedure. //off the wall comment// The powers finally lightened up about “Standing” vs. “Standard” in describing operating procedures. //end OTWC// ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [August 28, 2013, 3:20pm UTC](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166/32 "2013-08-28T15:20:33Z")
> [@smithsb](#): > > Still taught at some places and used though shock tube is the current preferred system for the combat engineers and EOD. My son-in-law at Ft. Leonard Wood told me they just phased out electrical training last year there for the combat engineers. > > McAlester Army Ammo Plant does 36 demolition pits per day (approx. 350 lbs of HE per pit counting items to be detonated and donor material), 5 to 6 days a week, year around using electric. The demolition range school there at MCAAP teaches all three methods - non-electric (time fuse), shock tube, and electric methods. Electric is controllable and considerably cheaper than the shock tube systems for large scale demolition operations. Crane AAP and Hawthorne AAP and many other locations still do it electrically. > > Any range that uses or teaches has gates/lights/signs warning of electrical transmission dangers. The storage areas are posted and prohibitions against radios and cellphones are in the area Standard Operating Procedure. > > //off the wall comment// The powers finally lightened up about “Standing” vs. “Standard” in describing operating procedures. //end OTWC// I am a Combat Engineer. I’ve never even seen the equipment for electrical detonation. I do know that commercial demo still uses it for the reasons you state. [Previous page](https://boards.straightdope.com/t/road-sign-turn-off-two-way-radios-and-cellular-telephones/667166.md?page=1)